Internet Engineering Task Force (IETF) M. Thomson
Request for Comments: 7105 Mozilla
Category: Standards Track J. Winterbottom
ISSN: 2070-1721 Unaffiliated
December 2013
January 2014
Using Device-Provided Location-Related Measurements
in Location Configuration Protocols
Abstract
This document describes a protocol for a Device to provide location-
related measurement data to a Location Information Server (LIS)
within a request for location information. Location-related
measurement information provides observations concerning properties
related to the position of a Device; this information could be data
about network attachment or about the physical environment. A LIS is
able to use the location-related measurement data to improve the
accuracy of the location estimate it provides to the Device. A basic
set of location-related measurements are defined, including common
modes of network attachment as well as assisted Global Navigation
Satellite System (GNSS) parameters.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7105.
Copyright Notice
Copyright (c) 2013 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Conventions Used in This Document . . . . . . . . . . . . . . 4
3. Location-Related Measurements in LCPs . . . . . . . . . . . . 5
4. Location-Related Measurement Data Types . . . . . . . . . . . 7
4.1. Measurement Container . . . . . . . . . . . . . . . . . . 7
4.1.1. Time of Measurement . . . . . . . . . . . . . . . . . 7
4.1.2. Expiry Time on Location-Related Measurement Data . . 8
4.2. RMS Error and Number of Samples . . . . . . . . . . . . . 8
4.2.1. Time RMS Error . . . . . . . . . . . . . . . . . . . 9
4.3. Measurement Request . . . . . . . . . . . . . . . . . . . 9
4.4. Identifying Location Provenance . . . . . . . . . . . . . 11
5. Location-Related Measurement Data Types . . . . . . . . . . . 12
5.1. LLDP Measurements . . . . . . . . . . . . . . . . . . . . 13
5.2. DHCP Relay Agent Information Measurements . . . . . . . . 14
5.3. 802.11 WLAN Measurements . . . . . . . . . . . . . . . . 14
5.3.1. WiFi Measurement Requests . . . . . . . . . . . . . . 18
5.4. Cellular Measurements . . . . . . . . . . . . . . . . . . 18
5.4.1. Cellular Measurement Requests . . . . . . . . . . . . 21
5.5. GNSS Measurements . . . . . . . . . . . . . . . . . . . . 21
5.5.1. GNSS: System Type and Signal . . . . . . . . . . . . 23
5.5.2. Time . . . . . . . . . . . . . . . . . . . . . . . . 24
5.5.3. Per-Satellite Measurement Data . . . . . . . . . . . 24
5.5.4. GNSS Measurement Requests . . . . . . . . . . . . . . 25
5.6. DSL Measurements . . . . . . . . . . . . . . . . . . . . 25
5.6.1. L2TP Measurements . . . . . . . . . . . . . . . . . . 26
5.6.2. RADIUS Measurements . . . . . . . . . . . . . . . . . 26
5.6.3. Ethernet VLAN Tag Measurements . . . . . . . . . . . 27
5.6.4. ATM Virtual Circuit Measurements . . . . . . . . . . 27
6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 28
6.1. Measurement Data Privacy Model . . . . . . . . . . . . . 28
6.2. LIS Privacy Requirements . . . . . . . . . . . . . . . . 29
6.3. Measurement Data and Location URIs . . . . . . . . . . . 29
6.4. Measurement Data Provided by a Third Party . . . . . . . 30
7. Security Considerations . . . . . . . . . . . . . . . . . . . 30
7.1. Threat Model . . . . . . . . . . . . . . . . . . . . . . 30
7.1.1. Acquiring Location Information without Authorization 31
7.1.2. Extracting Network Topology Data . . . . . . . . . . 31
7.1.3. Exposing Network Topology Data . . . . . . . . . . . 32
7.1.4. Lying by Proxy . . . . . . . . . . . . . . . . . . . 32
7.1.5. Measurement Replay . . . . . . . . . . . . . . . . . 33
7.1.6. Environment Spoofing . . . . . . . . . . . . . . . . 34
7.2. Mitigation . . . . . . . . . . . . . . . . . . . . . . . 35
7.2.1. Measurement Validation . . . . . . . . . . . . . . . 36
7.2.1.1. Effectiveness . . . . . . . . . . . . . . . . . . 36
7.2.1.2. Limitations (Unique Observer) . . . . . . . . . . 37
7.2.2. Location Validation . . . . . . . . . . . . . . . . . 37
7.2.2.1. Effectiveness . . . . . . . . . . . . . . . . . . 38
7.2.2.2. Limitations . . . . . . . . . . . . . . . . . . . 38
7.2.3. Supporting Observations . . . . . . . . . . . . . . . 39
7.2.3.1. Effectiveness . . . . . . . . . . . . . . . . . . 39
7.2.3.2. Limitations . . . . . . . . . . . . . . . . . . . 40
7.2.4. Attribution . . . . . . . . . . . . . . . . . . . . . 40
7.2.5. Stateful Correlation of Location Requests . . . . . . 41
7.3. An Unauthorized or Compromised LIS . . . . . . . . . . . 42
8. Measurement Schemas . . . . . . . . . . . . . . . . . . . . . 42
8.1. Measurement Container Schema . . . . . . . . . . . . . . 42
8.2. Measurement Source Schema . . . . . . . . . . . . . . . . 44
8.3. Base Types Schema . . . . . . . . . . . . . . . . . . . . 45
8.4. LLDP Measurement Schema . . . . . . . . . . . . . . . . . 48
8.5. DHCP Measurement Schema . . . . . . . . . . . . . . . . . 49
8.6. WiFi Measurement Schema . . . . . . . . . . . . . . . . . 50
8.7. Cellular Measurement Schema . . . . . . . . . . . . . . . 54
8.8. GNSS Measurement Schema . . . . . . . . . . . . . . . . . 56
8.9. DSL Measurement Schema . . . . . . . . . . . . . . . . . 58
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 60
9.1. IANA Registry for GNSS Types . . . . . . . . . . . . . . 60
9.2. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc . . . . . . . 61
9.3. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm . . . . . . . . . . . . 62
9.4. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:basetypes . . . . . . . 63
9.5. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:lldp . . . . . . . . . 63
9.6. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:dhcp . . . . . . . . . 64
9.7. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:wifi . . . . . . . . . 65
9.8. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:cell . . . . . . . . . 65
9.9. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:gnss . . . . . . . . . 66
9.10. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:dsl . . . . . . . . . . 67
9.11. XML Schema Registration for Measurement Source Schema . . 67
9.12. XML Schema Registration for Measurement Container Schema 67
9.13. XML Schema Registration for Base Types Schema . . . . . . 68
9.14. XML Schema Registration for LLDP Schema . . . . . . . . . 68
9.15. XML Schema Registration for DHCP Schema . . . . . . . . . 68
9.16. XML Schema Registration for WiFi Schema . . . . . . . . . 69
9.17. XML Schema Registration for Cellular Schema . . . . . . . 69
9.18. XML Schema Registration for GNSS Schema . . . . . . . . . 69
9.19. XML Schema Registration for DSL Schema . . . . . . . . . 69
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 70
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 70
11.1. Normative References . . . . . . . . . . . . . . . . . . 70
11.2. Informative References . . . . . . . . . . . . . . . . . 72
1. Introduction
A Location Configuration Protocol (LCP) provides a means for a Device
to request information about its physical location from an access
network. A Location Information Server (LIS) is the server that
provides location information that is available due to the knowledge
it has about the network and physical environment.
As a part of the access network, the LIS is able to acquire
measurement results related to Device location from network elements.
The LIS also has access to information about the network topology
that can be used to turn measurement data into location information.
This information can be further enhanced with information acquired
from the Device itself.
A Device is able to make observations about its network attachment,
or its physical environment. The location-related measurement data
might be unavailable to the LIS; alternatively, the LIS might be able
to acquire the data, but at a higher cost in terms of time or some
other metric. Providing measurement data gives the LIS more options
in determining location; this could in turn improve the quality of
the service provided by the LIS. Improvements in accuracy are one
potential gain, but improved response times and lower error rates are
also possible.
This document describes a means for a Device to report location-
related measurement data to the LIS. Examples based on the
HTTP-Enabled Location Delivery (HELD) [RFC5985] location
configuration protocol are provided.
2. Conventions Used in This Document
The terms "LIS" and "Device" are used in this document in a manner
consistent with the usage in [RFC5985].
This document also uses the following definitions:
Location Measurement: An observation about the physical properties
of a particular Device's position in time and space. The result
of a location measurement -- "location-related measurement data",
or simply "measurement data" given sufficient context -- can be
used to determine the location of a Device. Location-related
measurement data does not directly identify a Device, though it
could do so indirectly. Measurement data can change with time if
the location of the Device also changes.
Location-related measurement data does not necessarily contain
location information directly, but it can be used in combination
with contextual knowledge and/or algorithms to derive location
information. Examples of location-related measurement data are
radio signal strength or timing measurements, Ethernet switch
identifiers, and port identifiers.
Location-related measurement data can be considered sighting
information, based on the definition in [RFC3693].
Location Estimate: An approximation of where the Device is located.
Location estimates are derived from location measurements.
Location estimates are subject to uncertainty, which arises from
errors in measurement results.
GNSS: Global Navigation Satellite System. A satellite-based system
that provides positioning and time information -- for example, the
US Global Positioning System (GPS) or the European Galileo system.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
3. Location-Related Measurements in LCPs
This document defines a standard container for the conveyance of
location-related measurement parameters in location configuration
protocols. This is an XML container that identifies parameters by
type and allows the Device to provide the results of any measurement
it is able to perform. A set of measurement schemas are also defined
that can be carried in the generic container.
A simple example of measurement data conveyance is illustrated by the
example message in Figure 1. This shows a HELD location request
message with an Ethernet switch and port measurement taken using the
Link-Layer Discovery Protocol (LLDP) [IEEE.8021AB].
<locationRequest xmlns="urn:ietf:params:xml:ns:geopriv:held">
<locationType exact="true">civic</locationType>
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<lldp xmlns="urn:ietf:params:xml:ns:geopriv:lm:lldp">
<chassis type="4">0a01003c</chassis>
<port type="6">c2</port>
</lldp>
</measurements>
</locationRequest>
Figure 1: HELD Location Request with Measurement Data
This LIS can ignore measurement data that it does not support or
understand. The measurements defined in this document follow this
rule: extensions that could result in backward incompatibility MUST
be added as new measurement definitions rather than extensions to
existing types.
Multiple sets of measurement data, either of the same type or from
different sources, can be included in the "measurements" element.
See Section 4.1.1 for details on repetition of this element.
A LIS can choose to use or ignore location-related measurement data
in determining location, as long as rules regarding use and retention
(Section 6) are respected. The "method" parameter in the Presence
Information Data Format - Location Object (PIDF-LO) [RFC4119] SHOULD
be adjusted to reflect the method used. A correct "method" can
assist location recipients in assessing the quality (both accuracy
and integrity) of location information, though there could be reasons
to withhold information about the source of data.
Measurement data is typically only used to serve the request in which
it is included. There may be exceptions, particularly with respect
to location URIs. Section 6 provides more information on usage
rules.
Location-related measurement data need not be provided exclusively by
Devices. A third-party location requester (for example, see
[RFC6155]) can request location information using measurement data,
if the requester is able to acquire measurement data and authorized
to distribute it. There are specific privacy considerations relating
to the use of measurements by third parties, which are discussed in
Section 6.4.
Location-related measurement data and its use present a number of
privacy and security challenges. These are described in more detail
in Sections 6 and 7.
4. Location-Related Measurement Data Types
A common container is defined for the expression of location
measurement data, as well as a simple means of identifying specific
types of measurement data for the purposes of requesting them.
The following example shows a measurement container with measurement
time and expiration time included. A WiFi measurement is enclosed.
<lm:measurements xmlns:lm="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58"
expires="2008-04-29T17:33:58">
<wifi xmlns="urn:ietf:params:xml:ns:geopriv:lm:wifi">
<ap serving="true">
<bssid>00-12-F0-A0-80-EF</bssid>
<ssid>wlan-home</ssid>
</ap>
</wifi>
</lm:measurements>
Figure 2: Measurement Example
4.1. Measurement Container
The "measurements" element is used to encapsulate measurement data
that is collected at a certain point in time. It contains time-based
attributes that are common to all forms of measurement data, and it
permits the inclusion of arbitrary measurement data. The elements
that are included within the "measurements" element are generically
referred to as "measurement elements".
This container can be added to a request for location information in
any protocol capable of carrying XML, such as a HELD location request
[RFC5985].
4.1.1. Time of Measurement
The "time" attribute records the time that the measurement or
observation was made. This time can be different from the time that
the measurement information was reported. Time information can be
used to populate a timestamp on the location result or to determine
if the measurement information is used.
The "time" attribute SHOULD be provided whenever possible. This
allows a LIS to avoid selecting an arbitrary timestamp. Exceptions
to this, where omitting time might make sense, include relatively
static types of measurement (for instance, the DSL measurements in
Section 5.6) or for legacy Devices that don't record time information
(such as the Home Location Register/Home Subscriber Server for
cellular).
The "time" attribute is attached to the root "measurement" element.
Multiple measurements can often be given the same timestamp, even
when the measurements were not actually taken at the same time
(consider a set of measurements taken sequentially, where the
difference in time between observations is not significant).
Measurements cannot be grouped if they have different types or if
there is a need for independent time values on each measurement. In
these instances, multiple measurement sets are necessary.
4.1.2. Expiry Time on Location-Related Measurement Data
A Device is able to indicate an expiry time in the location
measurement using the "expires" attribute. Nominally, this attribute
indicates how long information is expected to be valid, but it can
also indicate a time limit on the retention and use of the
measurement data. A Device can use this attribute to request that
the LIS not retain measurement data beyond the indicated time.
Note: Movement of the Device might result in the measurement data
being invalidated before the expiry time.
A Device is advised to set the "expires" attribute to the earlier of
the time that measurements are likely to be unusable and the time
that it desires to have measurements discarded by the LIS. A Device
that does not desire measurement data to be retained can omit the
"expires" attribute. Section 6 describes more specific rules
regarding measurement data retention.
4.2. RMS Error and Number of Samples
Often a measurement is taken more than once. Reporting the average
of a number of measurement results mitigates the effects of random
errors that occur in the measurement process.
Reporting each measurement individually can be the most effective
method of reporting multiple measurements. This is achieved by
providing multiple measurement elements for different times.
The alternative is to aggregate multiple measurements and report a
mean value across the set of measurements. Additional information
about the distribution of the results can be useful in determining
location uncertainty.
Two attributes are provided for use on some measurement values:
rmsError: The root-mean-squared (RMS) error of the set of
measurement values used in calculating the result. RMS error is
expressed in the same units as the measurement, unless otherwise
stated. If an accurate value for the RMS error is not known, this
value can be used to indicate an upper bound or estimate for the
RMS error.
samples: The number of samples that were taken in determining the
measurement value. If omitted, this value can be assumed to be
large enough that the RMS error is an indication of the standard
deviation of the sample set.
For some measurement techniques, measurement error is largely
dependent on the measurement technique employed. In these cases,
measurement error is largely a product of the measurement technique
and not the specific circumstances, so the RMS error does not need to
be actively measured. A fixed value MAY be provided for the RMS
error where appropriate.
The "rmsError" and "samples" elements are added as attributes of
specific measurement data types.
4.2.1. Time RMS Error
Measurement of time can be significant in certain circumstances. The
GNSS measurements included in this document are one such case where a
small error in time can result in a large error in location. Factors
such as clock drift and errors in time synchronization can result in
small, but significant, time errors. Including an indication of the
quality of time measurements can be helpful.
A "timeError" attribute MAY be added to the "measurement" element to
indicate the RMS error in time. "timeError" indicates an upper bound
on the time RMS error in seconds.
The "timeError" attribute does not apply where multiple samples of a
measurement are taken over time. If multiple samples are taken, each
SHOULD be included in a different "measurement" element.
4.3. Measurement Request
A measurement request is used by a protocol peer to describe a set of
measurement data that it desires. A "measurementRequest" element is
defined that can be included in a protocol exchange.
For instance, a LIS can use a measurement request in HELD responses.
If the LIS is unable to provide location information, but it believes
that a particular measurement type would enable it to provide a
location, it can include a measurement request in an error response.
The "measurement" element of the measurement request identifies the
type of measurement that is requested. The "type" attribute of this
element indicates the type of measurement, as identified by an XML
qualified name. A "samples" attribute MAY be used to indicate how
many samples of the identified measurement are requested.
The "measurement" element can be repeated to request multiple (or
alternative) measurement types.
Additional XML content might be defined for a particular measurement
type that is used to further refine a request. These elements either
constrain what is requested or specify non-mandatory components of
the measurement data that are needed. These are defined along with
the specific measurement type.
In the HELD protocol, the inclusion of a measurement request in an
error response with a code of "locationUnknown" indicates that
providing measurements would increase the likelihood of a subsequent
request being successful.
The following example shows a HELD error response that indicates that
WiFi measurement data would be useful if a later request were made.
Additional elements indicate that received signal strength for an
802.11n access point is requested.
<error xmlns="urn:ietf:params:xml:ns:geopriv:held"
code="locationUnknown">
<message xml:lang="en">Insufficient measurement data</message>
<measurementRequest
xmlns="urn:ietf:params:xml:ns:geopriv:lm"
xmlns:wifi="urn:ietf:params:xml:ns:geopriv:lm:wifi">
<measurement type="wifi:wifi">
<wifi:type>n</wifi:type>
<wifi:parameter context="ap">wifi:rcpi</wifi:parameter>
</measurement>
</measurementRequest>
</error>
Figure 3: HELD Error Requesting Measurement Data
A measurement request that is included in other HELD messages has
undefined semantics and can be safely ignored. Other specifications
might define semantics for measurement requests under other
conditions.
4.4. Identifying Location Provenance
An extension is made to the PIDF-LO [RFC4119] that allows a location
recipient to identify the source (or sources) of location information
and the measurement data that was used to determine that location
information.
The "source" element is added to the "geopriv" element of the PIDF-
LO. This element does not identify specific entities. Instead, it
identifies the type of measurement source.
The following values are defined for the "source" element:
lis: Location information is based on measurement data that the LIS
or sources that it trusts have acquired. This label MAY be used
if measurement data provided by the Device has been completely
validated by the LIS.
device: A LIS MUST include this value if the location information is
based (in whole or in part) on measurement data provided by the
Device and if the measurement data isn't completely validated.
other: Location information is based on measurement data that a
third party has provided. This might be an authorized third party
that uses identity parameters [RFC6155] or any other entity. The
LIS MUST include this, unless the third party is trusted by the
LIS to provide measurement data.
No assertion is made about the veracity of the measurement data from
sources other than the LIS. A combination of tags MAY be included to
indicate that measurement data from multiple types of sources was
used.
For example, the first tuple of the following PIDF-LO indicates that
measurement data from a LIS and a Device was combined to produce the
result; the second tuple was produced by the LIS alone.
<presence xmlns="urn:ietf:params:xml:ns:pidf"
xmlns:gp="urn:ietf:params:xml:ns:pidf:geopriv10"
xmlns:gml="http://www.opengis.net/gml"
xmlns:gs="http://www.opengis.net/pidflo/1.0"
xmlns:lmsrc="urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc"
entity="pres:lm@example.com">
<tuple id="deviceLoc">
<status>
<gp:geopriv>
<gp:location-info>
<gs:Circle srsName="urn:ogc:def:crs:EPSG::4326">
<gml:pos>7.34324 134.47162</gml:pos>
<gs:radius uom="urn:ogc:def:uom:EPSG::9001">
850.24
</gs:radius>
</gs:Circle>
</gp:location-info>
<gp:usage-rules/>
<gp:method>OTDOA</gp:method>
<lmsrc:source>lis device</lmsrc:source>
</gp:geopriv>
</status>
</tuple>
<tuple id="lisLoc">
<status>
<gp:geopriv>
<gp:location-info>
<gs:Circle srsName="urn:ogc:def:crs:EPSG::4326">
<gml:pos>7.34379 134.46484</gml:pos>
<gs:radius uom="urn:ogc:def:uom:EPSG::9001">
9000
</gs:radius>
</gs:Circle>
</gp:location-info>
<gp:usage-rules/>
<gp:method>Cell</gp:method>
<lmsrc:source>lis</lmsrc:source>
</gp:geopriv>
</status>
</tuple>
</presence>
PIDF-LO Document with Source Labels
5. Location-Related Measurement Data Types
This document defines location-related measurement data types for a
range of common network types.
All included measurement data definitions allow for arbitrary
extension in the corresponding schema. New parameters that are
applicable to location determination are added as new XML elements in
a unique namespace, not by adding elements to an existing namespace.
5.1. LLDP Measurements
Link-Layer Discovery Protocol (LLDP) [IEEE.8021AB] messages are sent
between adjacent nodes in an IEEE 802 network (e.g., wired Ethernet,
WiFi, 802.16). These messages all contain identification information
for the sending node; the identification information can be used to
determine location information. A Device that receives LLDP messages
can report this information as a location-related measurement to the
LIS, which is then able to use the measurement data in determining
the location of the Device.
Note: The LLDP extensions defined in LLDP Media Endpoint Discovery
(LLDP-MED) [ANSI-TIA-1057] provide the ability to acquire location
information directly from an LLDP endpoint. Where this
information is available, it might be unnecessary to use any other
form of location configuration.
Values are provided as hexadecimal sequences. The Device MUST report
the values directly as they were provided by the adjacent node.
Attempting to adjust or translate the type of identifier is likely to
cause the measurement data to be useless.
Where a Device has received LLDP messages from multiple adjacent
nodes, it should provide information extracted from those messages by
repeating the "lldp" element.
An example of an LLDP measurement is shown in Figure 4. This shows
an adjacent node (chassis) that is identified by the IP address
192.0.2.45 (hexadecimal c000022d), and the port on that node is
numbered using an agent circuit ID [RFC3046] of 162 (hexadecimal a2).
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<lldp xmlns="urn:ietf:params:xml:ns:geopriv:lm:lldp">
<chassis type="4">c000022d</chassis>
<port type="6">a2</port>
</lldp>
</measurements>
Figure 4: LLDP Measurement Example
IEEE 802 Devices that are able to obtain information about adjacent
network switches and their attachment to them by other means MAY use
this data type to convey this information.
5.2. DHCP Relay Agent Information Measurements
The DHCP Relay Agent Information option [RFC3046] provides
measurement data about the network attachment of a Device. This
measurement data can be included in the "dhcp-rai" element.
The elements in the DHCP relay agent information options are opaque
data types assigned by the DHCP relay agent. The three items MAY be
omitted if unknown: circuit identifier ("circuit", circuit [RFC3046],
or Interface-Id [RFC3315]), remote identifier ("remote", Remote ID
[RFC3046], or remote-id [RFC4649]), and subscriber identifier
("subscriber", subscriber-id [RFC3993], or Subscriber-ID [RFC4580]).
The DHCPv6 remote-id has an associated enterprise number
[IANA.enterprise] as an XML attribute.
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<dhcp-rai xmlns="urn:ietf:params:xml:ns:geopriv:lm:dhcp">
<giaddr>192.0.2.158</giaddr>
<circuit>108b</circuit>
</dhcp-rai>
</measurements>
Figure 5: DHCP Relay Agent Information Measurement Example
The "giaddr" element is specified as a dotted quad IPv4 address or an
RFC 4291 [RFC4291] IPv6 address, using the forms defined in
[RFC3986]; IPv6 addresses SHOULD use the form described in [RFC5952].
The enterprise number is specified as a decimal integer. All other
information is included verbatim from the DHCP request in hexadecimal
format.
The "subscriber" element could be considered sensitive. This
information MUST NOT be provided to a LIS that is not authorized to
receive information about the access network. See Section 7.1.3 for
more details.
5.3. 802.11 WLAN Measurements
In WiFi, or 802.11 [IEEE.80211], networks, a Device might be able to
provide information about the access point (AP) to which it is
attached, or other WiFi points it is able to see. This is provided
using the "wifi" element, as shown in Figure 6, which shows a single
complete measurement for a single access point.
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2011-04-29T14:33:58">
<wifi xmlns="urn:ietf:params:xml:ns:geopriv:lm:wifi">
<nicType>Intel(r)PRO/Wireless 2200BG</nicType>
<ap serving="true">
<bssid>AB-CD-EF-AB-CD-EF</bssid>
<ssid>example</ssid>
<channel>5</channel>
<location>
<gml:Point xmlns:gml="http://opengis.net/gml">
<gml:pos>-34.4 150.8</gml:pos>
</gml:Point>
</location>
<type>a</type>
<band>5</band>
<regclass country="AU">2</regclass>
<antenna>2</antenna>
<flightTime rmsError="4e-9" samples="1">2.56e-9</flightTime>
<apSignal>
<transmit>23</transmit>
<gain>5</gain>
<rcpi dBm="true" rmsError="12" samples="1">-59</rcpi>
<rsni rmsError="15" samples="1">23</rsni>
</apSignal>
<deviceSignal>
<transmit>10</transmit>
<gain>9</gain>
<rcpi dBm="true" rmsError="9.5" samples="1">-98.5</rcpi>
<rsni rmsError="6" samples="1">7.5</rsni>
</deviceSignal>
</ap>
</wifi>
</measurements>
Figure 6: 802.11 WLAN Measurement Example
A "wifi" element is made up of one or more access points, and a
"nicType" element, which MAY be omitted. Each access point is
described using the "ap" element, which is comprised of the following
fields:
bssid: The Basic Service Set (BSS) identifier. In an Infrastructure
BSS network, the bssid is the 48-bit MAC address of the access
point.
The "verified" attribute of this element describes whether the
Device has verified the MAC address or it authenticated the access
point or the network operating the access point (for example, a
captive portal accessed through the access point has been
authenticated). This attribute defaults to a value of "false"
when omitted.
ssid: The service set identifier (SSID) for the wireless network
served by the access point.
The SSID is a 32-octet identifier that is commonly represented as
an ASCII [ASCII] or UTF-8 [RFC3629] encoded string. To represent
octets that cannot be directly included in an XML element,
escaping is used. Sequences of octets that do not represent a
valid UTF-8 encoding can be escaped using a backslash ('\')
followed by two case-insensitive hexadecimal digits representing
the value of a single octet.
The canonical or value-space form of an SSID is a sequence of up
to 32 octets that is produced from the concatenation of UTF-8
encoded sequences of unescaped characters and octets derived from
escaped components.
channel: The channel number (frequency) on which the access point
operates.
location: The location of the access point, as reported by the
access point. This element contains any valid location, using the
rules for a "location-info" element, as described in [RFC5491].
type: The network type for the network access. This element
includes the alphabetic suffix of the 802.11 specification that
introduced the radio interface, or PHY, e.g., "a", "b", "g", or
"n".
band: The frequency band for the radio, in gigahertz (GHz). 802.11
[IEEE.80211] specifies PHY layers that use 2.4, 3.7, and 5
gigahertz frequency bands.
regclass: The operating class (regulatory domain and class in older
versions of 802.11); see Annex E of [IEEE.80211]. The "country"
attribute optionally includes the applicable two-character country
identifier (dot11CountryString), which can be followed by an 'O',
'I', or 'X'. The element text content includes the value of the
regulatory class: an 8-bit integer in decimal form.
antenna: The antenna identifier for the antenna that the access
point is using to transmit the measured signals.
flightTime: Flight time is the difference between the time of
departure (TOD) of signal from a transmitting station and time of
arrival (TOA) of signal at a receiving station, as defined in
[IEEE.80211]. Measurement of this value requires that stations
synchronize their clocks. This value can be measured by an access
point or Device; because the flight time is assumed to be the same
in either direction -- aside from measurement errors -- only a
single element is provided. This element permits the use of the
"rmsError" and "samples" attributes. RMS error might be derived
from the reported RMS error in TOD and TOA.
apSignal: Measurement information for the signal transmitted by the
access point, as observed by the Device. Some of these values are
derived from 802.11v [IEEE.80211] messages exchanged between the
Device and access point. The contents of this element include:
transmit: The transmit power reported by the access point, in
dBm.
gain: The gain of the access point antenna reported by the access
point, in dB.
rcpi: The received channel power indicator for the access point
signal, as measured by the Device. This value SHOULD be in
units of dBm (with RMS error in dB). If power is measured in a
different fashion, the "dBm" attribute MUST be set to "false".
Signal strength reporting on current hardware uses a range of
different mechanisms; therefore, the value of the "nicType"
element SHOULD be included if the units are not known to be in
dBm, and the value reported by the hardware should be included
without modification. This element permits the use of the
"rmsError" and "samples" attributes.
rsni: The received signal-to-noise indicator in dB. This element
permits the use of the "rmsError" and "samples" attributes.
deviceSignal: Measurement information for the signal transmitted by
the Device, as reported by the access point. This element
contains the same child elements as the "ap" element, with the
access point and Device roles reversed.
The only mandatory element in this structure is "bssid".
The "nicType" element is used to specify the make and model of the
wireless network interface in the Device. Different 802.11 chipsets
report measurements in different ways, so knowing the network
interface type aids the LIS in determining how to use the provided
measurement data. The content of this field is unconstrained, and no
mechanisms are specified to ensure uniqueness. This field is
unlikely to be useful, except under tightly controlled circumstances.
5.3.1. WiFi Measurement Requests
Two elements are defined for requesting WiFi measurements in a
measurement request:
type: The "type" element identifies the desired type (or types that
are requested).
parameter: The "parameter" element identifies measurements that are
requested for each measured access point. An element is
identified by its qualified name. The "context" parameter can be
used to specify if an element is included as a child of the "ap"
or "device" elements; omission indicates that it applies to both.
Multiple types or parameters can be requested by repeating either
element.
5.4. Cellular Measurements
Cellular Devices are common throughout the world, and base station
identifiers can provide a good source of coarse location information.
Cellular measurements can be provided to a LIS run by the cellular
operator, or may be provided to an alternative LIS operator that has
access to one of several global cell-id to location mapping
databases.
A number of advanced location determination methods have been
developed for cellular networks. For these methods, a range of
measurement parameters can be collected by the network, Device, or
both in cooperation. This document includes a basic identifier for
the wireless transmitter only; future efforts might define additional
parameters that enable more accurate methods of location
determination.
The cellular measurement set allows a Device to report to a LIS any
LTE (Figure 7), UMTS (Figure 8), GSM (Figure 9), or CDMA (Figure 10)
cells that it is able to observe. Cells are reported using their
global identifiers. All Third Generation Partnership Project (3GPP)
cells are identified by a public land mobile network (PLMN), which
comprises a mobile country code (MCC) and mobile network code (MNC);
specific fields are added for each network type.
Formats for 3GPP cell identifiers are described in [TS.3GPP.23.003].
Bit-level formats for CDMA cell identifiers are described in
[TIA-2000.5]; decimal representations are used.
MCC and MNC are provided as decimal digit sequences; a leading zero
in an MCC or MNC is significant. All other values are decimal
integers.
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<cellular xmlns="urn:ietf:params:xml:ns:geopriv:lm:cell">
<servingCell>
<mcc>465</mcc><mnc>20</mnc><eucid>80936424</eucid>
</servingCell>
<observedCell>
<mcc>465</mcc><mnc>06</mnc><eucid>10736789</eucid>
</observedCell>
</cellular>
</measurements>
Long term evolution (LTE) cells are identified by a 28-bit cell
identifier (eucid).
Figure 7: Example LTE Cellular Measurement
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<cellular xmlns="urn:ietf:params:xml:ns:geopriv:lm:cell">
<servingCell>
<mcc>465</mcc><mnc>20</mnc>
<rnc>2000</rnc><cid>65000</cid>
</servingCell>
<observedCell>
<mcc>465</mcc><mnc>06</mnc>
<lac>16383</lac><cid>32767</cid>
</observedCell>
</cellular>
</measurements>
Universal mobile telephony service (UMTS) cells are identified by 12-
or 16-bit radio network controller (rnc) id and a 16-bit cell id
(cid).
Figure 8: Example UMTS Cellular Measurement
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<cellular xmlns="urn:ietf:params:xml:ns:geopriv:lm:cell">
<servingCell>
<mcc>465</mcc><mnc>06</mnc>
<lac>16383</lac><cid>32767</cid>
</servingCell>
</cellular>
</measurements>
Global System for Mobile communication (GSM) cells are identified by
a 16-bit location area code (lac) and a 16-bit cell id (cid).
Figure 9: Example GSM Cellular Measurement
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<cellular xmlns="urn:ietf:params:xml:ns:geopriv:lm:cell">
<servingCell>
<sid>15892</sid><nid>4723</nid><baseid>12</baseid>
</servingCell>
<observedCell>
<sid>15892</sid><nid>4723</nid><baseid>13</baseid>
</observedCell>
</cellular>
</measurements>
Code division multiple access (CDMA) cells are not identified by a
PLMN; instead, these use a 15-bit system id (sid), a 16-bit network
id (nid), and a 16-bit base station id (baseid).
Figure 10: Example CDMA Cellular Measurement
In general, a cellular Device will be attached to the cellular
network, so the notion of a serving cell exists. Cellular networks
also provide overlap between neighboring sites, so a mobile Device
can hear more than one cell. The measurement schema supports sending
both the serving cell and any other cells that the mobile might be
able to hear. In some cases, the Device could simply be listening to
cell information without actually attaching to the network; mobiles
without a SIM are an example of this. In this case, the Device could
report cells it can hear without identifying any particular cell as a
serving cell. An example of this is shown in Figure 11.
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<cellular xmlns="urn:ietf:params:xml:ns:geopriv:lm:cell">
<observedCell>
<mcc>465</mcc><mnc>20</mnc>
<rnc>2000</rnc><cid>65000</cid>
</observedCell>
<observedCell>
<mcc>465</mcc><mnc>06</mnc>
<lac>16383</lac><cid>32767</cid>
</observedCell>
</cellular>
</measurements>
Figure 11: Example Observed Cellular Measurement
5.4.1. Cellular Measurement Requests
Two elements can be used in measurement requests for cellular
measurements:
type: A label indicating the type of identifier to provide: one of
"gsm", "umts", "lte", or "cdma".
network: The network portion of the cell identifier. For 3GPP
networks, this is the combination of MCC and MNC; for CDMA, this
is the network identifier.
Multiple identifier types or networks can be identified by repeating
either element.
5.5. GNSS Measurements
A Global Navigation Satellite System (GNSS) uses orbiting satellites
to transmit signals. A Device with a GNSS receiver is able to take
measurements from the satellite signals. The results of these
measurements can be used to determine time and the location of the
Device.
Determining location and time in autonomous GNSS receivers follows
three steps:
Signal acquisition: During the signal acquisition stage, the
receiver searches for the repeating code that is sent by each GNSS
satellite. Successful operation typically requires measurement
data for a minimum of 5 satellites. At this stage, measurement
data is available to the Device.
Navigation message decode: Once the signal has been acquired, the
receiver then receives information about the configuration of the
satellite constellation. This information is broadcast by each
satellite and is modulated with the base signal at a low rate; for
instance, GPS sends this information at about 50 bits per second.
Calculation: The measurement data is combined with the data on the
satellite constellation to determine the location of the receiver
and the current time.
A Device that uses a GNSS receiver is able to report measurements
after the first stage of this process. A LIS can use the results of
these measurements to determine a location. In the case where there
are fewer results available than the optimal minimum, the LIS might
be able to use other sources of measurement information and combine
these with the available measurement data to determine a position.
Note: The use of different sets of GNSS assistance data can reduce
the amount of time required for the signal acquisition stage and
obviate the need for the receiver to extract data on the satellite
constellation. Provision of assistance data is outside the scope
of this document.
Figure 12 shows an example of GNSS measurement data. The measurement
shown is for the GPS satellite system and includes measurement data
for three satellites only.
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58" timeError="2e-5">
<gnss xmlns="urn:ietf:params:xml:ns:geopriv:lm:gnss"
system="gps" signal="L1">
<sat num="19">
<doppler>499.9395</doppler>
<codephase rmsError="1.6e-9">0.87595747</codephase>
<cn0>45</cn0>
</sat>
<sat num="27">
<doppler>378.2657</doppler>
<codephase rmsError="1.6e-9">0.56639479</codephase>
<cn0>52</cn0>
</sat>
<sat num="20">
<doppler>-633.0309</doppler>
<codephase rmsError="1.6e-9">0.57016835</codephase>
<cn0>48</cn0>
</sat>
</gnss>
</measurements>
Figure 12: Example GNSS Measurement
Each "gnss" element represents a single set of GNSS measurement data,
taken at a single point in time. Measurements taken at different
times can be included in different "gnss" elements to enable
iterative refinement of results.
GNSS measurement parameters are described in more detail in the
following sections.
5.5.1. GNSS: System Type and Signal
The GNSS measurement structure is designed to be generic and to apply
to different GNSS types. Different signals within those systems are
also accounted for and can be measured separately.
The GNSS type determines the time system that is used. An indication
of the type of system and signal can ensure that the LIS is able to
correctly use measurements.
Measurements for multiple GNSS types and signals can be included by
repeating the "gnss" element.
This document creates an IANA registry for GNSS types. Two satellite
systems are registered by this document: GPS [GPS.ICD] and Galileo
[Galileo.ICD]. Details for the registry are included in Section 9.1.
5.5.2. Time
Each set of GNSS measurements is taken at a specific point in time.
The "time" attribute is used to indicate the time that the
measurement was acquired, if the receiver knows how the time system
used by the GNSS relates to UTC time.
Alternative to (or in addition to) the measurement time, the
"gnssTime" element MAY be included. The "gnssTime" element includes
a relative time in milliseconds using the time system native to the
satellite system. For the GPS satellite system, the "gnssTime"
element includes the time of week in milliseconds. For the Galileo
system, the "gnssTime" element includes the time of day in
milliseconds.
The accuracy of the time measurement provided is critical in
determining the accuracy of the location information derived from
GNSS measurements. The receiver SHOULD indicate an estimated time
error for any time that is provided. An RMS error can be included
for the "gnssTime" element, with a value in milliseconds.
5.5.3. Per-Satellite Measurement Data
Multiple satellites are included in each set of GNSS measurements
using the "sat" element. Each satellite is identified by a number in
the "num" attribute. The satellite number is consistent with the
identifier used in the given GNSS.
Both the GPS and Galileo systems use satellite numbers between 1
and 64.
The GNSS receiver measures the following parameters for each
satellite:
doppler: The observed Doppler shift of the satellite signal,
measured in meters per second. This is converted from a value in
Hertz by the receiver to allow the measurement to be used without
knowledge of the carrier frequency of the satellite system. This
value permits the use of RMS error attributes, also measured in
meters per second.
codephase: The observed code phase for the satellite signal,
measured in milliseconds. This is converted from the system-
specific value of chips or wavelengths into a system-independent
value. Larger values indicate larger distances from satellite to
receiver. This value permits the use of RMS error attributes,
also measured in milliseconds.
cn0: The signal-to-noise ratio for the satellite signal, measured in
decibel-Hertz (dB-Hz). The expected range is between 20 and
50 dB-Hz.
mp: An estimation of the amount of error that multipath signals
contribute in meters. This parameter MAY be omitted.
cq: An indication of the carrier quality. Two attributes are
included: "continuous" (which can be either "true" or "false") and
"direct" (which can be either "direct" or "inverted"). This
parameter MAY be omitted.
adr: The accumulated Doppler range, measured in meters. This
parameter MAY be omitted and is not useful unless multiple sets of
GNSS measurements are provided or differential positioning is
being performed.
All values are converted from measures native to the satellite system
to generic measures to ensure consistency of interpretation. Unless
necessary, the schema does not constrain these values.
5.5.4. GNSS Measurement Requests
Measurement requests can include a "gnss" element, which includes the
"system" and "signal" attributes. Multiple elements can be included
to indicate requests for GNSS measurements from multiple systems or
signals.
5.6. DSL Measurements
Digital Subscriber Line (DSL) networks rely on a range of network
technologies. DSL deployments regularly require cooperation between
multiple organizations. These fall into two broad categories:
infrastructure providers and Internet service providers (ISPs). For
the same end user, an infrastructure and Internet service can be
provided by different entities. Infrastructure providers manage the
bulk of the physical infrastructure, including cabling. End users
obtain their service from an ISP, which manages all aspects visible
to the end user, including IP address allocation and operation of a
LIS. See [DSL.TR025] and [DSL.TR101] for further information on DSL
network deployments and the parameters that are available.
Exchange of measurement information between these organizations is
necessary for location information to be correctly generated. The
ISP LIS needs to acquire location information from the infrastructure
provider. However, since the infrastructure provider could have no
knowledge of Device identifiers, it can only identify a stream of
data that is sent to the ISP. This is resolved by passing
measurement data relating to the Device to a LIS operated by the
infrastructure provider.
5.6.1. L2TP Measurements
The Layer 2 Tunneling Protocol (L2TP) [RFC2661] is a common means of
linking the infrastructure provider and the ISP. The infrastructure
provider LIS requires measurement data that identifies a single L2TP
tunnel, from which it can generate location information. Figure 13
shows an example L2TP measurement.
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<dsl xmlns="urn:ietf:params:xml:ns:geopriv:lm:dsl">
<l2tp>
<src>192.0.2.10</src>
<dest>192.0.2.61</dest>
<session>528</session>
</l2tp>
</dsl>
</measurements>
Figure 13: Example DSL L2TP Measurement
5.6.2. RADIUS Measurements
When authenticating network access, the infrastructure provider might
employ a RADIUS [RFC2865] proxy at the DSL Access Module (DSLAM) or
Access Node (AN). These messages provide the ISP RADIUS server with
an identifier for the DSLAM or AN, plus the slot and port to which
the Device is attached. These data can be provided as a measurement
that allows the infrastructure provider LIS to generate location
information.
The format of the AN, slot, and port identifiers is not defined in
the RADIUS protocol. The slot and port together identify a circuit
on the AN, analogous to the circuit identifier in [RFC3046]. These
items are provided directly, as they would be in the RADIUS message.
An example is shown in Figure 14.
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<dsl xmlns="urn:ietf:params:xml:ns:geopriv:lm:dsl">
<an>AN-7692</an>
<slot>3</slot>
<port>06</port>
</dsl>
</measurements>
Figure 14: Example DSL RADIUS Measurement
5.6.3. Ethernet VLAN Tag Measurements
For Ethernet-based DSL access networks, the DSLAM or AN provides two
VLAN tags on packets. A C-TAG is used to identify the incoming
residential circuit, while the S-TAG is used to identify the DSLAM or
AN. The C-TAG and S-TAG together can be used to identify a single
point of network attachment. An example is shown in Figure 15.
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<dsl xmlns="urn:ietf:params:xml:ns:geopriv:lm:dsl">
<stag>613</stag>
<ctag>1097</ctag>
</dsl>
</measurements>
Figure 15: Example DSL VLAN Tag Measurement
Alternatively, the C-TAG can be replaced by data on the slot and port
to which the Device is attached. This information might be included
in RADIUS requests that are proxied from the infrastructure provider
to the ISP RADIUS server.
5.6.4. ATM Virtual Circuit Measurements
An ATM virtual circuit can be employed between the ISP and
infrastructure provider. Providing the virtual port ID (VPI) and
virtual circuit ID (VCI) for the virtual circuit gives the
infrastructure provider LIS the ability to identify a single data
stream. A sample measurement is shown in Figure 16.
<measurements xmlns="urn:ietf:params:xml:ns:geopriv:lm"
time="2008-04-29T14:33:58">
<dsl xmlns="urn:ietf:params:xml:ns:geopriv:lm:dsl">
<vpi>55</vpi>
<vci>6323</vci>
</dsl>
</measurements>
Figure 16: Example DSL ATM Measurement
6. Privacy Considerations
Location-related measurement data can be as privacy sensitive as
location information [RFC6280].
Measurement data is effectively equivalent to location information if
the contextual knowledge necessary to generate one from the other is
readily accessible. Even where contextual knowledge is difficult to
acquire, there can be no assurance that an authorized recipient of
the contextual knowledge is also authorized to receive location
information.
In order to protect the privacy of the subject of location-related
measurement data, measurement data MUST be protected with the same
degree of protection as location information. The confidentiality
and authentication provided by Transport Layer Security (TLS) MUST be
used in order to convey measurement data over HELD [RFC5985]. Other
protocols MUST provide comparable guarantees.
6.1. Measurement Data Privacy Model
It is not necessary to distribute measurement data in the same
fashion as location information. Measurement data is less useful to
location recipients than location information. A simple distribution
model is described in this document.
In this simple model, the Device is the only entity that is able to
distribute measurement data. To use an analogy from the GEOPRIV
architecture, the Device -- as the Location Generator or the
Measurement Data Generator -- is the sole entity that can act in the
role of both Rule Maker and Location Server.
A Device that provides location-related measurement data MUST only do
so as explicitly authorized by a Rule Maker. This depends on having
an interface that allows Rule Makers (for instance, users or
administrators) to control where and how measurement data is
provided.
No entity is permitted to redistribute measurement data. The Device
directs other entities regarding how measurement data is used and
retained.
The GEOPRIV model [RFC6280] protects the location of a Target using
direction provided by a Rule Maker. For the purposes of measurement
data distribution, this model relies on the assumptions made in
Section 3 of HELD [RFC5985]. These assumptions effectively declare
the Device to be a proxy for both Target and Rule Maker.
6.2. LIS Privacy Requirements
A LIS MUST NOT reveal location-related measurement data to any other
entity. A LIS MUST NOT reveal location information based on
measurement data to any other entity unless directed to do so by the
Device.
By adding measurement data to a request for location information, the
Device implicitly grants permission for the LIS to generate the
requested location information using the measurement data.
Permission to use this data for any other purpose is not implied.
As long as measurement data is only used in serving the request that
contains it, rules regarding data retention are not necessary. A LIS
MUST discard location-related measurement data after servicing a
request, unless the Device grants permission to use that information
for other purposes.
6.3. Measurement Data and Location URIs
A LIS MAY use measurement data provided by the Device to serve
requests to location URIs, if the Device permits it. A Device
permits this by including measurement data in a request that
explicitly requests a location URI. By requesting a location URI,
the Device grants permission for the LIS to use the measurement data
in serving requests to that location URI. The LIS cannot provide
location recipients with measurement data, as defined in Section 6.1.
Note: In HELD, the "any" type is not an explicit request for a
location URI, though a location URI might be provided.
The usefulness of measurement data that is provided in this fashion
is limited. The measurement data is only valid at the time that it
was acquired by the Device. At the time that a request is made to a
location URI, the Device might have moved, rendering the measurement
data incorrect.
A Device is able to explicitly limit the time that a LIS retains
measurement data by adding an expiry time to the measurement data. A
LIS MUST NOT retain location-related measurement data in memory,
storage, or logs beyond the time indicated in the "expires" attribute
(Section 4.1.2). A LIS MUST NOT retain measurement data if the
"expires" attribute is absent.
6.4. Measurement Data Provided by a Third Party
An authorized third-party request for the location of a Device (see
[RFC6155]) can include location-related measurement data. This is
possible where the third party is able to make observations about the
Device.
A third party that provides measurement data MUST be authorized to
provide the specific measurement for the identified Device. Either a
third party MUST be trusted by the LIS for the purposes of providing
measurement data of the provided type, or the measurement data MUST
be validated (see Section 7.2.1) before being used.
How a third party authenticates its identity or gains authorization
to use measurement data is not covered by this document.
7. Security Considerations
The use of location-related measurement data has privacy
considerations that are discussed in Section 6.
7.1. Threat Model
The threat model for location-related measurement data concentrates
on the Device providing falsified, stolen, or incorrect measurement
data.
A Device that provides location-related measurement data might use
data to:
o acquire the location of another Device, without authorization;
o extract information about network topology; or
o coerce the LIS into providing falsified location information based
on the measurement data.
Location-related measurement data describes the physical environment
or network attachment of a Device. A third-party adversary in the
proximity of the Device might be able to alter the physical
environment such that the Device provides measurement data that is
controlled by the third party. This might be used to indirectly
control the location information that is derived from measurement
data.
7.1.1. Acquiring Location Information without Authorization
Requiring authorization for location requests is an important part of
privacy protections of a location protocol. A location configuration
protocol usually operates under a restricted policy that allows a
requester to obtain their own location. HELD identity extensions
[RFC6155] allow other entities to be authorized, conditional on a
Rule Maker providing sufficient authorization.
The intent of these protections is to ensure that a location
recipient is authorized to acquire location information. Location-
related measurement data could be used by an attacker to circumvent
such authorization checks if the association between measurement data
and Target Device is not validated by a LIS.
A LIS can be coerced into providing location information for a Device
that a location recipient is not authorized to receive. A request
identifies one Device (implicitly or explicitly), but measurement
data is provided for another Device. If the LIS does not check that
the measurement data is for the identified Device, it could
incorrectly authorize the request.
By using unverified measurement data to generate a response, the LIS
provides information about a Device without appropriate
authorization.
The feasibility of this attack depends on the availability of
information that links a Device with measurement data. In some
cases, measurement data that is correlated with a Target is readily
available. For instance, LLDP measurements (Section 5.1) are
broadcast to all nodes on the same network segment. An attacker on
that network segment can easily gain measurement data that relates a
Device with measurements.
For some types of measurement data, it's necessary for an attacker to
know the location of the Target in order to determine what
measurements to use. This attack is meaningless for types of
measurement data that require that the attacker first know the
location of the Target before measurement data can be acquired or
fabricated. GNSS measurements (Section 5.5) share this trait with
many wireless location determination methods.
7.1.2. Extracting Network Topology Data
Allowing requests with measurements might be used to collect
information about network topology.
Network topology can be considered sensitive information by a network
operator for commercial or security reasons. While it is impossible
to completely prevent a Device from acquiring some knowledge of
network topology if a location service is provided, a network
operator might desire to limit how much of this information is made
available.
Mapping a network topology does not require that an attacker be able
to associate measurement data with a particular Device. If a
requester is able to try a number of measurements, it is possible to
acquire information about network topology.
It is not even necessary that the measurements are valid; random
guesses are sufficient, provided that there is no penalty or cost
associated with attempting to use the measurements.
7.1.3. Exposing Network Topology Data
A Device could reveal information about a network to entities outside
of that network if it provides location measurement data to a LIS
that is outside of that network. With the exception of GNSS
measurements, the measurements in this document provide information
about an access network that could reveal topology information to an
unauthorized recipient.
A Device MUST NOT provide information about network topology without
a clear signal that the recipient is authorized. A LIS that is
discovered using DHCP as described in LIS discovery [RFC5986] can be
considered to be authorized to receive information about the access
network.
7.1.4. Lying by Proxy
Location information, which includes measurement data, is a function
of its inputs. Thus, falsified measurement data can be used to alter
the location information that is provided by a LIS.
Some types of measurement data are relatively easy to falsify in a
way that causes the resulting location information to be selected
with little or no error. For instance, GNSS measurements are easy to
use for this purpose because all the contextual information necessary
to calculate a position using measurements is broadcast by the
satellites [HARPER].
An attacker that falsifies measurement data gains little if they are
the only recipient of the result. The attacker knows that the
location information is bad. The attacker only gains if the
information can somehow be attributed to the LIS by another location
recipient. By coercing the LIS into providing falsified location
information, any credibility that the LIS might have -- that the
attacker does not -- is gained by the attacker.
A third party that is reliant on the integrity of the location
information might base an evaluation of the credibility of the
information on the source of the information. If that third party is
able to attribute location information to the LIS, then an attacker
might gain.
Location information that is provided to the Device without any means
to identify the LIS as its source is not subject to this attack. The
Device is identified as the source of the data when it distributes
the location information to location recipients.
Location information is attributed to the LIS either through the use
of digital signatures or by having the location recipient directly
interact with the LIS. A LIS that digitally signs location
information becomes identifiable as the source of the data.
Similarly, the LIS is identified as a source of data if a location
recipient acquires information directly from a LIS using a location
URI.
7.1.5. Measurement Replay
The values of some measured properties do not change over time for a
single location. The time invariance of network properties is often
a direct result of the practicalities of operating the network.
Limiting the changes to a network ensures greater consistency of
service. A largely static network also greatly simplifies the data
management tasks involved with providing a location service.
However, time-invariant properties allow for simple replay attacks,
where an attacker acquires measurements that can later be used
without being detected as being invalid.
Measurement data is frequently an observation of a time-invariant
property of the environment at the subject location. For
measurements of this nature, nothing in the measurement itself is
sufficient proof that the Device is present at the resulting
location. Measurement data might have been previously acquired and
reused.
For instance, the identity of a radio transmitter, if broadcast by
that transmitter, can be collected and stored. An attacker that
wishes it known that they exist at a particular location can claim to
observe this transmitter at any time. Nothing inherent in the claim
reveals it to be false.
7.1.6. Environment Spoofing
Some types of measurement data can be altered or influenced by a
third party so that a Device unwittingly provides falsified data. If
it is possible for a third party to alter the measured phenomenon,
then any location information that is derived from this data can be
indirectly influenced.
Altering the environment in this fashion might not require
involvement with either a Device or LIS. Measurement that is passive
-- where the Device observes a signal or other phenomenon without
direct interaction -- is most susceptible to alteration by third
parties.
Measurement of radio signal characteristics is especially vulnerable,
since an adversary need only be in the general vicinity of the Device
and be able to transmit a signal. For instance, a GNSS spoofer is
able to produce fake signals that claim to be transmitted by any
satellite or set of satellites (see [GPS.SPOOF]).
Measurements that require direct interaction increase the complexity
of the attack. For measurements relating to the communication
medium, a third party cannot avoid direct interaction; they need only
be on the communications path (that is, man in the middle).
Even if the entity that is interacted with is authenticated, this
does not provide any assurance about the integrity of measurement
data. For instance, the Device might authenticate the identity of a
radio transmitter through the use of cryptographic means and obtain
signal strength measurements for that transmitter. Radio signal
strength is trivial for an attacker to increase simply by receiving
and amplifying the raw signal; it is not necessary for the attacker
to be able to understand the signal content.
Note: This particular "attack" is more often completely
legitimate. Radio repeaters are a commonplace mechanism used to
increase radio coverage.
Attacks that rely on altering the observed environment of a Device
require countermeasures that affect the measurement process. For
radio signals, countermeasures could include the use of authenticated
signals, or altered receiver design. In general, countermeasures are
highly specific to the individual measurement process. An exhaustive
discussion of these issues is left to the relevant literature for
each measurement technology.
A Device that provides measurement data is assumed to be responsible
for applying appropriate countermeasures against this type of attack.
Where a Device is the sole recipient of location information derived
from measurement data, a LIS might choose to provide location
information without any validation. The responsibility for ensuring
the veracity of the measurement data lies with the Device.
Measurement data that is susceptible to this sort of influence SHOULD
be treated as though it were produced by an untrusted Device for
those cases where a location recipient might attribute the location
information to the LIS. GNSS measurements and radio signal strength
measurements can be affected relatively cheaply, though almost all
other measurement types can be affected with varying costs to an
attacker, with the largest cost often being a requirement for
physical access. To the extent that it is feasible, measurement data
SHOULD be subjected to the same validation as for other types of
attacks that rely on measurement falsification.
Note: Altered measurement data might be provided by a Device that
has no knowledge of the alteration. Thus, an otherwise trusted
Device might still be an unreliable source of measurement data.
7.2. Mitigation
The following measures can be applied to limit or prevent attacks.
The effectiveness of each depends on the type of measurement data and
how that measurement data is acquired.
Two general approaches are identified for dealing with untrusted
measurement data:
1. Require independent validation of measurement data or the
location information that is produced.
2. Identify the types of sources that provided the measurement data
from which that location information was derived.
This section goes into more detail on the different forms of
validation in Sections 7.2.1, 7.2.2, and 7.2.3. The impact of
attributing location information to sources is discussed in more
detail in Section 7.2.4.
Any costs in validation are balanced against the degree of integrity
desired from the resulting location information.
7.2.1. Measurement Validation
Recognizing that measurement data has been falsified is difficult in
the absence of integrity mechanisms.
Independent confirmation of the veracity of measurement data ensures
that the measurement is accurate and that it applies to the correct
Device. When it's possible to gather the same measurement data from
a trusted and independent source without undue expense, the LIS can
use the trusted data in place of what the untrusted Device has sent.
In cases where that is impractical, the untrusted data can provide
hints that allow corroboration of the data (see Section 7.2.1.1).
Measurement information might not contain any inherent indication
that it is falsified. In addition, it can be difficult to obtain
information that would provide any degree of assurance that the
measurement device is physically at any particular location.
Measurements that are difficult to verify require other forms of
assurance before they can be used.
7.2.1.1. Effectiveness
Measurement validation MUST be used if measurement data for a
particular Device can be easily acquired by unauthorized location
recipients, as described in Section 7.1.1. This prevents
unauthorized access to location information using measurement data.
Validation of measurement data can be significantly more effective
than independent acquisition of the same. For instance, a Device in
a large Ethernet network could provide a measurement indicating its
point of attachment using LLDP measurements. For a LIS, acquiring
the same measurement data might require a request to all switches in
that network. With the measurement data, validation can target the
identified switch with a specific query.
Validation is effective in identifying falsified measurement data
(Section 7.1.4), including attacks involving replay of measurement
data (Section 7.1.5). Validation also limits the amount of network
topology information (Section 7.1.2) made available to Devices to
that portion of the network topology to which they are directly
attached.
Measurement validation has no effect if the underlying environment is
being altered (Section 7.1.6).
7.2.1.2. Limitations (Unique Observer)
A Device is often in a unique position to make a measurement. It
alone occupies the point in space-time that the location
determination process seeks to determine. The Device becomes a
unique observer for a particular property.
The ability of the Device to become a unique observer makes the
Device invaluable to the location determination process. As a unique
observer, it also makes the claims of a Device difficult to validate
and easy to spoof.
As long as no other entity is capable of making the same
measurements, there is also no other entity that can independently
check that the measurements are correct and applicable to the Device.
A LIS might be unable to validate all or part of the measurement data
it receives from a unique observer. For instance, a signal strength
measurement of the signal from a radio tower cannot be validated
directly.
Some portion of the measurement data might still be independently
verified, even if all information cannot. In the previous example,
the radio tower might be able to provide verification that the Device
is present if it is able to observe a radio signal sent by the
Device.
If measurement data can only be partially validated, the extent to
which it can be validated determines the effectiveness of validation
against these attacks.
The advantage of having the Device as a unique observer is that it
makes it difficult for an attacker to acquire measurements without
the assistance of the Device. Attempts to use measurements to gain
unauthorized access to measurement data (Section 7.1.1) are largely
ineffectual against a unique observer.
7.2.2. Location Validation
Location information that is derived from location-related
measurement data can also be verified against trusted location
information. Rather than validating inputs to the location
determination process, suspect locations are identified at the output
of the process.
Trusted location information is acquired using sources of measurement
data that are trusted. Untrusted location information is acquired
using measurement data provided from untrusted sources, which might
include the Device. These two locations are compared. If the
untrusted location agrees with the trusted location, the untrusted
location information is used.
Algorithms for the comparison of location information are not
included in this document. However, a simple comparison for
agreement might require that the untrusted location be entirely
contained within the uncertainty region of the trusted location.
There is little point in using a less accurate, less trusted
location. Untrusted location information that has worse accuracy
than trusted information can be immediately discarded. There are
multiple factors that affect accuracy, uncertainty and currency being
the most important. How location information is compared for
accuracy is not defined in this document.
7.2.2.1. Effectiveness
Location validation limits the extent to which falsified -- or
erroneous -- measurement data can cause an incorrect location to be
reported.
Location validation can be more efficient than validation of inputs,
particularly for a unique observer (Section 7.2.1.2).
Validating location ensures that the Device is at or near the
resulting location. Location validation can be used to limit or
prevent all of the attacks identified in this document.
7.2.2.2. Limitations
The trusted location that is used for validation is always less
accurate than the location that is being checked. The amount by
which the untrusted location is more accurate, is the same amount
that an attacker can exploit.
For example, a trusted location might indicate an uncertainty region
with a radius of five kilometers. An untrusted location that
describes a 100-meter uncertainty within the larger region might be
accepted as more accurate. An attacker might still falsify
measurement data to select any location within the larger uncertainty
region. While the 100-meter uncertainty that is reported seems more
accurate, a falsified location could be anywhere in the
five-kilometer region.
Where measurement data might have been falsified, the actual
uncertainty is effectively much higher. Local policy might allow
differing degrees of trust to location information derived from
untrusted measurement data. This might be a boolean operation with
only two possible outcomes: untrusted location information might be
used entirely or not at all. Alternatively, untrusted location
information could be combined with trusted location information using
different weightings, based on a value set in local policy.
7.2.3. Supporting Observations
Replay attacks using previously acquired measurement data are
particularly hard to detect without independent validation. Rather
than validate the measurement data directly, supplementary data might
be used to validate measurements or the location information derived
from those measurements.
These supporting observations could be used to convey information
that provides additional assurance that measurement data from the
Device was acquired at a specific time and place. In effect, the
Device is requested to provide proof of its presence at the resulting
location.
For instance, a Device that measures attributes of a radio signal
could also be asked to provide a sample of the measured radio signal.
If the LIS is able to observe the same signal, the two observations
could be compared. Providing that the signal cannot be predicted in
advance by the Device, this could be used to support the claim that
the Device is able to receive the signal. Thus, the Device is likely
to be within the range that the signal is transmitted. A LIS could
use this to attribute a higher level of trust in the associated
measurement data or resulting location.
7.2.3.1. Effectiveness
The use of supporting observations is limited by the ability of the
LIS to acquire and validate these observations. The advantage of
selecting observations independent of measurement data is that
observations can be selected based on how readily available the data
is for both LIS and Device. The amount and quality of the data can
be selected based on the degree of assurance that is desired.
The use of supporting observations is similar to both measurement
validation and location validation. All three methods rely on
independent validation of one or more properties. The applicability
of each method is similar.
The use of supporting observations can be used to limit or prevent
all of the attacks identified in this document.
7.2.3.2. Limitations
The effectiveness of the validation method depends on the quality of
the supporting observation: how hard it is for the entity performing
the validation to obtain the data at a different time or place, how
difficult it is to guess, and what other costs might be involved in
acquiring this data.
In the example of an observed radio signal, requesting a sample of
the signal only provides an assurance that the Device is able to
receive the signal transmitted by the measured radio transmitter.
This only provides some assurance that the Device is within range of
the transmitter.
As with location validation, a Device might still be able to provide
falsified measurements that could alter the value of the location
information as long as the result is within this region.
Requesting additional supporting observations can reduce the size of
the region over which location information can be altered by an
attacker, or increase trust in the result, but each additional
measurement imposes an acquisition cost. Supporting observations
contribute little or nothing toward the primary goal of determining
the location of the Device.
7.2.4. Attribution
Lying by proxy (Section 7.1.4) relies on the location recipient being
able to attribute location information to a LIS. The effectiveness
of this attack is negated if location information is explicitly
attributed to a particular source.
This requires an extension to the location object that explicitly
identifies the source (or sources) of each item of location
information.
Rather than relying on a process that seeks to ensure that location
information is accurate, this approach instead provides a location
recipient with the information necessary to reach their own
conclusion about the trustworthiness of the location information.
Including an authenticated identity for all sources of measurement
data presents a number of technical and operational challenges. It
is possible that the LIS has a transient relationship with a Device.
A Device is not expected to share authentication information with a
LIS. There is no assurance that Device identification is usable by a
potential location recipient. Privacy concerns might also prevent
the sharing of identification information, even if it were available
and usable.
Identifying the type of measurement source allows a location
recipient to make a decision about the trustworthiness of location
information without depending on having authenticated identity
information for each source. An element for this purpose is defined
in Section 4.4.
When including location information that is based on measurement data
from sources that might be untrusted, a LIS SHOULD include
alternative location information that is derived from trusted sources
of measurement data. Each item of location information can then be
labeled with the source of that data.
A location recipient that is able to identify a specific source of
measurement data (whether it be LIS or Device) can use this
information to attribute location information to either entity or to
both entities. The location recipient is then better able to make
decisions about trustworthiness based on the source of the data.
A location recipient that does not understand the "source" element is
unable to make this distinction. When constructing a PIDF-LO
document, trusted location information MUST be placed in the PIDF-LO
so that it is given higher priority to any untrusted location
information according to Rule #8 of [RFC5491].
Attribution of information does nothing to address attacks that alter
the observed parameters that are used in location determination
(Section 7.1.6).
7.2.5. Stateful Correlation of Location Requests
Stateful examination of requests can be used to prevent a Device from
attempting to map network topology using requests for location
information (Section 7.1.2).
Simply limiting the rate of requests from a single Device reduces the
amount of data that a Device can acquire about network topology. A
LIS could also make observations about the movements of a Device. A
Device that is attempting to gather topology information is likely to
be assigned a location that changes significantly between subsequent
requests, possibly violating physical laws (or lower limits that
might still be unlikely) with respect to speed and acceleration.
7.3. An Unauthorized or Compromised LIS
A compromised LIS, or a compromise in LIS discovery [RFC5986], could
lead to an unauthorized entity obtaining measurement data. This
information could then be used or redistributed. A Device MUST
ensure that it authenticates a LIS, as described in Section 9 of
[RFC5985].
An entity that is able to acquire measurement data can, in addition
to using those measurements to learn the location of a Device, also
use that information for other purposes. This information can be
used to provide insight into network topology (Section 7.1.2).
Measurement data might also be exploited in other ways. For example,
revealing the type of 802.11 transceiver that a Device uses could
allow an attacker to use specific vulnerabilities to attack a Device.
Similarly, revealing information about network elements could enable
targeted attacks on that infrastructure.
8. Measurement Schemas
The schemas are broken up into their respective functions. A base
container schema into which all measurements are placed is defined,
including the definition of a measurement request (Section 8.1). A
PIDF-LO extension is defined in a separate schema (Section 8.2). A
basic Types Schema contains common definitions, including the
"rmsError" and "samples" attributes, plus types for IPv4, IPv6, and
MAC addresses (Section 8.3). Each of the specific measurement types
is defined in a separate schema.
8.1. Measurement Container Schema
<?xml version="1.0"?>
<xs:schema
xmlns:lm="urn:ietf:params:xml:ns:geopriv:lm"
xmlns:bt="urn:ietf:params:xml:ns:geopriv:lm:basetypes"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="urn:ietf:params:xml:ns:geopriv:lm"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:annotation>
<xs:appinfo
source="urn:ietf:params:xml:schema:geopriv:lm">
</xs:appinfo>
<xs:documentation
source="http://www.rfc-editor.org/rfc/rfc7105.txt">
This schema defines a framework for location measurements.
</xs:documentation>
</xs:annotation>
<xs:import namespace="urn:ietf:params:xml:ns:geopriv:lm:basetypes"/>
<xs:element name="measurements">
<xs:complexType>
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="time" type="xs:dateTime"/>
<xs:attribute name="timeError" type="bt:positiveDouble"/>
<xs:attribute name="expires" type="xs:dateTime"/>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
</xs:element>
<xs:element name="measurementRequest"
type="lm:measurementRequestType"/>
<xs:complexType name="measurementRequestType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element ref="lm:measurement"
minOccurs="0" maxOccurs="unbounded"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:element name="measurement" type="lm:measurementType"/>
<xs:complexType name="measurementType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="type" type="xs:QName" use="required"/>
<xs:attribute name="samples" type="xs:positiveInteger"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<!-- PIDF-LO extension for source -->
<xs:element name="source" type="lm:sourceType"/>
<xs:simpleType name="sourceType">
<xs:list>
<xs:simpleType>
<xs:restriction base="xs:token">
<xs:enumeration value="lis"/>
<xs:enumeration value="device"/>
<xs:enumeration value="other"/>
</xs:restriction>
</xs:simpleType>
</xs:list>
</xs:simpleType>
</xs:schema>
Measurement Container Schema
8.2. Measurement Source Schema
<?xml version="1.0"?>
<xs:schema
xmlns:lmsrc="urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:annotation>
<xs:appinfo
source="urn:ietf:params:xml:schema:pidf:geopriv10:lmsrc">
</xs:appinfo>
<xs:documentation
source="http://www.rfc-editor.org/rfc/rfc7105.txt">
This schema defines an extension to PIDF-LO that indicates
the type of measurement source that produced the measurement
data used in generating the associated location information.
</xs:documentation>
</xs:annotation>
<xs:element name="source" type="lmsrc:sourceType"/>
<xs:simpleType name="sourceType">
<xs:list>
<xs:simpleType>
<xs:restriction base="xs:token">
<xs:enumeration value="lis"/>
<xs:enumeration value="device"/>
<xs:enumeration value="other"/>
</xs:restriction>
</xs:simpleType>
</xs:list>
</xs:simpleType>
</xs:schema>
Measurement Source PIDF-LO Extension Schema
8.3. Base Types Schema
Note that the pattern rules in the following schema wrap due to
length constraints. None of the patterns contain whitespace.
<?xml version="1.0"?>
<xs:schema
xmlns:bt="urn:ietf:params:xml:ns:geopriv:lm:basetypes"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="urn:ietf:params:xml:ns:geopriv:lm:basetypes"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:annotation>
<xs:appinfo
source="urn:ietf:params:xml:schema:geopriv:lm:basetypes">
</xs:appinfo>
<xs:documentation
source="http://www.rfc-editor.org/rfc/rfc7105.txt">
This schema defines a set of base type elements.
</xs:documentation>
</xs:annotation>
<xs:simpleType name="byteType">
<xs:restriction base="xs:integer">
<xs:minInclusive value="0"/>
<xs:maxInclusive value="255"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="twoByteType">
<xs:restriction base="xs:integer">
<xs:minInclusive value="0"/>
<xs:maxInclusive value="65535"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="nonNegativeDouble">
<xs:restriction base="xs:double">
<xs:minInclusive value="0.0"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="positiveDouble">
<xs:restriction base="bt:nonNegativeDouble">
<xs:minExclusive value="0.0"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="doubleWithRMSError">
<xs:simpleContent>
<xs:extension base="xs:double">
<xs:attribute name="rmsError" type="bt:positiveDouble"/>
<xs:attribute name="samples" type="xs:positiveInteger"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:complexType name="nnDoubleWithRMSError">
<xs:simpleContent>
<xs:restriction base="bt:doubleWithRMSError">
<xs:minInclusive value="0"/>
</xs:restriction>
</xs:simpleContent>
</xs:complexType>
<xs:simpleType name="ipAddressType">
<xs:union memberTypes="bt:IPv6AddressType bt:IPv4AddressType"/>
</xs:simpleType>
<!-- IPv6 format definition -->
<xs:simpleType name="IPv6AddressType">
<xs:annotation>
<xs:documentation>
An IP version 6 address, based on RFC 4291.
</xs:documentation>
</xs:annotation>
<xs:restriction base="xs:token">
<!-- Fully specified address -->
<xs:pattern value="[0-9A-Fa-f]{1,4}(:[0-9A-Fa-f]{1,4}){7}"/>
<!-- Double colon start -->
<xs:pattern value=":(:[0-9A-Fa-f]{1,4}){1,7}"/>
<!-- Double colon middle -->
<xs:pattern value="([0-9A-Fa-f]{1,4}:){1,6}
(:[0-9A-Fa-f]{1,4}){1}"/>
<xs:pattern value="([0-9A-Fa-f]{1,4}:){1,5}
(:[0-9A-Fa-f]{1,4}){1,2}"/>
<xs:pattern value="([0-9A-Fa-f]{1,4}:){1,4}
(:[0-9A-Fa-f]{1,4}){1,3}"/>
<xs:pattern value="([0-9A-Fa-f]{1,4}:){1,3}
(:[0-9A-Fa-f]{1,4}){1,4}"/>
<xs:pattern value="([0-9A-Fa-f]{1,4}:){1,2}
(:[0-9A-Fa-f]{1,4}){1,5}"/>
<xs:pattern value="([0-9A-Fa-f]{1,4}:){1}
(:[0-9A-Fa-f]{1,4}){1,6}"/>
<!-- Double colon end -->
<xs:pattern value="([0-9A-Fa-f]{1,4}:){1,7}:"/>
<!-- IPv4-Compatible and IPv4-Mapped Addresses -->
<xs:pattern value="((:(:0{1,4}){0,3}:[fF]{4})|(0{1,4}:
(:0{1,4}){0,2}:[fF]{4})|((0{1,4}:){2}
(:0{1,4})?:[fF]{4})|((0{1,4}:){3}:[fF]{4})
|((0{1,4}:){4}[fF]{4})):(25[0-5]|2[0-4][0-9]|
[0-1]?[0-9]?[0-9])\.(25[0-5]|2[0-4][0-9]|[0-1]
?[0-9]?[0-9])\.(25[0-5]|2[0-4][0-9]|[0-1]?
[0-9]?[0-9])\.(25[0-5]|2[0-4][0-9]|[0-1]?
[0-9]?[0-9])"/>
<!-- The unspecified address -->
<xs:pattern value="::"/>
</xs:restriction>
</xs:simpleType>
<!-- IPv4 format definition -->
<xs:simpleType name="IPv4AddressType">
<xs:restriction base="xs:token">
<xs:pattern value="(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])\.
(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])\.
(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])\.
(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]?[0-9])"/>
</xs:restriction>
</xs:simpleType>
<!-- MAC address (EUI-48) or EUI-64 address -->
<xs:simpleType name="macAddressType">
<xs:restriction base="xs:token">
<xs:pattern
value="[\da-fA-F]{2}(-[\da-fA-F]{2}){5}((-[\da-fA-F]{2}){2})?"/>
</xs:restriction>
</xs:simpleType>
</xs:schema>
Base Types Schema
8.4. LLDP Measurement Schema
<?xml version="1.0"?>
<xs:schema
xmlns:lldp="urn:ietf:params:xml:ns:geopriv:lm:lldp"
xmlns:bt="urn:ietf:params:xml:ns:geopriv:lm:basetypes"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="urn:ietf:params:xml:ns:geopriv:lm:lldp"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:annotation>
<xs:appinfo
source="urn:ietf:params:xml:schema:geopriv:lm:lldp">
</xs:appinfo>
<xs:documentation
source="http://www.rfc-editor.org/rfc/rfc7105.txt">
This schema defines a set of LLDP location measurements.
</xs:documentation>
</xs:annotation>
<xs:import namespace="urn:ietf:params:xml:ns:geopriv:lm:basetypes"/>
<xs:element name="lldp" type="lldp:lldpMeasurementType"/>
<xs:complexType name="lldpMeasurementType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="chassis" type="lldp:lldpDataType"/>
<xs:element name="port" type="lldp:lldpDataType"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="lldpDataType">
<xs:simpleContent>
<xs:extension base="lldp:lldpOctetStringType">
<xs:attribute name="type" type="bt:byteType"
use="required"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:simpleType name="lldpOctetStringType">
<xs:restriction base="xs:hexBinary">
<xs:minLength value="1"/>
<xs:maxLength value="255"/>
</xs:restriction>
</xs:simpleType>
</xs:schema>
LLDP Measurement Schema
8.5. DHCP Measurement Schema
<?xml version="1.0"?>
<xs:schema
xmlns:dhcp="urn:ietf:params:xml:ns:geopriv:lm:dhcp"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:bt="urn:ietf:params:xml:ns:geopriv:lm:basetypes"
targetNamespace="urn:ietf:params:xml:ns:geopriv:lm:dhcp"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:annotation>
<xs:appinfo
source="urn:ietf:params:xml:schema:geopriv:lm:dhcp">
</xs:appinfo>
<xs:documentation
source="http://www.rfc-editor.org/rfc/rfc7105.txt">
This schema defines a set of DHCP location measurements.
</xs:documentation>
</xs:annotation>
<xs:import namespace="urn:ietf:params:xml:ns:geopriv:lm:basetypes"/>
<!-- DHCP Relay Agent Information option -->
<xs:element name="dhcp-rai" type="dhcp:dhcpType"/>
<xs:complexType name="dhcpType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="giaddr" type="bt:ipAddressType"/>
<xs:element name="circuit"
type="xs:hexBinary" minOccurs="0"/>
<xs:element name="remote"
type="dhcp:dhcpRemoteType" minOccurs="0"/>
<xs:element name="subscriber"
type="xs:hexBinary" minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="dhcpRemoteType">
<xs:simpleContent>
<xs:extension base="xs:hexBinary">
<xs:attribute name="enterprise" type="xs:positiveInteger"
use="optional"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:schema>
DHCP Measurement Schema
8.6. WiFi Measurement Schema
<?xml version="1.0"?>
<xs:schema
xmlns:wifi="urn:ietf:params:xml:ns:geopriv:lm:wifi"
xmlns:bt="urn:ietf:params:xml:ns:geopriv:lm:basetypes"
xmlns:gml="http://www.opengis.net/gml"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="urn:ietf:params:xml:ns:geopriv:lm:wifi"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:annotation>
<xs:appinfo
source="urn:ietf:params:xml:schema:geopriv:lm:wifi">
802.11 location measurements
</xs:appinfo>
<xs:documentation
source="http://www.rfc-editor.org/rfc/rfc7105.txt">
This schema defines a basic set of 802.11 location
measurements.
</xs:documentation>
</xs:annotation>
<xs:import namespace="urn:ietf:params:xml:ns:geopriv:lm:basetypes"/>
<xs:import namespace="http://www.opengis.net/gml"/>
<xs:element name="wifi" type="wifi:wifiNetworkType"/>
<xs:complexType name="wifiNetworkType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="nicType" type="xs:token"
minOccurs="0"/>
<xs:element name="ap" type="wifi:wifiType"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="wifiType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="bssid" type="wifi:bssidType"/>
<xs:element name="ssid" type="wifi:ssidType"
minOccurs="0"/>
<xs:element name="channel" type="xs:nonNegativeInteger"
minOccurs="0"/>
<xs:element name="location" minOccurs="0"
type="xs:anyType"/>
<xs:element name="type" type="wifi:networkType"
minOccurs="0"/>
<xs:element name="regclass" type="wifi:regclassType"
minOccurs="0"/>
<xs:element name="antenna" type="wifi:octetType"
minOccurs="0"/>
<xs:element name="flightTime" minOccurs="0"
type="bt:nnDoubleWithRMSError"/>
<xs:element name="apSignal" type="wifi:signalType"
minOccurs="0"/>
<xs:element name="deviceSignal" type="wifi:signalType"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="serving" type="xs:boolean"
default="false"/>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="bssidType">
<xs:simpleContent>
<xs:extension base="bt:macAddressType">
<xs:attribute name="verified" type="xs:boolean"
default="false"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<!-- Note that this pattern does not prevent multibyte UTF-8
sequences that result in an SSID longer than 32 octets. -->
<xs:simpleType name="ssidType">
<xs:restriction base="xs:token">
<xs:pattern value="(\\[\da-fA-F]{2}|[^\\]){0,32}"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="networkType">
<xs:restriction base="xs:token">
<xs:pattern value="[a-zA-Z]+"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="regclassType">
<xs:simpleContent>
<xs:extension base="wifi:octetType">
<xs:attribute name="country">
<xs:simpleType>
<xs:restriction base="xs:token">
<xs:pattern value="[A-Z]{2}[OIX]?"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<xs:simpleType name="octetType">
<xs:restriction base="xs:nonNegativeInteger">
<xs:maxInclusive value="255"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="signalType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="transmit" type="xs:double"
minOccurs="0"/>
<xs:element name="gain" type="xs:double" minOccurs="0"/>
<xs:element name="rcpi" type="wifi:rssiType"
minOccurs="0"/>
<xs:element name="rsni" type="bt:doubleWithRMSError"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="rssiType">
<xs:simpleContent>
<xs:extension base="bt:doubleWithRMSError">
<xs:attribute name="dBm" type="xs:boolean" default="true"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<!-- Measurement Request elements -->
<xs:element name="type" type="wifi:networkType"/>
<xs:element name="parameter" type="wifi:parameterType"/>
<xs:complexType name="parameterType">
<xs:simpleContent>
<xs:extension base="xs:QName">
<xs:attribute name="context" use="optional">
<xs:simpleType>
<xs:restriction base="xs:token">
<xs:enumeration value="ap"/>
<xs:enumeration value="device"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:schema>
WiFi Measurement Schema
8.7. Cellular Measurement Schema
<?xml version="1.0"?>
<xs:schema
xmlns:cell="urn:ietf:params:xml:ns:geopriv:lm:cell"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="urn:ietf:params:xml:ns:geopriv:lm:cell"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:annotation>
<xs:appinfo
source="urn:ietf:params:xml:schema:geopriv:lm:cell">
</xs:appinfo>
<xs:documentation
source="http://www.rfc-editor.org/rfc/rfc7105.txt">
This schema defines a set of cellular location measurements.
</xs:documentation>
</xs:annotation>
<xs:element name="cellular" type="cell:cellularType"/>
<xs:complexType name="cellularType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:choice>
<xs:element name="servingCell" type="cell:cellType"/>
<xs:element name="observedCell" type="cell:cellType"/>
</xs:choice>
<xs:element name="observedCell" type="cell:cellType"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="cellType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:choice>
<xs:sequence>
<xs:element name="mcc" type="cell:mccType"/>
<xs:element name="mnc" type="cell:mncType"/>
<xs:choice>
<xs:sequence>
<xs:choice>
<xs:element name="rnc" type="cell:cellIdType"/>
<xs:element name="lac" type="cell:cellIdType"/>
</xs:choice>
<xs:element name="cid" type="cell:cellIdType"/>
</xs:sequence>
<xs:element name="eucid" type="cell:cellIdType"/>
</xs:choice>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:sequence>
<xs:element name="sid" type="cell:cellIdType"/>
<xs:element name="nid" type="cell:cellIdType"/>
<xs:element name="baseid" type="cell:cellIdType"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:choice>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:simpleType name="mccType">
<xs:restriction base="xs:token">
<xs:pattern value="[0-9]{3}"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="mncType">
<xs:restriction base="xs:token">
<xs:pattern value="[0-9]{2,3}"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="cellIdType">
<xs:restriction base="xs:nonNegativeInteger">
<xs:maxInclusive value="268435455"/> <!-- 2^28 (eucid) -->
</xs:restriction>
</xs:simpleType>
<!-- Measurement Request elements -->
<xs:element name="type" type="cell:typeType"/>
<xs:simpleType name="typeType">
<xs:restriction base="xs:token">
<xs:enumeration value="gsm"/>
<xs:enumeration value="umts"/>
<xs:enumeration value="lte"/>
<xs:enumeration value="cdma"/>
</xs:restriction>
</xs:simpleType>
<xs:element name="network" type="cell:networkType"/>
<xs:complexType name="networkType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:choice>
<xs:sequence>
<xs:element name="mcc" type="cell:mccType"/>
<xs:element name="mnc" type="cell:mncType"/>
</xs:sequence>
<xs:element name="nid" type="cell:cellIdType"/>
</xs:choice>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
</xs:schema>
Cellular Measurement Schema
8.8. GNSS Measurement Schema
<?xml version="1.0"?>
<xs:schema
xmlns:gnss="urn:ietf:params:xml:ns:geopriv:lm:gnss"
xmlns:bt="urn:ietf:params:xml:ns:geopriv:lm:basetypes"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="urn:ietf:params:xml:ns:geopriv:lm:gnss"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:annotation>
<xs:appinfo
source="urn:ietf:params:xml:schema:geopriv:lm:gnss">
</xs:appinfo>
<xs:documentation
source="http://www.rfc-editor.org/rfc/rfc7105.txt">
This schema defines a set of GNSS location measurements.
</xs:documentation>
</xs:annotation>
<xs:import namespace="urn:ietf:params:xml:ns:geopriv:lm:basetypes"/>
<!-- GNSS -->
<xs:element name="gnss" type="gnss:gnssMeasurementType">
<xs:unique name="gnssSatellite">
<xs:selector xpath="sat"/>
<xs:field xpath="@num"/>
</xs:unique>
</xs:element>
<xs:complexType name="gnssMeasurementType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="gnssTime" type="bt:nnDoubleWithRMSError"
minOccurs="0"/>
<xs:element name="sat" type="gnss:gnssSatelliteType"
minOccurs="1" maxOccurs="64"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="system" type="xs:token" use="required"/>
<xs:attribute name="signal" type="xs:token"/>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="gnssSatelliteType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="doppler" type="bt:doubleWithRMSError"/>
<xs:element name="codephase"
type="bt:nnDoubleWithRMSError"/>
<xs:element name="cn0" type="bt:nonNegativeDouble"/>
<xs:element name="mp" type="bt:positiveDouble"
minOccurs="0"/>
<xs:element name="cq" type="gnss:codePhaseQualityType"
minOccurs="0"/>
<xs:element name="adr" type="xs:double" minOccurs="0"/>
</xs:sequence>
<xs:attribute name="num" type="xs:positiveInteger"
use="required"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="codePhaseQualityType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:attribute name="continuous" type="xs:boolean"
default="true"/>
<xs:attribute name="direct" use="required">
<xs:simpleType>
<xs:restriction base="xs:token">
<xs:enumeration value="direct"/>
<xs:enumeration value="inverted"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
</xs:schema>
GNSS Measurement Schema
8.9. DSL Measurement Schema
<?xml version="1.0"?>
<xs:schema
xmlns:dsl="urn:ietf:params:xml:ns:geopriv:lm:dsl"
xmlns:bt="urn:ietf:params:xml:ns:geopriv:lm:basetypes"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="urn:ietf:params:xml:ns:geopriv:lm:dsl"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:annotation>
<xs:appinfo
source="urn:ietf:params:xml:schema:geopriv:lm:dsl">
DSL measurement definitions
</xs:appinfo>
<xs:documentation
source="http://www.rfc-editor.org/rfc/rfc7105.txt">
This schema defines a basic set of DSL location measurements.
</xs:documentation>
</xs:annotation>
<xs:import namespace="urn:ietf:params:xml:ns:geopriv:lm:basetypes"/>
<xs:element name="dsl" type="dsl:dslVlanType"/>
<xs:complexType name="dslVlanType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:choice>
<xs:element name="l2tp">
<xs:complexType>
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence>
<xs:element name="src" type="bt:ipAddressType"/>
<xs:element name="dest" type="bt:ipAddressType"/>
<xs:element name="session"
type="xs:nonNegativeInteger"/>
</xs:sequence>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
</xs:element>
<xs:sequence>
<xs:element name="an" type="xs:token"/>
<xs:group ref="dsl:dslSlotPort"/>
</xs:sequence>
<xs:sequence>
<xs:element name="stag" type="dsl:vlanIDType"/>
<xs:choice>
<xs:sequence>
<xs:element name="ctag" type="dsl:vlanIDType"/>
<xs:group ref="dsl:dslSlotPort" minOccurs="0"/>
</xs:sequence>
<xs:group ref="dsl:dslSlotPort"/>
</xs:choice>
</xs:sequence>
<xs:sequence>
<xs:element name="vpi" type="bt:byteType"/>
<xs:element name="vci" type="bt:twoByteType"/>
</xs:sequence>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:choice>
<xs:anyAttribute namespace="##other" processContents="lax"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:simpleType name="vlanIDType">
<xs:restriction base="xs:nonNegativeInteger">
<xs:maxInclusive value="4095"/>
</xs:restriction>
</xs:simpleType>
<xs:group name="dslSlotPort">
<xs:sequence>
<xs:element name="slot" type="xs:token"/>
<xs:element name="port" type="xs:token"/>
</xs:sequence>
</xs:group>
</xs:schema>
DSL Measurement Schema
9. IANA Considerations
This section creates a registry for GNSS types (Section 5.5) and
registers the namespaces and schemas defined in Section 8.
9.1. IANA Registry for GNSS Types
This document establishes a new IANA registry for "Global Navigation
Satellite System (GNSS)" types. The registry includes tokens for the
GNSS type and for each of the signals within that type. Referring to
[RFC5226], this registry operates under "Specification Required"
rules. The IESG will appoint an Expert Reviewer who will advise IANA
promptly on each request for a new or updated GNSS type.
Each entry in the registry requires the following information:
GNSS Name: the name of the GNSS
Brief Description: a brief description of the GNSS
GNSS Token: a token that can be used to identify the GNSS
Signals: a set of tokens that represent each of the signals that the
system provides
Documentation Reference: a reference to one or more stable, public
specifications that outline usage of the GNSS, including (but not
limited to) signal specifications and time systems
The registry initially includes two registrations:
GNSS Name: Global Positioning System (GPS)
Brief Description: a system of satellites that use spread-spectrum
transmission, operated by the US military for commercial and
military applications
GNSS Token: gps
Signals: L1, L2, L1C, L2C, L5
Documentation Reference: Navstar GPS Space Segment/Navigation User
Interface [GPS.ICD]
GNSS Name: Galileo
Brief Description: a system of satellites that operate in the same
spectrum as GPS, operated by the European Union for commercial
applications
GNSS Token: galileo
Signals: L1, E5A, E5B, E5A+B, E6
Documentation Reference: Galileo Open Service Signal In Space
Interface Control Document (SIS ICD) [Galileo.ICD]
9.2. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc
This section registers a new XML namespace,
"urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc", as per the guidelines
in [RFC3688].
URI: urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc
Registrant Contact: IETF, GEOPRIV working group
(geopriv@ietf.org), Martin Thomson (martin.thomson@gmail.com).
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>Measurement Source for PIDF-LO</title>
</head>
<body>
<h1>Namespace for Location Measurement Source</h1>
<h2>urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc</h2>
<p>See <a href="http://www.rfc-editor.org/rfc/rfc7105.txt">
RFC 7105</a>.</p>
</body>
</html>
END
9.3. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm
This section registers a new XML namespace,
"urn:ietf:params:xml:ns:geopriv:lm", as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:ns:geopriv:lm
Registrant Contact: IETF, GEOPRIV working group
(geopriv@ietf.org), Martin Thomson (martin.thomson@gmail.com).
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>Measurement Container</title>
</head>
<body>
<h1>Namespace for Location Measurement Container</h1>
<h2>urn:ietf:params:xml:ns:geopriv:lm</h2>
<p>See <a href="http://www.rfc-editor.org/rfc/rfc7105.txt">
RFC 7105</a>.</p>
</body>
</html>
END
9.4. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:basetypes
This section registers a new XML namespace,
"urn:ietf:params:xml:ns:geopriv:lm:basetypes", as per the guidelines
in [RFC3688].
URI: urn:ietf:params:xml:ns:geopriv:lm:basetypes
Registrant Contact: IETF, GEOPRIV working group
(geopriv@ietf.org), Martin Thomson (martin.thomson@gmail.com).
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>Base Device Types</title>
</head>
<body>
<h1>Namespace for Base Types</h1>
<h2>urn:ietf:params:xml:ns:geopriv:lm:basetypes</h2>
<p>See <a href="http://www.rfc-editor.org/rfc/rfc7105.txt">
RFC 7105</a>.</p>
</body>
</html>
END
9.5. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:lldp
This section registers a new XML namespace,
"urn:ietf:params:xml:ns:geopriv:lm:lldp", as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:ns:geopriv:lm:lldp
Registrant Contact: IETF, GEOPRIV working group
(geopriv@ietf.org), Martin Thomson (martin.thomson@gmail.com).
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>LLDP Measurement Set</title>
</head>
<body>
<h1>Namespace for LLDP Measurement Set</h1>
<h2>urn:ietf:params:xml:ns:geopriv:lm:lldp</h2>
<p>See <a href="http://www.rfc-editor.org/rfc/rfc7105.txt">
RFC 7105</a>.</p>
</body>
</html>
END
9.6. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:dhcp
This section registers a new XML namespace,
"urn:ietf:params:xml:ns:geopriv:lm:dhcp", as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:ns:geopriv:lm:dhcp
Registrant Contact: IETF, GEOPRIV working group
(geopriv@ietf.org), Martin Thomson (martin.thomson@gmail.com).
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>DHCP Measurement Set</title>
</head>
<body>
<h1>Namespace for DHCP Measurement Set</h1>
<h2>urn:ietf:params:xml:ns:geopriv:lm:dhcp</h2>
<p>See <a href="http://www.rfc-editor.org/rfc/rfc7105.txt">
RFC 7105</a>.</p>
</body>
</html>
END
9.7. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:wifi
This section registers a new XML namespace,
"urn:ietf:params:xml:ns:geopriv:lm:wifi", as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:ns:geopriv:lm:wifi
Registrant Contact: IETF, GEOPRIV working group
(geopriv@ietf.org), Martin Thomson (martin.thomson@gmail.com).
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>WiFi Measurement Set</title>
</head>
<body>
<h1>Namespace for WiFi Measurement Set</h1>
<h2>urn:ietf:params:xml:ns:geopriv:lm:wifi</h2>
<p>See <a href="http://www.rfc-editor.org/rfc/rfc7105.txt">
RFC 7105</a>.</p>
</body>
</html>
END
9.8. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:cell
This section registers a new XML namespace,
"urn:ietf:params:xml:ns:geopriv:lm:cell", as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:ns:geopriv:lm:cell
Registrant Contact: IETF, GEOPRIV working group
(geopriv@ietf.org), Martin Thomson (martin.thomson@gmail.com).
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>Cellular Measurement Set</title>
</head>
<body>
<h1>Namespace for Cellular Measurement Set</h1>
<h2>urn:ietf:params:xml:ns:geopriv:lm:cell</h2>
<p>See <a href="http://www.rfc-editor.org/rfc/rfc7105.txt">
RFC 7105</a>.</p>
</body>
</html>
END
9.9. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:gnss
This section registers a new XML namespace,
"urn:ietf:params:xml:ns:geopriv:lm:gnss", as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:ns:geopriv:lm:gnss
Registrant Contact: IETF, GEOPRIV working group
(geopriv@ietf.org), Martin Thomson (martin.thomson@gmail.com).
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>GNSS Measurement Set</title>
</head>
<body>
<h1>Namespace for GNSS Measurement Set</h1>
<h2>urn:ietf:params:xml:ns:geopriv:lm:gnss</h2>
<p>See <a href="http://www.rfc-editor.org/rfc/rfc7105.txt">
RFC 7105</a>.</p>
</body>
</html>
END
9.10. URN Sub-Namespace Registration for
urn:ietf:params:xml:ns:geopriv:lm:dsl
This section registers a new XML namespace,
"urn:ietf:params:xml:ns:geopriv:lm:dsl", as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:ns:geopriv:lm:dsl
Registrant Contact: IETF, GEOPRIV working group
(geopriv@ietf.org), Martin Thomson (martin.thomson@gmail.com).
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>DSL Measurement Set</title>
</head>
<body>
<h1>Namespace for DSL Measurement Set</h1>
<h2>urn:ietf:params:xml:ns:geopriv:lm:dsl</h2>
<p>See <a href="http://www.rfc-editor.org/rfc/rfc7105.txt">
RFC 7105</a>.</p>
</body>
</html>
END
9.11. XML Schema Registration for Measurement Source Schema
This section registers an XML schema as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:schema:pidf:geopriv10:lmsrc
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
Martin Thomson (martin.thomson@gmail.com).
Schema: The XML for this schema can be found in Section 8.2 of this
document.
9.12. XML Schema Registration for Measurement Container Schema
This section registers an XML schema as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:schema:geopriv:lm
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
Martin Thomson (martin.thomson@gmail.com).
Schema: The XML for this schema can be found in Section 8.1 of this
document.
9.13. XML Schema Registration for Base Types Schema
This section registers an XML schema as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:schema:geopriv:lm:basetypes
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
Martin Thomson (martin.thomson@gmail.com).
Schema: The XML for this schema can be found in Section 8.3 of this
document.
9.14. XML Schema Registration for LLDP Schema
This section registers an XML schema as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:schema:geopriv:lm:lldp
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
Martin Thomson (martin.thomson@gmail.com).
Schema: The XML for this schema can be found in Section 8.4 of this
document.
9.15. XML Schema Registration for DHCP Schema
This section registers an XML schema as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:schema:geopriv:lm:dhcp
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
Martin Thomson (martin.thomson@gmail.com).
Schema: The XML for this schema can be found in Section 8.5 of this
document.
9.16. XML Schema Registration for WiFi Schema
This section registers an XML schema as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:schema:geopriv:lm:wifi
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
Martin Thomson (martin.thomson@gmail.com).
Schema: The XML for this schema can be found in Section 8.6 of this
document.
9.17. XML Schema Registration for Cellular Schema
This section registers an XML schema as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:schema:geopriv:lm:cell
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
Martin Thomson (martin.thomson@gmail.com).
Schema: The XML for this schema can be found in Section 8.7 of this
document.
9.18. XML Schema Registration for GNSS Schema
This section registers an XML schema as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:schema:geopriv:lm:gnss
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
Martin Thomson (martin.thomson@gmail.com).
Schema: The XML for this schema can be found in Section 8.8 of this
document.
9.19. XML Schema Registration for DSL Schema
This section registers an XML schema as per the guidelines in
[RFC3688].
URI: urn:ietf:params:xml:schema:geopriv:lm:dsl
Registrant Contact: IETF, GEOPRIV working group (geopriv@ietf.org),
Martin Thomson (martin.thomson@gmail.com).
Schema: The XML for this schema can be found in Section 8.9 of this
document.
10. Acknowledgements
Thanks go to Simon Cox for his comments relating to terminology; his
comments have helped ensure that this document is aligned with
ongoing work in the Open Geospatial Consortium (OGC). Thanks to Neil
Harper for his review and comments on the GNSS sections of this
document. Thanks to Noor-E-Gagan Singh, Gabor Bajko, Russell Priebe,
and Khalid Al-Mufti for their significant input to, and suggestions
for, improving the 802.11 measurements. Thanks to Cullen Jennings
for feedback and suggestions. Bernard Aboba provided review and
feedback on a range of measurement data definitions. Mary Barnes and
Geoff Thompson provided a review and corrections. David Waitzman and
John Bressler both noted shortcomings with 802.11 measurements.
Keith Drage and Darren Pawson provided expert LTE knowledge.
11. References
11.1. Normative References
[ASCII] ANSI, "US-ASCII. Coded Character Set - 7-Bit American
Standard Code for Information Interchange. Standard ANSI
X3.4-1986", 1986.
[GPS.ICD] "Navstar GPS Space Segment/Navigation User Interface", ICD
GPS-200, April 2000.
[Galileo.ICD]
GJU, "Galileo Open Service Signal In Space Interface
Control Document (SIS ICD)", May 2006.
[IANA.enterprise]
IANA, "Private Enterprise Numbers", 2013, 2014,
<http://www.iana.org/assignments/enterprise-numbers>.
[IEEE.80211]
IEEE, "Wireless LAN Medium Access Control (MAC) and
Physical Layer (PHY) Specifications", IEEE Std
802.11-2012, March 2012.
[IEEE.8021AB]
IEEE, "IEEE Standard for Local and Metropolitan Area
Networks, Station and Media Access Control Connectivity
Discovery", IEEE Std 802.1AB-2009, September 2009.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3046] Patrick, M., "DHCP Relay Agent Information Option", RFC
3046, January 2001.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, November 2003.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, RFC
3986, January 2005.
[RFC3993] Johnson, R., Palaniappan, T., and M. Stapp, "Subscriber-ID
Suboption for the Dynamic Host Configuration Protocol
(DHCP) Relay Agent Option", RFC 3993, March 2005.
[RFC4119] Peterson, J., "A Presence-based GEOPRIV Location Object
Format", RFC 4119, December 2005.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, February 2006.
[RFC4580] Volz, B., "Dynamic Host Configuration Protocol for IPv6
(DHCPv6) Relay Agent Subscriber-ID Option", RFC 4580, June
2006.
[RFC4649] Volz, B., "Dynamic Host Configuration Protocol for IPv6
(DHCPv6) Relay Agent Remote-ID Option", RFC 4649, August
2006.
[RFC5491] Winterbottom, J., Thomson, M., and H. Tschofenig, "GEOPRIV
Presence Information Data Format Location Object (PIDF-LO)
Usage Clarification, Considerations, and Recommendations",
RFC 5491, March 2009.
[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
Address Text Representation", RFC 5952, August 2010.
[RFC5985] Barnes, M., "HTTP-Enabled Location Delivery (HELD)", RFC
5985, September 2010.
[RFC5986] Thomson, M. and J. Winterbottom, "Discovering the Local
Location Information Server (LIS)", RFC 5986, September
2010.
[TIA-2000.5]
TIA/EIA, "Upper Layer (Layer 3) Signaling Standard for
cdma2000(R) Spread Spectrum Systems", TR-45.5 / TSG-C
TIA-2000.5-E / C.S0005-E v1.0, September 2009.
[TS.3GPP.23.003]
3GPP, "Numbering, addressing and identification", 3GPP TS
23.003 12.0.0, September 2013,
<http://www.3gpp.org/ftp/Specs/html-info/23003.htm>.
11.2. Informative References
[ANSI-TIA-1057]
ANSI/TIA, "Link Layer Discovery Protocol for Media
Endpoint Devices", TIA 1057, April 2006.
[DSL.TR025]
Wang, R., "Core Network Architecture Recommendations for
Access to Legacy Data Networks over ADSL", September 1999.
[DSL.TR101]
Cohen, A. and E. Shrum, "Migration to Ethernet-Based DSL
Aggregation", April 2006.
[GPS.SPOOF]
Scott, L., "Anti-Spoofing and Authenticated Signal
Architectures for Civil Navigation Signals", ION-GNSS
Portland, Oregon, 2003.
[HARPER] Harper, N., "Server-side GPS and Assisted-GPS in Java",
December 2009.
[RFC2661] Townsley, W., Valencia, A., Rubens, A., Pall, G., Zorn,
G., and B. Palter, "Layer Two Tunneling Protocol "L2TP"",
RFC 2661, August 1999.
[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)", RFC
2865, June 2000.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
January 2004.
[RFC3693] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and
J. Polk, "Geopriv Requirements", RFC 3693, February 2004.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC6155] Winterbottom, J., Thomson, M., Tschofenig, H., and R.
Barnes, "Use of Device Identity in HTTP-Enabled Location
Delivery (HELD)", RFC 6155, March 2011.
[RFC6280] Barnes, R., Lepinski, M., Cooper, A., Morris, J.,
Tschofenig, H., and H. Schulzrinne, "An Architecture for
Location and Location Privacy in Internet Applications",
BCP 160, RFC 6280, July 2011.
Authors' Addresses
Martin Thomson
Mozilla
Suite 300
650 Castro Street
Mountain View, CA 94041
US
EMail: martin.thomson@gmail.com
James Winterbottom
Unaffiliated
AU
EMail: a.james.winterbottom@gmail.com