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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 GEOPRIV M. Thomson 3 Internet-Draft J. Winterbottom 4 Intended status: Standards Track Andrew 5 Expires: April 28, 2011 October 25, 2010 7 Using Device-provided Location-Related Measurements in Location 8 Configuration Protocols 9 draft-ietf-geopriv-held-measurements-02 11 Abstract 13 A method is described by which a Device is able to provide location- 14 related measurement data to a LIS within a request for location 15 information. Location-related measurement information are 16 observations concerning properties related to the position of a 17 Device, which could be data about network attachment or about the 18 physical environment. When a LIS generates location information for 19 a Device, information from the Device can improve the accuracy of the 20 location estimate. A basic set of location-related measurements are 21 defined, including common modes of network attachment as well as 22 assisted Global Navigation Satellite System (GNSS) parameters. 24 Status of this Memo 26 This Internet-Draft is submitted in full conformance with the 27 provisions of BCP 78 and BCP 79. 29 Internet-Drafts are working documents of the Internet Engineering 30 Task Force (IETF). Note that other groups may also distribute 31 working documents as Internet-Drafts. The list of current Internet- 32 Drafts is at http://datatracker.ietf.org/drafts/current/. 34 Internet-Drafts are draft documents valid for a maximum of six months 35 and may be updated, replaced, or obsoleted by other documents at any 36 time. It is inappropriate to use Internet-Drafts as reference 37 material or to cite them other than as "work in progress." 39 This Internet-Draft will expire on April 28, 2011. 41 Copyright Notice 43 Copyright (c) 2010 IETF Trust and the persons identified as the 44 document authors. All rights reserved. 46 This document is subject to BCP 78 and the IETF Trust's Legal 47 Provisions Relating to IETF Documents 48 (http://trustee.ietf.org/license-info) in effect on the date of 49 publication of this document. Please review these documents 50 carefully, as they describe your rights and restrictions with respect 51 to this document. Code Components extracted from this document must 52 include Simplified BSD License text as described in Section 4.e of 53 the Trust Legal Provisions and are provided without warranty as 54 described in the Simplified BSD License. 56 This document may contain material from IETF Documents or IETF 57 Contributions published or made publicly available before November 58 10, 2008. The person(s) controlling the copyright in some of this 59 material may not have granted the IETF Trust the right to allow 60 modifications of such material outside the IETF Standards Process. 61 Without obtaining an adequate license from the person(s) controlling 62 the copyright in such materials, this document may not be modified 63 outside the IETF Standards Process, and derivative works of it may 64 not be created outside the IETF Standards Process, except to format 65 it for publication as an RFC or to translate it into languages other 66 than English. 68 Table of Contents 70 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 6 71 2. Conventions used in this document . . . . . . . . . . . . . . 6 72 3. Location-Related Measurements in LCPs . . . . . . . . . . . . 7 73 4. Location-Related Measurement Data Types . . . . . . . . . . . 8 74 4.1. Measurement Container . . . . . . . . . . . . . . . . . . 9 75 4.1.1. Time of Measurement . . . . . . . . . . . . . . . . . 9 76 4.1.2. Expiry Time on Location-Related Measurement Data . . . 9 77 4.2. RMS Error and Number of Samples . . . . . . . . . . . . . 10 78 4.2.1. Time RMS Error . . . . . . . . . . . . . . . . . . . . 10 79 4.3. Measurement Request . . . . . . . . . . . . . . . . . . . 11 80 4.4. Identifying Location Provenance . . . . . . . . . . . . . 12 81 5. Location-Related Measurement Data Types . . . . . . . . . . . 15 82 5.1. LLDP Measurements . . . . . . . . . . . . . . . . . . . . 15 83 5.2. DHCP Relay Agent Information Measurements . . . . . . . . 16 84 5.3. 802.11 WLAN Measurements . . . . . . . . . . . . . . . . . 16 85 5.3.1. Wifi Measurement Requests . . . . . . . . . . . . . . 20 86 5.4. Cellular Measurements . . . . . . . . . . . . . . . . . . 20 87 5.4.1. Cellular Measurement Requests . . . . . . . . . . . . 23 88 5.5. GNSS Measurements . . . . . . . . . . . . . . . . . . . . 23 89 5.5.1. GNSS System and Signal . . . . . . . . . . . . . . . . 25 90 5.5.2. Time . . . . . . . . . . . . . . . . . . . . . . . . . 26 91 5.5.3. Per-Satellite Measurement Data . . . . . . . . . . . . 26 92 5.5.4. GNSS Measurement Requests . . . . . . . . . . . . . . 27 93 5.6. DSL Measurements . . . . . . . . . . . . . . . . . . . . . 27 94 5.6.1. L2TP Measurements . . . . . . . . . . . . . . . . . . 28 95 5.6.2. RADIUS Measurements . . . . . . . . . . . . . . . . . 28 96 5.6.3. Ethernet VLAN Tag Measurements . . . . . . . . . . . . 29 97 5.6.4. ATM Virtual Circuit Measurements . . . . . . . . . . . 29 98 6. Privacy Considerations . . . . . . . . . . . . . . . . . . . . 29 99 6.1. Measurement Data Privacy Model . . . . . . . . . . . . . . 30 100 6.2. LIS Privacy Requirements . . . . . . . . . . . . . . . . . 30 101 6.3. Measurement Data and Location URIs . . . . . . . . . . . . 30 102 6.4. Third-Party-Provided Measurement Data . . . . . . . . . . 31 103 7. Security Considerations . . . . . . . . . . . . . . . . . . . 31 104 7.1. Threat Model . . . . . . . . . . . . . . . . . . . . . . . 31 105 7.1.1. Acquiring Location Information Without 106 Authorization . . . . . . . . . . . . . . . . . . . . 32 107 7.1.2. Extracting Network Topology Data . . . . . . . . . . . 33 108 7.1.3. Lying By Proxy . . . . . . . . . . . . . . . . . . . . 33 109 7.1.4. Measurement Replay . . . . . . . . . . . . . . . . . . 34 110 7.1.5. Environment Spoofing . . . . . . . . . . . . . . . . . 35 111 7.2. Mitigation . . . . . . . . . . . . . . . . . . . . . . . . 36 112 7.2.1. Measurement Validation . . . . . . . . . . . . . . . . 37 113 7.2.1.1. Effectiveness . . . . . . . . . . . . . . . . . . 37 114 7.2.1.2. Limitations (Unique Observer) . . . . . . . . . . 37 115 7.2.2. Location Validation . . . . . . . . . . . . . . . . . 38 116 7.2.2.1. Effectiveness . . . . . . . . . . . . . . . . . . 39 117 7.2.2.2. Limitations . . . . . . . . . . . . . . . . . . . 39 118 7.2.3. Supporting Observations . . . . . . . . . . . . . . . 39 119 7.2.3.1. Effectiveness . . . . . . . . . . . . . . . . . . 40 120 7.2.3.2. Limitations . . . . . . . . . . . . . . . . . . . 40 121 7.2.4. Attribution . . . . . . . . . . . . . . . . . . . . . 41 122 7.2.5. Stateful Correlation of Location Requests . . . . . . 42 123 8. Measurement Schemas . . . . . . . . . . . . . . . . . . . . . 42 124 8.1. Measurement Container Schema . . . . . . . . . . . . . . . 42 125 8.2. Measurement Source Schema . . . . . . . . . . . . . . . . 45 126 8.3. Base Type Schema . . . . . . . . . . . . . . . . . . . . . 45 127 8.4. LLDP Measurement Schema . . . . . . . . . . . . . . . . . 48 128 8.5. DHCP Measurement Schema . . . . . . . . . . . . . . . . . 49 129 8.6. WiFi Measurement Schema . . . . . . . . . . . . . . . . . 51 130 8.7. Cellular Measurement Schema . . . . . . . . . . . . . . . 54 131 8.8. GNSS Measurement Schema . . . . . . . . . . . . . . . . . 57 132 8.9. DSL Measurement Schema . . . . . . . . . . . . . . . . . . 58 133 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 60 134 9.1. IANA Registry for GNSS Types . . . . . . . . . . . . . . . 60 135 9.2. URN Sub-Namespace Registration for 136 urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc . . . . . . . 61 137 9.3. URN Sub-Namespace Registration for 138 urn:ietf:params:xml:ns:geopriv:lm . . . . . . . . . . . . 62 139 9.4. URN Sub-Namespace Registration for 140 urn:ietf:params:xml:ns:geopriv:lm:basetypes . . . . . . . 63 141 9.5. URN Sub-Namespace Registration for 142 urn:ietf:params:xml:ns:geopriv:lm:lldp . . . . . . . . . . 64 143 9.6. URN Sub-Namespace Registration for 144 urn:ietf:params:xml:ns:geopriv:lm:dhcp . . . . . . . . . . 64 145 9.7. URN Sub-Namespace Registration for 146 urn:ietf:params:xml:ns:geopriv:lm:wifi . . . . . . . . . . 65 147 9.8. URN Sub-Namespace Registration for 148 urn:ietf:params:xml:ns:geopriv:lm:cell . . . . . . . . . . 66 149 9.9. URN Sub-Namespace Registration for 150 urn:ietf:params:xml:ns:geopriv:lm:gnss . . . . . . . . . . 66 151 9.10. URN Sub-Namespace Registration for 152 urn:ietf:params:xml:ns:geopriv:lm:dsl . . . . . . . . . . 67 153 9.11. XML Schema Registration for Measurement Source Schema . . 68 154 9.12. XML Schema Registration for Measurement Container 155 Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 68 156 9.13. XML Schema Registration for Base Types Schema . . . . . . 68 157 9.14. XML Schema Registration for LLDP Schema . . . . . . . . . 68 158 9.15. XML Schema Registration for DHCP Schema . . . . . . . . . 69 159 9.16. XML Schema Registration for WiFi Schema . . . . . . . . . 69 160 9.17. XML Schema Registration for Cellular Schema . . . . . . . 69 161 9.18. XML Schema Registration for GNSS Schema . . . . . . . . . 70 162 9.19. XML Schema Registration for DSL Schema . . . . . . . . . . 70 163 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 70 164 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 70 165 11.1. Normative References . . . . . . . . . . . . . . . . . . . 70 166 11.2. Informative References . . . . . . . . . . . . . . . . . . 71 167 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 73 169 1. Introduction 171 A location configuration protocol (LCP) provides a means for a Device 172 to request information about its physical location from an access 173 network. A location information server (LIS) is the server that 174 provides location information; information that is available due to 175 the knowledge about the network and physical environment that is 176 available to the LIS. 178 As a part of the access network, the LIS is able to acquire 179 measurement results from network Devices within the network that are 180 related to Device location. The LIS also has access to information 181 about the network topology that can be used to turn measurement data 182 into location information. However, this information can be enhanced 183 with information acquired from the Device itself. 185 A Device is able to make observations about its network attachment, 186 or its physical environment. The location-related measurement data 187 might be unavailable to the LIS; alternatively, the LIS might be able 188 to acquire the data, but at a higher cost in time or otherwise. 189 Providing measurement data gives the LIS more options in determining 190 location, which could improve the quality of the service provided by 191 the LIS. Improvements in accuracy are one potential gain, but 192 improved response times and lower error rates are also possible. 194 This document describes a means for a Device to report location- 195 related measurement data to the LIS. Examples based on the HELD 196 [I-D.ietf-geopriv-http-location-delivery] location configuration 197 protocol are provided. 199 2. Conventions used in this document 201 The terms LIS and Device are used in this document in a manner 202 consistent with the usage in 203 [I-D.ietf-geopriv-http-location-delivery]. 205 This document also uses the following definitions: 207 Location Measurement: An observation about the physical properties 208 of a particular Device's network access. The result of a location 209 measurement--"location-related measurement data", or simply 210 "measurement data" given sufficient context--can be used to 211 determine the location of a Device. Location-related measurement 212 data does not identify a Device; measurement data can change with 213 time if the location of the Device also changes. 215 Location-related measurement data does not necessarily contain 216 location information directly, but it can be used in combination 217 with contextual knowledge of the network, or algorithms to derive 218 location information. Examples of location-related measurement 219 data are: radio signal strength or timing measurements, Ethernet 220 switch and port identifiers. 222 Location-related measurement data can be considered sighting 223 information, based on the definition in [RFC3693]. 225 Location Estimate: The result of location determination, a location 226 estimate is an approximation of where the Device is located. 227 Location estimates are subject to uncertainty, which arise from 228 errors in measurement results. 230 GNSS: Global Navigation Satellite System. A satellite-based system 231 that provides positioning and time information. For example, the 232 US Global Positioning System (GPS) or the European Galileo system. 234 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 235 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 236 document are to be interpreted as described in [RFC2119]. 238 3. Location-Related Measurements in LCPs 240 This document defines a standard container for the conveyance of 241 location-related measurement parameters in location configuration 242 protocols. This is an XML container that identifies parameters by 243 type and allows the Device to provide the results of any measurement 244 it is able to perform. A set of measurement schemas are also defined 245 that can be carried in the generic container. 247 The simplest example of measurement data conveyance is illustrated by 248 the example message in Figure 1. This shows a HELD location request 249 message with an Ethernet switch and port measurement taken using LLDP 250 [IEEE.8021AB]. 252 253 civic 254 256 257 0a01003c 258 c2 259 260 261 262 Figure 1: HELD Location Request with Measurement Data 264 Measurement data that the LIS does not support or understand can be 265 ignored. The measurements defined in this document follow this rule; 266 extensions that could result in backward incompatibility MUST be 267 added as new measurement definitions rather than extensions to 268 existing types. 270 Multiple sets of measurement data, either of the same type or from 271 different sources can be included in the "measurements" element. See 272 Section 4.1.1 for details on repetition of this element. 274 Use of location-related measurement data is at the discretion of the 275 LIS, but the "method" parameter in the PIDF-LO SHOULD be adjusted to 276 reflect the method used. 278 Location-related measurement data need not be provided exclusively by 279 Devices. A third party location requester can request location 280 information using measurement data, if they are able and authorized. 281 There are privacy considerations relating to the use of measurements 282 by third parties, which are discussed in Section 6.4. 284 Location-related measurement data and its use presents a number of 285 security challenges. These are described in more detail in 286 Section 7. 288 4. Location-Related Measurement Data Types 290 A common container is defined for the expression of location 291 measurement data, as well as a simple means of identifying specific 292 types of measurement data for the purposes of requesting them. 294 The following example shows a measurement container with measurement 295 time and expiration time included. A WiFi measurement is enclosed. 297 300 301 302 00-12-F0-A0-80-EF 303 wlan-home 304 305 306 308 Figure 2: Measurement Example 310 4.1. Measurement Container 312 The "measurement" element is used to encapsulate measurement data 313 that is collected at a certain point in time. It contains time-based 314 attributes that are common to all forms of measurement data, and 315 permits the inclusion of arbitrary measurement data. 317 This container can be added to any request for location information, 318 such as a HELD location request 319 [I-D.ietf-geopriv-http-location-delivery]. 321 4.1.1. Time of Measurement 323 The "time" attribute records the time that the measurement or 324 observation was made. This time can be different to the time that 325 the measurement information was reported. Time information can be 326 used to populate a timestamp on the location result, or to determine 327 if the measurement information is used. 329 The "time" attribute is optional to avoid forcing an arbitrary choice 330 of timestamp for relatively static types of measurement (for 331 instance, the DSL measurements in Section 5.6) and for legacy Devices 332 that don't record time information (such as the Home Location 333 Register/Home Subscriber Server for cellular). However, time SHOULD 334 be provided whenever possible. 336 The "time" attribute is attached to the root "measurement" element. 337 If it is necessary to provide multiple sets of measurement data with 338 different times, multiple "measurement" elements SHOULD be provided. 340 4.1.2. Expiry Time on Location-Related Measurement Data 342 A Device is able to indicate an expiry time in the location 343 measurement using the "expires" attribute. Nominally, this attribute 344 indicates how long information is expected to be valid for, but it 345 can also indicate a time limit on the retention and use of the 346 measurement data. A Device can use this attribute to prevent the LIS 347 from retaining measurement data or limit the time that a LIS retains 348 this information. 350 Note: Movement of a Device might result in the measurement data 351 being invalidated before the expiry time. 353 The LIS MUST NOT keep location-related measurement data beyond the 354 time indicated in the "expires" attribute. 356 4.2. RMS Error and Number of Samples 358 Often a measurement is taken more than once over a period of time. 359 Reporting the average of a number of measurement results mitigates 360 the effects of random errors that occur in the measurement process. 362 Reporting each measurement individually can be the most effective 363 method of reporting multiple measurements. This is achieved by 364 providing multiple "measurement" elements for different times. 366 The alternative is to aggregate multiple measurements and report a 367 mean value across the set of measurements. Additional information 368 about the distribution of the results can be useful in determining 369 location uncertainty. 371 Two optional attributes are provided for certain measurement values: 373 rmsError: The root-mean-squared (RMS) error of the set of 374 measurement values used in calculating the result. RMS error is 375 expressed in the same units as the measurement, unless otherwise 376 stated. If an accurate value for RMS error is not known, this 377 value can be used to indicate an upper bound or estimate for the 378 RMS error. 380 samples: The number of samples that were taken in determining the 381 measurement value. If omitted, this value can be assumed to be a 382 very large value, so that the RMS error is an indication of the 383 standard deviation of the sample set. 385 For some measurement techniques, measurement error is largely 386 dependent on the measurement technique employed. In these cases, 387 measurement error is largely a product of the measurement technique 388 and not the specific circumstances, so RMS error does not need to be 389 actively measured. A fixed value MAY be provided for RMS error where 390 appropriate. 392 The "rmsError" and "samples" elements are added as attributes of 393 specific measurement data types. 395 4.2.1. Time RMS Error 397 Measurement of time can be significant in certain circumstances. The 398 GNSS measurements included in this document are one such case where a 399 small error in time can result in a large error in location. Factors 400 such as clock drift and errors in time sychronization can result in 401 small, but significant, time errors. Including an indication of the 402 quality of the time can be helpful. 404 An optional "timeError" attribute can be added to the "measurement" 405 element to indicate the RMS error in time. "timeError" indicates an 406 upper bound on the time RMS error in seconds. 408 The "timeError" attribute does not apply where multiple samples of a 409 measurement is taken over time. If multiple samples are taken, each 410 SHOULD be included in a different "measurement" element. 412 4.3. Measurement Request 414 A measurement request is used by a protocol peer to describe a set of 415 measurement data that it desires. A "measurementRequest" element is 416 defined that can be included in a protocol exchange. 418 For instance, a LIS can use a measurement request in HELD responses. 419 If the LIS is unable to provide location information, but it believes 420 that a particular measurement type would enable it to provide a 421 location, it can include a measurement request in an error response. 423 The "measurement" element of the measurement request identifies the 424 type of measurement that is requested. The "type" attribute of this 425 element indicates the type of measurement, as identified by an XML 426 qualified name. An optional "samples" attribute indicates how many 427 samples of the identified measurement are requested. 429 The "measurement" element can be repeated to request multiple (or 430 alternative) measurement types. 432 Additional XML content might be defined for a particular measurement 433 type that is used to further refine a request. These elements either 434 constrain what is requested or specify optional components of the 435 measurement data that are needed. These are defined along with the 436 specific measurement type. 438 In the HELD protocol, the inclusion of a measurement request in a 439 error response with a code of "locationUnknown" indicates that the 440 LIS believes that providing the indicated measurements would increase 441 the likelihood of a subsequent request being successful. 443 The following example shows a HELD error response that indicates that 444 WiFi measurement data would be useful if a later request were made. 445 Additional elements indicate that received signal strength for an 446 802.11n access point is requested. 448 450 Insufficient measurement data 451 454 455 n 456 wifi:rcpi 457 458 459 461 Figure 3: HELD Error Requesting Measurement Data 463 A measurement request that is included in other HELD messages has 464 undefined semantics and can be safely ignored. Other specifications 465 might define semantics for measurement requests under other 466 conditions. 468 4.4. Identifying Location Provenance 470 An extension is made to the PIDF-LO [RFC4119] that allows a location 471 recipient to identify the source (or sources) of location information 472 and the measurement data that was used to determine that location 473 information. 475 The "source" element is added to the "geopriv" element of the 476 PIDF-LO. This element does not identify specific entities. Instead, 477 it identifies the type of source. 479 The following types of measurement source are identified: 481 lis: Location information is based on measurement data that the LIS 482 or sources that it trusts have acquired. This label might be used 483 if measurement data provided by the Device has been completely 484 validated by the LIS. 486 device: Location information is based on measurement data that the 487 Device has provided to the LIS. 489 other: Location information is based on measurement data that a 490 third party has provided. This might be an authorized third party 491 that uses identity parameters 492 [I-D.ietf-geopriv-held-identity-extensions] or any other entity. 494 No assertion is made about the veracity of the measurement data from 495 sources other than the LIS. A combination of tags MAY be included to 496 indicate that measurement data from both sources was used. 498 For example, the first tuple of the following PIDF-LO indicates that 499 measurement data from a LIS and a device was combined to produce the 500 result, the second tuple was produced by the LIS alone. 502 508 509 510 511 512 513 7.34324 134.47162 514 515 850.24 516 517 518 519 520 OTDOA 521 lis device 522 523 524 525 526 527 528 529 530 7.34379 134.46484 531 532 9000 533 534 535 536 537 Cell 538 lis 539 540 541 542 544 5. Location-Related Measurement Data Types 546 This document defines location-related measurement data types for a 547 range of common network types. 549 All included measurement data definitions allow for arbitrary 550 extension in the corresponding schema. As new parameters that are 551 applicable to location determination are added, these can be added as 552 new XML elements in a unique namespace. Though many of the 553 underlying protocols support extension, creation of specific XML- 554 based extensions to the measurement format is favored over 555 accomodating protocol-specific extensions in generic containers. 557 5.1. LLDP Measurements 559 Link-Layer Discovery Protocol (LLDP) [IEEE.8021AB] messages are sent 560 between adjacent nodes in an IEEE 802 network (e.g. wired Ethernet, 561 WiFi, 802.16). These messages all contain identification information 562 for the sending node, which can be used to determine location 563 information. A Device that receives LLDP messages can report this 564 information as a location-related measurement to the LIS, which is 565 then able to use the measurement data in determining the location of 566 the Device. 568 Note: The LLDP extensions defined in LLDP Media Endpoint Discovery 569 (LLDP-MED) [ANSI/TIA-1057] provide the ability to acquire location 570 information directly from an LLDP endpoint. Where this 571 information is available, it might be unnecessary to use any other 572 form of location configuration. 574 The Device MUST report the values directly as they were provided by 575 the adjacent node. Attempting to adjust or translate the type of 576 identifier is likely to cause the measurement data to be useless. 578 Where a Device has received LLDP messages from multiple adjacent 579 nodes, it should provide information extracted from those messages by 580 repeating the "lldp" element. 582 An example of an LLDP measurement is shown in Figure 4. This shows 583 an adjacent node (chassis) that is identified by the IP address 584 192.0.2.45 (hexadecimal c000022d) and the port on that node is 585 numbered using an agent circuit ID [RFC3046] of 162 (hexadecimal a2). 587 589 590 c000022d 591 a2 592 593 595 Figure 4: LLDP Measurement Example 597 IEEE 802 Devices that are able to obtain information about adjacent 598 network switches and their attachment to them by other means MAY use 599 this data type to convey this information. 601 5.2. DHCP Relay Agent Information Measurements 603 The DHCP Relay Agent Information option [RFC3046] provides 604 measurement data about the network attachment of a Device. This 605 measurement data can be included in the "dhcp-rai" element. 607 The elements in the DHCP relay agent information options are opaque 608 data types assigned by the DHCP relay agent. The three items are all 609 optional: circuit identifier ("circuit", [RFC3046]), remote 610 identifier ("remote", [RFC3046], [RFC4649]) and subscriber identifier 611 ("subscriber", [RFC3993], [RFC4580]). The DHCPv6 remote identifier 612 has an associated enterprise number [IANA.enterprise] as an XML 613 attribute. 615 617 618 ::ffff:192.0.2.158 619 108b 620 621 623 Figure 5: DHCP Relay Agent Information Measurement Example 625 The "giaddr" is specified as a dotted quad IPv4 address or an RFC 626 4291 [RFC4291] IPv6 address. The enterprise number is specified as a 627 decimal integer. All other information is included verbatim from the 628 DHCP request in hexadecimal format. 630 5.3. 802.11 WLAN Measurements 632 In WiFi, or 802.11 [IEEE.80211], networks a Device might be able to 633 provide information about the access point (AP) that it is attached 634 to, or other WiFi points it is able to see. This is provided using 635 the "wifi" element, as shown in Figure 6, which shows a single 636 complete measurement for a single access point. 638 640 641 Intel(r)PRO/Wireless 2200BG 642 643 AB-CD-EF-AB-CD-EF 644 example 645 5 646 647 648 -34.4 150.8 649 650 651 a 652 5 653 2 654 2 655 2.56e-9 656 657 23 658 5 659 -59 660 23 661 662 663 10 664 9 665 -98.5 666 7.5 667 668 669 670 672 Figure 6: 802.11 WLAN Measurement Example 674 A wifi element is made up of one or more access points, and an 675 optional "nicType" element. Each access point is described using the 676 "ap" element, which is comprised of the following fields: 678 bssid: The basic service set identifier. In an Infrastructure BSS 679 network, the bssid is the 48 bit MAC address of the access point. 681 The "verified" attribute of this element describes whether the 682 device has verified the MAC address or it authenticated the access 683 point or the network operating the access point (for example, a 684 captive portal accessed through the access point has been 685 authenticated). This attributes defaults to a value of "false" 686 when omitted. 688 ssid: The service set identifier (SSID) for the wireless network 689 served by the access point. 691 The SSID is a 32-octet identifier that is commonly represented as 692 a ASCII [RFC0020] or UTF-8 [RFC3629] encoded string. To represent 693 octets that cannot be directly included in an XML element, 694 escaping is used. Sequences of octets that do not represent a 695 valid UTF-8 encoding can be escaped using a backslash ('\') 696 followed by two case-insensitive hexadecimal digits representing 697 the value of a single octet. 699 The canonical or value-space form of an SSID is a sequence of up 700 to 32 octets that is produced from the concatenation of UTF-8 701 encoded sequences of unescaped characters and octets derived from 702 escaped components. 704 channel: The channel number (frequency) that the access point 705 operates on. 707 location: The location of the access point, as reported by the 708 access point. This element contains any valid location, using the 709 rules for a "location-info" element, as described in [RFC5491]. 711 type: The network type for the network access. This element 712 includes the alphabetic suffix of the 802.11 specification that 713 introducted the radio interface, or PHY; e.g. "a", "b", "g", or 714 "n". 716 band: The frequency band for the radio, in gigahertz (GHz). 802.11 717 [IEEE.80211] specifies PHY layers that use 2.4, 3.7 and 5 718 gigahertz frequency bands. 720 regclass: The regulatory domain and class. The "country" attribute 721 optionally includes the applicable two character country 722 identifier (dot11CountryString), which can be followed by an 'O', 723 'I' or 'X'. The element text content includes the value of the 724 regulatory class: an 8-bit integer in decimal form. 726 antenna: The antenna identifier for the antenna that the access 727 point is using to transmit the measured signals. 729 flightTime: Flight time is the difference between the time of 730 departure (TOD) of signal from a transmitting station and time of 731 arrival (TOA) of signal at a receiving station, as defined in 732 [IEEE.80211V]. Measurement of this value requires that stations 733 synchronize their clocks. This value can be measured by access 734 point or Device; because the flight time is assumed to be the same 735 in either direction - aside from measurement errors - only a 736 single element is provided. This element includes optional 737 "rmsError" and "samples" attributes. RMS error might be derived 738 from the reported RMS error in TOD and TOA. 740 apSignal: Measurement information for the signal transmitted by the 741 access point, as observed by the Device. Some of these values are 742 derived from 802.11v [IEEE.80211V] messages exchanged between 743 Device and access point. The contents of this element include: 745 transmit: The transmit power reported by the access point, in dB. 747 gain: The gain of the access point antenna reported by the access 748 point, in dB. 750 rcpi: The received channel power indicator for the access point 751 signal, as measured by the Device. This value SHOULD be in 752 units of dBm (with RMS error in dB). If power is measured in a 753 different fashion, the "dBm" attribute MUST be set to "false". 754 Signal strength reporting on current hardware uses a range of 755 different mechanisms; therefore, the value of the "nicType" 756 element SHOULD be included if the units are not known to be in 757 dBm and the value reported by the hardware should be included 758 without modification. This element includes optional 759 "rmsError" and "samples" attributes. 761 rsni: The received signal to noise indicator in dBm. This 762 element includes optional "rmsError" and "samples" attributes. 764 deviceSignal: Measurement information for the signal transmitted by 765 the device, as reported by the access point. This element 766 contains the same child elements as the "ap" element, with the 767 access point and Device roles reversed. 769 All elements are optional except for "bssid". 771 The "nicType" element is used to specify the make and model of the 772 wireless network interface in the Device. Different 802.11 chipsets 773 report measurements in different ways, so knowing the network 774 interface type aids the LIS in determining how to use the provided 775 measurement data. The content of this field is unconstrained and no 776 mechanisms are specified to ensure uniqueness. 778 5.3.1. Wifi Measurement Requests 780 Two elements are defined for requesting WiFi measurements in a 781 measurement request: 783 type: The "type" element identifies the desired type (or types that 784 are requested. 786 parameter: The "parameter" element identifies an optional 787 measurements are requested for each measured access point. An 788 element is identified by its qualified name. The optional 789 "context" parameter can be used to specify if an element is 790 included as a child of the "ap" or "device" elements; omission 791 indicates that it applies to both. 793 Multiple types or parameters can be requested by repeating either 794 element. 796 5.4. Cellular Measurements 798 Cellular Devices are common throughout the world and base station 799 identifiers can provide a good source of coarse location information. 800 This information can be provided to a LIS run by the cellar operator, 801 or may be provided to an alternative LIS operator that has access to 802 one of several global cell-id to location mapping databases. 804 A number of advanced location determination methods have been 805 developed for cellular networks. For these methods a range of 806 measurement parameters can be collected by the network, Device, or 807 both in cooperation. This document includes a basic identifier for 808 the wireless transmitter only; future efforts might define additional 809 parameters that enable more accurate methods of location 810 determination. 812 The cellular measurement set allows a Device to report to a LIS any 813 LTE (Figure 7), UMTS (Figure 8), GSM (Figure 9) or CDMA (Figure 10) 814 cells that it is able to observe. Cells are reported using their 815 global identifiers. All 3GPP cells are identified by public land 816 mobile network (PLMN), which is formed of mobile country code (MCC) 817 and mobile network code (MNC); specific fields are added for each 818 network type. All other values are decimal integers. 820 822 823 824 46520 825 80936424 826 827 828 46506 829 10736789 830 831 832 834 Long term evolution (LTE) cells are identified by a 28-bit cell 835 identifier (eucid). 837 Figure 7: Example LTE Cellular Measurement 839 841 842 843 46520 844 200065000 845 846 847 46506 848 1638332767 849 850 851 853 Universal mobile telephony service (UMTS) cells are identified by 854 radio network controller (rnc) and cell id (cid). 856 Figure 8: Example UMTS Cellular Measurement 858 860 861 862 46506 863 1638332767 864 865 866 868 Global System for Mobile communication (GSM) cells are identified by 869 local radio network controller (rnc) and cell id (cid). 871 Figure 9: Example GSM Cellular Measurement 873 875 876 877 47231589212 878 879 880 47231589213 881 882 883 885 Code division multiple access (CDMA) cells are not identified by 886 PLMN, instead these use network id (nid), system id (sid) and base 887 station id (baseid). 889 Figure 10: Example CDMA Cellular Measurement 891 In general a cellular Device will be attached to the cellular network 892 and so the notion of a serving cell exists. Cellular network also 893 provide overlap between neighbouring sites, so a mobile Device can 894 hear more than one cell. The measurement schema supports sending 895 both the serving cell and any other cells that the mobile might be 896 able to hear. In some cases, the Device may simply be listening to 897 cell information without actually attaching to the network, mobiles 898 without a SIM are an example of this. In this case the Device may 899 simply report cells it can hear without flagging one as a serving 900 cell. An example of this is shown in Figure 11. 902 904 905 906 46520 907 200065000 908 909 910 46506 911 1638332767 912 913 914 916 Figure 11: Example Observed Cellular Measurement 918 5.4.1. Cellular Measurement Requests 920 Two elements can be used in measurement requests for cellular 921 measurements: 923 type: A label indicating the type of identifier to provide: one of 924 "gsm", "umts", "lte", or "cdma". 926 network: The network portion of the cell identifier. For 3GPP 927 networks, this is the combination of MCC and MNC; for CDMA, this 928 is the network identifier. 930 Multiple identifier types or networks can be identified by repeating 931 either element. 933 5.5. GNSS Measurements 935 GNSS use orbiting satellites to transmit signals. A Device with a 936 GNSS receiver is able to take measurements from the satellite 937 signals. The results of these measurements can be used to determine 938 time and the location of the Device. 940 Determining location and time in autonomous GNSS receivers follows 941 three steps: 943 Signal acquisition: During the signal acquisition stage, the 944 receiver searches for the repeating code that is sent by each GNSS 945 satellite. Successful operation typically requires measurement 946 data for a minimum of 5 satellites. At this stage, measurement 947 data is available to the Device. 949 Navigation message decode: Once the signal has been acquired, the 950 receiver then receives information about the configuration of the 951 satellite constellation. This information is broadcast by each 952 satellite and is modulated with the base signal at a low rate; for 953 instance, GPS sends this information at about 50 bits per second. 955 Calculation: The measurement data is combined with the data on the 956 satellite constellation to determine the location of the receiver 957 and the current time. 959 A Device that uses a GNSS receiver is able to report measurements 960 after the first stage of this process. A LIS can use the results of 961 these measurements to determine a location. In the case where there 962 are fewer results available than the optimal minimum, the LIS might 963 be able to use other sources of measurement information and combine 964 these with the available measurement data to determine a position. 966 Note: The use of different sets of GNSS _assistance data_ can 967 reduce the amount of time required for the signal acquisition 968 stage and obviate the need for the receiver to extract data on the 969 satellite constellation. Provision of assistance data is outside 970 the scope of this document. 972 Figure 12 shows an example of GNSS measurement data. The measurement 973 shown is for the GPS system and includes measurement data for three 974 satellites only. 976 978 980 981 499.9395 982 0.87595747 983 45 984 985 986 378.2657 987 0.56639479 988 52 989 990 991 -633.0309 992 0.57016835 993 48 994 995 996 998 Figure 12: Example GNSS Measurement 1000 Each "gnss" element represents a single set of GNSS measurement data, 1001 taken at a single point in time. Measurements taken at different 1002 times can be included in different "gnss" elements to enable 1003 iterative refinement of results. 1005 GNSS measurement parameters are described in more detail in the 1006 following sections. 1008 5.5.1. GNSS System and Signal 1010 The GNSS measurement structure is designed to be generic and to apply 1011 to different GNSS types. Different signals within those systems are 1012 also accounted for and can be measured separately. 1014 The GNSS type determines the time system that is used. An indication 1015 of the type of system and signal can ensure that the LIS is able to 1016 correctly use measurements. 1018 Measurements for multiple GNSS types and signals can be included by 1019 repeating the "gnss" element. 1021 This document creates an IANA registry for GNSS types. Two satellite 1022 systems are registered by this document: GPS and Galileo. Details 1023 for the registry are included in Section 9.1. 1025 5.5.2. Time 1027 Each set of GNSS measurements is taken at a specific point in time. 1028 The "time" attribute is used to indicate the time that the 1029 measurement was acquired, if the receiver knows how the time system 1030 used by the GNSS relates to UTC time. 1032 Alternative to (or in addition to) the measurement time, the 1033 "gnssTime" element MAY be included. The "gnssTime" element includes 1034 a relative time in milliseconds using the time system native to the 1035 satellite system. For the GPS satellite system, the "gnssTime" 1036 element includes the time of week in milliseconds. For the Galileo 1037 system, the "gnssTime" element includes the time of day in 1038 milliseconds. 1040 The accuracy of the time measurement provided is critical in 1041 determining the accuracy of the location information derived from 1042 GNSS measurements. The receiver SHOULD indicate an estimated time 1043 error for any time that is provided. An RMS error can be included 1044 for the "gnssTime" element, with a value in milliseconds. 1046 5.5.3. Per-Satellite Measurement Data 1048 Multiple satellites are included in each set of GNSS measurements 1049 using the "sat" element. Each satellite is identified by a number in 1050 the "num" attribute. The satellite number is consistent with the 1051 identifier used in the given GNSS. 1053 Both the GPS and Galileo systems use satellite numbers between 1 and 1054 64. 1056 The GNSS receiver measures the following parameters for each 1057 satellite: 1059 doppler: The observed Doppler shift of the satellite signal, 1060 measured in meters per second. This is converted from a value in 1061 Hertz by the receiver to allow the measurement to be used without 1062 knowledge of the carrier frequency of the satellite system. This 1063 value includes an optional RMS error attribute, also measured in 1064 meters per second. 1066 codephase: The observed code phase for the satellite signal, 1067 measured in milliseconds. This is converted from a value in chips 1068 or wavelengths. Increasing values indicate increasing 1069 pseudoranges. This value includes an optional RMS error 1070 attribute, also measured in milliseconds. 1072 cn0: The signal to noise ratio for the satellite signal, measured in 1073 decibel-Hertz (dB-Hz). The expected range is between 20 and 50 1074 dB-Hz. 1076 mp: An estimation of the amount of error that multipath signals 1077 contribute in metres. This parameter is optional. 1079 cq: An indication of the carrier quality. Two attributes are 1080 included: "continuous" may be either "true" or "false"; direct may 1081 be either "direct" or "inverted". This parameter is optional. 1083 adr: The accumulated Doppler range, measured in metres. This 1084 parameter is optional and is not necessary unless multiple sets of 1085 GNSS measurements are provided. 1087 All values are converted from measures native to the satellite system 1088 to generic measures to ensure consistency of interpretation. Unless 1089 necessary, the schema does not constrain these values. 1091 5.5.4. GNSS Measurement Requests 1093 Measurement requests can include a "gnss" element, which includes the 1094 "system" and "signal" attributes. Multiple elements can be included 1095 to indicate a requests for GNSS measurements from multiple systems or 1096 signals. 1098 5.6. DSL Measurements 1100 Digital Subscriber Line (DSL) networks rely on a range of network 1101 technology. DSL deployments regularly require cooperation between 1102 multiple organizations. These fall into two broad categories: 1103 infrastructure providers and Internet service providers (ISPs). 1104 Infrastructure providers manage the bulk of the physical 1105 infrastructure including cabling. End users obtain their service 1106 from an ISP, which manages all aspects visible to the end user 1107 including IP address allocation and operation of a LIS. See 1108 [DSL.TR025] and [DSL.TR101] for further information on DSL network 1109 deployments. 1111 Exchange of measurement information between these organizations is 1112 necessary for location information to be correctly generated. The 1113 ISP LIS needs to acquire location information from the infrastructure 1114 provider. However, the infrastructure provider has no knowledge of 1115 Device identifiers, it can only identify a stream of data that is 1116 sent to the ISP. This is resolved by passing measurement data 1117 relating to the Device to a LIS operated by the infrastructure 1118 provider. 1120 5.6.1. L2TP Measurements 1122 Layer 2 Tunneling Protocol (L2TP) is a common means of linking the 1123 infrastructure provider and the ISP. The infrastructure provider LIS 1124 requires measurement data that identifies a single L2TP tunnel, from 1125 which it can generate location information. Figure 13 shows an 1126 example L2TP measurement. 1128 1130 1131 1132 192.0.2.10 1133 192.0.2.61 1134 528 1135 1136 1137 1139 Figure 13: Example DSL L2TP Measurement 1141 5.6.2. RADIUS Measurements 1143 When authenticating network access, the infrastructure provider might 1144 employ a RADIUS [RFC2865] proxy at the DSL Access Module (DSLAM) or 1145 Access Node (AN). These messages provide the ISP RADIUS server with 1146 an identifier for the DSLAM or AN, plus the slot and port that the 1147 Device is attached on. These data can be provided as a measurement, 1148 which allows the infrastructure provider LIS to generate location 1149 information. 1151 The format of the AN, slot and port identifiers are not defined in 1152 the RADIUS protocol. Slot and port together identify a circuit on 1153 the AN, analogous to the circuit identifier in [RFC3046]. These 1154 items are provided directly, as they were in the RADIUS message. An 1155 example is shown in Figure 14. 1157 1159 1160 AN-7692 1161 3 1162 06 1163 1164 1166 Figure 14: Example DSL RADIUS Measurement 1168 5.6.3. Ethernet VLAN Tag Measurements 1170 For Ethernet-based DSL access networks, the DSL Access Module (DSLAM) 1171 or Access Node (AN) provide two VLAN tags on packets. A C-TAG is 1172 used to identify the incoming residential circuit, while the S-TAG is 1173 used to identify the DSLAM or AN. The C-TAG and S-TAG together can 1174 be used to identify a single point of network attachment. An example 1175 is shown in Figure 15. 1177 1179 1180 613 1181 1097 1182 1183 1185 Figure 15: Example DSL VLAN Tag Measurement 1187 Alternatively, the C-TAG can be replaced by data on the slot and port 1188 that the Device is attached to. This information might be included 1189 in RADIUS requests that are proxied from the infrastructure provider 1190 to the ISP RADIUS server. 1192 5.6.4. ATM Virtual Circuit Measurements 1194 An ATM virtual circuit can be employed between the ISP and 1195 infrastructure provider. Providing the virtual port ID (VPI) and 1196 virtual circuit ID (VCI) for the virtual circuit gives the 1197 infrastructure provider LIS the ability to identify a single data 1198 stream. A sample measurement is shown in Figure 16. 1200 1202 1203 55 1204 6323 1205 1206 1208 Figure 16: Example DSL ATM Measurement 1210 6. Privacy Considerations 1212 Location-related measurement data can be as privacy sensitive as 1213 location information. 1215 Measurement data is effectively equivalent to location information if 1216 the contextual knowledge necessary to generate one from the other is 1217 readily accessible. Even where contextual knowledge is difficult to 1218 acquire, there can be no assurance that an authorized recipient of 1219 the contextual knowledge is also authorized to receive location 1220 information. 1222 In order to protect the privacy of the subject of location-related 1223 measurement data, this implies that measurement data is protected 1224 with the same degree of protection as location information. 1226 6.1. Measurement Data Privacy Model 1228 It is less desirable to distribute measurement data in the same 1229 fashion as location information. Measurement data is less useful to 1230 location recipients than location information. Therefore, a simple 1231 distribution model is desirable. 1233 In this simple model, the Device is the only entity that is able to 1234 distribute measurement data. To use an analogy from the GEOPRIV 1235 architecture, the Device - as the Location Generator (or the 1236 Measurement Data Generator) - is the sole entity that can assume the 1237 roles of Rule Maker and Location Server. 1239 No entity can redistribute measurement data. The Device directs 1240 other entities in how measurement data is used and retained. 1242 6.2. LIS Privacy Requirements 1244 A LIS MUST NOT reveal location-related measurement data or location 1245 information based on measurement data to any other entity unless 1246 directed to do so by the Device. 1248 By adding measurement data to a request for location information, the 1249 Device implicitly grants permission for the LIS to generate the 1250 requested location information using the measurement data. 1251 Permission to use this data for any other purpose is not implied. 1253 As long as measurement data is only used in serving the request that 1254 contains it, rules regarding data retention are not necessary. A LIS 1255 MUST discard location-related measurement data after servicing a 1256 request, unless the Device grants permission to use that information 1257 for other purposes. 1259 6.3. Measurement Data and Location URIs 1261 A LIS MAY use measurement data provided by the Device to serve 1262 requests to location URIs, if the Device permits it. A Device 1263 permits this by including measurement data in a request that 1264 explcitly requests a location URI. By requesting a location URI, the 1265 Device grants permission for the LIS to use the measurement data in 1266 serving requests to that URI. 1268 Note: In HELD, the "any" type is not an explicit request for a 1269 location URI, though a location URI might be provided. 1271 The usefulness of measurement data that is provided in this fashion 1272 is limited. The measurement data is only valid at the time that it 1273 was acquired by the Device. At the time that a request is made to a 1274 location URI, the Device might have moved, rendering the measurement 1275 data incorrect. 1277 A Device is able to explicitly limit the time that a LIS retains 1278 measurement data by adding an expiry time to the measurement data, 1279 see Section 4.1.2. 1281 6.4. Third-Party-Provided Measurement Data 1283 An authorized third-party request for the location of a Device (see 1284 [I-D.ietf-geopriv-held-identity-extensions]) can include location- 1285 related measurement data. This is possible where the third-party is 1286 able to make observations about the Device. 1288 A third-party that provides measurement data MUST be authorized to 1289 provide the specific measurement for the identified device. A third- 1290 party MUST either be trusted by the LIS for the purposes of providing 1291 measurement data of the provided type, or the measurement data MUST 1292 be validated (see Section 7.2.1) before being used. 1294 How a third-party authenticates its identity or gains authorization 1295 to use measurement data is not covered by this document. 1297 7. Security Considerations 1299 Use of location-related measurement data has privacy considerations 1300 that are discussed in Section 6. 1302 7.1. Threat Model 1304 The threat model for location-related measurement data concentrates 1305 on the Device providing falsified, stolen or incorrect measurement 1306 data. 1308 A Device that provides location location-related measurement data 1309 might use data to: 1311 o acquire the location of another Device, without authorization; 1313 o extract information about network topology; or 1315 o coerce the LIS into providing falsified location information based 1316 on the measurement data. 1318 Location-related measurement data describes the physical environment 1319 or network attachment of a Device. A third party adversary in the 1320 proximity of the Device might be able to alter the physical 1321 environment such that the Device provides measurement data that is 1322 controlled by the third party. This might be used to indirectly 1323 control the location information that is derived from measurement 1324 data. 1326 7.1.1. Acquiring Location Information Without Authorization 1328 Requiring authorization for location requests is an important part of 1329 privacy protections of a location protocol. A location configuration 1330 protocol usually operates under a restricted policy that allows a 1331 requester to obtain their own location. HELD identity extensions 1332 [I-D.ietf-geopriv-held-identity-extensions] allows other entities to 1333 be authorized, conditional on a Rule Maker providing sufficient 1334 authorization. 1336 The intent of these protections is to ensure that a location 1337 recipient is authorized to acquire location information. Location- 1338 related measurement data could be used by an attacker to circumvent 1339 such authorization checks if the association between measurement data 1340 and Target Device is not validated by a LIS. 1342 A LIS can be coerced into providing location information for a Device 1343 that a location recipient is not authorized to receive. A request 1344 identifies one Device (implicitly or explicitly), but measurement 1345 data is provided for another Device. If the LIS does not check that 1346 the measurement data is for the identified Device, it could 1347 incorrectly authorize the request. 1349 By using unvalidated measurement data to generate a response, the LIS 1350 provides information about a Device without appropriate 1351 authorization. 1353 The feasibility of this attack depends on the availability of 1354 information that links a Device with measurement data. In some 1355 cases, measurement data that is correlated with a target is readily 1356 available. For instance, LLDP measurements (Section 5.1) are 1357 broadcast to all nodes on the same network segment. An attacker on 1358 that network segment can easily gain measurement data that relates a 1359 Device with measurements. 1361 For some types of measurement data, it's necessary for an attacker to 1362 know the location of the target in order to determine what 1363 measurements to use. This attack is meaningless for types of 1364 measurement data that require that the attacker first know the 1365 location of the target before measurement data can be acquired or 1366 fabricated. GNSS measurements (Section 5.5) share this trait with 1367 many wireless location determination methods. 1369 7.1.2. Extracting Network Topology Data 1371 Allowing requests with measurements might be used to collect 1372 information about a network topology. This is possible if requests 1373 containing measurements are permitted. 1375 Network topology can be considered sensitive information by a network 1376 operator for commercial or security reasons. While it is impossible 1377 to completely prevent a Device from acquiring some knowledge of 1378 network topology if a location service is provided, a network 1379 operator might desire to limit how much of this information is made 1380 available. 1382 Mapping a network topology does not require that an attacker be able 1383 to associate measurement data with a particular Device. If a 1384 requester is able to try a number of measurements, it is possible to 1385 acquire information about network topology. 1387 It is not even necessary that the measurements are valid; random 1388 guesses are sufficient, provided that there is no penalty or cost 1389 associated with attempting to use the measurements. 1391 7.1.3. Lying By Proxy 1393 Location information is a function of its inputs, which includes 1394 measurement data. Thus, falsified measurement data can be used to 1395 alter the location information that is provided by a LIS. 1397 Some types of measurement data are relatively easy to falsify in a 1398 way that the resulting location information to be selected with 1399 little or no error. For instance, GNSS measurements are easy to use 1400 for this purpose because all the contextual information necessary to 1401 calculate a position using measurements is broadcast by the 1402 satellites [HARPER]. 1404 An attacker that falsifies measurement data gains little if they are 1405 the only recipients of the result. The attacker knows that the 1406 location information is bad. The attacker only gains if the 1407 information can somehow be attributed to the LIS by another location 1408 recipient. 1410 A recipient might evaluate the trustworthiness of the location 1411 information based on the credibility of its source. By coercing the 1412 LIS into providing falsified location information, any credibility 1413 that the LIS might have - that the attacker does not - is gained by 1414 the attacker. 1416 A third-party that is reliant on the integrity of the location 1417 information might base an evaluation of the credibility of the 1418 information on the source of the information. If that third party is 1419 able to attribute location information to the LIS, then an attacker 1420 might gain. 1422 Location information that is provided to the Device without any means 1423 to identify the LIS as its source is not subject to this attack. The 1424 Device is identified as the source of the data when it distributes 1425 the location information to location recipients. 1427 An attacker gains if they are able to coerce the LIS into providing 1428 location information based on falsified measurement data and that 1429 information can be attributed to the LIS. 1431 Location information is attributed to the LIS either through the use 1432 of digital signatures or by having the location recipient directly 1433 interact with the LIS. A LIS that digitally signs location 1434 information becomes identifiable as the source of the data. 1435 Similarly, the LIS is identified as a source of data if a location 1436 recipient acquires information directly from a LIS using a location 1437 URI. 1439 7.1.4. Measurement Replay 1441 The value of some measured properties do not change over time for a 1442 single location. This allows for simple replay attacks, where an 1443 attacker acquires measurements that can later be used without being 1444 detected as being invalid. 1446 Measurement data is frequently an observation of an time-invariant 1447 property of the environment at the subject location. For 1448 measurements of this nature, nothing in the measurement itself is 1449 sufficient proof that the Device is present at the resulting 1450 location. Measurement data might have been previously acquired and 1451 reused. 1453 For instance, the identity of a radio transmitter, if broadcast by 1454 that transmitter, can be collected and stored. An attacker that 1455 wishes it known that they exist at a particular location, can claim 1456 to observe this transmitter at any time. Nothing inherent in the 1457 claim reveals it to be false. 1459 For properties of a network, time-invariance is often directly as a 1460 result of the practicalities of operating the network. Limiting the 1461 changes to a network ensures greater consistency of service. A 1462 largely static network also greatly simplifies the data management 1463 tasks involved with providing a location service. 1465 7.1.5. Environment Spoofing 1467 Some types of measurement data can be altered or influenced by a 1468 third party so that a Device. If it is possible for a third party to 1469 alter the measured phenomenon, then any location information that is 1470 derived from this data can be indirectly influenced. 1472 Altering the environment in this fashion might not require 1473 involvement with either Device or LIS. Measurement that is passive - 1474 where the Device observes a signal or other phenomenon without direct 1475 interaction - are most susceptible to alteration by third parties. 1477 Measurement of radio signal characteristics is especially vulnerable 1478 since an adversary need only be in the general vicinity of the Device 1479 and be able to transmit a signal. For instance, a GNSS spoofer is 1480 able to produce fake signals that claim to be transmitted by any 1481 satellite or set of satellites (see [GPS.SPOOF]). 1483 Measurements that require direct interaction increases the complexity 1484 of the attack. For measurements relating to the communication 1485 medium, a third party cannot avoid direct interaction, they need only 1486 be on the comminications path (that is, man in the middle). 1488 Even if the entity that is interacted with is authenticated, this 1489 does not provide any assurance about the integrity of measurement 1490 data. For instance, the Device might authenticate the identity of a 1491 radio transmitter through the use of cryptographic means and obtain 1492 signal strength measurements for that transmitter. Radio signal 1493 strength is trivial for an attacker to increase simply by receiving 1494 and amplifying the raw signal; it is not necessary for the attacker 1495 to be able to understand the signal content. 1497 Note: This particular "attack" is more often completely legitimate. 1498 Radio repeaters are commonplace mechanism used to increase radio 1499 coverage. 1501 Attacks that rely on altering the observed environment of a Device 1502 require countermeasures that affect the measurement process. For 1503 radio signals, countermeasures could include the use of authenticated 1504 signals, altered receiver design. In general, countermeasures are 1505 highly specific to the individual measurement process. An exhaustive 1506 discussion of these issues is left to the relevant literature for 1507 each measurement technology. 1509 A Device that provides measurement data is assumed to be responsible 1510 for applying appropriate countermeasures against this type of attack. 1512 For a Device that is the ultimate recipient of location information 1513 derived from measurement data, a LIS might choose to provide location 1514 information without any validation. The responsibility for ensuring 1515 the veracity of the measurement data lies with the Device. 1517 Measurement data that is susceptible to this sort of influence MUST 1518 be treated as though it were produced by an untrusted Device for 1519 those cases where a location recipient might attribute the location 1520 information to the LIS. Such measurement data MUST be subjected to 1521 the same validation as for other types of attacks that rely on 1522 measurement falsification. 1524 Note: Altered measurement data might be provided by a Device that 1525 has no knowledge of the alteration. Thus, an otherwise trusted 1526 Device might still be an unreliable source of measurement data. 1528 7.2. Mitigation 1530 The following measures can be applied to limit or prevent attacks. 1531 The effectiveness of each depends on the type of measurement data and 1532 how that measurement data is acquired. 1534 Two general approaches are identified for dealing with untrusted 1535 measurement data: 1537 1. Require independent validation of measurement data or the 1538 location information that is produced. 1540 2. Identify the types of sources that provided the measurement data 1541 that location information was derived from. 1543 This section goes into more detail on the different forms of 1544 validation in Section 7.2.1, Section 7.2.2, and Section 7.2.3. The 1545 impact of attributing location information to sources is discussed in 1546 more detail in Section 7.2.4. 1548 7.2.1. Measurement Validation 1550 Detecting that measurement data has been falsified is difficult in 1551 the absence of integrity mechanisms. 1553 Independent confirmation of the veracity of measurement data ensures 1554 that the measurement is accurate and that it applies to the correct 1555 Device. By gathering the same measurement data from a trusted and 1556 independent source, the LIS is able to check that the measurement 1557 data is correct. 1559 Measurement information might contain no inherent indication that it 1560 is falsified. On the contrary, it can be difficult to obtain 1561 information that would provide any degree of assurance that the 1562 measurement device is physically at any particular location. 1563 Measurements that are difficult to verify require other forms of 1564 assurance before they can be used. 1566 7.2.1.1. Effectiveness 1568 Measurement validation MUST be used if measurement data for a 1569 particular Device can be easily acquired by unauthorized location 1570 recipients, as described in Section 7.1.1. This prevents 1571 unauthorized access to location information using measurement data. 1573 Validation of measurement data can be significantly more effective 1574 than independent acquisition of the same. For instance, a Device in 1575 a large Ethernet network could provide a measurement indicating its 1576 point of attachment using LLDP measurements. For a LIS, acquiring 1577 the same measurement data might require a request to all switches in 1578 that network. With the measurement data, validation can target the 1579 identified switch with a specific query. 1581 Validation is effective in identifying falsified measurement data 1582 (Section 7.1.3), including attacks involving replay of measurement 1583 data (Section 7.1.4). Validation also limits the amount of network 1584 topology information (Section 7.1.2) made available to Devices to 1585 that portion of the network topology that they are directly attached. 1587 Measurement validation has no effect if the underlying effect is 1588 being spoofed (Section 7.1.5). 1590 7.2.1.2. Limitations (Unique Observer) 1592 A Device is often in a unique position to make a measurement. It 1593 alone occupies the point in space-time that the location 1594 determination process seeks to determine. The Device becomes a 1595 unique observer for a particular property. 1597 The ability of the Device to become a unique observer makes the 1598 Device invaluable to the location determination process. As a unique 1599 observer, it also makes the claims of a Device difficult to validate 1600 and easily to spoof. 1602 As long as no other entity is capable of making the same 1603 measurements, there is also no other entity that can independently 1604 check that the measurements are correct and applicable to the Device. 1605 A LIS might be unable to validate all or part of the measurement data 1606 it receives from a unique observer. For instance, a signal strength 1607 measurement of the signal from a radio tower cannot be validated 1608 directly. 1610 Some portion of the measurement data might still be independently 1611 verified, even if all information cannot. In the previous example, 1612 the radio tower might be able to provide verification that the Device 1613 is present if it is able to observe a radio signal sent by the 1614 Device. 1616 If measurement data can only be partially validated, the extent to 1617 which it can be validated determines the effectiveness of validation 1618 against these attacks. 1620 The advantage of having the Device as a unique observer is that it 1621 makes it difficult for an attacker to acquire measurements without 1622 the assistance of the Device. Attempts to use measurements to gain 1623 unauthorized access to measurement data (Section 7.1.1) are largely 1624 ineffectual against a unique observer. 1626 7.2.2. Location Validation 1628 Location information that is derived from location-related 1629 measurement data can also be verified against trusted location 1630 information. Rather than validating inputs to the location 1631 determination process, suspect locations are identified at the output 1632 of the process. 1634 Trusted location information is acquired using sources of measurement 1635 data that are trusted. Untrusted location information is acquired 1636 using measurement data provided from untrusted sources, which might 1637 include the Device. These two locations are compared. If the 1638 untrusted location agrees with the trusted location, the untrusted 1639 location information is used. 1641 Algorithms for the comparison of location information are not 1642 included in this document. However, a simple comparison for 1643 agreement might require that the untrusted location be entirely 1644 contained within the uncertainty region of the trusted location. 1646 There is little point in using a less accurate, less trusted 1647 location. Untrusted location information that has worse accuracy 1648 than trusted information can be immediately discarded. There are 1649 multiple factors that affect accuracy, uncertainty and currency being 1650 the most important. How location information is compared for 1651 accuracy is not defined in this document. 1653 7.2.2.1. Effectiveness 1655 Location validation limits the extent to which falsified - or 1656 erroneous - measurement data can cause an incorrect location to be 1657 reported. 1659 Location validation can be more efficient than validation of inputs, 1660 particularly for a unique observer (Section 7.2.1.2). 1662 Validating location ensures that the Device is at or near the 1663 resulting location. Location validation can be used to limit or 1664 prevent all of the attacks identified in this document. 1666 7.2.2.2. Limitations 1668 The trusted location that is used for validation is always less 1669 accurate than the location that is being checked. The amount by 1670 which the untrusted location is more accurate, is the same amount 1671 that an attacker can exploit. 1673 For example, a trusted location might indicate a five kilometer 1674 radius uncertainty region. An untrusted location that describes a 1675 100 meter uncertainty within the larger region might be accepted as 1676 more accurate. An attacker might still falsify measurement data to 1677 select any location within the larger uncertainty region. While the 1678 100 meter uncertainty that is reported seems more accurate, a 1679 falsified location could be anywhere in the five kilometer region. 1681 Where measurement data might have been falsified, the actual 1682 uncertainty is effectively much higher. Local policy might allow 1683 differing degrees of trust to location information derived from 1684 untrusted measurement data. This might not be a boolean operation 1685 with only two possible outcomes: untrusted location information might 1686 be used entirely or not at all, or it could be combined with trusted 1687 location information with the degree to which each contributes based 1688 on a value set in local policy. 1690 7.2.3. Supporting Observations 1692 Replay attacks using previously acquired measurement data are 1693 particularly hard to detect without independent validation. Rather 1694 than validate the measurement data directly, supplementary data might 1695 be used to validate measurements or the location information derived 1696 from those measurements. 1698 These supporting observations could be used to convey information 1699 that provides additional assurance that the Device was acquired at a 1700 specific time and place. In effect, the Device is requested to 1701 provide proof of its presence at the resulting location. 1703 For instance, a Device that measures attributes of a radio signal 1704 could also be asked to provide a sample of the measured radio signal. 1705 If the LIS is able to observe the same signal, the two observations 1706 could be compared. Providing that the signal cannot be predicted in 1707 advance by the Device, this could be used to support the claim that 1708 the Device is able to receive the signal. Thus, the Device is likely 1709 to be within the range that the signal is transmitted. A LIS could 1710 use this to attribute a higher level of trust in the associated 1711 measurement data or resulting location. 1713 7.2.3.1. Effectiveness 1715 The use of supporting observations is limited by the ability of the 1716 LIS to acquire and validate these observations. The advantage of 1717 selecting observations independent of measurement data is that 1718 observations can be selected based on how readily available the data 1719 is for both LIS and Device. The amount and quality of the data can 1720 be selected based on the degree of assurance that is desired. 1722 Use of supporting observations is similar to both measurement 1723 validation and location validation. All three methods rely on 1724 independent validation of one or more properties. Applicability of 1725 each method is similar. 1727 Use of supporting observations can be used to limit or prevent all of 1728 the attacks identified in this document. 1730 7.2.3.2. Limitations 1732 The effectiveness of the validation method depends on the quality of 1733 the supporting observation: how hard it is to obtain at a different 1734 time or place, how difficult it is to guess and what other costs 1735 might be involved in acquiring this data. 1737 In the example of an observed radio signal, requesting a sample of 1738 the signal only provides an assurance that the Device is able to 1739 receive the signal transmitted by the measured radio transmitter. 1740 This only provides some assurance that the Device is within range of 1741 the transmitter. 1743 As with location validation, a Device might still be able to provide 1744 falsified measurements that could alter the value of the location 1745 information as long as the result is within this region. 1747 Requesting additional supporting observations can reduce the size of 1748 the region over which location information can be altered by an 1749 attacker, or increase trust in the result, but each additional has a 1750 cost. Supporting observations contribute little or nothing toward 1751 the primary goal of determining the location of the Device. Any 1752 costs in acquiring supporting observations are balanced against the 1753 degree of integrity desired of the resulting location information. 1755 7.2.4. Attribution 1757 Lying by proxy (Section 7.1.3) relies on the location recipient being 1758 able to attribute location information to a LIS. The effectiveness 1759 of this attack is negated if location information is explicitly 1760 attributed to a particular source. 1762 This requires an extension to the location object that explicitly 1763 identifies the source (or sources) of each item of location 1764 information. 1766 Rather than relying on a process that seeks to ensure that location 1767 information is accurate, this approach instead provides a location 1768 recipient with the information necessary to reach their own 1769 conclusion about the trustworthiness of the location information. 1771 Including an authenticated identity for all sources of measurement 1772 data is presents a number of technical and operational challenges. 1773 It is possible that the LIS has a transient relationship with a 1774 Device. A Device is not expected to share authentication information 1775 with a LIS. There is no assurance that Device identification is 1776 usable by a potential location recipient. Privacy concerns might 1777 also prevent the sharing identification information, even if it were 1778 available and usable. 1780 Identifying the type of measurement source allows a location 1781 recipient to make a decision about the trustworthiness of location 1782 information without depending on having authenticated identity 1783 information for each source. An element for this purpose is defined 1784 in Section 4.4. 1786 When including location information that is based on measurement data 1787 from sources that might be untrusted, a LIS SHOULD include 1788 alternative location information that is derived from trusted sources 1789 of measurement data. Each item of location information can then be 1790 labelled with the source of that data. 1792 A location recipient that is able to identify a specific source of 1793 measurement data (whether it be LIS or Device) can use this 1794 information to attribute location information to either or both 1795 entity. The location recipient is then better able to make decisions 1796 about trustworthiness based on the source of the data. 1798 A location recipient that does not understand the "source" element is 1799 unable to make this distinction. When constructing a PIDF-LO 1800 document, trusted location information MUST be placed in the PIDF-LO 1801 so that it is given higher priority to any untrusted location 1802 information according to Rule #8 of [RFC5491]. 1804 Attribution of information does nothing to address attacks that alter 1805 the observed parameters that are used in location determination 1806 (Section 7.1.5). 1808 7.2.5. Stateful Correlation of Location Requests 1810 Stateful examination of requests can be used to prevent a Device from 1811 attempting to map network topology using requests for location 1812 information (Section 7.1.2). 1814 Simply limiting the rate of requests from a single Device reduces the 1815 amount of data that a Device can acquire about network topology. 1817 8. Measurement Schemas 1819 The schema are broken up into their respective functions. There is a 1820 base container schema into which all measurements are placed, plus 1821 definitions for a measurement request (Section 8.1). A PIDF-LO 1822 extension is defined in a separate schema (Section 8.2). There is a 1823 basic types schema, that contains various base type definitions for 1824 things such as the "rmsError" and "samples" attributes IPv4, IPv6 and 1825 MAC addresses (Section 8.3). Then each of the specific measurement 1826 types is defined in its own schema. 1828 8.1. Measurement Container Schema 1830 1831 1839 1840 1842 1843 1844 1846 This schema defines a framework for location measurements. 1847 1848 1850 1852 1853 1854 1855 1856 1857 1859 1860 1861 1862 1863 1864 1865 1866 1867 1869 1871 1872 1873 1874 1875 1877 1879 1880 1881 1882 1884 1885 1886 1887 1888 1889 1891 1892 1893 1894 1895 1896 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1913 Measurement Container Schema 1915 8.2. Measurement Source Schema 1917 1918 1925 1926 1928 1929 1930 1932 This schema defines an extension to PIDF-LO that indicates the 1933 type of source that produced the measurement data used in 1934 generating the associated location information. 1935 1936 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1952 Measurement Source PIDF-LO Extension Schema 1954 8.3. Base Type Schema 1956 Note that the pattern rules in the following schema wrap due to 1957 length constraints. None of the patterns contain whitespace. 1959 1960 1967 1968 1970 1971 1972 1974 This schema defines a set of base type elements. 1975 1976 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2018 2019 2020 2022 2023 2024 2025 2026 An IP version 6 address, based on RFC 4291. 2027 2028 2029 2030 2031 2032 2033 2034 2035 2037 2039 2041 2043 2045 2047 2048 2049 2050 2058 2059 2060 2061 2063 2064 2065 2066 2070 2071 2073 2074 2075 2076 2078 2079 2081 2083 Base Type Schema 2085 8.4. LLDP Measurement Schema 2087 2088 2096 2097 2099 2100 2101 2103 This schema defines a set of LLDP location measurements. 2104 2105 2106 2108 2109 2110 2111 2112 2113 2114 2115 2117 2118 2119 2120 2121 2123 2124 2125 2126 2128 2129 2130 2132 2133 2134 2135 2136 2137 2139 2141 LLDP measurement schema 2143 8.5. DHCP Measurement Schema 2145 2146 2154 2155 2157 2158 2159 2161 This schema defines a set of DHCP location measurements. 2162 2163 2165 2167 2168 2169 2170 2171 2172 2173 2174 2176 2178 2180 2182 2183 2184 2185 2186 2188 2189 2190 2191 2193 2194 2195 2197 2199 DHCP measurement schema 2201 8.6. WiFi Measurement Schema 2202 2203 2212 2213 2215 802.11 location measurements 2216 2217 2218 2220 This schema defines a basic set of 802.11 location measurements. 2221 2222 2224 2225 2227 2229 2230 2231 2232 2233 2235 2237 2238 2239 2240 2241 2243 2244 2245 2246 2247 2248 2251 2253 2255 2257 2259 2261 2263 2265 2267 2269 2270 2272 2273 2274 2275 2277 2278 2279 2280 2282 2283 2284 2286 2288 2289 2290 2291 2292 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2313 2314 2315 2316 2317 2319 2320 2321 2322 2323 2325 2326 2328 2330 2332 2333 2334 2335 2337 2338 2339 2340 2341 2342 2343 2345 2346 2347 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2364 2366 WiFi measurement schema 2368 8.7. Cellular Measurement Schema 2370 2371 2378 2379 2381 2382 2383 2385 This schema defines a set of cellular location measurements. 2386 2387 2389 2391 2392 2393 2394 2395 2396 2397 2398 2399 2401 2402 2403 2404 2405 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2426 2427 2428 2429 2430 2431 2433 2434 2436 2437 2438 2439 2441 2442 2443 2444 2445 2447 2448 2449 2450 2451 2453 2454 2455 2456 2457 2459 2461 2462 2463 2464 2465 2466 2467 2468 2469 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2486 2488 Cellular measurement schema 2490 8.8. GNSS Measurement Schema 2491 2492 2500 2501 2503 2504 2505 2507 This schema defines a set of GNSS location measurements 2508 2509 2511 2513 2514 2515 2516 2517 2518 2519 2521 2522 2523 2524 2525 2527 2529 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2547 2549 2550 2551 2553 2554 2555 2557 2558 2559 2560 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2575 GNSS measurement Schema 2577 8.9. DSL Measurement Schema 2579 2580 2588 2589 2591 DSL measurement definitions 2592 2593 2594 2596 This schema defines a basic set of DSL location measurements. 2597 2598 2600 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2635 2636 2637 2638 2639 2640 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2659 2661 DSL measurement schema 2663 9. IANA Considerations 2665 This section creates a registry for GNSS types (Section 5.5) and 2666 registers the namespaces and schema defined in Section 8. 2668 9.1. IANA Registry for GNSS Types 2670 This document establishes a new IANA registry for Global Navigation 2671 Satellite System (GNSS) types. The registry includes tokens for the 2672 GNSS type and for each of the signals within that type. Referring to 2673 [RFC5226], this registry operates under "Specification Required" 2674 rules. The IESG will appoint an Expert Reviewer who will advise IANA 2675 promptly on each request for a new or updated GNSS type. 2677 Each entry in the registry requires the following information: 2679 GNSS name: the name and a brief description of the GNSS 2681 Brief description: the name and a brief description of the GNSS 2683 GNSS token: a token that can be used to identify the GNSS 2685 Signals: a set of tokens that represent each of the signals that the 2686 system provides 2688 Documentation reference: a reference to one or more stable, public 2689 specifications that outline usage of the GNSS, including (but not 2690 limited to) signal specifications and time systems 2692 The registry initially includes two registrations: 2694 GNSS name: Global Positioning System (GPS) 2696 Brief description: a system of satellites that use spread-spectrum 2697 transmission, operated by the US military for commercial and 2698 military applications 2700 GNSS token: gps 2702 Signals: L1, L2, L1C, L2C, L5 2704 Documentation reference: Navstar GPS Space Segment/Navigation User 2705 Interface [GPS.ICD] 2707 GNSS name: Galileo 2709 Brief description: a system of satellites that operate in the same 2710 spectrum as GPS, operated by the European Union for commercial 2711 applications 2713 GNSS Token: galileo 2715 Signals: L1, E5A, E5B, E5A+B, E6 2717 Documentation Reference: Galileo Open Service Signal In Space 2718 Interface Control Document (SIS ICD) [Galileo.ICD] 2720 9.2. URN Sub-Namespace Registration for 2721 urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc 2723 This section registers a new XML namespace, 2724 "urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc", as per the guidelines 2725 in [RFC3688]. 2727 URI: urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc 2729 Registrant Contact: IETF, GEOPRIV working group, 2730 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2732 XML: 2734 BEGIN 2735 2736 2738 2739 2740 Measurement Source for PIDF-LO 2741 2742 2743

Namespace for Location Measurement Source

2744

urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc

2745 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2746 with the RFC number for this specification.]] 2747

See RFCXXXX.

2748 2749 2750 END 2752 9.3. URN Sub-Namespace Registration for 2753 urn:ietf:params:xml:ns:geopriv:lm 2755 This section registers a new XML namespace, 2756 "urn:ietf:params:xml:ns:geopriv:lm", as per the guidelines in 2757 [RFC3688]. 2759 URI: urn:ietf:params:xml:ns:geopriv:lm 2761 Registrant Contact: IETF, GEOPRIV working group, 2762 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2764 XML: 2766 BEGIN 2767 2768 2770 2771 2772 Measurement Container 2773 2774 2775

Namespace for Location Measurement Container

2776

urn:ietf:params:xml:ns:geopriv:lm

2777 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2778 with the RFC number for this specification.]] 2779

See RFCXXXX.

2780 2781 2782 END 2784 9.4. URN Sub-Namespace Registration for 2785 urn:ietf:params:xml:ns:geopriv:lm:basetypes 2787 This section registers a new XML namespace, 2788 "urn:ietf:params:xml:ns:geopriv:lm:basetypes", as per the guidelines 2789 in [RFC3688]. 2791 URI: urn:ietf:params:xml:ns:geopriv:lm:basetypes 2793 Registrant Contact: IETF, GEOPRIV working group, 2794 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2796 XML: 2798 BEGIN 2799 2800 2802 2803 2804 Base Device Types 2805 2806 2807

Namespace for Base Types

2808

urn:ietf:params:xml:ns:geopriv:lm:basetypes

2809 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2810 with the RFC number for this specification.]] 2811

See RFCXXXX.

2812 2813 2815 END 2817 9.5. URN Sub-Namespace Registration for 2818 urn:ietf:params:xml:ns:geopriv:lm:lldp 2820 This section registers a new XML namespace, 2821 "urn:ietf:params:xml:ns:geopriv:lm:lldp", as per the guidelines in 2822 [RFC3688]. 2824 URI: urn:ietf:params:xml:ns:geopriv:lm:lldp 2826 Registrant Contact: IETF, GEOPRIV working group, 2827 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2829 XML: 2831 BEGIN 2832 2833 2835 2836 2837 LLDP Measurement Set 2838 2839 2840

Namespace for LLDP Measurement Set

2841

urn:ietf:params:xml:ns:geopriv:lm:lldp

2842 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2843 with the RFC number for this specification.]] 2844

See RFCXXXX.

2845 2846 2847 END 2849 9.6. URN Sub-Namespace Registration for 2850 urn:ietf:params:xml:ns:geopriv:lm:dhcp 2852 This section registers a new XML namespace, 2853 "urn:ietf:params:xml:ns:geopriv:lm:dhcp", as per the guidelines in 2854 [RFC3688]. 2856 URI: urn:ietf:params:xml:ns:geopriv:lm:dhcp 2858 Registrant Contact: IETF, GEOPRIV working group, 2859 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2861 XML: 2863 BEGIN 2864 2865 2867 2868 2869 DHCP Measurement Set 2870 2871 2872

Namespace for DHCP Measurement Set

2873

urn:ietf:params:xml:ns:geopriv:lm:dhcp

2874 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2875 with the RFC number for this specification.]] 2876

See RFCXXXX.

2877 2878 2879 END 2881 9.7. URN Sub-Namespace Registration for 2882 urn:ietf:params:xml:ns:geopriv:lm:wifi 2884 This section registers a new XML namespace, 2885 "urn:ietf:params:xml:ns:geopriv:lm:wifi", as per the guidelines in 2886 [RFC3688]. 2888 URI: urn:ietf:params:xml:ns:geopriv:lm:wifi 2890 Registrant Contact: IETF, GEOPRIV working group, 2891 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2893 XML: 2895 BEGIN 2896 2897 2899 2900 2901 WiFi Measurement Set 2902 2903 2904

Namespace for WiFi Measurement Set

2905

urn:ietf:params:xml:ns:geopriv:lm:wifi

2906 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2907 with the RFC number for this specification.]] 2908

See RFCXXXX.

2909 2910 2912 END 2914 9.8. URN Sub-Namespace Registration for 2915 urn:ietf:params:xml:ns:geopriv:lm:cell 2917 This section registers a new XML namespace, 2918 "urn:ietf:params:xml:ns:geopriv:lm:cell", as per the guidelines in 2919 [RFC3688]. 2921 URI: urn:ietf:params:xml:ns:geopriv:lm:cell 2923 Registrant Contact: IETF, GEOPRIV working group, 2924 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2926 XML: 2928 BEGIN 2929 2930 2932 2933 2934 Cellular Measurement Set 2935 2936 2937

Namespace for Cellular Measurement Set

2938

urn:ietf:params:xml:ns:geopriv:lm:cell

2939 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2940 with the RFC number for this specification.]] 2941

See RFCXXXX.

2942 2943 2944 END 2946 9.9. URN Sub-Namespace Registration for 2947 urn:ietf:params:xml:ns:geopriv:lm:gnss 2949 This section registers a new XML namespace, 2950 "urn:ietf:params:xml:ns:geopriv:lm:gnss", as per the guidelines in 2951 [RFC3688]. 2953 URI: urn:ietf:params:xml:ns:geopriv:lm:gnss 2955 Registrant Contact: IETF, GEOPRIV working group, 2956 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2958 XML: 2960 BEGIN 2961 2962 2964 2965 2966 GNSS Measurement Set 2967 2968 2969

Namespace for GNSS Measurement Set

2970

urn:ietf:params:xml:ns:geopriv:lm:gnss

2971 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2972 with the RFC number for this specification.]] 2973

See RFCXXXX.

2974 2975 2976 END 2978 9.10. URN Sub-Namespace Registration for 2979 urn:ietf:params:xml:ns:geopriv:lm:dsl 2981 This section registers a new XML namespace, 2982 "urn:ietf:params:xml:ns:geopriv:lm:dsl", as per the guidelines in 2983 [RFC3688]. 2985 URI: urn:ietf:params:xml:ns:geopriv:lm:dsl 2987 Registrant Contact: IETF, GEOPRIV working group, 2988 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2990 XML: 2992 BEGIN 2993 2994 2996 2997 2998 DSL Measurement Set 2999 3000 3001

Namespace for DSL Measurement Set

3002

urn:ietf:params:xml:ns:geopriv:lm:dsl

3003 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 3004 with the RFC number for this specification.]] 3005

See RFCXXXX.

3006 3007 3009 END 3011 9.11. XML Schema Registration for Measurement Source Schema 3013 This section registers an XML schema as per the guidelines in 3014 [RFC3688]. 3016 URI: urn:ietf:params:xml:schema:pidf:geopriv10:lmsrc 3018 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3019 Martin Thomson (martin.thomson@andrew.com). 3021 Schema: The XML for this schema can be found in Section 8.2 of this 3022 document. 3024 9.12. XML Schema Registration for Measurement Container Schema 3026 This section registers an XML schema as per the guidelines in 3027 [RFC3688]. 3029 URI: urn:ietf:params:xml:schema:lm 3031 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3032 Martin Thomson (martin.thomson@andrew.com). 3034 Schema: The XML for this schema can be found in Section 8.1 of this 3035 document. 3037 9.13. XML Schema Registration for Base Types Schema 3039 This section registers an XML schema as per the guidelines in 3040 [RFC3688]. 3042 URI: urn:ietf:params:xml:schema:lm:basetypes 3044 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3045 Martin Thomson (martin.thomson@andrew.com). 3047 Schema: The XML for this schema can be found in Section 8.3 of this 3048 document. 3050 9.14. XML Schema Registration for LLDP Schema 3052 This section registers an XML schema as per the guidelines in 3053 [RFC3688]. 3055 URI: urn:ietf:params:xml:schema:lm:lldp 3057 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3058 Martin Thomson (martin.thomson@andrew.com). 3060 Schema: The XML for this schema can be found in Section 8.4 of this 3061 document. 3063 9.15. XML Schema Registration for DHCP Schema 3065 This section registers an XML schema as per the guidelines in 3066 [RFC3688]. 3068 URI: urn:ietf:params:xml:schema:lm:dhcp 3070 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3071 Martin Thomson (martin.thomson@andrew.com). 3073 Schema: The XML for this schema can be found in Section 8.5 of this 3074 document. 3076 9.16. XML Schema Registration for WiFi Schema 3078 This section registers an XML schema as per the guidelines in 3079 [RFC3688]. 3081 URI: urn:ietf:params:xml:schema:lm:wifi 3083 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3084 Martin Thomson (martin.thomson@andrew.com). 3086 Schema: The XML for this schema can be found in Section 8.6 of this 3087 document. 3089 9.17. XML Schema Registration for Cellular Schema 3091 This section registers an XML schema as per the guidelines in 3092 [RFC3688]. 3094 URI: urn:ietf:params:xml:schema:lm:cellular 3096 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3097 Martin Thomson (martin.thomson@andrew.com). 3099 Schema: The XML for this schema can be found in Section 8.7 of this 3100 document. 3102 9.18. XML Schema Registration for GNSS Schema 3104 This section registers an XML schema as per the guidelines in 3105 [RFC3688]. 3107 URI: urn:ietf:params:xml:schema:lm:gnss 3109 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3110 Martin Thomson (martin.thomson@andrew.com). 3112 Schema: The XML for this schema can be found in Section 8.8 of this 3113 document. 3115 9.19. XML Schema Registration for DSL Schema 3117 This section registers an XML schema as per the guidelines in 3118 [RFC3688]. 3120 URI: urn:ietf:params:xml:schema:lm:dsl 3122 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3123 Martin Thomson (martin.thomson@andrew.com). 3125 Schema: The XML for this schema can be found in Section 8.9 of this 3126 document. 3128 10. Acknowledgements 3130 Thanks go to Simon Cox for his comments relating to terminology that 3131 have helped ensure that this document is aligns with ongoing work in 3132 the Open Geospatial Consortium (OGC). Thanks to Neil Harper for his 3133 review and comments on the GNSS sections of this document. Thanks to 3134 Noor-E-Gagan Singh, Gabor Bajko and Russell Priebe for their 3135 significant input to and suggestions for improving the 802.11 3136 measurements. Thanks to Cullen Jennings for feedback and 3137 suggestions. Bernard Aboba provided review and feedback on a range 3138 of measurement data definitions. Mary Barnes provided a review and 3139 corrections. David Waitzman and John Bressler both noted 3140 shortcomings with 802.11 measurements. 3142 11. References 3144 11.1. Normative References 3146 [DSL.TR025] 3147 Wang, R., "Core Network Architecture Recommendations for 3148 Access to Legacy Data Networks over ADSL", September 1999. 3150 [DSL.TR101] 3151 Cohen, A. and E. Shrum, "Migration to Ethernet-Based DSL 3152 Aggregation", April 2006. 3154 [GPS.ICD] "Navstar GPS Space Segment/Navigation User Interface", 3155 ICD GPS-200, Apr 2000. 3157 [Galileo.ICD] 3158 GJU, "Galileo Open Service Signal In Space Interface 3159 Control Document (SIS ICD)", May 2006. 3161 [I-D.ietf-geopriv-http-location-delivery] 3162 Barnes, M., Winterbottom, J., Thomson, M., and B. Stark, 3163 "HTTP Enabled Location Delivery (HELD)", 3164 draft-ietf-geopriv-http-location-delivery-16 (work in 3165 progress), August 2009. 3167 [RFC0020] Cerf, V., "ASCII format for network interchange", RFC 20, 3168 October 1969. 3170 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 3171 Requirement Levels", BCP 14, RFC 2119, March 1997. 3173 [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 3174 10646", STD 63, RFC 3629, November 2003. 3176 [RFC4119] Peterson, J., "A Presence-based GEOPRIV Location Object 3177 Format", RFC 4119, December 2005. 3179 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 3180 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 3181 May 2008. 3183 [RFC5491] Winterbottom, J., Thomson, M., and H. Tschofenig, "GEOPRIV 3184 Presence Information Data Format Location Object (PIDF-LO) 3185 Usage Clarification, Considerations, and Recommendations", 3186 RFC 5491, March 2009. 3188 11.2. Informative References 3190 [ANSI/TIA-1057] 3191 ANSI/TIA, "Link Layer Discovery Protocol for Media 3192 Endpoint Devices", TIA 1057, April 2006. 3194 [GPS.SPOOF] 3195 Scott, L., "Anti-Spoofing and Authenticated Signal 3196 Architectures for Civil Navigation Signals", ION- 3197 GNSS Portland, Oregon, 2003. 3199 [HARPER] Harper, N., Dawson, M., and D. Evans, "Server-side 3200 spoofing and detection for Assisted-GPS", Proceedings of 3201 International Global Navigation Satellite Systems Society 3202 (IGNSS) Symposium 2009 16, December 2009, 3203 . 3205 [I-D.ietf-geopriv-held-identity-extensions] 3206 Winterbottom, J., Thomson, M., Tschofenig, H., and R. 3207 Barnes, "Use of Device Identity in HTTP-Enabled Location 3208 Delivery (HELD)", 3209 draft-ietf-geopriv-held-identity-extensions-05 (work in 3210 progress), October 2010. 3212 [I-D.thomson-geopriv-uncertainty] 3213 Thomson, M. and J. Winterbottom, "Representation of 3214 Uncertainty and Confidence in PIDF-LO", 3215 draft-thomson-geopriv-uncertainty-05 (work in progress), 3216 May 2010. 3218 [IANA.enterprise] 3219 IANA, "Private Enterprise Numbers", 3220 . 3222 [IEEE.80211] 3223 IEEE, "Wireless LAN Medium Access Control (MAC) and 3224 Physical Layer (PHY) specifications - IEEE 802.11 Wireless 3225 Network Management", IEEE Std 802.11-2007, June 2007. 3227 [IEEE.80211V] 3228 IEEE, "Wireless LAN Medium Access Control (MAC) and 3229 Physical Layer (PHY) specifications - IEEE 802.11 Wireless 3230 Network Management (Draft)", P802.11v D12.0, June 2010. 3232 [IEEE.8021AB] 3233 IEEE, "IEEE Standard for Local and Metropolitan area 3234 networks, Station and Media Access Control Connectivity 3235 Discovery", 802.1AB, June 2005. 3237 [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, 3238 "Remote Authentication Dial In User Service (RADIUS)", 3239 RFC 2865, June 2000. 3241 [RFC3046] Patrick, M., "DHCP Relay Agent Information Option", 3242 RFC 3046, January 2001. 3244 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 3245 January 2004. 3247 [RFC3693] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and 3248 J. Polk, "Geopriv Requirements", RFC 3693, February 2004. 3250 [RFC3993] Johnson, R., Palaniappan, T., and M. Stapp, "Subscriber-ID 3251 Suboption for the Dynamic Host Configuration Protocol 3252 (DHCP) Relay Agent Option", RFC 3993, March 2005. 3254 [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing 3255 Architecture", RFC 4291, February 2006. 3257 [RFC4580] Volz, B., "Dynamic Host Configuration Protocol for IPv6 3258 (DHCPv6) Relay Agent Subscriber-ID Option", RFC 4580, 3259 June 2006. 3261 [RFC4649] Volz, B., "Dynamic Host Configuration Protocol for IPv6 3262 (DHCPv6) Relay Agent Remote-ID Option", RFC 4649, 3263 August 2006. 3265 [RFC5808] Marshall, R., "Requirements for a Location-by-Reference 3266 Mechanism", RFC 5808, May 2010. 3268 Authors' Addresses 3270 Martin Thomson 3271 Andrew 3272 Andrew Building (39) 3273 University of Wollongong 3274 Northfields Avenue 3275 Wollongong, NSW 2522 3276 AU 3278 Phone: +61 2 4221 2915 3279 Email: martin.thomson@andrew.com 3280 URI: http://www.andrew.com/ 3281 James Winterbottom 3282 Andrew 3283 Andrew Building (39) 3284 University of Wollongong 3285 Northfields Avenue 3286 NSW 2522 3287 AU 3289 Phone: +61 2 4221 2938 3290 Email: james.winterbottom@andrew.com 3291 URI: http://www.andrew.com/