wdiff rfc8578.original rfc8578.txt

Internet Engineering Task Force (IETF) E. Grossman, Ed.
Internet-Draft
Request for Comments: 8578 DOLBY
Intended status:
Category: Informational December 19, 2018
Expires: June 22, May 2019
ISSN: 2070-1721

Deterministic Networking Use Cases
draft-ietf-detnet-use-cases-20

Abstract

This draft document presents use cases from for diverse industries which that have in
common a need for "deterministic flows". "Deterministic" in this
context means that such flows provide guaranteed bandwidth, bounded
latency, and other properties germane to the transport of time-
sensitive data. These use cases differ notably in their network
topologies and specific desired behavior, providing as a group broad
industry context for DetNet. Deterministic Networking (DetNet). For each use
case, this document will identify the use case, identify
representative solutions used today, and describe potential
improvements that DetNet can enable. The Use
Case Common Themes section then extracts and enumerates the set of
common properties implied by these use cases.

Status of This Memo

This Internet-Draft document is not an Internet Standards Track specification; it is
published for informational purposes.

This document is submitted in full conformance with the
provisions of BCP 78 and BCP 79.

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approved by the IESG are candidates for a maximum any level of Internet
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This Internet-Draft will expire on June 22, 2019.
https://www.rfc-editor.org/info/rfc8578.

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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Pro Audio and Video . . . . . . . . . . . . . . . . . . . . . 7
2.1. Use Case Description . . . . . . . . . . . . . . . . . . 7
2.1.1. Uninterrupted Stream Playback . . . . . . . . . . . . 7
2.1.2. Synchronized Stream Playback . . . . . . . . . . . . 8
2.1.3. Sound Reinforcement . . . . . . . . . . . . . . . . . 8
2.1.4. Secure Transmission . . . . . . . . . . . . . . . . . 9
2.1.4.1. Safety . . . . . . . . . . . . . . . . . . . . . 9
2.2. Pro Audio Today . . . . . . . . . . . . . . . . . . . . . 9
2.3. Pro Audio in the Future . . . . . . . . . . . . . . . . . . . . 9
2.3.1. Layer 3 Interconnecting Layer 2 Islands . . . . . . . 9
2.3.2. High Reliability High-Reliability Stream Paths . . . . . . . . . . . . 10
2.3.3. Integration of Reserved Streams into IT Networks . . 10
2.3.4. Use of Unused Reservations by Best-Effort Traffic . . 10
2.3.5. Traffic Segregation . . . . . . . . . . . . . . . . . 11
2.3.5.1. Packet Forwarding Packet-Forwarding Rules, VLANs VLANs, and Subnets . . . 11
2.3.5.2. Multicast Addressing (IPv4 and IPv6) . . . . . . 11
2.3.6. Latency Optimization by a Central Controller . . . . 12
2.3.7. Reduced Device Cost Due To Costs due to Reduced Buffer Memory . . 12
2.4. Pro Audio Asks . . . . . . . . Requests to the IETF . . . . . . . . . . . . . 12
3. Electrical Utilities . . . . . . . . . . . . . . . . . . . . 13
3.1. Use Case Description . . . . . . . . . . . . . . . . . . 13
3.1.1. Transmission Use Cases . . . . . . . . . . . . . . . 13
3.1.1.1. Protection . . . . . . . . . . . . . . . . . . . 13
3.1.1.2. Intra-Substation Intra-substation Process Bus Communications . . . 18 20
3.1.1.3. Wide Area Wide-Area Monitoring and Control Systems . . . . 19 21
3.1.1.4. IEC 61850 WAN engineering guidelines requirement
classification Engineering Guidelines Requirement
Classification . . . . . . . . . . . . . . . . . 20 23
3.1.2. Generation Use Case . . . . . . . . . . . . . . . . . 21 23
3.1.2.1. Control of the Generated Power . . . . . . . . . 21 24
3.1.2.2. Control of the Generation Infrastructure . . . . 22 24
3.1.3. Distribution use case Use Case . . . . . . . . . . . . . . . . 27 29
3.1.3.1. Fault Location Isolation Location, Isolation, and Service
Restoration (FLISR) . . . . . . . . . . . . . . . . . . . . . 27 29
3.2. Electrical Utilities Today . . . . . . . . . . . . . . . 28 30
3.2.1. Security Current Security Practices and Their Limitations . . . . . 28 31
3.3. Electrical Utilities in the Future . . . . . . . . . . . . . . . 30 32
3.3.1. Migration to Packet-Switched Network Networks . . . . . . . . 31 33
3.3.2. Telecommunications Trends . . . . . . . . . . . . . . 31 34
3.3.2.1. General Telecommunications Requirements . . . . . 31 34
3.3.2.2. Specific Network topologies Topologies of Smart Grid Smart-Grid
Applications . . . . . . . . . . . . . . . . . . 32 35
3.3.2.3. Precision Time Protocol . . . . . . . . . . . . . 33 36
3.3.3. Security Trends in Utility Networks . . . . . . . . . 34 36
3.4. Electrical Utilities Asks . . . . . . . . Requests to the IETF . . . . . . . . 36 38
4. Building Automation Systems (BASs) . . . . . . . . . . . . . . . . . 36 39
4.1. Use Case Description . . . . . . . . . . . . . . . . . . 36 39
4.2. Building Automation Systems BASs Today . . . . . . . . . . . . 37 . . . . . . . . . . . 39
4.2.1. BAS Architecture . . . . . . . . . . . . . . . . . . 37 39
4.2.2. BAS Deployment Model . . . . . . . . . . . . . . . . 38 41
4.2.3. Use Cases for Field Networks . . . . . . . . . . . . 40 43
4.2.3.1. Environmental Monitoring . . . . . . . . . . . . 40 43
4.2.3.2. Fire Detection . . . . . . . . . . . . . . . . . 40 44
4.2.3.3. Feedback Control . . . . . . . . . . . . . . . . 41 44
4.2.4. BAS Security Considerations . . . . . . . . . . . . . . . 41 44
4.3. BAS BASs in the Future . . . . . . . . . . . . . . . . . . . . . . . 41 44
4.4. BAS Asks . . . . . . . . Requests to the IETF . . . . . . . . . . . . . . . . 42 45
5. Wireless for Industrial Applications . . . . . . . . . . . . 42 45
5.1. Use Case Description . . . . . . . . . . . . . . . . . . 42 45
5.1.1. Network Convergence using Using 6TiSCH . . . . . . . . . . 43 46
5.1.2. Common Protocol Development for 6TiSCH . . . . . . . 43 46
5.2. Wireless Industrial Today . . . . . . . . . . . . . . . . 44 47
5.3. Wireless Industrial in the Future . . . . . . . . . . . . . . . 44 47
5.3.1. Unified Wireless Network Networks and Management . . . . . . . 44 47
5.3.1.1. PCE and 6TiSCH ARQ Retries . . . . . . . . . . . 46 49
5.3.2. Schedule Management by a PCE . . . . . . . . . . . . 47 50
5.3.2.1. PCE Commands and 6TiSCH CoAP Requests . . . . . . 47 50
5.3.2.2. 6TiSCH IP Interface . . . . . . . . . . . . . . . 48 52
5.3.3. 6TiSCH Security Considerations . . . . . . . . . . . 49 52
5.4. Wireless Industrial Asks . . . . . . . . Requests to the IETF . . . . . . . . 49 52
6. Cellular Radio . . . . . . . . . . . . . . . . . . . . . . . 49 52
6.1. Use Case Description . . . . . . . . . . . . . . . . . . 49 52
6.1.1. Network Architecture . . . . . . . . . . . . . . . . 49 52
6.1.2. Delay Constraints . . . . . . . . . . . . . . . . . . 50 53
6.1.3. Time Synchronization Time-Synchronization Constraints . . . . . . . . . . 52 55
6.1.4. Transport Loss Transport-Loss Constraints . . . . . . . . . . . . . 54 57
6.1.5. Cellular Radio Network Security Considerations . . . . . . . . . . . . . . . 54 58
6.2. Cellular Radio Networks Today . . . . . . . . . . . . . . 55 58
6.2.1. Fronthaul . . . . . . . . . . . . . . . . . . . . . . 55 58
6.2.2. Midhaul and Backhaul . . . . . . . . . . . . . . . . 55 58
6.3. Cellular Radio Networks in the Future . . . . . . . . . . . . . 56 59
6.4. Cellular Radio Networks Asks . . . . . . . . Requests to the IETF . . . . . . 58 61
7. Industrial Machine to Machine (M2M) . . . . . . . . . . . . . 59 62
7.1. Use Case Description . . . . . . . . . . . . . . . . . . 59 62
7.2. Industrial M2M Communication Communications Today . . . . . . . . . . . 60 63
7.2.1. Transport Parameters . . . . . . . . . . . . . . . . 60 64
7.2.2. Stream Creation and Destruction . . . . . . . . . . . 61 65
7.3. Industrial M2M in the Future . . . . . . . . . . . . . . . . . . 61 65
7.4. Industrial M2M Asks . . . . . . . . Requests to the IETF . . . . . . . . . . . 62 65
8. Mining Industry . . . . . . . . . . . . . . . . . . . . . . . 62 66
8.1. Use Case Description . . . . . . . . . . . . . . . . . . 62 66
8.2. Mining Industry Today . . . . . . . . . . . . . . . . . . 63 66
8.3. Mining Industry in the Future . . . . . . . . . . . . . . . . . 63 67
8.4. Mining Industry Asks . . . . . . . . Requests to the IETF . . . . . . . . . . 64 68
9. Private Blockchain . . . . . . . . . . . . . . . . . . . . . 64 68
9.1. Use Case Description . . . . . . . . . . . . . . . . . . 64 68
9.1.1. Blockchain Operation . . . . . . . . . . . . . . . . 65 68
9.1.2. Blockchain Network Architecture . . . . . . . . . . . 65 69
9.1.3. Blockchain Security Considerations . . . . . . . . . . . . . . . 66 69
9.2. Private Blockchain Today . . . . . . . . . . . . . . . . 66 70
9.3. Private Blockchain in the Future . . . . . . . . . . . . 70
9.4. Private Blockchain Requests to the IETF . . . . 66
9.4. Private Blockchain Asks . . . . . 70
10. Network Slicing . . . . . . . . . . . . 67
10. Network Slicing . . . . . . . . . . . . . . . . . . . . . . . 67 70
10.1. Use Case Description . . . . . . . . . . . . . . . . . . 67 70
10.2. DetNet Applied to Network Slicing . . . . . . . . . . . 67 71
10.2.1. Resource Isolation Across across Slices . . . . . . . . . . 67 71
10.2.2. Deterministic Services Within within Slices . . . . . . . . 68 71
10.3. A Network Slicing Use Case Example - 5G Bearer Network . 68 72
10.4. Non-5G Applications of Network Slicing . . . . . . . . . 69 72
10.5. Limitations of DetNet in Network Slicing . . . . . . . . 69 72
10.6. Network Slicing Today and in the Future . . . . . . . . . . . . 69 73
10.7. Network Slicing Asks . . . . . . . . Requests to the IETF . . . . . . . . . . 69 73
11. Use Case Common Themes . . . . . . . . . . . . . . . . . . . 69 73
11.1. Unified, standards-based network . Standards-Based Networks . . . . . . . . . . . 70 73
11.1.1. Extensions to Ethernet . . . . . . . . . . . . . . . 70 73
11.1.2. Centrally Administered Networks . . . . . . . . . . . . . . . 70 73
11.1.3. Standardized Data Flow Data-Flow Information Models . . . . . 70 74
11.1.4. L2 Layer 2 and L3 Layer 3 Integration . . . . . . . . . . . . . . . 70 74
11.1.5. Consideration for IPv4 Considerations . . . . . . . . . . . . . . . 70 . 74
11.1.6. Guaranteed End-to-End Delivery . . . . . . . . . . . 71 74
11.1.7. Replacement for Multiple Proprietary Deterministic
Networks . . . . . . . . . . . . . . . . . . . . . . 71 74
11.1.8. Mix of Deterministic and Best-Effort Traffic . . . . 71 75
11.1.9. Unused Reserved BW Bandwidth to be Be Available to
Best-Effort Traffic . . . . . . . . . . . . . . . . . . . . . . 71 75
11.1.10. Lower Cost, Lower-Cost, Multi-Vendor Solutions . . . . . . . . . 71 75
11.2. Scalable Size . . . . . . . . . . . . . . . . . . . . . 71 75
11.2.1. Scalable Number of Flows . . . . . . . . . . . . . . 72 75
11.3. Scalable Timing Parameters and Accuracy . . . . . . . . 72 76
11.3.1. Bounded Latency . . . . . . . . . . . . . . . . . . 72 76
11.3.2. Low Latency . . . . . . . . . . . . . . . . . . . . 72 76
11.3.3. Bounded Jitter (Latency Variation) . . . . . . . . . 72 76
11.3.4. Symmetrical Path Delays . . . . . . . . . . . . . . 72 76
11.4. High Reliability and Availability . . . . . . . . . . . 73 76
11.5. Security . . . . . . . . . . . . . . . . . . . . . . . . 73 77
11.6. Deterministic Flows . . . . . . . . . . . . . . . . . . 73 77
12. Security Considerations . . . . . . . . . . . . . . . . . . . 73 77
13. Contributors . . . IANA Considerations . . . . . . . . . . . . . . . . . . . . . 74 77
14. Acknowledgments . . . Informative References . . . . . . . . . . . . . . . . . . . 77
Appendix A. Use Cases Explicitly Out of Scope for DetNet . 75
14.1. Pro Audio . . . 87
A.1. DetNet Scope Limitations . . . . . . . . . . . . . . . . 87
A.2. Internet-Based Applications . . . . 75
14.2. Utility Telecom . . . . . . . . . . . 88
A.2.1. Use Case Description . . . . . . . . . 76
14.3. Building Automation Systems . . . . . . . 88
A.2.1.1. Media Content Delivery . . . . . . . 76
14.4. Wireless for Industrial Applications . . . . . . 88
A.2.1.2. Online Gaming . . . . 76
14.5. Cellular Radio . . . . . . . . . . . . . . 88
A.2.1.3. Virtual Reality . . . . . . . 76
14.6. Industrial Machine to Machine (M2M) . . . . . . . . . . 77
14.7. Internet 88
A.2.2. Internet-Based Applications and CoMP . . . Today . . . . . . . . . . 77
14.8. Network Slicing 88
A.2.3. Internet-Based Applications in the Future . . . . . . 88
A.2.4. Internet-Based Applications Requests to the IETF . . 89
A.3. Pro Audio and Video - Digital Rights Management (DRM) . . 89
A.4. Pro Audio and Video - Link Aggregation . . . . . . . . . . 77
14.9. Mining . . . . . . . . . . . . . . . . . . . . . . . . . 77
14.10. Private Blockchain . . . . . . . . . . . . . . . . . . . 77
15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 77
16. Informative References . . . . . . . . . . . . . . . . . . . 77
Appendix A. Use Cases Explicitly Out of Scope for DetNet . . . . 84
A.1. DetNet Scope Limitations . . . . . . . . . . . . . . . . 85
A.2. Internet-based Applications . . . . . . . . . . . . . . . 85
A.2.1. Use Case Description . . . . . 90
A.5. Pro Audio and Video - Deterministic Time to Establish
Streaming . . . . . . . . . . . 86
A.2.1.1. Media Content Delivery . . . . . . . . . . . . . 86
A.2.1.2. Online Gaming 90
Acknowledgments . . . . . . . . . . . . . . . . . . 86
A.2.1.3. Virtual Reality . . . . . . . 90
Contributors . . . . . . . . . . 86
A.2.2. Internet-Based Applications Today . . . . . . . . . . 86
A.2.3. Internet-Based Applications Future . . . . . . 92
Author's Address . . . 86
A.2.4. Internet-Based Applications Asks . . . . . . . . . . 86
A.3. Pro Audio and Video - Digital Rights Management (DRM) . . 87
A.4. Pro Audio and Video - Link Aggregation . . . . . . . . . 87
A.5. Pro Audio and Video - 94

1. Introduction

This memo documents use cases for diverse industries that require
deterministic flows over multi-hop paths. Deterministic Time to Establish
Streaming . . . . . . . . . . . . . . . . . . . . . . . . 87
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 88

1. Introduction

This draft documents use cases in diverse industries which require
deterministic flows over multi-hop paths. DetNet Networking
(DetNet) flows can be established from either a Layer 2 or Layer 3
(IP) interface, and such flows can co-exist coexist on an IP network with
best-effort traffic. DetNet also provides for highly reliable flows
through provision for redundant paths.

The DetNet Use Cases use cases explicitly do not suggest any specific design
for DetNet architecture or protocols; these are topics of for other
DetNet drafts. documents.

The DetNet use cases cases, as originally submitted submitted, explicitly were not
considered by the DetNet Working Group (WG) to be concrete requirements;
requirements. The DetNet Working Group WG and Design Team considered these use
cases, identifying which elements of them their elements could be feasibly
implemented within the charter of DetNet, and DetNet; as a result result, certain of the
originally submitted use cases (or elements of them) have been be thereof) were moved to the Use
Appendix A ("Use Cases Explicitly Out of Scope for DetNet section.

The DetNet Use Cases DetNet") of this
document.

This document provide provides context regarding DetNet design decisions. It
also serves a long-lived purpose of helping those learning (or new
to) DetNet to understand the types of applications that can be supported
by DetNet. It also allow allows those WG contributors who are users to
ensure that their concerns are addressed by the WG; for them them, this
document both (1) covers their contribution contributions and (2) provides a
long term long-term
reference to regarding the problems that they expect to will be served by
the technology, both in terms of the short term short-term deliverables and also as
the technology evolves in the future.

The DetNet Use Cases

This document has served as a "yardstick" against which proposed
DetNet designs can be measured, answering the question
"to "To what
extent does a proposed design satisfy these various use cases?"

The Use Case industries covered by the use cases in this document are

o professional audio, audio and video (Section 2)

o electrical
utilities, utilities (Section 3)

o building automation systems, systems (BASs) (Section 4)

o wireless for industrial
applications, applications (Section 5)

o cellular radio, radio (Section 6)

o industrial machine-to-machine, mining, machine to machine (M2M) (Section 7)

o mining (Section 8)

o private blockchain, and blockchain (Section 9)

o network slicing. slicing (Section 10)

For each use case case, the following questions are answered:

o What is the use case?

o How is it addressed today?

o How should it be addressed in the future?

o What should the IETF deliver to enable this use case?

The level of detail in each use case is intended to be sufficient to
express the relevant elements of the use case, case but not greater no more than that.

DetNet does not directly address clock distribution or time
synchronization; these are considered to be part of the overall
design and implementation of a time-sensitive network, using existing
(or future) time-specific protocols (such as [IEEE8021AS] [IEEE-8021AS] and/or
[RFC5905]).

Section 11 enumerates the set of common properties implied by these
use cases.

2. Pro Audio and Video

2.1. Use Case Description

The professional audio and video industry ("ProAV") includes:

o Music and film content creation

o Broadcast

o Cinema

o Live sound

o Public address, media media, and emergency systems at large venues
(airports,
(e.g., airports, stadiums, churches, theme parks). parks)

These industries have already transitioned audio and video signals
from analog to digital. However, the digital interconnect systems
remain primarily point-to-point point to point, with a single (or signal or a small
number of) of signals per link, interconnected with purpose-built
hardware.

These industries are now transitioning to packet-based infrastructure
infrastructures to reduce cost, increase routing flexibility, and
integrate with existing IT infrastructure.

Today infrastructures.

Today, ProAV applications have no way to establish deterministic
flows from a standards-based Layer 3 (IP) interface, which interface; this is a
fundamental limitation to of the use cases described here. Today Today,
deterministic flows can be created within standards-based layer Layer 2
LANs (e.g. (e.g., using IEEE 802.1 AVB) however TSN ("TSN" stands for "Time-Sensitive
Networking")); however, these flows are not routable via IP and thus
are not effective for distribution over wider areas (for example example,
broadcast events that span wide geographical areas).

It would be highly desirable if such flows could be routed over the
open Internet, however Internet; however, solutions with more limited of more-limited scope (e.g. (e.g.,
enterprise networks) would still provide a substantial improvement. improvements.

The following sections describe specific ProAV use cases.

2.1.1. Uninterrupted Stream Playback

Transmitting audio and video streams for live playback is unlike
common file transfer because in that uninterrupted stream playback in the
presence of network errors cannot be achieved by re-trying retrying the
transmission; by the time the missing or corrupt packet has been
identified
identified, it is too late to execute a re-try retry operation. Buffering
can be used to provide enough delay to allow time for one or more
retries, however
retries; however, this is not an effective solution in applications
where large delays (latencies) are not acceptable (as discussed
below).

Streams with guaranteed bandwidth can eliminate congestion on the
network as a cause of transmission errors that would lead to playback
interruption. Use The use of redundant paths can further mitigate
transmission errors to and thereby provide greater stream reliability.

Additional techniques techniques, such as forward error correction Forward Error Correction (FEC), can
also be used to improve stream reliability.

2.1.2. Synchronized Stream Playback

Latency in this context is the time between when a signal is
initially sent over a stream and when it is received. A common
example in ProAV is time-synchronizing audio and video when they take
separate paths through the playback system. In this case case, the
latency of both the audio stream and the video streams stream must be bounded
and consistent if the sound is to remain matched to the movement in
the video. A common tolerance for audio/video sync synchronization is one NTSC
National Television System Committee (NTSC) video frame (about
33ms) and
33 ms); to maintain the audience audience's perception of correct lip sync lip-sync,
the latency needs to be consistent within some reasonable tolerance, tolerance
-- for
example example, 10%.

A common architecture for synchronizing multiple streams that have
different paths through the network (and thus potentially different
latencies) is to enable enables measurement of the latency of each path, path and
have has
the data sinks (for example example, speakers) delay (buffer) all packets on
all but the slowest path. Each packet of each stream is assigned a
presentation time which that is based on the longest required delay. This
implies that all sinks must maintain a common time reference of
sufficient accuracy, which can be achieved by any of various techniques.

This type of architecture is commonly implemented using a central
controller that determines path delays and arbitrates buffering
delays.

2.1.3. Sound Reinforcement

Consider the latency (delay) from between the time when a person speaks
into a microphone to and when their voice emerges from the speaker. If
this delay is longer than about 10-15 milliseconds ms, it is noticeable and can
make a sound reinforcement sound-reinforcement system unusable (see slide 6 of
[SRP_LATENCY]). (If you have ever tried to speak in the presence of
a delayed echo of your voice voice, you may know might be familiar with this experience).
experience.)

Note that the 15ms 15 ms latency bound includes all parts of the signal
path,
path -- not just the network, network -- so the network latency must be
significantly less than 15ms. 15 ms.

In some cases cases, local performers must perform in synchrony with a
remote broadcast. In such cases cases, the latencies of the broadcast
stream and the local performer must be adjusted to match each other,
with a worst case of one video frame (33ms (33 ms for NTSC video).

In cases where audio phase is a consideration, consideration -- for example beam-
forming example,
beam-forming using multiple speakers, speakers -- latency can be in the 10 microsecond us
range (1 (one audio sample at 96kHz). 96 kHz).

2.1.4. Secure Transmission

2.1.4.1. Safety

Professional audio systems can include amplifiers that are capable of
generating hundreds or thousands of watts of audio power which if power. If used incorrectly
incorrectly, such amplifiers can cause hearing damage to those in the
vicinity. Apart from the usual care required by the systems
operators to prevent such incidents, the network traffic that
controls these devices must be secured (as with any sensitive
application traffic).

2.2. Pro Audio Today

Some proprietary systems have been created which that enable deterministic
streams at Layer 3 however 3; however, they are "engineered networks" which that
require careful configuration to operate, operate and often require that the
system be over-provisioned, and over-provisioned. Also, it is implied that all devices on
the network voluntarily play by the rules of that network. To enable
these industries to successfully transition to an interoperable
multi-vendor packet-based infrastructure requires effective open
standards, and establishing
standards. Establishing relevant IETF standards is a crucial factor.

2.3. Pro Audio in the Future

2.3.1. Layer 3 Interconnecting Layer 2 Islands

It would be valuable to enable IP to connect multiple Layer 2 LANs.

As an example, ESPN constructed a state-of-the-art 194,000 sq ft,
$125 million sq. ft.,
$125-million broadcast studio called DC2. "Digital Center 2" (DC2). The
DC2 network is capable of handling 46 Tbps of throughput with 60,000
simultaneous signals. Inside the facility are 1,100 miles of fiber
feeding four audio control rooms (see [ESPN_DC2] ). [ESPN_DC2]).

In designing DC2 DC2, they replaced as much point-to-point technology as
they could with packet-based technology. They constructed seven
individual studios using layer Layer 2 LANS LANs (using IEEE 802.1 AVB) TSN) that
were entirely effective at routing audio within the LANs. However However,
to interconnect these layer Layer 2 LAN islands together together, they ended up
using dedicated paths in a custom SDN (Software Defined (Software-Defined Networking)
router because there is no standards-based routing solution
available.

2.3.2. High Reliability High-Reliability Stream Paths

On-air and other live media streams are often backed up with
redundant links that seamlessly act to deliver the content when the
primary link fails for any reason. In point-to-point systems systems, this
redundancy is provided by an additional point-to-point link; the
analogous requirement in a packet-based system is to provide an
alternate path through the network such that no individual link can
bring down the system.

2.3.3. Integration of Reserved Streams into IT Networks

A commonly cited goal of moving to a packet based packet-based media
infrastructure is that costs can be reduced by using off the shelf,
commodity network off-the-shelf,
commodity-network hardware. In addition, economy of scale can be
realized by combining media infrastructure with IT infrastructure.
In keeping with these goals, stream reservation stream-reservation technology should be
compatible with existing protocols, protocols and should not compromise the use
of the network for best-effort (non-time-sensitive) traffic.

2.3.4. Use of Unused Reservations by Best-Effort Traffic

In cases where stream bandwidth is reserved but not currently used
(or is under-utilized) underutilized), that bandwidth must be available to best-
effort (i.e.
best-effort (i.e., non-time-sensitive) traffic. For example example, a
single stream may be nailed up "nailed up" (reserved) for specific media
content that needs to be presented at different times of the day,
ensuring timely delivery of that content, yet in between those times
the full bandwidth of the network can be utilized for best-effort
tasks such as file transfers.

This also addresses a concern of IT network administrators that are
considering adding reserved bandwidth reserved-bandwidth traffic to their networks that
"users will reserve large quantities of bandwidth and then never un-
reserve
unreserve it even though they are not using it, and soon the network
will have no bandwidth left". left."

2.3.5. Traffic Segregation

Sink devices may be low cost low-cost devices with limited processing power.
In order to not overwhelm the CPUs in these devices devices, it is important
to limit the amount of traffic that these devices must process.

As an example, consider the use of individual seat speakers in a
cinema. These speakers are typically required to be cost reduced reduced,
since the quantities in a single theater can reach hundreds of seats.
Discovery protocols alone in a one thousand seat 1,000-seat theater can generate enough
broadcast traffic to overwhelm a low powered low-powered CPU. Thus Thus, an
installation like this will benefit greatly from some type of traffic
segregation that can define groups of seats to reduce traffic within
each group. All seats in the theater must still be able to
communicate with a central controller.

There are many techniques that can be used to support this feature feature,
including (but not limited to) the following examples.

2.3.5.1. Packet Forwarding Packet-Forwarding Rules, VLANs VLANs, and Subnets

Packet forwarding

Packet-forwarding rules can be used to eliminate some extraneous
streaming traffic from reaching potentially low powered low-powered sink devices,
however devices;
however, there may be other types of broadcast traffic that should be
eliminated using via other means -- for example example, VLANs or IP subnets.

2.3.5.2. Multicast Addressing (IPv4 and IPv6)

Multicast addressing is commonly used to keep bandwidth utilization
of shared links to a minimum.

Because of the MAC Address forwarding nature of Layer 2 bridges by design forward Media Access Control (MAC)
addresses, it is important that a multicast MAC address is only be
associated with one stream. This will prevent reservations from
forwarding packets from one stream down a path that has no interested
sinks simply because there is another stream on that same path that
shares the same multicast MAC address.

Since

In other words, since each multicast MAC Address address can represent 32
different IPv4 multicast addresses addresses, there must be a process put in place
to make sure
this does not occur. that any given multicast MAC address is only associated
with exactly one IPv4 multicast address. Requiring the use of IPv6
addresses could help in this regard, due to the much larger address can achieve this,
however
range of IPv6; however, due to their the continued prevalence, prevalence of IPv4
installations, solutions that are effective for IPv4 installations are also desirable.
would be practical in many more use cases.

2.3.6. Latency Optimization by a Central Controller

A central network controller might also perform optimizations based
on the individual path delays, delays; for example example, sinks that are closer to
the source can inform the controller that they can accept greater
latency
latency, since they will be buffering packets to match presentation
times of sinks that are farther away sinks. away. The controller might then move
a stream reservation on a short path to a longer path in order to
free up bandwidth for other critical streams on that short path. See
slides 3-5 of [SRP_LATENCY].

Additional optimization can be achieved in cases where sinks have
differing latency requirements, requirements; for example in example, at a live outdoor concert
concert, the speaker sinks have stricter latency requirements than
the
recording hardware recording-hardware sinks. See slide 7 of [SRP_LATENCY].

2.3.7. Reduced Device Cost Due To Costs due to Reduced Buffer Memory

Device cost costs can be reduced in a system with guaranteed reservations
with a small bounded latency due to the reduced requirements for
buffering (i.e. (i.e., memory) on sink devices. For example, a theme park
might broadcast a live event across the globe via a layer Layer 3 protocol;
in protocol.
In such cases cases, the size of the buffers required is proportional to defined by the
worst-case latency bounds and jitter caused by delivery, which depends on values of the
worst case worst-case segment of the
end-to-end network path. For example example, on
todays today's open internet Internet, the
latency is typically unacceptable for audio and video streaming
without many seconds of buffering. In such
scenarios scenarios, a single
gateway device at the local network that receives the feed from the
remote site would provide the expensive buffering required to mask
the latency and jitter issues associated with long
distance long-distance delivery.
Sink devices in the local location would have no additional buffering
requirements, and thus no additional costs, beyond those required for
delivery of local content. The sink device would be receiving the identical
packets as those identical to those sent by the source and would be unaware that there were of
any latency or jitter issues along the path.

2.4. Pro Audio Asks Requests to the IETF

o Layer 3 routing on top of AVB Audio Video Bridging (AVB) (and/or other high QoS
high-QoS (Quality of Service) networks)

o Content delivery with bounded, lowest possible latency

o IntServ and DiffServ integration with AVB (where practical)

o Single network for A/V and IT traffic

o Standards-based, interoperable, multi-vendor solutions
o IT department friendly IT-department-friendly networks

o Enterprise-wide networks (e.g. (e.g., the size of San Francisco but not
the whole Internet (yet...))

3. Electrical Utilities

3.1. Use Case Description

Many systems that an electrical utility deploys today rely on high
availability and deterministic behavior of the underlying networks.
Presented here are use cases in Transmission, Generation for transmission, generation, and
Distribution,
distribution, including key timing and reliability metrics. In
addition, security issues and industry trends which that affect the
architecture of next generation next-generation utility networks are discussed.

3.1.1. Transmission Use Cases

3.1.1.1. Protection

Protection

"Protection" means not only the protection of human operators but
also the protection of the electrical equipment and the preservation
of the stability and frequency of the grid. If a fault occurs in the
transmission or distribution of electricity electricity, then severe damage can
occur to human operators, electrical equipment equipment, and the grid itself,
leading to blackouts.

Communication links links, in conjunction with protection relays relays, are used
to selectively isolate faults on high voltage high-voltage lines, transformers,
reactors
reactors, and other important electrical equipment. The role of the
teleprotection system is to selectively disconnect a faulty part by
transferring command signals within the shortest possible time.

3.1.1.1.1. Key Criteria

The key criteria for measuring teleprotection performance are command
transmission time, dependability dependability, and security. These criteria are
defined by the IEC standard International Electrotechnical Commission (IEC)
Standard 60834 [IEC-60834] as follows:

o Transmission time (Speed): (speed): The time between the moment where when a
state
changes change occurs at the transmitter input and the moment of the
corresponding change at the receiver output, including propagation
delay. Overall The overall operating time for a teleprotection system
includes is
the sum of (1) the time for initiating required to initiate the command at the
transmitting end, (2) the propagation delay over the network
(including equipments) equipment), and (3) the selection and decision time required to make the
necessary selections and decisions at the receiving end, including
any additional delay due to a noisy environment.

o Dependability: The ability to issue and receive valid commands in
the presence of interference and/or noise, by minimizing the
probability
Probability of missing command Missing Commands (PMC). Dependability targets are
typically set for a specific bit error rate Bit Error Rate (BER) level.

o Security: The ability to prevent false tripping due to a noisy
environment, by minimizing the probability Probability of unwanted commands Unwanted Commands
(PUC). Security targets are also set for a specific bit error
rate (BER) BER level.

Additional elements of the teleprotection system that impact its
performance include:

o Network bandwidth

o Failure recovery capacity (aka resiliency)

3.1.1.1.2. Fault Detection and Clearance Timing

Most power line power-line equipment can tolerate short circuits or faults for
up to approximately five power cycles before sustaining irreversible
damage or affecting other segments in the network. This translates
to a total fault clearance time of 100ms. 100 ms. As a safety precaution,
however, the actual operation time of protection systems is limited
to
70- 80 percent 70-80% of this period, including fault recognition time, command
transmission time time, and line breaker switching time.

Some system components, such as large electromechanical switches,
require a particularly long time to operate and take up the majority
of the total clearance time, leaving only a 10ms 10 ms window for the
telecommunications part of the protection scheme, independent of the
distance to of travel. Given the sensitivity of the issue, new
networks impose requirements that are even more stringent: IEC standard 61850
Standard 61850-5:2013 [IEC-61850-5:2013] limits the transfer time for
protection messages to 1/4 - 1/2 1/4-1/2 cycle or 4 - 8ms 4-8 ms (for 60Hz 60 Hz lines) for
messages considered the most critical messages. critical.

3.1.1.1.3. Symmetric Channel Delay

Teleprotection channels which that are differential must be synchronous,
which synchronous;
this means that any delays on the transmit and receive paths must
match each other. Teleprotection Ideally, teleprotection systems ideally support zero
asymmetric delay; typical legacy relays can tolerate delay
discrepancies of up to 750us. 750 us.

Some tools available for lowering delay variation below this
threshold are: are as follows:

o For legacy systems using Time Division Time-Division Multiplexing (TDM), jitter
buffers at the multiplexers on each end of the line can be used to
offset delay variation by queuing sent and received packets. The
length of the queues must balance the need to regulate the rate of
transmission with the need to limit overall delay, as larger
buffers result in increased latency.

o For jitter-prone IP packet networks, traffic management tools can ensure
that the teleprotection signals receive the highest transmission
priority to minimize jitter.

o Standard packet-based synchronization technologies, such as the
IEEE 1588-2008 Precision Time Protocol (PTP) [IEEE-1588] and Synchronous
synchronous Ethernet
(Sync-E), (syncE) [syncE], can help keep networks
stable by maintaining a highly accurate clock source on the
various network devices.

3.1.1.1.4. Teleprotection Network Requirements (IEC 61850)

The following table

Table 1 captures the main network metrics. (These metrics as are based
on the IEC 61850 standard.

Table 1: Teleprotection network requirements Network Requirements

3.1.1.1.5. Inter-Trip Inter-trip Protection scheme Scheme

"Inter-tripping" is the signal-controlled tripping of a circuit
breaker to complete the isolation of a circuit or piece of apparatus
in concert with the tripping of other circuit breakers.

+--------------------------------+----------------------------------+

Table 2: Inter-Trip protection network requirements Inter-trip Protection Network Requirements

3.1.1.1.6. Current Differential Protection Scheme

Current differential protection is commonly used for line protection, protection
and is typical for protecting typically used to protect parallel circuits. At both end ends of
the
lines lines, the current is measured by the differential relays, and relays; both
relays will trip the circuit breaker if the current going into the
line does not equal the current going out of the line. This type of
protection scheme assumes that some form of communications being communication is present
between the relays at both end ends of the line, to allow both relays to
compare measured current values. Line differential protection
schemes assume a very low that the telecommunications delay between both
relays, relays
is very low -- often as low as 5ms. 5 ms. Moreover, as those systems are
often not time-synchronized, they also assume that the delay over
symmetric telecommunications paths with constant delay, which is constant; this allows comparing the
comparison of current measurement values taken at exactly the exact same
time.

+----------------------------------+--------------------------------+

Table 3: Current Differential Protection metrics Metrics

3.1.1.1.7. Distance Protection Scheme

Distance (Impedance Relay)

The distance (impedance relay) protection scheme is based on voltage
and current measurements. The network metrics are similar (but not
identical to) Current Differential
identical) to the metrics for current differential protection.

+-------------------------------+-----------------------------------+

Table 4: Distance Protection requirements Requirements

3.1.1.1.8. Inter-Substation Inter-substation Protection Signaling

This use case describes the exchange of Sampled Value sampled values and/or GOOSE
(Generic Object Oriented Substation Events) message messages between
Intelligent Electronic Devices (IED) (IEDs) in two substations for
protection and tripping coordination. The two IEDs are in a master-
slave
master-slave mode.

The Current Transformer or Voltage Transformer (CT/VT) in one
substation sends the sampled analog voltage or current value to the
Merging Unit (MU) over hard wire. The MU sends the time-synchronized
61850-9-2
sampled values (as specified by IEC 61850-9-2:2011
[IEC-61850-9-2:2011]) to the slave IED. The slave IED forwards the
information to the Master master IED in the other substation. The master
IED makes the determination (for example example, based on sampled value
differentials) to send a trip command to the originating IED. Once
the slave IED/Relay IED/relay receives the GOOSE message containing the command
to trip for breaker
tripping, the breaker, it opens the breaker. It then sends a
confirmation message back to the master. All data exchanges between
IEDs are either through Sampled Value sampled values and/or GOOSE messages.

+----------------------------------+--------------------------------+

Table 5: Inter-Substation Inter-substation Protection requirements Requirements

3.1.1.2. Intra-Substation Intra-substation Process Bus Communications

This use case describes the data flow from the CT/VT to the IEDs in
the substation via the MU. The CT/VT in the substation send sends the
analog voltage or current values to the MU over hard wire. The MU
converts the analog values into digital format (typically time-
synchronized Sampled Values
time-synchronized sampled values as specified by IEC 61850-9-2) 61850-9-2:2011
[IEC-61850-9-2:2011]) and sends them to the IEDs in the substation.
The GPS Global Positioning System (GPS) Master Clock can send 1PPS or
IRIG-B format to the MU through a serial port or IEEE 1588 protocol
via a network. Process bus communication using 61850
simplifies connectivity within the substation and removes the
requirement for multiple serial connections 1PPS (One Pulse Per Second) is an electrical signal
that has a width of less than 1 second and removes the slow
serial bus architectures a sharply rising or
abruptly falling edge that accurately repeats once per second. 1PPS
signals are output by radio beacons, frequency standards, other types
of precision oscillators, and some GPS receivers. IRIG (Inter-Range
Instrumentation Group) time codes are standard formats for
transferring timing information. Atomic frequency standards and GPS
receivers designed for precision timing are often equipped with an
IRIG output. Process bus communication using IEC 61850-9-2:2011
[IEC-61850-9-2:2011] simplifies connectivity within the substation,
removes the requirement for multiple serial connections, and removes
the slow serial-bus architectures that are typically used. This also
ensures increased flexibility and increased speed with the use of
multicast messaging between multiple devices.

+----------------------------------+--------------------------------+

Table 6: Intra-Substation Intra-substation Protection requirements Requirements

3.1.1.3. Wide Area Wide-Area Monitoring and Control Systems

The application of synchrophasor measurement data from Phasor
Measurement Units (PMU) (PMUs) to Wide Area Monitoring wide-area monitoring and Control Systems control systems
promises to provide important new capabilities for improving system
stability. Access to PMU data enables more timely more-timely situational
awareness over larger portions of the grid than what has been
possible historically with normal SCADA (Supervisory Control and Data
Acquisition) data. Handling the volume and the real-time nature of
synchrophasor data presents unique challenges for existing
application architectures. Wide Area management The Wide-Area Management System (WAMS)
makes it possible for the condition of the bulk power system to be
observed and understood in real-time real time so that protective,
preventative, or corrective action can be taken. Because of the very
high sampling rate of measurements and the strict requirement for
time synchronization of the samples, the WAMS has stringent
telecommunications requirements in an IP network that are network, as captured in the following
table:

+----------------------+--------------------------------------------+
Table 7:

Table 7: WAMS Special Communication Requirements

3.1.1.4. IEC 61850 WAN engineering guidelines requirement
classification Engineering Guidelines Requirement Classification

The IEC (International Electrotechnical Commission) has published a
Technical Report which technical report (TR) that offers guidelines
on how to define and deploy
Wide Area Wide-Area Networks (WANs) for the interconnections
interconnection of electric substations, generation plants plants, and SCADA
operation centers. The IEC 61850-90-12
is providing a classification TR 61850-90-12:2015 [IEC-61850-90-12:2015]
provides four classes of WAN communication requirements into
4 classes. requirements, as
summarized in Table 8 summarizes these requirements:

+----------------+------------+------------+------------+-----------+ 8:

+----------------+-----------+----------+----------+----------------+
| WAN | Class WA | Class WB | Class WC | Class WD |
| Requirement | | | | |
+----------------+------------+------------+------------+-----------+
+----------------+-----------+----------+----------+----------------+
| Application | EHV (Extra | HV (High | MV (Medium | General General- |
| field | High (Extra- | Voltage) | Voltage) (Medium | purpose |
| | High | | Voltage) | |
| | Voltage) | | | |
| | | | | |
| Latency | 5 ms | 10 ms | 100 ms | > 100 >100 ms |
| Jitter | | | | |
| Jitter | 10 us | 100 us | 1 ms | 10 ms |
| | | | | |
| Latency | 100 us | 1 ms | 10 ms | 100 ms |
| Asymetry asymmetry | | | | |
| | | | | |
| Time Accuracy accuracy | 1 us | 10 us | 100 us | 10 to 100 ms |
| | | | | ms |
| Bit Error rate BER | 10-7 10^-7 to | 10-5 10^-5 to | 10-3 10^-3 | |
| | 10^-6 | 10^-4 | | |
| | 10-6 | 10-4 | | |
| Unavailability | 10-7 10^-7 to | 10-5 10^-5 to | 10-3 10^-3 | |
| | 10^-6 | 10^-4 | | |
| | 10-6 | 10-4 | | |
| Recovery delay | Zero | 50 ms | 5 s | 50 s |
| Cyber security | extremely | | | |
| Cybersecurity | Extremely | High | Medium | Medium |
| | high | | | |
+----------------+------------+------------+------------+-----------+
+----------------+-----------+----------+----------+----------------+

Table 8: 61850-90-12 Communication Requirements; Courtesy Requirements (Courtesy of
IEC TR 61850-90-12:2015)

3.1.2. Generation Use Case

Energy generation systems are complex infrastructures that require
control of both the generated power and the generation
infrastructure.

3.1.2.1. Control of the Generated Power

The electrical power generation frequency must be maintained within a
very narrow band. Deviations from the acceptable frequency range are
detected
detected, and the required signals are sent to the power plants for
frequency regulation.

Automatic Generation Control (AGC) is a system for adjusting the
power output of generators at different power plants, in response to
changes in the load.

+---------------------------------------------------+---------------+

Table 9: FCAG Communication Requirements

3.1.2.2. Control of the Generation Infrastructure

The control of the generation infrastructure combines requirements
from industrial automation systems and energy generation systems.
This section considers describes the use case of the for control of the generation
infrastructure of a wind turbine.

Figure 1 presents the subsystems that operate a wind turbine.

Figure 1: Wind Turbine Control Network

The subsystems shown in Figure 1 presents the subsystems that operate a wind turbine. These
subsystems include the following:

o WROT (Rotor Control) (rotor control)

o WNAC (Nacelle Control) (nacelle control) (nacelle: housing containing the generator)

o WTRM (Transmission Control) (transmission control)

o WGEN (Generator) (generator)

o WYAW (Yaw Controller) (yaw controller) (of the tower head)

o WCNV (In-Turbine Power Converter) (in-turbine power converter)

o WTRF (wind turbine transformer information)

o WMET (External Meteorological Station (external meteorological station providing real time real-time
information to the controllers of the tower) tower's controllers)

o WTUR (wind turbine general information)

o WREP (wind turbine report information)

o WSLG (wind turbine state log information)
o WALG (wind turbine analog log information)

o WTOW (wind turbine tower information)

Traffic characteristics relevant for to the network planning and
dimensioning process in a wind turbine scenario are listed below.
The values in this section are based mainly on the relevant
references [Ahm14] and [Spe09]. Each logical node (Figure 1) is a
part of the metering network and produces analog measurements and
status information which that must comply with their respective data rate data-rate
constraints.

+-----------+--------+--------+-------------+---------+-------------+

+-----------+--------+----------+-----------+-----------+-----------+
| Subsystem | Sensor | Analog | Data Rate | Status | Data rate Rate |
| | Count | Sample | (bytes/sec) (bytes/s) | Sample | (bytes/sec) (bytes/s) |
| | | Count | | Count | |
+-----------+--------+--------+-------------+---------+-------------+
+-----------+--------+----------+-----------+-----------+-----------+
| WROT | 14 | 9 | 642 | 5 | 10 |
| | | | | | |
| WTRM | 18 | 10 | 2828 | 8 | 16 |
| | | | | | |
| WGEN | 14 | 12 | 73764 | 2 | 4 |
| | | | | | |
| WCNV | 14 | 12 | 74060 | 2 | 4 |
| | | | | | |
| WTRF | 12 | 5 | 73740 | 2 | 4 |
| | | | | | |
| WNAC | 12 | 9 | 112 | 3 | 6 |
| | | | | | |
| WYAW | 7 | 8 | 220 | 4 | 8 |
| | | | | | |
| WTOW | 4 | 1 | 8 | 3 | 6 |
| | | | | | |
| WMET | 7 | 7 | 228 | - | - |
+-----------+--------+--------+-------------+---------+-------------+
+-----------+--------+----------+-----------+-----------+-----------+

Table 10: Wind Turbine Data Rate Data-Rate Constraints

Quality of Service (QoS)

QoS constraints for different services are presented in Table 11.
These constraints are defined by IEEE Standard 1646
standard [IEEE1646] [IEEE-1646] and
IEC Standard 61400 standard [IEC61400]. Part 25 [IEC-61400-25].

+---------------------+---------+-------------+---------------------+
| Service | Latency | Reliability | Packet Loss Rate |
+---------------------+---------+-------------+---------------------+
| Analogue measure Analog measurement | 16 ms | 99.99% | < 10-6 <10^-6 |
| | | | |
| Status information | 16 ms | 99.99% | < 10-6 <10^-6 |
| | | | |
| Protection traffic | 4 ms | 100.00% | < 10-9 <10^-9 |
| | | | |
| Reporting and | 1 s | 99.99% | < 10-6 <10^-6 |
| logging | | | |
| | | | |
| Video surveillance | 1 s | 99.00% | No specific |
| | | | requirement |
| | | | |
| Internet connection | 60 min | 99.00% | No specific |
| | | | requirement |
| Control traffic | 16 ms | | |
| Control traffic | 16 ms | 100.00% | < 10-9 <10^-9 |
| | | | |
| Data polling | 16 ms | 99.99% | < 10-6 <10^-6 |
+---------------------+---------+-------------+---------------------+

Table 11: Wind Turbine Reliability and Latency Constraints

3.1.2.2.1. Intra-Domain Intra-domain Network Considerations

A wind turbine is composed of a large set of subsystems subsystems, including
sensors and actuators which that require time-critical operation. The
reliability and latency constraints of these different subsystems is are
shown in Table 11. These subsystems are connected to an intra-domain
network which that is used to monitor and control the operation of the
turbine and connect it to the SCADA subsystems. The different
components are interconnected using fiber optics, industrial buses,
industrial Ethernet, EtherCat, EtherCAT [EtherCAT], or a combination of them. thereof.
Industrial signaling and control protocols such as Modbus, Profibus, Profinet Modbus [MODBUS],
PROFIBUS [PROFIBUS], PROFINET [PROFINET], and EtherCat EtherCAT are used
directly on top of the Layer 2 transport or encapsulated over TCP/IP.

The Data data collected from the sensors and condition monitoring condition-monitoring systems
is multiplexed onto fiber cables for transmission to the base of the
tower,
tower and to remote control centers. The turbine controller
continuously monitors the condition of the wind turbine and collects
statistics on its operation. This controller also manages a large
number of switches, hydraulic pumps, valves, and motors within the
wind turbine.

There is usually a controller both at the bottom of the tower and also in
the nacelle. The communication between these two controllers usually
takes place using fiber optics instead of copper links. Sometimes, a
third controller is installed in the hub of the rotor and manages the
pitch of the blades. That unit usually communicates with the nacelle
unit using serial communications.

3.1.2.2.2. Inter-Domain network considerations Inter-domain Network Considerations

A remote control center belonging to a grid operator regulates the
power output, enables remote actuation, and monitors the health of
one or more wind parks in tandem. It connects to the local control
center in a wind park over the Internet (Figure 2) via firewalls at
both ends. The AS Autonomous System (AS) path between the local control
center and the Wind
Park wind park typically involves several ISPs at different
tiers. For example, a remote control center in Denmark can regulate
a wind park in Greece over the normal public AS path between the two
locations.

Figure 2: Wind Turbine Control via Internet

The remote control center is part of the SCADA system, setting the
desired power output to the wind park and reading back the result
once the new power output level has been set. Traffic between the
remote control center and the wind park typically consists of
protocols like IEC 60870-5-104 [IEC-60870-5-104], OPC XML-DA XML-Data Access
(XML-DA) [OPCXML], Modbus [MODBUS], and SNMP [RFC3411]. At the time
of this writing, traffic flows between the wind farm and the remote control center and
the wind park are best effort. QoS requirements are not strict, so
no SLAs Service Level Agreements (SLAs) or service provisioning service-provisioning mechanisms
(e.g., VPN) VPNs) are employed. In the case of such events like as equipment
failure, tolerance for alarm delay is on the order of minutes, due to
redundant systems already in place.

Figure 2: Wind Turbine Control via Internet

Future use cases will require bounded latency, bounded jitter jitter, and
extraordinary
extraordinarily low packet loss for inter-domain traffic flows due to
the softwarization and virtualization of core wind farm wind-park equipment
(e.g.
(e.g., switches, firewalls firewalls, and SCADA server components). These
factors will create opportunities for service providers to install
new services and dynamically manage them from remote locations. For
example, to enable fail-over failover of a local SCADA server, a SCADA server
in another wind farm wind-park site (under the administrative control of the
same operator) could be utilized temporarily (Figure 3). In that
case
case, local traffic would be forwarded to the remote SCADA server server,
and existing intra-domain QoS and timing parameters would have to be
met for inter-domain traffic flows.

Figure 3: Wind Turbine Control via Operator Administered Operator-Administered WAN

3.1.3. Distribution use case Use Case

3.1.3.1. Fault Location Isolation Location, Isolation, and Service Restoration (FLISR)

Fault

"Fault Location, Isolation, and Service Restoration (FLISR) (FLISR)" refers
to the ability to automatically locate the fault, isolate the fault,
and restore service in the distribution network. This will likely
be the first widespread application of distributed intelligence in
the grid.

Static power switch

The static power-switch status (open/closed) in the network dictates
the power flow to secondary substations. Reconfiguring the network
in the event of a fault is typically done manually on site to energize/
de-energize
energize/de-energize alternate paths. Automating the operation of
substation switchgear allows the flow of power to be altered
automatically under fault conditions.

FLISR can be managed centrally from a Distribution Management System
(DMS) or executed locally through distributed control via intelligent
switches and fault sensors.

+----------------------+--------------------------------------------+

Table 12: FLISR Communication Requirements

3.2. Electrical Utilities Today

Many utilities still rely on complex environments formed consisting of
multiple application-specific proprietary networks, including TDM
networks.

In this kind of environment environment, there is no mixing of OT Operation
Technology (OT) and IT applications on the same network, and
information is siloed between operational areas.

Specific calibration of the full chain is required, which required; this is costly.

This kind of environment prevents utility operations from realizing
the
operational efficiency benefits, visibility, and functional
integration of operational information across grid applications and
data networks.

In addition, there are many security-related issues issues, as discussed in
the following section.

3.2.1. Security Current Security Practices and Their Limitations

Grid monitoring

Grid-monitoring and control devices are already targets for cyber
attacks, and legacy telecommunications protocols have many intrinsic
network-related vulnerabilities. For example, DNP3, the Distributed
Network Protocol (DNP3) [IEEE-1815], Modbus, PROFIBUS/PROFINET, and
other protocols are designed around a common paradigm of request "request and respond.
respond". Each protocol is designed for a master device such as an
HMI (Human Machine (Human-Machine Interface) system to send commands to subordinate
slave devices to retrieve perform data retrieval (reading inputs) or control
functions (writing to outputs). Because many of these protocols lack
authentication, encryption, or other basic security measures, they
are prone to network-based attacks, allowing a malicious actor or
attacker to utilize the request-and-respond system as a mechanism for command-and-control like functionality.
functionality similar to command and control. Specific security
concerns common to most industrial control, including
utility telecommunication industrial-control protocols (including
utility telecommunications protocols) include the following:

o Network or transport errors (e.g. (e.g., malformed packets or excessive
latency) can cause protocol failure.

o Protocol commands may be available that are capable of forcing
slave devices into inoperable states, including powering-off
devices, powering devices
off, forcing them into a listen-only state, or disabling alarming.

o Protocol commands may be available that are capable of restarting
communications and otherwise
interrupting processes. processes (e.g., restarting communications).

o Protocol commands may be available that are capable of clearing,
erasing, or resetting diagnostic information such as counters and
diagnostic registers.

o Protocol commands may be available that are capable of requesting
sensitive information about the controllers, their configurations,
or other need-to-know information.

o Most protocols are application layer application-layer protocols transported over
TCP; therefore it is therefore easy to transport commands over non-standard
ports or inject commands into authorized traffic flows.

o Protocol commands may be available that are capable of
broadcasting messages to many devices at once (i.e. (i.e., a
potential DoS).

o Protocol commands may be available to that will query the device
network to obtain defined points and their values (i.e. (i.e., perform a
configuration scan).

o Protocol commands may be available that will list all available
function codes (i.e. (i.e., perform a function scan).

These inherent vulnerabilities, along with increasing connectivity
between IT an and OT networks, make network-based attacks very feasible.

Simple injection of
By injecting malicious protocol commands provides commands, an attacker could take
control over the target process. Altering legitimate protocol
traffic can also alter information about a process and disrupt the
legitimate controls that are in place over that process. A
man-in-the-middle attack could provide both result in (1) improper control over a
process and (2) misrepresentation of data that is sent back to
operator consoles.

3.3. Electrical Utilities in the Future

The business and technology trends that are sweeping the utility
industry will drastically transform the utility business from the way
it has been for many decades. At the core of many of these changes
is a drive to modernize the electrical grid with an integrated
telecommunications infrastructure. However, interoperability
concerns, legacy networks, disparate tools, and stringent security
requirements all add complexity to the grid grid's transformation. Given
the range and diversity of the requirements that should be addressed
by the next generation next-generation telecommunications infrastructure, utilities
need to adopt a holistic architectural approach to integrate the
electrical grid with digital telecommunications across the entire
power delivery chain.

The key to modernizing grid telecommunications is to provide a
common, adaptable, multi-service network infrastructure for the
entire utility organization. Such a network serves as the platform
for current capabilities while enabling future expansion of the
network to accommodate new applications and services.

To meet this diverse set of requirements, requirements both today and in the
future, the next generation next-generation utility telecommunnications telecommunications network will
be based on an open-standards-based IP architecture. An end-to-end
IP architecture takes advantage of nearly three decades of IP
technology development, facilitating interoperability and device
management across disparate networks and devices, as it has been already been
demonstrated in many mission-critical and highly secure networks.

IPv6 is seen as a future telecommunications technology for the Smart
Grid; smart
grid; the IEC (International Electrotechnical Commission) and different National Committees national committees have mandated a
specific adhoc ad hoc group (AHG8) to define the migration strategy for migration to
IPv6 for all the IEC TC57 Technical Committee 57 (TC 57) power automation
standards. The AHG8 has finalised the finalized its work on the migration strategy
strategy, and the following Technical Report has been
issued: IEC TR 62357-200:2015: Guidelines for migration from Internet
Protocol version 4 (IPv4) to Internet Protocol version 6 (IPv6). 62357-200:2015 [IEC-62357-200:2015] has been
issued.

Cloud-based SCADA systems will control and monitor the critical and
non-critical subsystems of generation systems, systems -- for example example, wind
farms.
parks.

3.3.1. Migration to Packet-Switched Network Networks

Throughout the world, utilities are increasingly planning for a
future based on smart grid smart-grid applications requiring advanced
telecommunications systems. Many of these applications utilize
packet connectivity for communicating information and control signals
across the utility's Wide Area Network (WAN), WAN, made possible by technologies such as multiprotocol label switching
Multiprotocol Label Switching (MPLS). The data that traverses the
utility WAN includes:

o Grid monitoring, control, and protection data

o Non-control grid data (e.g. (e.g., asset data for condition-based condition monitoring)

o Physical safety and security data (e.g. Data (e.g., voice and video) related to physical safety and
security

o Remote worker access to corporate applications (voice, maps,
schematics, etc.)

o Field area network backhaul Backhaul for smart metering, and distribution
grid metering

o Distribution-grid management
o Enterprise traffic (email, collaboration tools, business
applications)

WANs support this wide variety of traffic to and from substations,
the transmission and distribution grid, and generation sites, sites; between
control centers, centers; and between work locations and data centers. To
maintain this rapidly expanding set of applications, many utilities
are taking steps to evolve present time-division multiplexing (TDM)
based TDM-based and frame relay
infrastructures to packet systems. Packet-
based Packet-based networks are
designed to provide greater functionalities and higher levels of
service for applications, while continuing to deliver reliability and
deterministic (real-time) traffic support.

3.3.2. Telecommunications Trends

These general telecommunications topics are provided in addition to
the use cases that have been addressed so far. These include both
current and future telecommunications related telecommunications-related topics that should be
factored into the network architecture and design.

3.3.2.1. General Telecommunications Requirements

o IP Connectivity connectivity everywhere

o Monitoring services everywhere everywhere, and from different remote centers

o Move Moving services to a virtual data center

o Unify Unified access to applications / information applications/information from the corporate
network

o Unify Unified services

o Unified Communications Solutions communications solutions

o Mix of fiber and microwave technologies - obsolescence of SONET/
SDH the
Synchronous Optical Network / Synchronous Digital Hierarchy
(SONET/SDH) or TDM

o Standardize Standardizing grid telecommunications protocol protocols to opened standard open standards,
to ensure interoperability

o Reliable Telecommunications telecommunications for Transmission transmission and Distribution
Substations distribution
substations

o IEEE 1588 time synchronization Client / Server Capabilities time-synchronization client/server capabilities

o Integration of Multicast Design multicast design
o QoS Requirements Mapping of QoS requirements

o Enable Future Network Expansion Enabling future network expansion

o Substation Network Resilience network resilience

o Fast Convergence Design convergence design

o Scalable Headend Design headend design

o Define Service Level Agreements (SLA) Defining SLAs and Enable enabling SLA Monitoring monitoring

o Integration of 3G/4G Technologies technologies and future technologies

o Ethernet Connectivity connectivity for Station Bus Architecture station bus architecture

o Ethernet Connectivity connectivity for Process Bus Architecture process bus architecture

o Protection, teleprotection teleprotection, and PMU (Phaser Measurement Unit) PMUs on IP

3.3.2.2. Specific Network topologies Topologies of Smart Grid Smart-Grid Applications

Utilities often have very large private telecommunications networks.
It covers networks
that can cover an entire territory / country. The territory/country. Until now, the main purpose
purposes of the
network, until now, has these networks have been to (1) support transmission
network monitoring, control, and automation, (2) support remote
control of generation sites, and providing (3) provide FCAPS (Fault,
Configuration, Accounting, Performance, and Security) services from
centralized network operation centers.

Going forward, one network will support the operation and maintenance
of electrical networks (generation, transmission, and distribution),
voice and data services for ten tens of thousands of employees and for
exchange
exchanges with neighboring interconnections, and administrative
services. To meet those requirements, a utility may deploy several
physical networks leveraging different technologies across the
country:
country -- for instance, an optical network and a microwave network for instance. network.
Each protection and automatism automation system between two points has two
telecommunications circuits, one on each network. Path diversity
between two substations is key. Regardless of the event type
(hurricane, ice storm, etc.), one path needs to stay available so the
system can still operate.

In the optical network, signals are transmitted over more than tens
of thousands of circuits using fiber optic links, microwave links,
and telephone cables. This network is the nervous system of the
utility's power transmission operations. The optical network
represents ten tens of thousands of km kilometers of cable deployed along
the power lines, with individual runs as long as 280 km.

3.3.2.3. Precision Time Protocol

Some utilities do not use GPS clocks in generation substations. One
of the main reasons is that some of the generation plants are 30 to
50 meters deep under ground underground and the GPS signal can be weak and
unreliable. Instead, atomic clocks are used. Clocks are
synchronized amongst each other. Rubidium clocks provide clock and
1ms
1 ms timestamps for IRIG-B.

Some companies plan to transition to the Precision Time Protocol
(PTP, [IEEE1588]), PTP [IEEE-1588], distributing
the synchronization signal over the IP/MPLS network. PTP provides a
mechanism for synchronizing the clocks of participating nodes to a
high degree of accuracy and precision.

PTP operates based on the following assumptions:

It is assumed that the

o The network eliminates cyclic forwarding of PTP messages within
each communication path (e.g. (e.g., by using a spanning tree protocol).

o PTP is tolerant of an occasional missed message, duplicated
message, or message that arrived out of order. However, PTP
assumes that such impairments are relatively rare.

o As designed, PTP was designed assuming expects a multicast communication model, however model; however,
PTP also supports a unicast communication model as long as the
behavior of the protocol is preserved.

o Like all message-based time transfer protocols, PTP time accuracy
is degraded by delay asymmetry in the paths taken by event
messages. Asymmetry is not detectable by PTP, however, PTP cannot detect asymmetry, but if such delays are
known a priori, PTP time values can be adjusted to correct for
asymmetry.

IEC 61850 defines the

The use of IEC/IEEE 61850-9-3:2016. The title is:
Precision time protocol profile PTP for power utility automation. automation is defined in
IEC/IEEE 61850-9-3:2016 [IEC-IEEE-61850-9-3:2016]. It is based on
Annex B/IEC 62439 B of IEC 62439-3:2016 [IEC-62439-3:2016], which offers the
support of redundant attachment of clocks to Parallel Redundancy
Protocol (PRP) and High-
availability High-availability Seamless Redundancy (HSR)
networks.

3.3.3. Security Trends in Utility Networks

Although advanced telecommunications networks can assist in
transforming the energy industry by playing a critical role in
maintaining high levels of reliability, performance, and
manageability, they also introduce the need for an integrated
security infrastructure. Many of the technologies being deployed to
support smart grid smart-grid projects such as smart meters and sensors can
increase the vulnerability of the grid to attack. Top security
concerns for utilities migrating to an intelligent smart grid smart-grid
telecommunications platform center on the following trends:

o Integration of distributed energy resources

o Proliferation of digital devices to enable management, automation,
protection, and control

o Regulatory mandates to comply with standards for critical
infrastructure protection

o Migration to new systems for outage management, distribution
automation, condition-based maintenance, load forecasting, and
smart metering

o Demand for new levels of customer service and energy management

This development of a diverse set of networks to support the
integration of microgrids, open-access energy competition, and the
use of network-controlled devices is driving the need for a converged
security infrastructure for all participants in the smart grid,
including utilities, energy service providers, large commercial and
industrial, as well as
industrial customers, and residential customers. Securing the assets
of electric power delivery systems (from the control center to the
substation, to the feeders and down to customer meters) requires an
end-to-end security infrastructure that protects the myriad of
telecommunications assets used to operate, monitor, and control power
flow and measurement.

"Cyber security"

"Cybersecurity" refers to all the security issues in automation and
telecommunications that affect any functions related to the operation
of the electric power systems. Specifically, it involves the
concepts of:

o Integrity : Integrity: data cannot be altered undetectably

o Authenticity (data origin authentication): the telecommunications
parties involved must be validated as genuine

o Authorization : Authorization: only requests and commands from the authorized users
can be accepted by the system

o Confidentiality : Confidentiality: data must not be accessible to any
unauthenticated users
When designing and deploying new smart grid smart-grid devices and
telecommunications systems, it is imperative to understand the
various impacts of these new components under a variety of attack
situations on the power grid. Consequences The consequences of a cyber attack on
the grid telecommunications network can be catastrophic. This is why
security for the smart grid is not just an ad hoc feature or product, product;
it's a complete framework integrating both physical and Cyber
security cybersecurity
requirements and covering the entire smart grid smart-grid networks from
generation to distribution. Security has therefore become one of the
main foundations of the utility telecom network architecture and must
be considered at every layer with a defense-in-depth approach.
Migrating to IP based IP-based protocols is key to address addressing these challenges
for two reasons:

o IP enables a rich set of features and capabilities to enhance the
security posture posture.

o IP is based on open standards, which standards; this allows interoperability
between different vendors and products, driving down the costs
associated with implementing security solutions in OT networks.

Securing OT (Operation technology) telecommunications over packet-
switched packet-switched IP networks follow
follows the same principles that are foundational for securing the IT
infrastructure, i.e., consideration must be given to (1) enforcing
electronic access control for both person-to-machine and
machine-to-machine communications, machine-to-
machine communications and (2) providing the appropriate levels of
data privacy, device and platform integrity, and threat detection and
mitigation.

3.4. Electrical Utilities Asks Requests to the IETF

o Mixed L2 Layer 2 and L3 Layer 3 topologies

o Deterministic behavior

o Bounded latency and jitter

o Tight feedback intervals

o High availability, low recovery time

o Redundancy, low packet loss

o Precise timing

o Centralized computing of deterministic paths

o Distributed configuration may (may also be useful useful)

4. Building Automation Systems (BASs)

4.1. Use Case Description

A Building Automation System (BAS) BAS manages equipment and sensors in a building for improving
residents' comfort, reducing energy consumption, and responding to
failures and emergencies. For example, the BAS measures the
temperature of a room using sensors and then controls the HVAC
(heating, ventilating, and air conditioning) to maintain a set
temperature and minimize energy consumption.

A BAS primarily performs the following functions:

o Periodically measures states of devices, devices -- for example example, humidity
and illuminance of rooms, open/close state of doors, FAN speed, etc. fan speed.

o Stores the measured data.

o Provides the measured data to BAS systems and operators.

o Generates alarms for abnormal state of devices.

o Controls devices (e.g. turn off (e.g., turns room lights off at 10:00 PM).

4.2. Building Automation Systems BASs Today

4.2.1. BAS Architecture

A typical present-day BAS architecture of today is shown in Figure 4.

+----------------------------+
| |
| BMS HMI |
| | | |
| +----------------------+ |
| | Management Network | |
| +----------------------+ |
| | | |
| LC LC |
| | | |
| +----------------------+ |
| | Field Network | |
| +----------------------+ |
| | | | | |
| Dev Dev Dev Dev |
| |
+----------------------------+

BMS :=

BMS: Building Management Server
HMI := Human Machine
HMI: Human-Machine Interface
LC :=
LC: Local Controller

Figure 4: BAS architecture Architecture

There are typically two layers of a network in a BAS. The upper one
layer is called the Management Network management network, and the lower one layer is called
the Field
Network. field network. In management networks networks, an IP-based communication
protocol is used, while in field networks non-IP based networks, non-IP-based communication
protocols ("field protocols") are mainly used. Field networks have
specific timing requirements, whereas management networks can be best-effort.

A Human Machine Interface (HMI) best
effort.

An HMI is typically a desktop PC used by operators to monitor and
display device states, send device control commands to Local
Controllers (LCs), and configure building schedules (for example example,
"turn off all room lights in the building at 10:00 PM").

A Building Management Server building management server (BMS) performs the following operations.

o Collect Collects and store stores device states from LCs at regular intervals.

o Send Sends control values to LCs according to a building schedule.

o Send Sends an alarm signal to operators if it detects abnormal devices device
states.

The BMS and HMI communicate with LCs via IP-based "management
protocols" (see standards [bacnetip], [knx]).

A [BACnet-IP] and [KNX]).

An LC is typically a Programmable Logic Controller (PLC) which that is
connected to several tens or hundreds of devices using "field
protocols". An LC performs the following kinds of operations:

o Measure Measures device states and provide provides the information to a BMS
or HMI.

o Send Sends control values to devices, unilaterally or as part of a
feedback control loop.

There are many field protocols used at

At the time of this writing; writing, many field protocols are in use; some
are standards-based protocols, and others are proprietary (see
standards
[lontalk], [modbus], [profibus] [LonTalk], [MODBUS], [PROFIBUS], and [flnet]). [FL-net]). The result
is that BASs have multiple MAC/PHY modules and interfaces. This
makes BASs more expensive, expensive and slower to develop, develop and can result in
"vendor lock-in" with multiple types of management applications.

4.2.2. BAS Deployment Model

An example BAS for medium or large buildings is shown in Figure 5.
The physical layout spans multiple floors, floors and there is includes a monitoring
room where the BAS management entities are located. Each floor will
have one or more LCs LCs, depending upon on the number of devices connected to
the field network.

+--------------------------------------------------+
| Floor 3 |
| +----LC~~~~+~~~~~+~~~~~+ |
| | | | | |
| | Dev Dev Dev |
| | |
|--- | ------------------------------------------|
| | Floor 2 |
| +----LC~~~~+~~~~~+~~~~~+ Field Network |
| | | | | |
| | Dev Dev Dev |
| | |
|--- | ------------------------------------------|
| | Floor 1 |
| +----LC~~~~+~~~~~+~~~~~+ +-----------------|
| | | | | | Monitoring Room |
| | Dev Dev Dev | |
| | | BMS HMI |
| | Management Network | | | |
| +--------------------------------+-----+ |
| | |
+--------------------------------------------------+

Figure 5: BAS Deployment model Model for Medium/Large Buildings

Each LC is connected to the monitoring room via the Management management
network, and the management functions are performed within the
building. In most cases, fast Fast Ethernet (e.g. (e.g., 100BASE-T) is used for
the management network. Since the management network is non-
realtime, not a
real-time network, the use of Ethernet without quality of service QoS is sufficient for
today's deployment.

In the field network a variety of deployments.

Many physical interfaces such as RS232C
and RS485 are used, which used in field networks have specific timing requirements. Thus
requirements -- for example, RS232C and RS485. Thus, if a field
network is to be replaced with an Ethernet or wireless network, such
networks must support time-critical deterministic flows.

Figure 6, 6 shows another deployment model is presented model, in which the management
system is hosted remotely. This model is becoming popular for small office
offices and residential buildings buildings, in which a standalone monitoring
system is not cost-effective. cost effective.

+---------------+
| Remote Center |
| |
| BMS HMI |
+------------------------------------+ | | | |
| Floor 2 | | +---+---+ |
| +----LC~~~~+~~~~~+ Field Network| | | |
| | | | | | Router |
| | Dev Dev | +-------|-------+
| | | |
|--- | ------------------------------| |
| | Floor 1 | |
| +----LC~~~~+~~~~~+ | |
| | | | | |
| | Dev Dev | |
| | | |
| | Management Network | WAN |
| +------------------------Router-------------+
| |
+------------------------------------+

Figure 6: Deployment model Model for Small Buildings

Some interoperability is possible today in the Management Network, today's management networks but
is not possible in today's field networks due to their non-IP-based
design.

4.2.3. Use Cases for Field Networks

Below are use cases for Environmental Monitoring, Fire Detection, environmental monitoring, fire detection, and
Feedback Control,
feedback control, and their implications for field network
performance.

4.2.3.1. Environmental Monitoring

The BMS polls each LC at a maximum measurement interval of 100ms 100 ms
(for
example example, to draw a historical chart of 1 second 1-second granularity with
a 10x sampling interval) and then performs the operations as
specified by the operator. Each LC needs to measure each of its
several hundred sensors once per measurement interval. Latency is
not critical in this scenario as long as all sensor values value
measurements are completed in within the measurement interval.
Availability is expected to be 99.999 %. 99.999%.

4.2.3.2. Fire Detection

On detection of a fire, the BMS must stop the HVAC, close the fire
shutters, turn on the fire sprinklers, send an alarm, etc. There are
typically ~10s tens of fire sensors per LC that the BMS needs to manage.
In this
scenario scenario, the measurement interval is 10-50ms, 10-50 ms, the
communication delay is 10ms, 10 ms, and the availability must be 99.9999 %. 99.9999%.

4.2.3.3. Feedback Control

BAS systems

BASs utilize feedback control in various ways; the most time-
critial time-critical
is control of DC motors, which require a short feedback interval (1-5ms)
(1-5 ms) with low communication delay (10ms) (10 ms) and jitter
(1ms). (1 ms). The
feedback interval depends on the characteristics of the device and a target quality of on
the requirements for the control value. values. There are typically
~10s tens of such devices
feedback sensors per LC.

Communication delay is expected to be less than 10ms, 10 ms and jitter less
than 1ms 1 ms, while the availability must be 99.9999% . 99.9999%.

4.2.4. BAS Security Considerations

When BAS field networks were developed developed, it was assumed that the field
networks would always be physically isolated from external networks
and therefore networks;
therefore, security was not a concern. In today's world world, many BASs
are managed remotely and are thus connected to shared IP networks and
so networks;
therefore, security is definitely a concern, yet definite concern. Note, however, that
security features are not currently available in the majority of BAS
field network deployments . deployments.

The management network, being an IP-based network, has the protocols
available to enable network security, but in practice many BAS
systems BASs do
not implement even the such available security features such as device
authentication or encryption for data in transit.

4.3. BAS BASs in the Future

In the future more fine-grained environmental monitoring and future, lower energy consumption and environmental monitoring
that is more fine-grained will emerge which emerge; these will require more
sensors and devices, thus requiring larger and more complex more-complex building
networks.

Building networks will be connected to or converged with other
networks (Enterprise network, Home network, (enterprise networks, home networks, and the Internet).

Therefore

Therefore, better facilities for network management, control,
reliability
reliability, and security are critical in order to improve resident
and operator convenience and comfort. For example example, the ability to
monitor and control building devices via the internet Internet would enable
(for example) control of room lights or HVAC from a resident's
desktop PC or phone application.

4.4. BAS Asks Requests to the IETF

The community would like to see an interoperable protocol
specification that can satisfy the timing, security, availability availability,
and QoS constraints described above, such that the resulting
converged network can replace the disparate field networks. Ideally Ideally,
this connectivity could extend to the open Internet.

This would imply an architecture that can guarantee

o Low communication delays (from <10ms <10 ms to 100ms 100 ms in a network of
several hundred devices)

o Low jitter (< 1 (<1 ms)

o Tight feedback intervals (1ms - 10ms) (1-10 ms)

o High network availability (up to 99.9999% ) 99.9999%)

o Availability of network data in disaster scenario scenarios

o Authentication between management devices and field devices (both
local and remote)

o Integrity and data origin authentication of communication data
between field and management devices and field devices

o Confidentiality of data when communicated to a remote device

5. Wireless for Industrial Applications

5.1. Use Case Description

Wireless networks are useful for industrial applications, applications -- for example
example, (1) when portable, fast-moving fast-moving, or rotating objects are involved,
involved and (2) for the resource-constrained devices found in the
Internet of Things (IoT).

Such network-connected sensors, actuators, control loops (etc.) loops, etc.
typically require that the underlying network support real-time
quality of service (QoS), QoS,
as well as such specific classes of other network properties such as reliability,
redundancy, and security.

These networks may also contain very large numbers of devices, devices -- for
example
example, for factories, "big data" acquisition, and the IoT. Given
the large numbers of devices installed, installed and the potential
pervasiveness of the IoT, this is a huge and very cost-sensitive
market such that small cost reductions can save large amounts of
money.

5.1.1. Network Convergence using Using 6TiSCH

Some wireless network technologies support real-time QoS, QoS and are thus
useful for these kinds of networks, but others do not.

This use case focuses on one specific wireless network technology
which
that provides the required deterministic QoS, which is QoS: "IPv6 over the TSCH
mode of IEEE 802.15.4e" (6TiSCH, where TSCH "TSCH" stands for
"Time-Slotted Channel Hopping", Hopping"; see [I-D.ietf-6tisch-architecture],
[IEEE802154], [IEEE802154e], [Arch-for-6TiSCH], [IEEE-802154],
and [RFC7554]).

There are other deterministic wireless busses buses and networks available
today, however
today; however, they are imcompatible incompatible with each other, other and
incompatible with IP
traffic (for example [ISA100], example, see [ISA100] and [WirelessHART]).

Thus

Thus, the primary goal of this use case is to apply 6TiSCH as a
converged IP- IP-based and standards-based wireless network for
industrial applications, i.e. i.e., to replace multiple proprietary and/or
incompatible wireless networking and wireless network management
standards.

5.1.2. Common Protocol Development for 6TiSCH

Today

Today, there are a number of protocols required by 6TiSCH which that are
still in development, and a second intent development. Another goal of this use case is to highlight
the ways in which these "missing" protocols share goals in common
with DetNet. Thus Thus, it is possible that some of the protocol
technology developed for DetNet will also be applicable to 6TiSCH.

These protocol goals are identified here, along with their
relationship to DetNet. It is likely that ultimately the resulting
protocols will not be identical, identical but will share design principles
which that
contribute to the eficiency efficiency of enabling both DetNet and 6TiSCH.

One such commonality is that -- although at on a different time scale, scale --
in both TSN [IEEE802.1TSNTG] [IEEE-8021TSNTG] and TSCH TSCH, a packet that crosses the
network from node to node follows a precise schedule, as does a train
that leaves intermediate stations at precise times along its path.
This kind of operation reduces collisions, saves energy, and enables
engineering of the network for deterministic properties.

Another commonality is remote monitoring and scheduling management of
a TSCH network by a Path Computation Element (PCE) and Network
Management Entity (NME). The PCE/NME PCE and NME manage timeslots and device
resources in a manner that minimizes the interaction with with, and the
load placed on on, resource-constrained devices. For example, a tiny
IoT device may have just enough buffers to store one or a few IPv6
packets, and
packets; it will have limited bandwidth between peers such that it
can maintain only a small amount of peer information, and it will not
be able to store many packets waiting to be forwarded. It is
advantageous then
advantageous, then, for it the IoT device to only be required to carry
out the specific behavior assigned to it by the PCE/NME PCE and NME (as
opposed to maintaining its own IP stack, for example).

It is possible that there will be some peer-to-peer communication, communication;
for example example, the PCE may communicate only indirectly with some
devices in order to enable hierarchical configuration of the system.

6TiSCH depends on [PCE] and [I-D.ietf-detnet-architecture]. [DetNet-Arch].

6TiSCH also depends on the fact that DetNet will maintain consistency
with [IEEE802.1TSNTG]. [IEEE-8021TSNTG].

5.2. Wireless Industrial Today

Today

Today, industrial wireless technology ("wireless industrial") is
accomplished using multiple deterministic wireless networks which that are
incompatible with each other and with IP traffic.

6TiSCH is not yet fully specified, so it cannot be used in today's
applications.

5.3. Wireless Industrial in the Future

5.3.1. Unified Wireless Network Networks and Management

DetNet and 6TiSCH together can enable converged transport of
deterministic and best-effort traffic flows between real-time
industrial devices and wide area networks WANs via IP routing. A high
level high-level view of a
this type of basic such network is shown in Figure 7.

---+-------- ............ ------------
| External Network |
| +-----+
+-----+ | NME |
| | LLN Border | |
| | router Router +-----+
+-----+
o o o
o o o o
o o LLN o o o
o o o o
o

LLN: Low-Power and Lossy Network

Figure 7: Basic 6TiSCH Network

Figure 8 shows a backbone router federating multiple synchronized
6TiSCH subnets into a single subnet connected to the external
network.

---+-------- ............ ------------
| External Network |
| +-----+
| +-----+ | NME |
+-----+ | +-----+ | |
| | Router | | PCE | +-----+
| | +--| |
+-----+ +-----+
| |
| Subnet Backbone |
+--------------------+------------------+
| | |
+-----+ +-----+ +-----+
| | Backbone | | Backbone | | Backbone
o | | router Router | | router Router | | router Router
+-----+ +-----+ +-----+
o o o o o
o o o o o o o o o o o
o o o LLN o o o o
o o o o o o o o o o o o

Figure 8: Extended 6TiSCH Network

The backbone router must ensure end-to-end deterministic behavior
between the LLN and the backbone. This should be accomplished in
conformance with the work done in [I-D.ietf-detnet-architecture] [DetNet-Arch] with respect to Layer-3
Layer 3 aspects of deterministic networks that span multiple Layer-2 Layer 2
domains.

The PCE must compute a deterministic path end-to-end end to end across the TSCH
network and IEEE802.1 IEEE 802.1 TSN Ethernet backbone, and DetNet protocols
are expected to enable end-to-end deterministic forwarding.

+-----+
| IoT |
| G/W |
+-----+
^ <---- Elimination
| |
Track branch | |
+-------+ +--------+ Subnet Backbone
| |
+--|--+ +--|--+
| | | Backbone | | | Backbone
o | | | router | | | router
+--/--+ +--|--+
o / o o---o----/ o
o o---o--/ o o o o o
o \ / o o LLN o
o v <---- Replication
o

Figure 9: 6TiSCH Network with PRE

5.3.1.1. PCE and 6TiSCH ARQ Retries

6TiSCH uses the IEEE802.15.4 Automatic Repeat-reQuest Repeat reQuest (ARQ) mechanism
[IEEE-802154] to provide higher reliability of packet delivery. ARQ
is related to
packet replication Packet Replication and elimination Elimination (PRE) because there
are two independent paths for packets to arrive at the destination, and if destination.
If an expected
packed packet does not arrive on one path path, then it checks for
the packet on the second path.

Although to date this mechanism is only used by wireless networks,
this may be a technique that would might be appropriate for DetNet DetNet, and so aspects of the
enabling protocol could therefore be co-developed.

For example, in Figure 9, a Track track is laid out from a field device in
a 6TiSCH network to an IoT gateway that is located on a IEEE802.1 an IEEE 802.1
TSN backbone.

+-----+
| IoT |
| G/W |
+-----+
^ <---- Elimination
| |
Track Branch | |
+-------+ +--------+ Subnet Backbone
| |
+--|--+ +--|--+
| | | Backbone | | | Backbone
o | | | Router | | | Router
+--/--+ +--|--+
o / o o---o----/ o
o o---o--/ o o o o o
o \ / o o LLN o
o v <---- Replication
o

Figure 9: 6TiSCH Network with PRE

In ARQ ARQ, the Replication replication function in the field device sends a copy of
each packet over two different branches, and the PCE schedules each
hop of both branches so that the two copies arrive in due time at the
gateway. In the case of a loss on one branch, hopefully one hopes that the
other copy of the packet will still arrives arrive within the allocated time.
If two copies make it to the IoT gateway, the Elimination elimination function in
the gateway ignores the extra packet and presents only one copy to
upper layers.

At each 6TiSCH hop along the Track, track, the PCE may schedule more than
one timeSlot timeslot for a packet, so as to support Layer-2 retries Layer 2 retries (ARQ).

In deployments at

At the time of this writing, a deployment's TSCH Track track does not
necessarily support PRE but is systematically multi-path. multipath. This means
that a Track track is scheduled so as to ensure that each hop has at least
two forwarding solutions, and the solutions. The forwarding decision is will be to try the
preferred one solution and use the other solution in the case of Layer-2 Layer 2
transmission failure as detected by ARQ.

5.3.2. Schedule Management by a PCE

A common feature of 6TiSCH and DetNet is the action of actions taken by a PCE to
configure when
configuring paths through the network. Specifically, what is needed
is a protocol and data model that the PCE will use to get/set the
relevant configuration from/to the devices, as well as perform
operations on the devices. This Specifically, both DetNet and 6TiSCH need
to develop a protocol should (and associated data model) that the PCE can
use to (1) get/set the relevant configuration from/to the devices and
(2) perform operations on the devices. These could be initially
developed by
DetNet DetNet, with consideration for its their reuse by 6TiSCH.
The remainder of this section provides a bit more context from the
6TiSCH side.

5.3.2.1. PCE Commands and 6TiSCH CoAP Requests

The 6TiSCH device does not expect to place the request for bandwidth
between itself and another device in the network. Rather, an
operation control system invoked through a human interface specifies
the required traffic specification requirements and the end nodes (in terms of latency and
reliability). Based on this information, the PCE must compute a path
between the end nodes and provision the network with per-flow state
that describes the per-hop operation for a given packet, the
corresponding timeslots, and the flow identification that enables
recognizing that a certain packet belongs to a certain path, etc.

For a static configuration that serves a certain purpose for a long
period of time, it is expected that a node will be provisioned in one
shot with a full schedule, which incorporates i.e., a schedule that defines the aggregation of its behavior for multiple paths.
of the node with respect to all data flows through that node. 6TiSCH
expects that the programing programming of the schedule will be done over COAP the
Constrained Application Protocol (CoAP) as discussed in
[I-D.ietf-6tisch-coap].
[CoAP-6TiSCH].

6TiSCH expects that the PCE commands will be mapped back and forth
into CoAP by a gateway function at the edge of the 6TiSCH network.
For instance, it is possible that a mapping entity on the backbone
transforms a non-CoAP protocol such as PCEP the Path Computation Element
Communication Protocol (PCEP) into the RESTful interfaces that the
6TiSCH devices support. This architecture will be refined to comply
with DetNet [I-D.ietf-detnet-architecture] [DetNet-Arch] when the work is formalized. Related
information about 6TiSCH can be found at [I-D.ietf-6tisch-6top-interface] in [Interface-6TiSCH-6top] and RPL [RFC6550].
[RFC6550] ("RPL: IPv6 Routing Protocol for Low-Power and Lossy
Networks").

A protocol may be used to update the state in the devices during
runtime,
runtime -- for example example, if it appears that a path through the network
has ceased to perform as expected, but in 6TiSCH that flow was not
designed and no protocol was selected. DetNet should define the
appropriate end-to-end protocols to be used in that case. The
implication is that these state updates take place once the system is
configured and running, i.e. i.e., they are not limited to the initial
communication of the configuration of the system.

A "slotFrame" is the base object that a PCE would manipulate to
program a schedule into an LLN node ([I-D.ietf-6tisch-architecture]). [Arch-for-6TiSCH].

The PCE should read energy data from devices and compute paths that
will implement policies on how energy in devices is consumed, consumed -- for
instance
instance, to ensure that the spent energy does not exceeded exceed the
available energy over a period of time. Note: Note that this statement
implies that an extensible protocol for communicating device info
information to the PCE and enabling the PCE to act on it will be part
of the DetNet
architecture, however architecture; however, for subnets with specific
protocols (e.g.
CoAP) (e.g., CoAP), a gateway may be required.

6TiSCH devices can discover their neighbors over the radio using a
mechanism such as beacons, but even though the neighbor information
is available in the 6TiSCH interface data model, 6TiSCH does not
describe a protocol to proactively push the neighborhood neighbor information to a
PCE. DetNet should define such a protocol; one possible design
alternative is that it could operate over CoAP, alternatively CoAP. Alternatively, it
could be converted to/from CoAP by a gateway. Such a protocol could
carry multiple metrics, metrics -- for example example, metrics similar to those used
for RPL operations [RFC6551] [RFC6551].

5.3.2.2. 6TiSCH IP Interface

"6top" ([I-D.wang-6tisch-6top-sublayer]) is a logical link control
sitting

Protocol translation between the IP layer and the TSCH MAC layer which provides
the link abstraction that is required for and IP operations. is
accomplished via the "6top" sublayer [Sublayer-6TiSCH-6top]. The
6top data model and management interfaces are further discussed in
[I-D.ietf-6tisch-6top-interface]
[Interface-6TiSCH-6top] and [I-D.ietf-6tisch-coap]. [CoAP-6TiSCH].

An IP packet that is sent along a 6TiSCH path uses the Differentiated
Services Per-Hop-Behavior a differentiated
services Per-Hop Behavior Group (PHB) called Deterministic Forwarding, "deterministic
forwarding", as described in [I-D.svshah-tsvwg-deterministic-forwarding]. [Det-Fwd-PHB].

5.3.3. 6TiSCH Security Considerations

On top of

In addition to the classical requirements for protection of control
signaling, it must be noted that 6TiSCH networks operate on limited
resources that can be depleted rapidly in a DoS attack on the system, system
-- for instance instance, by placing a rogue device in the network, network or by
obtaining management control and setting up unexpected additional
paths.

5.4. Wireless Industrial Asks Requests to the IETF

6TiSCH depends on DetNet to define:

o Configuration (state) and operations for deterministic paths

o End-to-end protocols for deterministic forwarding (tagging, IP)

o Protocol A protocol for packet replication and elimination PRE

6. Cellular Radio

6.1. Use Case Description

This use case describes the application of deterministic networking
in the context of cellular telecom transport networks. Important
elements include time synchronization, clock distribution, and ways
of establishing
to establish time-sensitive streams for both Layer-2 Layer 2 and Layer-3
user plane Layer 3
user-plane traffic.

6.1.1. Network Architecture

Figure 10 illustrates a 3GPP-defined cellular network architecture
typical at the time of this writing, which writing. The architecture includes
"Fronthaul",
"Midhaul" "Midhaul", and "Backhaul" network segments. The
"Fronthaul" is the network connecting base stations (baseband processing units) (Baseband Units
(BBUs)) to the
remote radio heads (antennas). Remote Radio Heads (RRHs) (also referred to here as
"antennas"). The "Midhaul" is the network inter-
connecting that interconnects base
stations (or small cell small-cell sites). The "Backhaul" is the network or
links connecting the radio base station sites to the network
controller/gateway sites (i.e. (i.e., the core of the 3GPP cellular
network).

In Figure 10 "eNB" ("E-UTRAN Node B") is the hardware that is
connected to the mobile phone network which communicates directly
with mobile handsets ([TS36300]).

Y (remote radio heads (RRHs (antennas))
\
Y__ \.--. .--. +------+
\_( `. +---+ _(Back`. _( `. | 3GPP |
Y------( Front Front- )----|eNB|----( Haul )----| Back- )------| core |
( ` .Haul .haul ) +---+ ( ` . ) .haul) ) | netw |
/`--(___.-' \ `--(___.-' +------+
Y_/ / \.--. \
Y_/ _( Mid`. _(Mid-`. \
( Haul haul ) \
( ` . ) ) \
`--(___.-'\_____+---+ (small cell (small-cell sites)
\ |SCe|__Y
+---+ +---+
Y__|eNB|__Y
+---+
Y_/ \_Y ("local" radios)

Figure 10: Generic 3GPP-based 3GPP-Based Cellular Network Architecture

In Figure 10, "eNB" ("E-UTRAN Node B") is the hardware that is
connected to the mobile phone network and enables the mobile phone
network to communicate with mobile handsets [TS36300]. ("E-UTRAN"
stands for "Evolved Universal Terrestrial Radio Access Network".)

6.1.2. Delay Constraints

The available processing time for Fronthaul networking overhead is
limited to the available time after the baseband processing of the
radio frame has completed. For example example, in Long Term Evolution (LTE)
radio, 3 ms is allocated for the processing of a radio frame is allocated 3ms frame, but
typically the baseband processing uses most of it, allowing only a
small fraction to be used by the Fronthaul network (e.g. up network. In this example,
out of 3 ms, the maximum time allocated to 250us the Fronthaul network for
one-way delay, though delay is 250 us, and the existing spec ([NGMN-fronth]) supports specification [NGMN-Fronth]
specifies a maximum delay of only up to 100us). 100 us. This ultimately determines
the distance the remote radio heads RRHs can be located from the base stations (e.g., 100us
100 us equals roughly 20 km of optical fiber-based transport).
Allocation options of regarding the available time budget between
processing and transport are under currently undergoing heavy
discussions discussion in
the mobile industry.

For packet-based transport transport, the allocated transport time (e.g. CPRI
would allow for 100us delay [CPRI]) is consumed by all nodes and
buffering between the remote radio head
RRH and the baseband processing
unit, plus the BBU is consumed by node processing, buffering, and
distance-incurred delay. An example of the allocated transport time
is 100 us (from the Common Public Radio Interface [CPRI]).

The baseband processing time and the available "delay budget" for the
fronthaul
Fronthaul is likely to change in the forthcoming "5G" due to reduced
radio round trip round-trip times and other architectural and service
requirements [NGMN].

The transport time budget, as noted above, places limitations on the
distance that remote radio heads RRHs can be located from base stations
(i.e. (i.e., the link
length). In the above analysis, it is assumed that the entire
transport time budget is assumed to be available for link propagation delay.
However
However, the transport time budget can be broken down into three
components: scheduling /queueing scheduling/queuing delay, transmission delay, and link
propagation delay. Using today's Fronthaul networking technology,
the queuing, scheduling scheduling, and transmission components might become the
dominant factors in the total transport time time, rather than the link
propagation delay. This is especially true in cases where the
Fronthaul link is relatively short and it is shared among multiple
Fronthaul flows, flows -- for example example, in indoor and small cell small-cell networks,
massive MIMO Multiple Input Multiple Output (MIMO) antenna networks, and
split Fronthaul architectures.

DetNet technology can improve this application Fronthaul networks by controlling and
reducing the time required for the queuing, scheduling scheduling, and
transmission operations by properly assigning the network resources, thus
(1) leaving more of the transport time budget available for link
propagation,
propagation and thus (2) enabling longer link lengths. However, link
length is usually a given predetermined parameter and is not a controllable
network parameter, since RRH and BBU sights sites are usually located in
predetermined locations. However, the number of antennas in an RRH
sight
site might increase -- for example example, by adding more antennas,
increasing the MIMO capability of the network network, or adding support of for
massive MIMO. This means increasing the number of the fronthaul Fronthaul flows
sharing the same
fronthaul Fronthaul link. DetNet can now control the
bandwidth assignment of the fronthaul Fronthaul link and the scheduling of fronthaul
Fronthaul packets over this link and can provide adequate buffer
provisioning for each flow to reduce the packet loss rate.

Another way in which DetNet technology can aid Fronthaul networks is
by providing effective isolation from best-effort (and other classes
of) traffic, which can arise as a result of network slicing in 5G
networks where Fronthaul traffic generated between flows -- for example,
between flows originating in different network slices might within a network-sliced
5G network. Note, however, that this isolation applies to DetNet
flows for which resources have differing performance requirements. been preallocated, i.e., it does not
apply to best-effort flows within a DetNet. DetNet technology can
also dynamically control the bandwidth assignment,
scheduling and packet forwarding decisions bandwidth-assignment, scheduling, and
packet-forwarding decisions, as well as the buffer provisioning of
the Fronthaul flows to guarantee the end-to-end delay of the
Fronthaul packets and minimize the packet loss rate.

[METIS] documents the fundamental challenges as well as overall
technical goals of the future 5G mobile and wireless system systems as the
starting point. These future systems should support much higher data
volumes and rates and significantly lower end-to-end latency for 100x
more connected devices (at similar cost and energy consumption energy-consumption levels
as similar
to today's system). systems).

For Midhaul connections, delay constraints are driven by Inter-Site inter-site
radio functions like such as Coordinated Multipoint Processing (CoMP, see Multi-Point (CoMP) processing
(see [CoMP]). CoMP reception and transmission is constitute a framework
in which multiple geographically distributed antenna nodes cooperate
to improve the performance of for the users served in the common cooperation
area. The design principal principle of CoMP is to extend single-cell to single-cell-to-
multi-UE (User Equipment) transmission to a multi-cell-to-multi-UEs multi-cell-to-multi-UE
transmission by via cooperation among base station cooperation. stations.

CoMP has delay-sensitive performance parameters, which are "midhaul parameters: "Midhaul latency"
and "CSI (Channel State Information) reporting and accuracy". The
essential feature of CoMP is signaling between eNBs, so Midhaul
latency is the dominating limitation of CoMP performance. Generally,
CoMP can benefit from coordinated scheduling (either distributed or
centralized) of different cells if the signaling delay between eNBs
is within 1-10ms. 1-10 ms. This delay requirement is both rigid and absolute
absolute, because any uncertainty in delay will degrade the performance
significantly.

Inter-site CoMP is one of the key requirements for 5G and is also a
goal for 4.5G network architecture. architectures.

6.1.3. Time Synchronization Time-Synchronization Constraints

Fronthaul time synchronization time-synchronization requirements are given by [TS25104],
[TS36104], [TS36211], and [TS36133]. These can be summarized for the
3GPP LTE-based networks as:

Delay Accuracy:
+-8ns (i.e. accuracy:
+-8 ns (i.e., +-1/32 Tc, where Tc is the UMTS Universal Mobile
Telecommunications System (UMTS) Chip time of 1/3.84
MHz) MHz),
resulting in a round trip round-trip accuracy of +-16ns. +-16 ns. The value is this
low in order to meet the 3GPP Timing Alignment Error (TAE)
measurement requirements. Note: Note that performance guarantees of low nanosecond
low-nanosecond values such as these are considered to be below the
DetNet layer - -- it is assumed that the underlying implementation, e.g. implementation
(e.g., the
hardware, hardware) will provide sufficient support (e.g. (e.g.,
buffering) to enable this level of accuracy. These values are
maintained in the use case to give an indication of the overall
application.

Timing Alignment Error:
Timing Alignment Error (TAE)

TAE:
TAE is problematic to for Fronthaul networks and must be minimized.
If the transport network cannot guarantee
low enough TAE levels that are low
enough, then additional buffering has to be introduced at the
edges of the network to buffer out the jitter. Buffering is not desirable
desirable, as it reduces the total available delay budget.

Packet Delay Variation (PDV) requirements can be derived from TAE
measurements for packet based packet-based Fronthaul networks.

* For multiple input multiple output (MIMO) MIMO or TX diversity transmissions, at each carrier
frequency, TAE measurements shall not exceed 65 ns (i.e. (i.e.,
1/4 Tc).

* For intra-band contiguous carrier aggregation, with or without
MIMO or TX diversity, TAE measurements shall not exceed 130 ns (i.e.
(i.e., 1/2 Tc).

* For intra-band non-contiguous carrier aggregation, with or
without MIMO or TX diversity, TAE measurements shall not exceed
260 ns (i.e.
one (i.e., 1 Tc).

* For inter-band carrier aggregation, with or without MIMO or TX
diversity, TAE measurements shall not exceed 260 ns.

Transport link contribution to radio frequency error: errors:
+-2 PPB. This value is considered to be "available" for the
Fronthaul link out of the total 50 PPB budget reserved for the
radio interface. Note: the reason Note that the transport link contributes to
radio frequency error is as follows. At errors for the following reason: at the time of
this writing, Fronthaul communication is direct communication from
the radio unit to
remote radio head directly. the RRH. The remote radio head RRH is essentially a passive
device (without buffering etc.) (e.g., without buffering). The transport drives the
antenna directly by feeding it with samples samples, and everything the
transport adds will be introduced to the radio as-is. So "as is". So, if
the transport causes any additional frequency error that shows errors, the errors
will show up immediately on the radio as well. Note: Note that
performance guarantees of low
nanosecond low-nanosecond values such as these are
considered to be below the DetNet layer - -- it is assumed that the
underlying implementation,
e.g. implementation (e.g., the hardware, hardware) will provide
sufficient support to enable this level of performance. These
values are maintained in the use case to give an indication of the
overall application.

The above listed time synchronization above-listed time-synchronization requirements are difficult to
meet with point-to-point connected networks, networks and are more difficult to
meet when the network includes multiple hops. It is expected that
networks must include buffering at the ends of the connections as
imposed by the jitter requirements, since trying to meet the jitter
requirements in every intermediate node is likely to be too costly.
However, every measure to reduce jitter and delay on the path makes
it easier to meet the end-to-end requirements.

In order to meet the timing requirements requirements, both senders and receivers
must remain time synchronized, demanding very accurate clock
distribution,
distribution -- for example example, support for IEEE 1588 transparent clocks
or boundary clocks in every intermediate node.

In cellular networks from the LTE radio era onward, phase
synchronization is needed in addition to frequency synchronization
([TS36300], [TS23401]).
[TS36300] [TS23401]. Time constraints are also important due to
their impact on packet loss. If a packet is delivered too late, then
the packet may be dropped by the host.

6.1.4. Transport Loss Transport-Loss Constraints

Fronthaul and Midhaul networks assume that transport is almost error-free transport.
error free. Errors can result in cause a reset of the radio interfaces, which can cause in
turn causing reduced throughput or broken radio connectivity for
mobile customers.

For packetized Fronthaul and Midhaul connections connections, packet loss may be
caused by BER, congestion, or network failure scenarios. Different
fronthaul functional splits
Fronthaul "functional splits" are being considered by 3GPP, requiring
strict frame loss ratio Frame Loss Ratio (FLR) guarantees. As one example (referring
to the legacy CPRI split split, which is option 8 in 3GPP) lower layers 3GPP), lower-layer
splits may imply an FLR of less than 10E-7 10^-7 for data traffic and less
than 10E-6 10^-6 for control and management traffic.

Many of the tools available for eliminating packet loss for Fronthaul
and Midhaul networks have serious challenges, challenges; for example example,
retransmitting lost packets and/or or using forward error correction
(FEC) FEC to circumvent bit errors (or
both) is practically impossible impossible, due to the additional delay
incurred. Using redundant streams for better guarantees for of delivery
is also practically impossible in many cases cases, due to high bandwidth
requirements of for Fronthaul and Midhaul networks. Protection
switching is also a candidate candidate, but at the time of this writing,
available technologies for the path switch are too slow to avoid a
reset of mobile interfaces.

It is assumed that Fronthaul links are assumed to be symmetric, and all symmetric. All Fronthaul
streams (i.e. (i.e., those carrying radio data) have equal priority and
cannot delay or pre-empt preempt each other. This

All of this implies that it is up to the network
must to guarantee that
each time-sensitive flow meets their its schedule.

6.1.5. Cellular Radio Network Security Considerations

Establishing time-sensitive streams in the network entails reserving
networking resources for long periods of time. It is important that
these reservation requests be authenticated to prevent malicious
reservation attempts from hostile nodes (or accidental
misconfiguration). This is particularly important in the case where
the reservation requests span administrative domains. Furthermore,
the reservation information itself should be digitally signed to
reduce the risk of a legitimate node pushing a stale or hostile
configuration into another networking node.

Note: This is considered important for the security policy of the
network,
network but does not affect the core DetNet architecture and design.

6.2. Cellular Radio Networks Today

6.2.1. Fronthaul

Today's Fronthaul networks typically consist of:

o Dedicated point-to-point fiber connection is common (common)

o Proprietary protocols and framings

o Custom equipment and no real networking

At the time of this writing, solutions for Fronthaul are direct
optical cables or Wavelength-Division Multiplexing (WDM) connections.

6.2.2. Midhaul and Backhaul

Today's Midhaul and Backhaul networks typically consist of:

o Mostly normal IP networks, MPLS-TP, etc.

o Clock distribution and sync synchronization using IEEE 1588 and SyncE

Telecommunication syncE

Telecommunications networks in the Mid- Midhaul and Backhaul are already
heading towards transport networks where precise time synchronization time-synchronization
support is one of the basic building blocks. While the transport
networks themselves have practically transitioned to all-IP packet-
based networks In order to meet the
bandwidth and cost requirements, most transport networks have already
transitioned to all-IP packet-based networks; however, highly
accurate clock distribution has become a challenge.

In the past, Mid- Midhaul and Backhaul connections were typically based on
Time Division Multiplexing (TDM-based)
TDM and provided frequency
synchronization frequency-synchronization capabilities as a part of
the transport media.
Alternatively More recently, other technologies such as Global Positioning System
(GPS) GPS
or Synchronous Ethernet (SyncE) are used [SyncE].

Both Ethernet and syncE [syncE] have been used.

Ethernet, IP/MPLS [RFC3031] (and PseudoWires (PWE) [RFC3031], and pseudowires (as described in
[RFC3985] ("Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture")
for legacy transport support) support)) have become popular tools to build for building
and
manage managing new all-IP Radio Access Networks (RANs)
[I-D.kh-spring-ip-ran-use-case].
[SR-IP-RAN-Use-Case]. Although various timing and synchronization
optimizations have already been proposed and
implemented implemented, including 1588
PTP enhancements
[I-D.ietf-tictoc-1588overmpls] [IEEE-1588] (see also [Timing-over-MPLS] and [RFC8169],
[RFC8169]), these solution solutions are not necessarily sufficient for the
forthcoming RAN architectures architectures, nor do they guarantee the more
stringent time-synchronization requirements such as [CPRI].

There are also existing

Existing solutions for TDM over IP such as include those discussed in
[RFC4553], [RFC5086], and [RFC5087], as well as [RFC5087]; [MEF8] addresses TDM over
Ethernet transports
such as [MEF8]. transports.

6.3. Cellular Radio Networks in the Future

Future Cellular Radio Networks cellular radio networks will be based on a mix of different
xHaul networks (xHaul = front-, mid- Fronthaul, Midhaul, and backhaul), Backhaul), and future
transport networks should be able to support all of them
simultaneously. It is already envisioned today that:

o Not all "cellular radio network" traffic will be IP, IP; for example example,
some will remain at Layer 2 (e.g. (e.g., Ethernet based). DetNet
solutions must address all traffic types (Layer 2, 2 and Layer 3)
with the same tools and allow their transport simultaneously.

o All forms types of xHaul networks will need some form types of DetNet
solutions. For example example, with the advent of 5G 5G, some Backhaul
traffic will also have DetNet requirements, for example requirements (for example, traffic
belonging to time-critical 5G applications. applications).

o Different functional splits of the functionality run on between the base stations and the
on-site units could co-exist coexist on the same Fronthaul and Backhaul
network.

Future Cellular Radio cellular radio networks should contain the following:

o Unified standards-based transport protocols and standard
networking equipment that can make use of underlying deterministic
link-layer services

o Unified and standards-based network management systems and
protocols in all parts of the network (including Fronthaul)

New radio access network RAN deployment models and architectures may require time- sensitive networking TSN services
with strict requirements on other parts of the network that
previously were not considered to be packetized at all. Time and
synchronization support are already topical for Backhaul and Midhaul
packet networks [MEF22.1.1] and are also becoming a real issue for
Fronthaul networks also. Specifically networks. Specifically, in Fronthaul networks networks, the timing
and synchronization requirements can be extreme for packet based technologies, packet-based
technologies -- for example, on the order of
sub a PDV of +-20 ns packet delay variation (PDV) or less
and frequency accuracy of
+0.002 +-0.002 PPM [Fronthaul].

The actual transport protocols and/or solutions to establish for establishing
required transport "circuits" (pinned-down paths) for Fronthaul
traffic are still undefined. Those protocols are likely to include
(but are not limited to) solutions directly over Ethernet, over IP,
and using MPLS/
PseudoWire MPLS/pseudowire transport.

Interesting and important work for time-sensitive networking TSN has been done for Ethernet [TSNTG], which
[IEEE-8021TSNTG]; this work specifies the use of IEEE 1588 time
precision protocol (PTP) [IEEE1588] PTP [IEEE-1588] in
the context of IEEE 802.1D and IEEE 802.1Q. [IEEE8021AS] [IEEE-8021AS] specifies
a Layer 2 time synchronizing time-synchronizing service, and other specifications such
as IEEE 1722 [IEEE1722] [IEEE-1722] specify Ethernet-based Layer-2 Layer 2 transport for
time-sensitive streams.

However

However, even these Ethernet TSN features may not be sufficient for
Fronthaul traffic. Therefore, having specific profiles that take the
requirements of
Fronthaul requirements into account is desirable [IEEE8021CM]. [IEEE-8021CM].

New promising work seeks to enable the transport of time-sensitive
fronthaul
Fronthaul streams in Ethernet bridged networks [IEEE8021CM]. [IEEE-8021CM].
Analogous to IEEE 1722 there is an ongoing 1722, standardization effort efforts in the IEEE 1914.3
Task Force [IEEE-19143] to define the Layer-2 Layer 2 transport encapsulation
format for transporting
radio Radio over Ethernet (RoE) in the IEEE 1904.3 Task Force [IEEE19143]. are ongoing.

As mentioned in Section 6.1.2, 5G communications will provide one of
the most challenging cases for delay sensitive delay-sensitive networking. In order
to meet the challenges of ultra-low latency and ultra-high
throughput, 3GPP has studied various "functional splits" functional splits for 5G, i.e.,
physical decomposition of the gNodeB 5G "gNodeB" base station and deployment
of its functional blocks in different locations [TR38801].

These splits are numbered from split option 1 (Dual Connectivity, (dual connectivity, a
split in which the radio resource control is centralized and other
radio stack layers are in distributed units) to split option 8 (a
PHY-RF split in which RF functionality is in a distributed unit and
the rest of the radio stack is in the centralized unit), with each
intermediate split having its own data rate data-rate and delay requirements.
Packetized versions of different splits have been proposed proposed, including
eCPRI
enhanced CPRI (eCPRI) [eCPRI] and RoE (as previously noted). Both
provide Ethernet encapsulations, and eCPRI is also capable of IP
encapsulation.

All-IP RANs and xHaul networks would benefit from time
synchronization and time-sensitive transport services. Although
Ethernet appears to be the unifying technology for the transport,
there is still a disconnect when it comes to providing Layer 3
services. The protocol stack typically has a number of layers below the
Ethernet Layer 2 that shows up might be "visible" to the Layer 3 IP transport. It is not uncommon that 3. In a fairly
common scenario, on top of the lowest layer lowest-layer (optical) transport there is
the first
layer of (lowest) Ethernet followed layer, then one or more layers of MPLS, PseudoWires
pseudowires, and/or other tunneling protocols protocols, and finally carrying the one or
more Ethernet layer layers that are visible to the user plane IP traffic.

While Layer 3.

Although there are existing exist technologies to establish for establishing circuits through
the routed and switched networks (especially in the MPLS/PWE space),
there is still no way to signal the time synchronization time-synchronization and time-
sensitive
time-sensitive stream requirements/reservations for Layer-3 Layer 3 flows in
a way that addresses the entire transport stack, including the
Ethernet layers that need to be configured.

Furthermore, not all "user plane" "user-plane" traffic will be IP. Therefore, the
same
solution in question also must address the use cases where the user plane
user-plane traffic is on a different layer, for example layer (for example, Ethernet frames.

There is existing work describing the problem statement
[I-D.ietf-detnet-problem-statement] and the architecture
[I-D.ietf-detnet-architecture] for deterministic networking (DetNet)
that targets solutions for time-sensitive (IP/transport) streams with
deterministic properties over Ethernet-based switched networks.
frames).

6.4. Cellular Radio Networks Asks Requests to the IETF

A standard for data plane data-plane transport specification which specifications that is:

o Unified among all xHauls (meaning that different flows with
diverse DetNet requirements can coexist in the same network and
traverse the same nodes without interfering with each other)

o Deployed in a highly deterministic network environment

o Capable of supporting multiple functional splits simultaneously,
including existing Backhaul and CPRI Fronthaul Fronthaul, and potentially (potentially)
new modes as defined defined, for example example, in 3GPP; these goals can be
supported by the existing DetNet Use Case Common Themes, notably "Mix use case "common themes"
(Section 11); of special note are Sections 11.1.8 ("Mix of
Deterministic and Best-Effort Traffic", "Bounded Latency", "Low
Latency", "Symmetrical Traffic"), 11.3.1 ("Bounded
Latency"), 11.3.2 ("Low Latency"), 11.3.4 ("Symmetrical Path Delays",
Delays"), and "Deterministic Flows". 11.6 ("Deterministic Flows")

o Capable of supporting Network Slicing network slicing and Multi-tenancy; multi-tenancy; these
goals can be supported by the same DetNet themes noted above. above

o Capable of transporting both in-band and out-band out-of-band control
traffic
(OAM info, ...). (e.g., Operations, Administration, and Maintenance (OAM)
information)

o Deployable over multiple data link data-link technologies (e.g., IEEE 802.3,
mmWave, etc.).
mmWave)

A standard for data flow data-flow information models that are: is:

o Aware of the time sensitivity and constraints of the target
networking environment

o Aware of underlying deterministic networking services (e.g., on
the Ethernet layer)

7. Industrial Machine to Machine (M2M)

7.1. Use Case Description

Industrial Automation

"Industrial automation" in general refers to automation of
manufacturing, quality control control, and material processing. This
"machine to machine" (M2M) M2M
use case considers focuses on machine units in on a plant floor which that periodically
exchange data with upstream or downstream machine modules and/or a
supervisory controller within a
local area network.

The actors of M2M communication LAN.

PLCs are Programmable Logic Controllers
(PLCs). the "actors" in M2M communications. Communication between PLCs
PLCs, and between PLCs and the supervisory PLC (S-PLC) (S-PLC), is achieved
via critical control/data streams
Figure 11. (Figure 11).

S (Sensor)
\ +-----+
PLC__ \.--. .--. ---| MES |
\_( `. _( `./ +-----+
A------( Local )-------------( L2 )
( Net ) ( Net ) +-------+
/`--(___.-' `--(___.-' ----| S-PLC |
S_/ / PLC .--. / +-------+
A_/ \_( `.
(Actuator) ( Local )
( Net )
/`--(___.-'\
/ \ A
S A

Figure 11: Current Generic Industrial M2M Network Architecture

This use case focuses on PLC-related communications; communication to
Manufacturing-Execution-Systems
Manufacturing Execution Systems (MESs) are not addressed.

This use case covers only critical control/data streams; non-critical
traffic between industrial automation applications (such as
communication of state, configuration, set-up, setup, and database
communication) are is adequately served by prioritizing techniques
available at the time of this writing. Such traffic can use up to
80% of the total bandwidth required. There is also a subset of non-
time-critical
non-time-critical traffic that must be reliable even though it is not
time-sensitive.
time sensitive.

In this use case the primary need for case, deterministic networking is primarily needed to
provide end-to-end delivery of M2M messages within specific timing
constraints,
constraints -- for example example, in closed loop closed-loop automation control. Today
Today, this level of determinism is provided by proprietary
networking technologies. In addition, standard networking
technologies are used to connect the local network to remote
industrial automation sites,
e.g. e.g., over an enterprise or metro
network which that also carries other types of traffic. Therefore, flows
that should be forwarded with deterministic guarantees need to be sustained
sustained, regardless of the amount of other flows in those networks.

7.2. Industrial M2M Communication Communications Today

Today, proprietary networks fulfill the needed timing and
availability for M2M networks.

The network topologies used today by industrial automation are
similar to those used by telecom networks: Daisy Chain, Ring, Hub daisy chain, ring,
hub-and-spoke, and
Spoke, and Comb "comb" (a subset of Daisy Chain). daisy chain).

PLC-related control/data streams are transmitted periodically and
carry either a pre-configured preconfigured payload or a payload configured during
runtime.

Some industrial applications require time synchronization at the end
nodes. For such time-coordinated PLCs, accuracy of 1 microsecond us is required.
Even in the case of "non-time-coordinated" PLCs PLCs, time sync synchronization
may be needed e.g. needed, e.g., for timestamping of sensor data.

Industrial network

Industrial-network scenarios require advanced security solutions. At
the time of this writing, many industrial production networks are
physically separated. Preventing Filtering policies that are typically enforced
in firewalls are used to prevent critical flows from being leaked
outside a domain is handled by filtering policies that are typically
enforced in firewalls. domain.

7.2.1. Transport Parameters

The Cycle Time cycle time defines the frequency of message(s) between industrial
actors. The Cycle Time cycle time is application dependent, in the range of 1ms
- 100ms
1-100 ms for critical control/data streams.

Because industrial applications assume that deterministic transport
will be used for critical Control-Data-Stream control-data-stream parameters (instead of defining
having to define latency and delay variation parameters) delay-variation parameters), it is
sufficient to fulfill requirements regarding the upper bound of
latency (maximum latency). The underlying networking infrastructure
must ensure a maximum end-to-end message delivery time of
messages in the range
of 100 microseconds us to 50 milliseconds ms, depending on the control loop control-loop application.

The bandwidth requirements of control/data streams are usually
calculated directly from the bytes-per-cycle parameter of the control
loop. For PLC-to-PLC communication communication, one can expect 2 - 32 2-32 streams with
packet size sizes in the range of 100 - 700 100-700 bytes. For S-PLC to PLCs S-PLC-to-PLC
communication, the number of streams is higher - -- up to 256 streams. Usually
Usually, no more than 20% of available bandwidth is used for critical
control/data streams. In today's networks 1Gbps networks, 1 Gbps links are commonly
used.

Most PLC control loops are rather tolerant of packet loss, however loss; however,
critical control/data streams accept a loss of no more than 1 one
packet loss per consecutive communication cycle (i.e. (i.e., if a packet gets
lost in cycle "n", then the next cycle ("n+1") must be lossless).
After the loss of two or more consecutive packet losses packets, the network may be
considered to be "down" by the Application. application.

As network downtime may impact the whole production system system, the
required network availability is rather high (99.999%).

Based on the above parameters parameters, some form of redundancy will be
required for M2M communications, however communications; however, any individual solution
depends on several parameters parameters, including cycle time, time and delivery time,
etc.
time.

7.2.2. Stream Creation and Destruction

In an industrial environment, critical control/data streams are
created rather infrequently, on the order of ~10 times per day / week
/ month.
day/week/month. Most of these critical control/data streams get
created at machine startup, however startup; however, flexibility is also needed
during runtime, runtime -- for example example, when adding or removing a machine. Going forward as As
production systems become more flexible, flexible going forward, there will be
a significant increase in the rate at which streams are created, changed
changed, and destroyed.

7.3. Industrial M2M in the Future

We foresee a converged IP-standards-based network with deterministic
properties that can satisfy the timing, security security, and reliability
constraints described above. Today's proprietary networks could then
be interfaced to such a network via gateways or, gateways; alternatively, in the
case of new installations, devices could be connected directly to the
converged network.

For this use case time synchronization case, time-synchronization accuracy on the order of 1us 1 us
is expected.

7.4. Industrial M2M Asks Requests to the IETF

o Converged IP-based network

o Deterministic behavior (bounded latency and jitter ) jitter)

o High availability (presumably through redundancy) (99.999 %) (99.999%)

o Low message delivery time (100us - 50ms) (100 us to 50 ms)

o Low packet loss (with a bounded number of consecutive lost
packets)

o Security (e.g. prevent (e.g., preventing critical flows from being leaked
between physically separated networks)

8. Mining Industry

8.1. Use Case Description

The mining industry is highly dependent on networks to monitor and
control their systems both systems, in both open-pit and underground extraction, extraction as
well as in transport and refining processes. In order to reduce
risks and increase operational efficiency in mining operations, a number of
processes have migrated the
location of operators has been relocated (as much as possible) from
the extraction site to remote control and monitoring. monitoring sites.

In the case of open pit open-pit mining, autonomous trucks are used to
transport the raw materials from the open pit to the refining factory
where the final product (e.g. Copper) (e.g., copper) is obtained. Although the
operation is autonomous, the tracks are remotely monitored from a
central facility.

In pit mines, the monitoring of the tailings or mine dumps is
critical in order to minimize environmental pollution. In the past,
monitoring has been was conducted through manual inspection of pre-
installed preinstalled
dataloggers. Cabling is not usually exploited typically used in such
scenarios scenarios, due to the
its high cost and complex deployment requirements. At the time of
this writing, wireless technologies are being employed to monitor
these cases permanently. Slopes are also monitored in order to
anticipate possible mine collapse. Due to the unstable terrain,
cable maintenance is costly and complex and hence complex; hence, wireless technologies
are employed.

In the case of underground monitoring case, monitoring, autonomous vehicles with
extraction tools travel autonomously independently through the tunnels, but their
operational tasks (such as excavation, stone breaking stone-breaking, and transport)
are controlled remotely from a central facility. This generates
upstream video and feedback upstream traffic plus downstream actuator control actuator-control
traffic.

8.2. Mining Industry Today

At the time of this writing, the mining industry uses a packet
switched
packet-switched architecture supported by high speed ethernet. However high-speed Ethernet.
However, in order to achieve the comply with requirements regarding delay and
packet loss requirements loss, the network bandwidth is overestimated, thus providing overestimated. This results in
very low efficiency in terms of resource usage.

QoS is implemented at the Routers routers to separate video, management,
monitoring
monitoring, and process control process-control traffic for each stream.

Since mobility is involved in this process, the connection connections between
the backbone and the mobile devices (e.g. (e.g., trucks, trains trains, and
excavators) is solved are implemented using a wireless link. These links are
based on IEEE 802.11 [IEEE-80211] for open-pit mining and "leaky
feeder" communications for underground mining. (A "leaky feeder"
communication system consists of a coaxial cable cable, run along tunnels which tunnels,
that emits and receives radio waves, functioning as an extended
antenna. The cable is "leaky" in that it has gaps or slots in its
outer conductor to allow the radio signal to leak into or out of the
cable along its entire length.)

Lately

Lately, in pit mines the use of LPWAN Low-Power WAN (LPWAN) technologies
has been extended:
Tailings, slopes tailings, slopes, and mine dumps are monitored by
battery-powered dataloggers that make use of robust long range long-range radio
technologies. Reliability is usually ensured through retransmissions
at L2. Layer 2. Gateways or concentrators act as bridges bridges, forwarding the
data to the backbone ethernet Ethernet network. Deterministic requirements
are biased towards reliability rather than latency latency, as events are slowly
triggered slowly or can be anticipated in advance.

At the mineral processing mineral-processing stage, conveyor belts and refining
processes are controlled by a SCADA system, which system that provides the in-
factory an
in-factory delay-constrained networking requirements. environment.

At the time of this writing, voice communications are served by a
redundant trunking infrastructure, independent from data networks.

8.3. Mining Industry in the Future

Mining operations and management are converging towards a combination
of autonomous operation and teleoperation of transport and extraction
machines. This means that video, audio, monitoring monitoring, and process process-
control traffic will increase dramatically. Ideally, all activities
on
at the mine will rely on network infrastructure.

Wireless for open-pit mining is already a reality with LPWAN
technologies and
technologies; it is expected to evolve to more advanced more-advanced LPWAN
technologies
technologies, such as those based on LTE LTE, to increase last hop last-hop
reliability or novel LPWAN flavours flavors with deterministic access.

One area in which DetNet can improve this use case is in the wired
networks that make up the "backbone network" of the system, which system. These
networks connect together many wireless access points (APs). Access Points (APs) together. The
mobile machines (which are connected to the network via wireless)
transition from one AP to the next as they move about. A
deterministic, reliable, low latency low-latency backbone can enable these
transitions to be more reliable.

Connections which that extend all the way from the base stations to the
machinery via a mix of wired and wireless hops would also be
beneficial,
beneficial -- for example example, to improve remote control the responsiveness of digging machines. However
machines to remote control. However, to guarantee deterministic
performance of a DetNet, the end-to-end underlying network must be
deterministic.
Thus Thus, for this use case case, if a deterministic wireless
transport is integrated with a wire-based DetNet network, it could
create the desired wired plus wireless end-to-end deterministic
network.

8.4. Mining Industry Asks Requests to the IETF

o Improved bandwidth efficiency

o Very low delay delay, to enable machine teleoperation

o Dedicated bandwidth usage for high resolution high-resolution video streams

o Predictable delay delay, to enable realtime real-time monitoring

o Potential to construct for constructing a unified DetNet network over a
combination of wired and deterministic wireless links

9. Private Blockchain

9.1. Use Case Description

Blockchain was created with bitcoin Bitcoin as a 'public' "public" blockchain on the
open Internet, however Internet; however, blockchain has also spread far beyond its
original host into various industries industries, such as smart manufacturing,
logistics, security, legal rights rights, and others. In these industries industries,
blockchain runs in designated and carefully managed networks in which
deterministic networking requirements could be addressed by DetNet.
Such implementations are referred to as 'private' "private" blockchain.

The sole distinction between public and private blockchain is defined
by who is allowed to participate in the network, execute the
consensus protocol, and maintain the shared ledger.

Today's networks treat manage the traffic from blockchain on a best-effort
basis, but blockchain operation could be made much more efficient if
deterministic networking services were available to minimize latency
and packet loss in the network.

9.1.1. Blockchain Operation

A 'block' "block" runs as a container of a batch of primary items such as (e.g.,
transactions, property records etc. records). The blocks are chained in such a
way that the hash of the previous block works as the pointer to the
header of the new block. Confirmation of each block requires a
consensus mechanism. When an item arrives at a blockchain node, the
latter broadcasts this item to the rest of the nodes nodes, which receive
and
it, verify it it, and put it in the ongoing block. The block
confirmation process begins as the number of items reaches the
predefined block capacity, at which time the node broadcasts its
proved block to the rest of the nodes, to be verified and chained.
The result is that block N+1 of each chain transitively vouches for
blocks N and before previous of that chain.

9.1.2. Blockchain Network Architecture

Blockchain node communication and coordination is are achieved mainly
through frequent point-to-multi-point communication, however point-to-multipoint communication; however,
persistent point-to-point connections are used to transport both the
items and the blocks to the other nodes. For example, consider the
following implementation.

When a node is initiated, it first requests the other nodes' address
addresses from a specific entity entity, such as DNS, DNS. The node then it creates
persistent connections with each of with the other nodes. If a node
confirms an item, it sends the item to the other nodes via these
persistent connections.

As a new block in a node is completed and is proven by the
surrounding nodes, it propagates towards its neighbor nodes. When
node A receives a block, it verifies it, it and then sends an invite
message to its neighbor B. Neighbor B checks to see if the
designated block is available, available and responds to A if it is unavailable, then unavailable;
A then sends the complete block to B. B repeats the process (as was
done by A above) A) to start the next round of block propagation.

The challenge of blockchain network operation is not overall data
rates, since the volume from both the block and the item stays
between hundreds of bytes to and a couple of megabytes per second, but second;
rather, the challenge is in transporting the blocks with minimum
latency to maximize the efficiency of the blockchain consensus
process. The efficiency of differing implementations of the
consensus process may be affected to a differing degree by the
latency (and variation of latency) of the network.

9.1.3. Blockchain Security Considerations

Security is crucial to blockchain applications, and applications; at the time of this
writing, blockchain systems address security issues mainly at the
application level, where cryptography as well as hash-based consensus
play a leading role in preventing both double-spending and malicious
service attacks. However, there is concern that in the proposed use
case of for a private blockchain network which that is dependent on
deterministic properties, properties the network could be vulnerable to delays
and other specific attacks against determinism which determinism, as these delays and
attacks could interrupt service.

9.2. Private Blockchain Today

Today

Today, private blockchain runs in L2 Layer 2 or L3 VPN, in general Layer 3 VPNs, generally
without guaranteed determinism. The industry players are starting to
realize that improving determinism in their blockchain networks could
improve the performance of their service, but as of today at present these goals
are not being met.

9.3. Private Blockchain in the Future

Blockchain system performance can be greatly improved through
deterministic networking service services, primarily because it low latency
would accelerate the consensus process. It would be valuable to be
able to design a private blockchain network with the following
properties:

o Transport of point-to-multi-point point-to-multipoint traffic in a coordinated network
architecture rather than at the application layer (which typically
uses point-to-point connections)

o Guaranteed transport latency

o Reduced packet loss (to the point where packet retransmission-
incurred delay incurred by packet
retransmissions would be negligible.) negligible)

9.4. Private Blockchain Asks Requests to the IETF

o Layer 2 and Layer 3 multicast of blockchain traffic

o Item and block delivery with bounded, low latency and negligible
packet loss

o Coexistence in a single network of blockchain and IT traffic. traffic in a single network

o Ability to scale the network by distributing the centralized
control of the network across multiple control entities. entities

10. Network Slicing

10.1. Use Case Description

Network Slicing slicing divides one physical network infrastructure into
multiple logical networks. Each slice, corresponding which corresponds to a
logical network, uses resources and network functions independently
from each other. Network Slicing slicing provides flexibility of resource
allocation and service quality customization.

Future services will demand network performance with a wide variety
of characteristics such as high data rate, low latency, low loss
rate, security security, and many other parameters. Ideally Ideally, every service
would have its own physical network satisfying its particular
performance requirements, however requirements; however, that would be prohibitively
expensive. Network Slicing slicing can provide a customized slice for a
single service, and multiple slices can share the same physical
network. This method can optimize the performance for the service at
lower cost, and the flexibility of setting up and release releasing the
slices also allows the user to allocate the network resources
dynamically.

Unlike the other use cases presented here, Network Slicing network slicing is not a
specific application that depends on specific deterministic
properties; rather rather, it is introduced as an area of networking to
which DetNet might be applicable.

10.2. DetNet Applied to Network Slicing

10.2.1. Resource Isolation Across across Slices

One of the requirements discussed for Network Slicing network slicing is the "hard"
separation of various users' deterministic performance. That is, it
should be impossible for activity, lack of activity, or changes in
activity of one or more users to have any appreciable effect on the
deterministic performance parameters of any other slices. Typical
techniques used today, which share a physical network among users, do
not offer this level of isolation. DetNet can supply point-to-point
or point-to-multipoint paths that offer a user bandwidth and latency
guarantees to a user that cannot be affected by other users' data traffic. Thus
Thus, DetNet is a powerful tool when latency and reliability and low latency are
required in Network Slicing. network slicing.

10.2.2. Deterministic Services Within within Slices

Slices may need to provide services with DetNet-type performance
guarantees, however note
guarantees; note, however, that a system can be implemented to
provide such services in more than one way. For example example, the slice
itself might be implemented using DetNet, and thus the slice can
provide service guarantees and isolation to its users without any
particular DetNet awareness on the part of the users' applications.
Alternatively, a "non-DetNet-aware" slice may host an application
that itself implements DetNet services and thus can enjoy similar
service guarantees.

10.3. A Network Slicing Use Case Example - 5G Bearer Network

Network Slicing slicing is a core feature of 5G as defined in 3GPP, which 3GPP. The
system architecture for 5G is under development at the time of this
writing [TR38501]. [TS23501]. A network slice in a mobile network is a complete
logical network network, including
Radio Access Network (RAN) RANs and Core Network (CN). Networks (CNs). It provides
telecommunication
telecommunications services and network capabilities, which may vary
from slice to slice. A 5G bearer network is a typical use case of
Network Slicing; for example
network slicing; for example, consider three 5G service scenarios:
eMMB,
eMBB, URLLC, and mMTC.

o eMBB (Enhanced Mobile Broadband) focuses on services characterized
by high data rates, such as high definition videos, virtual
reality, high-definition video, Virtual Reality
(VR), augmented reality, and fixed mobile convergence.

o URLLC (Ultra-Reliable and Low Latency Communications) focuses on
latency-sensitive services, such as self-driving vehicles, remote
surgery, or drone control.

o mMTC (massive Machine Type Communications) focuses on services
that have high requirements for connection density, connection-density requirements, such as those
typical for smart city
typically used in smart-city and smart agriculture use cases. smart-agriculture scenarios.

A 5G bearer network could use DetNet to provide hard resource
isolation across slices and within the a given slice. For example example,
consider Slice-A and Slice-B, with DetNet used to transit services
URLLC-A and URLLC-B over them. Without DetNet, URLLC-A and URLLC-B
would compete for bandwidth resource, resources, and latency and reliability
requirements would not be guaranteed. With DetNet, URLLC-A and
URLLC-B have separate bandwidth
reservation and reservations; there is no resource
conflict between them, as though they were in different logical physical
networks.

10.4. Non-5G Applications of Network Slicing

Although the operation of services not related to 5G is not part of
the 5G Network Slicing network slicing definition and scope, Network Slicing network slicing is
likely to become a preferred approach to for providing various services
across a shared physical infrastructure. Examples include providing
services for electrical utilities services and pro audio services via slices. Use
cases like these could become more common once the work for the 5G
core network CN
evolves to include wired as well as wireless access.

10.5. Limitations of DetNet in Network Slicing

DetNet cannot cover every Network Slicing network slicing use case. One issue is
that DetNet is a point-to-point or point-to-multipoint technology,
however Network Slicing technology;
however, network slicing ultimately needs multi-point to multi-point multipoint-to-multipoint
guarantees. Another issue is that the number of flows that can be
carried by DetNet is limited by DetNet scalability; flow aggregation
and queuing management modification may help address this. this issue.
Additional work and discussion are needed to address these topics.

10.6. Network Slicing Today and in the Future

Network Slicing slicing has the promise to satisfy in terms of satisfying many requirements
of future network deployment scenarios, but it is still a collection
of ideas and analysis, analyses without a specific technical solution. DetNet
is one of various technologies that have potential to could potentially be used in Network
Slicing,
network slicing, along with with, for example example, Flex-E and Segment Routing. segment routing.
For more
information information, please see the IETF99 IETF 99 Network Slicing BOF BoF
session agenda and materials. materials as provided in [IETF99-netslicing-BoF].

10.7. Network Slicing Asks Requests to the IETF

o Isolation from other flows through Queuing Management queuing management

o Service Quality Customization quality customization and Guarantee guarantees

o Security

11. Use Case Common Themes

This section summarizes the expected properties of a DetNet network,
based on the use cases as described in this draft. document.

11.1. Unified, standards-based network Standards-Based Networks

11.1.1. Extensions to Ethernet

A DetNet network is not "a new kind of network" - -- it is based on
extensions to existing Ethernet standards, including elements of
IEEE 802.1 AVB/TSN TSN and related standards. Presumably Presumably, it will be
possible to run DetNet over other underlying transports besides
Ethernet, but Ethernet is explicitly supported.

11.1.2. Centrally Administered Networks

In general general, a DetNet network is not expected to be "plug and play" -
it is expected that there is play";
rather, some type of centralized network configuration and control system.
system is expected. Such a system may be in a single central
location, or it maybe may be distributed across multiple control entities
that function together as a unified control system for the network.
However, the ability to "hot swap" components (e.g. (e.g., due to
malfunction) is similar enough to "plug and play" that this kind of
behavior may be expected in DetNet networks, depending on the
implementation.

11.1.3. Standardized Data Flow Information Models

Data Flow Data-Flow Information Models

Data-flow information models to be used with DetNet networks are to
be specified by DetNet.

11.1.4. L2 Layer 2 and L3 Layer 3 Integration

A DetNet network is intended to integrate between Layer 2 (bridged)
network(s) (e.g. (e.g., an AVB/TSN LAN) and Layer 3 (routed) network(s) (e.g.
(e.g., using IP-based protocols). One example of this is "making AVB/TSN-
type making
AVB/TSN-type deterministic performance available from Layer 3
applications,
e.g. e.g., using RTP". RTP. Another example is "connecting connecting two
AVB/TSN LANs ("islands") together through a standard router". router.

11.1.5. Consideration for IPv4 Considerations

This Use Cases draft document explicitly does not specify any particular
implementation or protocol, however protocol; however, it has been observed that
various
of the use cases described (and their associated industries) described herein
are explicitly based on IPv4 (as opposed to IPv6) IPv6), and it is not
considered practical to expect them such implementations to migrate to
IPv6 in order to use DetNet. Thus Thus, the expectation is that even if
not every feature of DetNet is available in an IPv4 context, at least
some of the significant benefits (such as guaranteed end-to-end
delivery and low latency) are expected to will be available.

11.1.6. Guaranteed End-to-End Delivery

Packets in a DetNet flow are guaranteed not to be dropped by the
network due to congestion. However, the network may drop packets for
intended reasons, e.g. e.g., per security measures. Similarly Similarly,
best-effort traffic on a DetNet is subject to being dropped (as on a
non-DetNet IP network). Also note that this guarantee applies to the
actions of taken by DetNet protocol software, software and does not provide any
guarantee against
lower level lower-level errors such as media errors or checksum
errors.

11.1.7. Replacement for Multiple Proprietary Deterministic Networks

There are many proprietary non-interoperable deterministic Ethernet-
based networks available; DetNet is intended to provide an open-
standards-based
open-standards-based alternative to such networks.

11.1.8. Mix of Deterministic and Best-Effort Traffic

DetNet is intended to support coexistance the coexistence of time-sensitive
operational (OT) traffic and information informational (IT) traffic on the same
("unified") network.

11.1.9. Unused Reserved BW Bandwidth to be Be Available to Best-Effort
Traffic

If bandwidth reservations are made for a stream but the associated
bandwidth is not used at any point in time, that bandwidth is made
available on the network for best-effort traffic. If the owner of
the reserved stream then starts transmitting again, the bandwidth is
no longer available for best-effort traffic, traffic; this occurs on a
moment-to-moment basis. Note that such "temporarily available"
bandwidth is not available for time-sensitive traffic, which must
have its own reservation.

11.1.10. Lower Cost, Lower-Cost, Multi-Vendor Solutions

The DetNet network specifications are intended to enable an ecosystem
in which multiple vendors can create interoperable products, thus
promoting device diversity and potentially higher numbers of each
device manufactured, promoting cost reduction and cost competition
among vendors. The intent is that DetNet networks In other words, vendors should be able to
be created create
DetNet networks at lower cost and with greater diversity of available
devices than existing proprietary networks.

11.2. Scalable Size

DetNet networks range in size from very small, e.g. small (e.g., inside a single
industrial machine, machine) to very large, for example large (e.g., a Utility Grid utility-grid network
spanning a whole country, country and involving many "hops" over various kinds
of links -- for example example, radio repeaters, microwave linkes, links, or fiber
optic links, etc.. However links). However, recall that the scope of DetNet is confined
to networks that are centrally administered, administered and thereby explicitly
excludes unbounded decentralized networks such as the Internet.

11.2.1. Scalable Number of Flows

The number of flows in a given network application can potentially be
large,
large and can potentially grow faster than the number of nodes and
hops. So
hops, so the network should provide a sufficient (perhaps
configurable) maximum number of flows for any given application.

11.3. Scalable Timing Parameters and Accuracy

11.3.1. Bounded Latency

The

DetNet Data Flow Information Model is data-flow information models are expected to provide means to
configure the network that include parameters for querying network
path latency, requesting bounded latency for a given stream,
requesting worst case worst-case maximum and/or minimum latency for a given path
or stream, and so on. It is an expected case that the network may not be
able to provide a given requested service level, and level; if so this is indeed
the case, the network control system should reply that the requested
services is are not available (as opposed to accepting the parameter but
then not delivering the desired behavior).

11.3.2. Low Latency

Applications

Various applications may state that they require "extremely low latency" however
latency"; however, depending on the application these application, "extremely low" may mean
imply very different latency values; for
example bounds. For example, "low latency"
across a Utility grid utility-grid network is on a different
time scale than order of magnitude of
latency values compared to "low latency" in a motor control loop in a
small machine. The intent It is intended that the mechanisms for specifying
desired latency include wide ranges, ranges and that architecturally there is
nothing to prevent arbirtrarily arbitrarily low latencies from being implemented
in a given network.

11.3.3. Bounded Jitter (Latency Variation)

As with the other Latency-related latency-related elements noted above, parameters
should be available to
that can determine or request the allowed variation permitted variations in
latency. latency should
be available.

11.3.4. Symmetrical Path Delays

Some applications would like to specify that the transit delay time
values be equal for both the transmit path and the return paths. path.

11.4. High Reliability and Availability

Reliablity

Reliability is of critical importance to many DetNet applications, in
which
because the consequences of failure can be extraordinarily high in
terms of cost and even human life. DetNet based DetNet-based systems are expected
to be implemented with essentially arbitrarily high availability (for
example --
for example, 99.9999% up time, uptime (where 99.9999 means "six nines") or
even 12 nines). The intent is that the nines. DetNet designs should not make any assumptions about
the level of reliability and availability that may be required of a
given system, system and should define parameters for communicating these
kinds of metrics within the network.

A strategy used by DetNet for providing such extraordinarily high
levels of reliability is to provide redundant paths so that a system
can be seamlessly switched between, switch between the paths while maintaining the its
required
performance level of that system. performance.

11.5. Security

Security is of critical importance to many DetNet applications. A
DetNet network must be able have the ability to be made secure against devices device
failures, attackers, misbehaving devices, and so on. In a DetNet
network
network, the data traffic is expected to be be time-sensitive, thus time sensitive; thus, in
addition to arriving with the data content as intended, the data must
also arrive at the expected time. This may present "new" security
challenges to implementers, implementers and must be addressed accordingly. There
are other security implications, including (but not limited to) the
change in attack surface presented by packet replication and
elimination. PRE.

11.6. Deterministic Flows

Reserved bandwidth

Reserved-bandwidth data flows must be isolated from each other and
from best-effort traffic, so that even if the network is saturated
with best-effort (and/or reserved bandwidth) reserved-bandwidth) traffic, the configured
flows are not adversely affected.

12. Security Considerations

This document covers a number of representative applications and
network scenarios that are expected to make use of DetNet
technologies. Each of the potential DetNet uses use cases will have
security considerations from both the use-specific perspective and
the DetNet technology perspectives. perspective. While some use-specific security
considerations are discussed above, a more comprehensive discussion
of such considerations is captured in DetNet [DetNet-Security]
("Deterministic Networking (DetNet) Security Considerations
[I-D.ietf-detnet-security]. Considerations").
Readers are encouraged to review this
document [DetNet-Security] to gain a more
complete understanding of DetNet related DetNet-related security considerations.

13. Contributors

RFC7322 limits the number of authors listed on IANA Considerations

This document has no IANA actions.

14. Informative References

[Ahm14] Ahmed, M. and R. Kim, "Communication Network Architectures
for Smart-Wind Power Farms", Energies 2014, pp. 3900-3921,
DOI 10.3390/en7063900, June 2014.

[Arch-for-6TiSCH]
Thubert, P., Ed., "An Architecture for IPv6 over the front page of a
draft to a maximum TSCH
mode of 5, far fewer than the 20 individuals below who
made important contributions IEEE 802.15.4", Work in Progress, draft-ietf-
6tisch-architecture-20, March 2019.

[BACnet-IP]
ASHRAE, "Annex J to this draft. The editor wishes to
thank and acknowledge each of the following authors for contributing
text to this draft. See also Section 14.

Craig Gunther (Harman International)
10653 South River Front Parkway, South Jordan,UT 84095
phone +1 801 568-7675, email craig.gunther@harman.com

Pascal Thubert (Cisco Systems, Inc)
Building D, 45 Allee des Ormes - BP1200, MOUGINS
Sophia Antipolis 06254 FRANCE
phone +33 497 23 26 34, email pthubert@cisco.com

Patrick Wetterwald (Cisco Systems)
45 Allees des Ormes, Mougins, 06250 FRANCE
phone +33 4 97 23 26 36, email pwetterw@cisco.com

Jean Raymond (Hydro-Quebec)
1500 University, Montreal, H3A3S7, Canada
phone +1 514 840 3000, email raymond.jean@hydro.qc.ca

Jouni Korhonen (Broadcom Corporation)
3151 Zanker Road, San Jose, 95134, CA, USA
email jouni.nospam@gmail.com

Yu Kaneko (Toshiba)
1 Komukai-Toshiba-cho, Saiwai-ku, Kasasaki-shi, Kanagawa, Japan
email yu1.kaneko@toshiba.co.jp

Subir Das (Vencore Labs)
150 Mount Airy Road, Basking Ridge, New Jersey, 07920, USA
email sdas@appcomsci.com

Balazs Varga (Ericsson)
Konyves Kalman krt. 11/B, Budapest, Hungary, 1097
email balazs.a.varga@ericsson.com

Janos Farkas (Ericsson)
Konyves Kalman krt. 11/B, Budapest, Hungary, 1097
email janos.farkas@ericsson.com
Franz-Josef Goetz (Siemens)
Gleiwitzerstr. 555, Nurnberg, Germany, 90475
email franz-josef.goetz@siemens.com

Juergen Schmitt (Siemens)
Gleiwitzerstr. 555, Nurnberg, Germany, 90475
email juergen.jues.schmitt@siemens.com

Xavier Vilajosana (Worldsensing)
483 Arago, Barcelona, Catalonia, 08013, Spain
email xvilajosana@worldsensing.com

Toktam Mahmoodi (King's College London)
Strand, London WC2R 2LS, United Kingdom
email toktam.mahmoodi@kcl.ac.uk

Spiros Spirou (Intracom Telecom)
19.7 km Markopoulou Ave., Peania, Attiki, 19002, Greece
email spiros.spirou@gmail.com

Petra Vizarreta (Technical University of Munich)
Maxvorstadt, ArcisstraBe 21, Munich, 80333, Germany
email petra.stojsavljevic@tum.de

Daniel Huang (ZTE Corporation, Inc.)
No. 50 Software Avenue, Nanjing, Jiangsu, 210012, P.R. China
email huang.guangping@zte.com.cn

Xuesong Geng (Huawei Technologies)
email gengxuesong@huawei.com

Diego Dujovne (Universidad Diego Portales)
email diego.dujovne@mail.udp.cl

Maik Seewald (Cisco Systems)
email maseewal@cisco.com

14. Acknowledgments

14.1. Pro Audio

This section was derived from draft-gunther-detnet-proaudio-req-01.

The editors would like to acknowledge the help of the following
individuals and the companies they represent:

Jeff Koftinoff, Meyer Sound
Jouni Korhonen, Associate Technical Director, Broadcom

Pascal Thubert, CTAO, Cisco

Kieran Tyrrell, Sienda New Media Technologies GmbH

14.2. Utility Telecom

This section was derived from draft-wetterwald-detnet-utilities-reqs-
02.

Faramarz Maghsoodlou, Ph. D. IoT Connected Industries and Energy
Practice Cisco

Pascal Thubert, CTAO Cisco

The wind power generation use case has been extracted from the study
of Wind Farms conducted within the 5GPPP Virtuwind Project. The
project is funded by the European Union's Horizon 2020 research and
innovation programme under grant agreement No 671648 (VirtuWind).

14.3. Building Automation Systems

This section was derived from draft-bas-usecase-detnet-00.

14.4. Wireless for Industrial Applications

This section was derived from draft-thubert-6tisch-4detnet-01.

This specification derives from the 6TiSCH architecture, which is the
result of multiple interactions, in particular during the 6TiSCH
(bi)Weekly Interim call, relayed through the 6TiSCH mailing list at
the IETF.

The authors wish to thank: Kris Pister, Thomas Watteyne, Xavier
Vilajosana, Qin Wang, Tom Phinney, Robert Assimiti, Michael
Richardson, Zhuo Chen, Malisa Vucinic, Alfredo Grieco, Martin Turon,
Dominique Barthel, Elvis Vogli, Guillaume Gaillard, Herman Storey,
Maria Rita Palattella, Nicola Accettura, Patrick Wetterwald, Pouria
Zand, Raghuram Sudhaakar, and Shitanshu Shah for their participation ANSI/ASHRAE 135-1995 - BACnet/IP",
January 1999,
<http://www.bacnet.org/Addenda/Add-1995-135a.pdf>.

[BAS-DetNet]
Kaneko, Y. and various contributions.

14.5. Cellular Radio

This section was derived from draft-korhonen-detnet-telreq-00.

14.6. Industrial Machine to Machine (M2M)

The authors would like to thank Feng Chen S. Das, "Building Automation Use Cases and Marcel Kiessling
Requirements for
their comments and suggestions.

14.7. Internet Applications and CoMP

This section was derived from draft-zha-detnet-use-case-00 by Yiyong
Zha.

This document has benefited from reviews, suggestions, comments and
proposed text provided by the following members, listed Deterministic Networking", Work in
alphabetical order: Jing Huang, Junru Lin, Lehong Niu
Progress, draft-bas-usecase-detnet-00, October 2015.

[CoAP-6TiSCH]
Sudhaakar, R., Ed. and Oilver
Huang.

14.8. Network Slicing

This section was written by Xuesong Geng, who would like to
acknowledge Norm Finn P. Zand, "6TiSCH Resource
Management and Mach Chen for their useful comments.

14.9. Mining

This section was written by Diego Dujovne Interaction using CoAP", Work in conjunction with Xavier
Vilasojana.

14.10. Private Blockchain

This section was written by Daniel Huang.

15. IANA Considerations

This memo includes no requests from IANA.

16. Informative References

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for smart-wind power farms.", Energies, p. 3900-3921. ,
June 2014.

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[IEEE-1815]
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Power Systems Communications-Distributed Network Protocol
(DNP3)", IEEE Standard 1815,
<https://ieeexplore.ieee.org/servlet/
opac?punumber=6327576>.

[IEEE-19143]
IEEE Standards Association, "P1914.3/D3.1 Draft "IEEE Standard for Radio over
Ethernet Encapsulations and Mappings", IEEE 1914.3, 2018,
<https://standards.ieee.org/develop/project/1914.3.html>.

[IEEE802.1TSNTG]

[IEEE-80211]
IEEE Standards Association, "IEEE 802.1 Time-Sensitive
Networks Task Group", March 2013,
<http://www.ieee802.org/1/pages/avbridges.html>.

[IEEE802154]
IEEE standard Standard for Information Technology, technology, "IEEE std.
802.15.4, Part. 15.4: Std.
802.11, Telecommunications and information exchange
between systems--Local and metropolitan area networks--
Specific requirements - Part 11: Wireless LAN Medium
Access Control (MAC) and Physical Layer (PHY) Specifications for Low-Rate
Wireless Personal Area Networks".

[IEEE802154e]
Specifications",
<https://standards.ieee.org/standard/802_11-2016.html>.

[IEEE-802154]
IEEE standard Standard for Information Technology, technology, "IEEE standard
for Information Technology, IEEE std. Std.
802.15.4, Part. Part 15.4: Wireless Medium Access Control (MAC)
and Physical Layer (PHY) Specifications for Low-Rate Wireless Personal
Area Networks, June 2011 as amended by IEEE std.
802.15.4e, Part. 15.4: Low-Rate Low Rate
Wireless Personal Area Networks (LR-WPANs) Amendment 1: MAC sublayer", April
2012.

[IEEE8021AS] (WPANs)",
<https://standards.ieee.org/standard/802_15_4-2015.html>.

[IEEE-8021AS]
IEEE, "Timing "IEEE Standard for Local and Metropolitan Area
Networks - Timing and Synchronizations (IEEE 802.1AS-2011)", Synchronization for Time-Sensitive
Applications in Bridged Local Area Networks",
IEEE 802.1AS-2001, 2011,
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download/802.1AS-2011.pdf>.

[IEEE8021CM]
Farkas, J., "Time-Sensitive 802.1AS,
<http://www.ieee802.org/1/pages/802.1as.html>.

[IEEE-8021CM]
"IEEE Standard for Local and metropolitan area networks -
Time-Sensitive Networking for Fronthaul",
Unapproved PAR, PAR for a New IEEE Standard;
Standard 802.1CM,
<https://standards.ieee.org/standard/802_1CM-2018.html>.

[IEEE-8021TSNTG]
IEEE P802.1CM, April 2015,
<http://www.ieee802.org/1/files/public/docs2015/
new-P802-1CM-dr aft-PAR-0515-v02.pdf>. Standards Association, "IEEE 802.1 Time-Sensitive
Networking Task Group",
<http://www.ieee802.org/1/pages/avbridges.html>.

[IETF99-netslicing-BoF]
"Network Slicing (netslicing) BoF", IETF 99, Prague, July
2017, <https://datatracker.ietf.org/meeting/99/materials/
slides-99-netslicing-chairs-netslicing-bof-04>.

[Interface-6TiSCH-6top]
Wang, Q., Ed. and X. Vilajosana, "6TiSCH Operation
Sublayer (6top) Interface", Work in Progress, draft-ietf-
6tisch-6top-interface-04, July 2015.

[ISA100] ISA/ANSI, "ISA100, Wireless Systems for Automation",
<https://www.isa.org/isa100/>.

[knx]

[KNX] KNX Association, "ISO/IEC 14543-3 - KNX", November 2006.

[lontalk] ECHELON,

[LonTalk] Echelon Corp., "LonTalk(R) Protocol Specification
Version 3.0",
1994. 1994, <http://www.enerlon.com/JobAids/
Lontalk%20Protocol%20Spec.pdf>.

[MailingList-6TiSCH]
IETF, "6TiSCH Mailing List",
<https://mailarchive.ietf.org/arch/browse/6tisch/>.

[MEF22.1.1]
MEF,
Metro Ethernet Forum, "Mobile Backhaul Phase 2 Amendment 1
-- Small Cells", MEF 22.1.1, July 2014,
<http://www.mef.net/Assets/Technical_Specifications/PDF/
MEF_22.1.1.pdf>.

[MEF8] MEF, Metro Ethernet Forum, "Implementation Agreement for the
Emulation of PDH Circuits over Metro Ethernet Networks",
MEF 8, October 2004,
<https://www.mef.net/Assets/Technical_Specifications/PDF/
MEF_8.pdf>.

[METIS] METIS, "Scenarios, requirements and KPIs for 5G mobile and
wireless system", ICT-317669-METIS/D1.1 ICT-
317669-METIS/D1.1, Document Number ICT-317669-METIS/D1.1,
April 2013, <https://www.metis2020.com/
wp-content/uploads/deliverables/METIS_D1.1_v1.pdf>.

[modbus] Modbus Organization, "MODBUS APPLICATION PROTOCOL
SPECIFICATION V1.1b", December 2006. <https://metis2020.com/wp-
content/uploads/deliverables/METIS_D1.1_v1.pdf>.

[MODBUS] Modbus Organization, Inc., "MODBUS Application Protocol
Specification", Apr 2012. April 2012,
<http://www.modbus.org/specs.php>.

[NGMN] NGMN Alliance, "5G White Paper", NGMN 5G White Paper v1.0,
February 2015, <https://www.ngmn.org/uploads/media/
NGMN_5G_White_Paper_V1_0.pdf>.

[NGMN-fronth]
<https://www.ngmn.org/fileadmin/ngmn/content/downloads/
Technical/2015/NGMN_5G_White_Paper_V1_0.pdf>.

[NGMN-Fronth]
NGMN Alliance, "Fronthaul Requirements for C-RAN", March
2015, <https://www.ngmn.org/uploads/media/ <https://www.ngmn.org/fileadmin/user_upload/
NGMN_RANEV_D1_C-RAN_Fronthaul_Requirements_v1.0.pdf>.

[OPCXML] OPC Foundation, "OPC XML-Data Data Access (OPC DA) Specification", Dec
2004.
<http://www.opcti.com/opc-da-specification.aspx>.

[PCE] IETF, "Path Computation Element",
<https://datatracker.ietf.org/doc/charter-ietf-pce/>.

[profibus]

[PROFIBUS]
IEC, "IEC "PROFIBUS Standard - DP Specification (IEC 61158
Type 3 - Profibus DP", January 2001. 3)", <https://www.profibus.com/>.

[PROFINET]
"PROFINET Technology",
<https://us.profinet.com/technology/profinet/>.

[RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
Label Switching Architecture", RFC 3031,
DOI 10.17487/RFC3031, January 2001,
<https://www.rfc-editor.org/info/rfc3031>.

[RFC3411] Harrington, D., Presuhn, R., and B. Wijnen, "An
Architecture for Describing Simple Network Management
Protocol (SNMP) Management Frameworks", STD 62, RFC 3411,
DOI 10.17487/RFC3411, December 2002,
<https://www.rfc-editor.org/info/rfc3411>.

[RFC3985] Bryant, S., Ed. and P. Pate, Ed., "Pseudo Wire Emulation
Edge-to-Edge (PWE3) Architecture", RFC 3985,
DOI 10.17487/RFC3985, March 2005,
<https://www.rfc-editor.org/info/rfc3985>.

[RFC4553] Vainshtein, A., Ed. and YJ. Stein, Ed., "Structure-
Agnostic Time Division Multiplexing (TDM) over Packet
(SAToP)", RFC 4553, DOI 10.17487/RFC4553, June 2006,
<https://www.rfc-editor.org/info/rfc4553>.

[RFC5086] Vainshtein, A., Ed., Sasson, I., Metz, E., Frost, T., and
P. Pate, "Structure-Aware Time Division Multiplexed (TDM)
Circuit Emulation Service over Packet Switched Network
(CESoPSN)", RFC 5086, DOI 10.17487/RFC5086, December 2007,
<https://www.rfc-editor.org/info/rfc5086>.

[RFC5087] Stein, Y(J)., Shashoua, R., Insler, R., and M. Anavi,
"Time Division Multiplexing over IP (TDMoIP)", RFC 5087,
DOI 10.17487/RFC5087, December 2007,
<https://www.rfc-editor.org/info/rfc5087>.

[RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch,
"Network Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010,
<https://www.rfc-editor.org/info/rfc5905>.

[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
Low-Power and Lossy Networks", RFC 6550,
DOI 10.17487/RFC6550, March 2012,
<https://www.rfc-editor.org/info/rfc6550>.

[RFC6551] Vasseur, JP., Ed., Kim, M., Ed., Pister, K., Dejean, N.,
and D. Barthel, "Routing Metrics Used for Path Calculation
in Low-Power and Lossy Networks", RFC 6551,
DOI 10.17487/RFC6551, March 2012,
<https://www.rfc-editor.org/info/rfc6551>.

[RFC7554] Watteyne, T., Ed., Palattella, M., and L. Grieco, "Using
IEEE 802.15.4e Time-Slotted Channel Hopping (TSCH) in the
Internet of Things (IoT): Problem Statement", RFC 7554,
DOI 10.17487/RFC7554, May 2015,
<https://www.rfc-editor.org/info/rfc7554>.

[RFC8169] Mirsky, G., Ruffini, S., Gray, E., Drake, J., Bryant, S.,
and A. Vainshtein, "Residence Time Measurement in MPLS
Networks", RFC 8169, DOI 10.17487/RFC8169, May 2017,
<https://www.rfc-editor.org/info/rfc8169>.

[Spe09] Sperotto, A., Barbosa, R., Sadre, R., Vliet, F., and A. Pras, "A First Look into
SCADA Network Traffic", IP Network Operations and
Management, p. 518-521. ,
Management Symposium, DOI 10.1109/NOMS.2012.6211945, June 2009.
2012, <https://ieeexplore.ieee.org/document/6211945>.

[SR-IP-RAN-Use-Case]
Khasnabish, B., Hu, F., and L. Contreras, "Segment Routing
in IP RAN use case", Work in Progress, draft-kh-spring-ip-
ran-use-case-02, November 2014.

[SRP_LATENCY]
Gunther, C., "Specifying SRP Acceptable Latency", March
2014, <http://www.ieee802.org/1/files/public/docs2014/
cc-cgunther-acceptable-latency-0314-v01.pdf>.

[SyncE] ITU-T, "G.8261 : Timing

[Sublayer-6TiSCH-6top]
Wang, Q., Ed. and X. Vilajosana, "6TiSCH Operation
Sublayer (6top)", Work in Progress, draft-wang-6tisch-
6top-sublayer-04, November 2015.

[syncE] International Telecommunication Union, "Timing and
synchronization aspects in packet networks", ITU-T
Recommendation G.8261, August 2013,
<http://www.itu.int/rec/T-REC-G.8261>.

[TR38501] 3GPP, "3GPP TS 38.501, Technical Specification System
Architecture for the 5G System (Release 15)", 2017,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=3144>.

[Timing-over-MPLS]
Davari, S., Oren, A., Bhatia, M., Roberts, P., and L.
Montini, "Transporting Timing messages over MPLS
Networks", Work in Progress, draft-ietf-tictoc-
1588overmpls-07, October 2015.

[TR38801] 3GPP, "3GPP TR 38.801, Technical Specification Group Radio
Access Network; Study "Study on new radio access technology: Radio access
architecture and interfaces (Release 14)", 3GPP TR 38.801,
April 2017,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=3056>.

[TS23401] 3GPP, "General Packet Radio Service (GPRS) enhancements
for Evolved Universal Terrestrial Radio Access Network
(E-UTRAN) access", access (Release 16)", 3GPP TS 23.401 10.10.0, 23.401, March 2013.
2019,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=849>.

[TS23501] 3GPP, "System architecture for the 5G System (5GS)
(Release 15)", 3GPP TS 23.501, March 2019,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=3144>.

[TS25104] 3GPP, "Base Station (BS) radio transmission and reception
(FDD)",
(FDD) (Release 16)", 3GPP TS 25.104 3.14.0, March 2007. 25.104, January 2019,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=1154>.

[TS36104] 3GPP, "Evolved Universal Terrestrial Radio Access
(E-UTRA); Base Station (BS) radio transmission and
reception",
reception (Release 16)", 3GPP TS 36.104 10.11.0, July 2013. 36.104, January 2019,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=2412>.

[TS36133] 3GPP, "Evolved Universal Terrestrial Radio Access
(E-UTRA); Requirements for support of radio resource
management",
management (Release 16)", 3GPP TS 36.133 12.7.0, April 2015. 36.133, January 2019,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=2420>.

[TS36211] 3GPP, "Evolved Universal Terrestrial Radio Access
(E-UTRA); Physical channels and modulation", modulation (Release 15)",
3GPP TS 36.211 10.7.0, March 2013. 36.211, January 2019,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=2425>.

[TS36300] 3GPP, "Evolved Universal Terrestrial Radio Access (E-UTRA)
and Evolved Universal Terrestrial Radio Access Network
(E-UTRAN); Overall description; Stage 2", 2 (Release 15)",
3GPP TS 36.300
10.11.0, September 2013.

[TSNTG] IEEE Standards Association, "IEEE 802.1 Time-Sensitive
Networks Task Group", 2013,
<http://www.IEEE802.org/1/pages/avbridges.html>. 36.300, January 2019,
<https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=2430>.

[WirelessHART]
www.hartcomm.org,
International Electrotechnical Commission, "Industrial Communication Networks
networks - Wireless Communication Network communication network and Communication Profiles
- WirelessHART
communication profiles - WirelessHART(TM)",
IEC 62591", 2010. 62591:2016, March 2016.

Appendix A. Use Cases Explicitly Out of Scope for DetNet

This section appendix contains use case text regarding use cases that has have been
determined to be outside of the scope of the present DetNet work.

A.1. DetNet Scope Limitations

The scope of DetNet is deliberately limited to specific use cases
that are consistent with the WG charter, subject to the
interpretation of the WG. At the time that the DetNet Use Cases use cases were
solicited and provided by the authors authors, the scope of DetNet was not
clearly defined, and as that clarity defined. As the scope has emerged, been clarified, certain of the use cases
have been determined to be outside the scope of the present DetNet
work. Such text has been Text regarding these use cases was moved into to this section appendix to
clarify that these use cases they will not be supported by the DetNet work.

The text in this section was moved here to this appendix based on the following
"exclusion" principles. Or, Please note that as an alternative to moving
all such text to this section, appendix some draft text has been modified in situ to
reflect these same principles.

The following principles have been established to clarify the scope
of the present DetNet work.

o The scope of network networks addressed by DetNet is limited to networks
that can be centrally controlled, i.e. i.e., an "enterprise" aka
"corporate" (aka
"corporate") network. This explicitly excludes "the open
Internet".

o Maintaining synchronized time synchronization across a DetNet network is
crucial to its operation, however operation; however, DetNet assumes that time is to
be maintained using other means, for example (but not limited to)
Precision Time Protocol ([IEEE1588]). other means. One example would be PTP
[IEEE-1588]. A use case may state the accuracy and reliability
that it expects from the DetNet network as part of a whole system, however system;
however, it is understood that such timing properties are not
guaranteed by DetNet itself. At the
time of this writing it time of this writing, two
open questions remain: (1) whether DetNet protocols will include a
way for an application to communicate expectations regarding such
timing properties to the network and (2) if so, whether those
properties would likely have a material effect on network
performance as a result.

A.2. Internet-Based Applications

There are many applications that communicate over the open Internet
that could benefit from guaranteed delivery and bounded latency.
However, as noted above, all such applications, when run over the
open Internet, are out of scope for DetNet. These same applications
may be in scope when run in constrained environments, i.e., within a
centrally controlled DetNet network. The following are some examples
of such applications.

A.2.1. Use Case Description

A.2.1.1. Media Content Delivery

Media content delivery continues to be an important use of the
Internet, yet users often experience poor-quality audio and video due
to the delay and jitter inherent in today's Internet.

A.2.1.2. Online Gaming

Online gaming is a significant part of the gaming market; however,
latency can degrade the end user's experience. For example, "First
Person Shooter" (FPS) games are highly delay sensitive.

A.2.1.3. Virtual Reality

VR has many commercial applications, including real estate
presentations, remote medical procedures, and so on. Low latency is
critical to interacting with the virtual world, because perceptual
delays can cause motion sickness.

A.2.2. Internet-Based Applications Today

Internet service today is by definition "best effort", with no
guarantees regarding delivery or bandwidth.

A.2.3. Internet-Based Applications in the Future

One should be able to play Internet videos without glitches and play
Internet games without lag.

For online gaming, the desired maximum allowance for round-trip delay
is an open question as to whether DetNet
protocols will include a way typically 100 ms. However, it may be less for an application to communicate
such timing expectations to specific types of
games; for example, for FPS games, the network, and if so whether they
would maximum delay should be expected to materially affect 50 ms.
Transport delay is the performance they would
receive from dominant part, with a budget of 5-20 ms.

For VR, a maximum delay of 1-10 ms is needed; if doing remote VR, the
total network as delay budget is 1-5 ms.

Flow identification can be used for gaming and VR, i.e., it can
recognize a result.

A.2. Internet-based critical flow and provide appropriate latency bounds.

A.2.4. Internet-Based Applications

There are many applications Requests to the IETF

o Unified control and management protocols that communicate over handle time-critical
data flows

o An application-aware flow-filtering mechanism that recognizes
time-critical flows without doing 5-tuple matching

o A unified control plane that provides low-latency service on
Layer 3 without changing the open Internet data plane

o An OAM system and protocols that could benefit from guaranteed delivery can help provide service
provisioning that is sensitive to end-to-end delays

A.3. Pro Audio and bounded latency.
However as noted above, all such applications when run over the open
Internet are out of scope for DetNet. These same applications may be
in-scope when run in constrained environments, i.e. within a
centrally controlled DetNet network. Video - Digital Rights Management (DRM)

The following are some examples
of such applications.

A.2.1. Use Case Description

A.2.1.1. Media Content Delivery

Media content delivery continues text was moved to be an this appendix because this
information is considered a link-layer topic for which DetNet is not
directly responsible.

Digital Rights Management (DRM) is very important use of to the
Internet, yet users often experience poor quality audio and
video due
to the delay and jitter inherent in today's Internet.

A.2.1.2. Online Gaming

Online gaming industries. Whenever protected content is introduced into a significant part
network, there are DRM concerns that must be taken into account (see
[Content_Protection]). Many aspects of DRM are outside the gaming market, however
latency can degrade the end user experience. For example "First
Person Shooter" games scope of
network technology; however, there are highly delay-sensitive.

A.2.1.3. Virtual Reality

Virtual reality has many commercial applications including real
estate presentations, remote medical procedures, cases when a secure link
supporting authentication and so on. Low
latency is critical to interacting with the virtual world because
perceptual delays can cause motion sickness.

A.2.2. Internet-Based Applications Today

Internet service today encryption is required by definition "best-effort", with no
guarantees on delivery content
owners to carry their audio or bandwidth.

A.2.3. Internet-Based Applications Future

An Internet from which one can play a video without glitches content when it is outside their
own secure environment (for example, see [DCI]).

As an example, two such techniques are Digital Transmission Content
Protection (DTCP) and play
games without lag.

For online gaming, High-bandwidth Digital Content Protection
(HDCP). HDCP content is not approved for retransmission within any
other type of DRM, while DTCP content may be retransmitted under
HDCP. Therefore, if the maximum round-trip delay can source of a stream is outside of the network
and it uses HDCP, it is only allowed to be 100ms placed on the network with
that same type of protection (i.e., HDCP).

A.4. Pro Audio and
stricter for FPS gaming which can be 10-50ms. Transport delay Video - Link Aggregation

Note: The term "link aggregation" is used here as defined by the
dominate part with text
in the following paragraph, i.e., not following a 5-20ms budget. more common
network-industry definition.

For VR, 1-10ms maximum delay is needed and total transmitting streams that require more bandwidth than a single
link in the target network budget is
1-5ms if doing remote VR.

Flow identification can be used for gaming and VR, i.e. it can
recognize support, link aggregation is a critical flow and provide appropriate latency bounds.

A.2.4. Internet-Based Applications Asks

o Unified control and management protocols
technique for combining (aggregating) the bandwidth available on
multiple physical links to handle time-critical
data flow

o Application-aware flow filtering mechanism create a single logical link that provides
the required bandwidth. However, if aggregation is to recognize be used, the timing
critical flow without doing 5-tuple matching
o Unified control plane
network controller (or equivalent) must be able to provide low determine the
maximum latency service on Layer-3
without changing of any path through the data plane

o OAM system and protocols which can help to provide E2E-delay
sensitive service provisioning

A.3. aggregate link.

A.5. Pro Audio and Video - Digital Rights Management (DRM)

This section was moved here because this is considered Deterministic Time to Establish Streaming

The DetNet WG decided that guidelines for establishing a Link layer
topic,
deterministic time to establish stream startup are not direct responsibility within the
scope of DetNet.

Digital Rights Management (DRM) If the bounded timing for establishing or
re-establishing streams is very important required in a given use case, it is up to
the application/system to achieve it.

Acknowledgments

Pro audio (Section 2)

As also acknowledged in [DetNet-Audio-Reqs], the editor would like
to acknowledge the help of the audio following individuals and
video industries. Any time protected content is introduced into a
network there are DRM concerns the
companies they represent.

Jeff Koftinoff, Meyer Sound
Jouni Korhonen, Associate Technical Director, Broadcom
Pascal Thubert, CTAO, Cisco
Kieran Tyrrell, Sienda New Media Technologies GmbH

Utility telecom (Section 3)

Information regarding utility telecom was derived from
[DetNet-Util-Reqs]. As in that must be maintained (see
[CONTENT_PROTECTION]). Many aspects of DRM are outside document, the scope of
network technology, however there following
individuals are cases when a secure link
supporting authentication acknowledged here.

Faramarz Maghsoodlou, Ph.D., IoT Connected Industries
and encryption Energy Practice, Cisco
Pascal Thubert, CTAO, Cisco

The wind power generation use case has been extracted from the
study of wind parks conducted within the 5GPPP VirtuWind Project.
The project is required funded by content
owners to carry their audio or video content when it is outside their
own secure environment (for example see [DCI]).

As an example, two techniques are Digital Transmission Content
Protection (DTCP) the European Union's Horizon 2020
research and High-Bandwidth Digital Content Protection
(HDCP). HDCP content is not approved for retransmission within any
other type of DRM, while DTCP may be retransmitted innovation programme under HDCP.
Therefore if grant agreement No. 671648
(VirtuWind).

Building automation systems (Section 4)

Please see [BAS-DetNet].

Wireless for industrial applications (Section 5)

See [DetNet-6TiSCH].

[DetNet-6TiSCH] derives from the source of a stream 6TiSCH architecture, which is outside the
result of multiple interactions -- in particular, during the network
6TiSCH (bi)weekly interim call, relayed through the 6TiSCH mailing
list at the IETF [MailingList-6TiSCH].

As also acknowledged in [DetNet-6TiSCH], the editor wishes to
thank Kris Pister, Thomas Watteyne, Xavier Vilajosana, Qin Wang,
Tom Phinney, Robert Assimiti, Michael Richardson, Zhuo Chen,
Malisa Vucinic, Alfredo Grieco, Martin Turon, Dominique Barthel,
Elvis Vogli, Guillaume Gaillard, Herman Storey, Maria Rita
Palattella, Nicola Accettura, Patrick Wetterwald, Pouria Zand,
Raghuram Sudhaakar, and it
uses HDCP protection it is only allowed Shitanshu Shah for their participation and
various contributions.

Cellular radio (Section 6)

See [DetNet-RAN].

Internet applications and CoMP (Section 6)

As also acknowledged in [DetNet-Mobile], authored by Yiyong Zha,
the editor would like to be placed on thank the network
with that same HDCP protection.

A.4. Pro Audio following people for their
reviews, suggestions, comments, and Video - Link Aggregation

Note: proposed text: Jing Huang,
Junru Lin, Lehong Niu, and Oliver Huang.

Industrial Machine to Machine (M2M) (Section 7)

The term "Link Aggregation" is used here as defined by the editor would like to thank Feng Chen and Marcel Kiessling for
their comments and suggestions.

Mining industry (Section 8)

This text was written by Diego Dujovne, who worked in the following paragraph, i.e. not following a more common conjunction
with Xavier Vilasojana.

Private blockchain (Section 9)
This text was written by Daniel Huang.

Network
Industry definition.

For transmitting streams that require more bandwidth than a single
link in the target network can support, link aggregation is a
technique slicing (Section 10)

This text was written by Xuesong Geng, who would like to
acknowledge Norm Finn and Mach Chen for combining (aggregating) their useful comments.

Contributors

RFC 7322 ("RFC Style Guide") generally limits the bandwidth available on
multiple physical links to create a single logical link number of authors
listed on the
required bandwidth. However, if aggregation is to be used, the
network controller (or equivalent) must be able to determine the
maximum latency front page of any path through a document to five individuals -- far
fewer than the aggregate link.

A.5. Pro Audio and Video - Deterministic Time 19 individuals listed below, who also made important
contributions to Establish Streaming this document. The DetNet Working Group has decided that guidelines for establishing
a deterministic time editor wishes to establish stream startup are not within scope
of DetNet. If bounded timing thank and
acknowledge each of establishing or re-establish streams
is required in a given use case, it is up to the application/system following authors for contributing text to achieve this.
this document. See also the Acknowledgments section.

Craig Gunther (Harman International)
10653 South River Front Parkway
South Jordan, UT 84095
United States of America
Phone: +1 801 568 7675
Email: craig.gunther@harman.com

Pascal Thubert (Cisco Systems, Inc.)
Building D, 45 Allee des Ormes - BP1200
Mougins - Sophia Antipolis 06254
France
Phone: +33 4 97 23 26 34
Email: pthubert@cisco.com

Patrick Wetterwald (Cisco Systems)
45 Allee des Ormes
Mougins 06250
France
Phone: +33 4 97 23 26 36
Email: pwetterw@cisco.com

Jean Raymond (Hydro-Quebec)
1500 University
Montreal, Quebec H3A 3S7
Canada
Phone: +1 514 840 3000
Email: raymond.jean@hydro.qc.ca

Jouni Korhonen (Broadcom Corporation)
3151 Zanker Road
San Jose, CA 95134
United States of America
Email: jouni.nospam@gmail.com

Yu Kaneko (Toshiba)
1 Komukai-Toshiba-cho
Saiwai-ku, Kasasaki-shi, Kanagawa
Japan
Email: yu1.kaneko@toshiba.co.jp

Subir Das (Vencore Labs)
150 Mount Airy Road
Basking Ridge, NJ 07920
United States of America
Email: sdas@appcomsci.com

Balazs Varga (Ericsson)
Konyves Kalman krt. 11/B
Budapest 1097
Hungary
Email: balazs.a.varga@ericsson.com

Janos Farkas (Ericsson)
Konyves Kalman krt. 11/B
Budapest 1097
Hungary
Email: janos.farkas@ericsson.com

Franz-Josef Goetz (Siemens)
Gleiwitzerstr. 555
Nurnberg 90475
Germany
Email: franz-josef.goetz@siemens.com

Juergen Schmitt (Siemens)
Gleiwitzerstr. 555
Nurnberg 90475
Germany
Email: juergen.jues.schmitt@siemens.com

Xavier Vilajosana (Worldsensing)
483 Arago
Barcelona, Catalonia 08013
Spain
Email: xvilajosana@worldsensing.com

Toktam Mahmoodi (King's College London)
Strand, London WC2R 2LS
United Kingdom
Email: toktam.mahmoodi@kcl.ac.uk
Spiros Spirou (Intracom Telecom)
19.7 km Markopoulou Ave.
Peania, Attiki 19002
Greece
Email: spiros.spirou@gmail.com

Petra Vizarreta (Technical University of Munich)
Maxvorstadt, Arcisstrasse 21
Munich 80333
Germany
Email: petra.stojsavljevic@tum.de

Daniel Huang (ZTE Corporation, Inc.)
No. 50 Software Avenue
Nanjing, Jiangsu 210012
China
Email: huang.guangping@zte.com.cn

Xuesong Geng (Huawei Technologies)
Email: gengxuesong@huawei.com

Diego Dujovne (Universidad Diego Portales)
Email: diego.dujovne@mail.udp.cl

Maik Seewald (Cisco Systems)
Email: maseewal@cisco.com

Author's Address

Ethan Grossman (editor)
Dolby Laboratories, Inc.
1275 Market Street
San Francisco, CA 94103
USA
United States of America

Phone: +1 415 645 4726
Email: ethan.grossman@dolby.com
URI: http://www.dolby.com