idnits 2.17.1 draft-ietf-geopriv-held-measurements-03.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** There are 801 instances of lines with control characters in the document. -- The document has examples using IPv4 documentation addresses according to RFC6890, but does not use any IPv6 documentation addresses. Maybe there should be IPv6 examples, too? Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document seems to contain a disclaimer for pre-RFC5378 work, but was first submitted on or after 10 November 2008. The disclaimer is usually necessary only for documents that revise or obsolete older RFCs, and that take significant amounts of text from those RFCs. If you can contact all authors of the source material and they are willing to grant the BCP78 rights to the IETF Trust, you can and should remove the disclaimer. Otherwise, the disclaimer is needed and you can ignore this comment. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (March 11, 2011) is 4794 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: '0-5' is mentioned on line 2073, but not defined == Missing Reference: '0-4' is mentioned on line 2073, but not defined == Missing Reference: '0-9' is mentioned on line 2073, but not defined == Missing Reference: '0-1' is mentioned on line 2073, but not defined == Unused Reference: 'I-D.thomson-geopriv-uncertainty' is defined on line 3223, but no explicit reference was found in the text == Unused Reference: 'RFC5808' is defined on line 3276, but no explicit reference was found in the text ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) == Outdated reference: A later version (-08) exists of draft-thomson-geopriv-uncertainty-06 Summary: 2 errors (**), 0 flaws (~~), 9 warnings (==), 2 comments (--). 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: September 12, 2011 March 11, 2011 7 Using Device-provided Location-Related Measurements in Location 8 Configuration Protocols 9 draft-ietf-geopriv-held-measurements-03 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 September 12, 2011. 41 Copyright Notice 43 Copyright (c) 2011 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 . . . . . . . . . . . . . . . . . 38 117 7.2.2.1. Effectiveness . . . . . . . . . . . . . . . . . . 39 118 7.2.2.2. Limitations . . . . . . . . . . . . . . . . . . . 39 119 7.2.3. Supporting Observations . . . . . . . . . . . . . . . 39 120 7.2.3.1. Effectiveness . . . . . . . . . . . . . . . . . . 40 121 7.2.3.2. Limitations . . . . . . . . . . . . . . . . . . . 40 122 7.2.4. Attribution . . . . . . . . . . . . . . . . . . . . . 41 123 7.2.5. Stateful Correlation of Location Requests . . . . . . 42 124 8. Measurement Schemas . . . . . . . . . . . . . . . . . . . . . 42 125 8.1. Measurement Container Schema . . . . . . . . . . . . . . . 42 126 8.2. Measurement Source Schema . . . . . . . . . . . . . . . . 45 127 8.3. Base Type Schema . . . . . . . . . . . . . . . . . . . . . 45 128 8.4. LLDP Measurement Schema . . . . . . . . . . . . . . . . . 48 129 8.5. DHCP Measurement Schema . . . . . . . . . . . . . . . . . 49 130 8.6. WiFi Measurement Schema . . . . . . . . . . . . . . . . . 51 131 8.7. Cellular Measurement Schema . . . . . . . . . . . . . . . 54 132 8.8. GNSS Measurement Schema . . . . . . . . . . . . . . . . . 57 133 8.9. DSL Measurement Schema . . . . . . . . . . . . . . . . . . 58 134 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 60 135 9.1. IANA Registry for GNSS Types . . . . . . . . . . . . . . . 60 136 9.2. URN Sub-Namespace Registration for 137 urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc . . . . . . . 61 138 9.3. URN Sub-Namespace Registration for 139 urn:ietf:params:xml:ns:geopriv:lm . . . . . . . . . . . . 62 140 9.4. URN Sub-Namespace Registration for 141 urn:ietf:params:xml:ns:geopriv:lm:basetypes . . . . . . . 63 142 9.5. URN Sub-Namespace Registration for 143 urn:ietf:params:xml:ns:geopriv:lm:lldp . . . . . . . . . . 64 144 9.6. URN Sub-Namespace Registration for 145 urn:ietf:params:xml:ns:geopriv:lm:dhcp . . . . . . . . . . 64 146 9.7. URN Sub-Namespace Registration for 147 urn:ietf:params:xml:ns:geopriv:lm:wifi . . . . . . . . . . 65 148 9.8. URN Sub-Namespace Registration for 149 urn:ietf:params:xml:ns:geopriv:lm:cell . . . . . . . . . . 66 150 9.9. URN Sub-Namespace Registration for 151 urn:ietf:params:xml:ns:geopriv:lm:gnss . . . . . . . . . . 66 152 9.10. URN Sub-Namespace Registration for 153 urn:ietf:params:xml:ns:geopriv:lm:dsl . . . . . . . . . . 67 154 9.11. XML Schema Registration for Measurement Source Schema . . 68 155 9.12. XML Schema Registration for Measurement Container 156 Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 68 157 9.13. XML Schema Registration for Base Types Schema . . . . . . 68 158 9.14. XML Schema Registration for LLDP Schema . . . . . . . . . 68 159 9.15. XML Schema Registration for DHCP Schema . . . . . . . . . 69 160 9.16. XML Schema Registration for WiFi Schema . . . . . . . . . 69 161 9.17. XML Schema Registration for Cellular Schema . . . . . . . 69 162 9.18. XML Schema Registration for GNSS Schema . . . . . . . . . 70 163 9.19. XML Schema Registration for DSL Schema . . . . . . . . . . 70 164 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 70 165 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 70 166 11.1. Normative References . . . . . . . . . . . . . . . . . . . 70 167 11.2. Informative References . . . . . . . . . . . . . . . . . . 72 168 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 73 170 1. Introduction 172 A location configuration protocol (LCP) provides a means for a Device 173 to request information about its physical location from an access 174 network. A location information server (LIS) is the server that 175 provides location information; information that is available due to 176 the knowledge about the network and physical environment that is 177 available to the LIS. 179 As a part of the access network, the LIS is able to acquire 180 measurement results from network Devices within the network that are 181 related to Device location. The LIS also has access to information 182 about the network topology that can be used to turn measurement data 183 into location information. However, this information can be enhanced 184 with information acquired from the Device itself. 186 A Device is able to make observations about its network attachment, 187 or its physical environment. The location-related measurement data 188 might be unavailable to the LIS; alternatively, the LIS might be able 189 to acquire the data, but at a higher cost in time or otherwise. 190 Providing measurement data gives the LIS more options in determining 191 location, which could improve the quality of the service provided by 192 the LIS. Improvements in accuracy are one potential gain, but 193 improved response times and lower error rates are also possible. 195 This document describes a means for a Device to report location- 196 related measurement data to the LIS. Examples based on the HELD 197 [RFC5985] location configuration 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 [RFC5985]. 204 This document also uses the following definitions: 206 Location Measurement: An observation about the physical properties 207 of a particular Device's network access. The result of a location 208 measurement--"location-related measurement data", or simply 209 "measurement data" given sufficient context--can be used to 210 determine the location of a Device. Location-related measurement 211 data does not identify a Device; measurement data can change with 212 time if the location of the Device also changes. 214 Location-related measurement data does not necessarily contain 215 location information directly, but it can be used in combination 216 with contextual knowledge of the network, or algorithms to derive 217 location information. Examples of location-related measurement 218 data are: radio signal strength or timing measurements, Ethernet 219 switch and port identifiers. 221 Location-related measurement data can be considered sighting 222 information, based on the definition in [RFC3693]. 224 Location Estimate: The result of location determination, a location 225 estimate is an approximation of where the Device is located. 226 Location estimates are subject to uncertainty, which arise from 227 errors in measurement results. 229 GNSS: Global Navigation Satellite System. A satellite-based system 230 that provides positioning and time information. For example, the 231 US Global Positioning System (GPS) or the European Galileo system. 233 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 234 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 235 document are to be interpreted as described in [RFC2119]. 237 3. Location-Related Measurements in LCPs 239 This document defines a standard container for the conveyance of 240 location-related measurement parameters in location configuration 241 protocols. This is an XML container that identifies parameters by 242 type and allows the Device to provide the results of any measurement 243 it is able to perform. A set of measurement schemas are also defined 244 that can be carried in the generic container. 246 The simplest example of measurement data conveyance is illustrated by 247 the example message in Figure 1. This shows a HELD location request 248 message with an Ethernet switch and port measurement taken using LLDP 249 [IEEE.8021AB]. 251 252 civic 253 255 256 0a01003c 257 c2 258 259 260 262 Figure 1: HELD Location Request with Measurement Data 263 Measurement data that the LIS does not support or understand can be 264 ignored. The measurements defined in this document follow this rule; 265 extensions that could result in backward incompatibility MUST be 266 added as new measurement definitions rather than extensions to 267 existing types. 269 Multiple sets of measurement data, either of the same type or from 270 different sources can be included in the "measurements" element. See 271 Section 4.1.1 for details on repetition of this element. 273 Use of location-related measurement data is at the discretion of the 274 LIS, but the "method" parameter in the PIDF-LO SHOULD be adjusted to 275 reflect the method used. 277 Location-related measurement data need not be provided exclusively by 278 Devices. A third party location requester can request location 279 information using measurement data, if they are able and authorized. 280 There are privacy considerations relating to the use of measurements 281 by third parties, which are discussed in Section 6.4. 283 Location-related measurement data and its use presents a number of 284 security challenges. These are described in more detail in 285 Section 7. 287 4. Location-Related Measurement Data Types 289 A common container is defined for the expression of location 290 measurement data, as well as a simple means of identifying specific 291 types of measurement data for the purposes of requesting them. 293 The following example shows a measurement container with measurement 294 time and expiration time included. A WiFi measurement is enclosed. 296 299 300 301 00-12-F0-A0-80-EF 302 wlan-home 303 304 305 307 Figure 2: Measurement Example 308 4.1. Measurement Container 310 The "measurement" element is used to encapsulate measurement data 311 that is collected at a certain point in time. It contains time-based 312 attributes that are common to all forms of measurement data, and 313 permits the inclusion of arbitrary measurement data. 315 This container can be added to any request for location information, 316 such as a HELD location request [RFC5985]. 318 4.1.1. Time of Measurement 320 The "time" attribute records the time that the measurement or 321 observation was made. This time can be different to the time that 322 the measurement information was reported. Time information can be 323 used to populate a timestamp on the location result, or to determine 324 if the measurement information is used. 326 The "time" attribute is optional to avoid forcing an arbitrary choice 327 of timestamp for relatively static types of measurement (for 328 instance, the DSL measurements in Section 5.6) and for legacy Devices 329 that don't record time information (such as the Home Location 330 Register/Home Subscriber Server for cellular). However, time SHOULD 331 be provided whenever possible. 333 The "time" attribute is attached to the root "measurement" element. 334 If it is necessary to provide multiple sets of measurement data with 335 different times, multiple "measurement" elements SHOULD be provided. 337 4.1.2. Expiry Time on Location-Related Measurement Data 339 A Device is able to indicate an expiry time in the location 340 measurement using the "expires" attribute. Nominally, this attribute 341 indicates how long information is expected to be valid for, but it 342 can also indicate a time limit on the retention and use of the 343 measurement data. A Device can use this attribute to prevent the LIS 344 from retaining measurement data or limit the time that a LIS retains 345 this information. 347 Note: Movement of a Device might result in the measurement data 348 being invalidated before the expiry time. 350 The LIS MUST NOT keep location-related measurement data beyond the 351 time indicated in the "expires" attribute. 353 4.2. RMS Error and Number of Samples 355 Often a measurement is taken more than once over a period of time. 356 Reporting the average of a number of measurement results mitigates 357 the effects of random errors that occur in the measurement process. 359 Reporting each measurement individually can be the most effective 360 method of reporting multiple measurements. This is achieved by 361 providing multiple "measurement" elements for different times. 363 The alternative is to aggregate multiple measurements and report a 364 mean value across the set of measurements. Additional information 365 about the distribution of the results can be useful in determining 366 location uncertainty. 368 Two optional attributes are provided for certain measurement values: 370 rmsError: The root-mean-squared (RMS) error of the set of 371 measurement values used in calculating the result. RMS error is 372 expressed in the same units as the measurement, unless otherwise 373 stated. If an accurate value for RMS error is not known, this 374 value can be used to indicate an upper bound or estimate for the 375 RMS error. 377 samples: The number of samples that were taken in determining the 378 measurement value. If omitted, this value can be assumed to be a 379 very large value, so that the RMS error is an indication of the 380 standard deviation of the sample set. 382 For some measurement techniques, measurement error is largely 383 dependent on the measurement technique employed. In these cases, 384 measurement error is largely a product of the measurement technique 385 and not the specific circumstances, so RMS error does not need to be 386 actively measured. A fixed value MAY be provided for RMS error where 387 appropriate. 389 The "rmsError" and "samples" elements are added as attributes of 390 specific measurement data types. 392 4.2.1. Time RMS Error 394 Measurement of time can be significant in certain circumstances. The 395 GNSS measurements included in this document are one such case where a 396 small error in time can result in a large error in location. Factors 397 such as clock drift and errors in time sychronization can result in 398 small, but significant, time errors. Including an indication of the 399 quality of the time can be helpful. 401 An optional "timeError" attribute can be added to the "measurement" 402 element to indicate the RMS error in time. "timeError" indicates an 403 upper bound on the time RMS error in seconds. 405 The "timeError" attribute does not apply where multiple samples of a 406 measurement is taken over time. If multiple samples are taken, each 407 SHOULD be included in a different "measurement" element. 409 4.3. Measurement Request 411 A measurement request is used by a protocol peer to describe a set of 412 measurement data that it desires. A "measurementRequest" element is 413 defined that can be included in a protocol exchange. 415 For instance, a LIS can use a measurement request in HELD responses. 416 If the LIS is unable to provide location information, but it believes 417 that a particular measurement type would enable it to provide a 418 location, it can include a measurement request in an error response. 420 The "measurement" element of the measurement request identifies the 421 type of measurement that is requested. The "type" attribute of this 422 element indicates the type of measurement, as identified by an XML 423 qualified name. An optional "samples" attribute indicates how many 424 samples of the identified measurement are requested. 426 The "measurement" element can be repeated to request multiple (or 427 alternative) measurement types. 429 Additional XML content might be defined for a particular measurement 430 type that is used to further refine a request. These elements either 431 constrain what is requested or specify optional components of the 432 measurement data that are needed. These are defined along with the 433 specific measurement type. 435 In the HELD protocol, the inclusion of a measurement request in a 436 error response with a code of "locationUnknown" indicates that the 437 LIS believes that providing the indicated measurements would increase 438 the likelihood of a subsequent request being successful. 440 The following example shows a HELD error response that indicates that 441 WiFi measurement data would be useful if a later request were made. 442 Additional elements indicate that received signal strength for an 443 802.11n access point is requested. 445 447 Insufficient measurement data 448 451 452 n 453 wifi:rcpi 454 455 456 458 Figure 3: HELD Error Requesting Measurement Data 460 A measurement request that is included in other HELD messages has 461 undefined semantics and can be safely ignored. Other specifications 462 might define semantics for measurement requests under other 463 conditions. 465 4.4. Identifying Location Provenance 467 An extension is made to the PIDF-LO [RFC4119] that allows a location 468 recipient to identify the source (or sources) of location information 469 and the measurement data that was used to determine that location 470 information. 472 The "source" element is added to the "geopriv" element of the 473 PIDF-LO. This element does not identify specific entities. Instead, 474 it identifies the type of source. 476 The following types of measurement source are identified: 478 lis: Location information is based on measurement data that the LIS 479 or sources that it trusts have acquired. This label might be used 480 if measurement data provided by the Device has been completely 481 validated by the LIS. 483 device: Location information is based on measurement data that the 484 Device has provided to the LIS. 486 other: Location information is based on measurement data that a 487 third party has provided. This might be an authorized third party 488 that uses identity parameters 489 [I-D.ietf-geopriv-held-identity-extensions] or any other entity. 491 No assertion is made about the veracity of the measurement data from 492 sources other than the LIS. A combination of tags MAY be included to 493 indicate that measurement data from both sources was used. 495 For example, the first tuple of the following PIDF-LO indicates that 496 measurement data from a LIS and a device was combined to produce the 497 result, the second tuple was produced by the LIS alone. 499 505 506 507 508 509 510 7.34324 134.47162 511 512 850.24 513 514 515 516 517 OTDOA 518 lis device 519 520 521 522 523 524 525 526 527 7.34379 134.46484 528 529 9000 530 531 532 533 534 Cell 535 lis 536 537 538 539 541 5. Location-Related Measurement Data Types 543 This document defines location-related measurement data types for a 544 range of common network types. 546 All included measurement data definitions allow for arbitrary 547 extension in the corresponding schema. As new parameters that are 548 applicable to location determination are added, these can be added as 549 new XML elements in a unique namespace. Though many of the 550 underlying protocols support extension, creation of specific XML- 551 based extensions to the measurement format is favored over 552 accomodating protocol-specific extensions in generic containers. 554 5.1. LLDP Measurements 556 Link-Layer Discovery Protocol (LLDP) [IEEE.8021AB] messages are sent 557 between adjacent nodes in an IEEE 802 network (e.g. wired Ethernet, 558 WiFi, 802.16). These messages all contain identification information 559 for the sending node, which can be used to determine location 560 information. A Device that receives LLDP messages can report this 561 information as a location-related measurement to the LIS, which is 562 then able to use the measurement data in determining the location of 563 the Device. 565 Note: The LLDP extensions defined in LLDP Media Endpoint Discovery 566 (LLDP-MED) [ANSI-TIA-1057] provide the ability to acquire location 567 information directly from an LLDP endpoint. Where this 568 information is available, it might be unnecessary to use any other 569 form of location configuration. 571 Values are provided as hexadecimal sequences. The Device MUST report 572 the values directly as they were provided by the adjacent node. 573 Attempting to adjust or translate the type of identifier is likely to 574 cause the measurement data to be useless. 576 Where a Device has received LLDP messages from multiple adjacent 577 nodes, it should provide information extracted from those messages by 578 repeating the "lldp" element. 580 An example of an LLDP measurement is shown in Figure 4. This shows 581 an adjacent node (chassis) that is identified by the IP address 582 192.0.2.45 (hexadecimal c000022d) and the port on that node is 583 numbered using an agent circuit ID [RFC3046] of 162 (hexadecimal a2). 585 587 588 c000022d 589 a2 590 591 593 Figure 4: LLDP Measurement Example 595 IEEE 802 Devices that are able to obtain information about adjacent 596 network switches and their attachment to them by other means MAY use 597 this data type to convey this information. 599 5.2. DHCP Relay Agent Information Measurements 601 The DHCP Relay Agent Information option [RFC3046] provides 602 measurement data about the network attachment of a Device. This 603 measurement data can be included in the "dhcp-rai" element. 605 The elements in the DHCP relay agent information options are opaque 606 data types assigned by the DHCP relay agent. The three items are all 607 optional: circuit identifier ("circuit", [RFC3046]), remote 608 identifier ("remote", [RFC3046], [RFC4649]) and subscriber identifier 609 ("subscriber", [RFC3993], [RFC4580]). The DHCPv6 remote identifier 610 has an associated enterprise number [IANA.enterprise] as an XML 611 attribute. 613 615 616 ::ffff:192.0.2.158 617 108b 618 619 621 Figure 5: DHCP Relay Agent Information Measurement Example 623 The "giaddr" is specified as a dotted quad IPv4 address or an RFC 624 4291 [RFC4291] IPv6 address, using the forms defined in [RFC3986]. 625 The enterprise number is specified as a decimal integer. All other 626 information is included verbatim from the DHCP request in hexadecimal 627 format. 629 5.3. 802.11 WLAN Measurements 631 In WiFi, or 802.11 [IEEE.80211], networks a Device might be able to 632 provide information about the access point (AP) that it is attached 633 to, or other WiFi points it is able to see. This is provided using 634 the "wifi" element, as shown in Figure 6, which shows a single 635 complete measurement for a single access point. 637 639 640 Intel(r)PRO/Wireless 2200BG 641 642 AB-CD-EF-AB-CD-EF 643 example 644 5 645 646 647 -34.4 150.8 648 649 650 a 651 5 652 2 653 2 654 2.56e-9 655 656 23 657 5 658 -59 659 23 660 661 662 10 663 9 664 -98.5 665 7.5 666 667 668 669 671 Figure 6: 802.11 WLAN Measurement Example 673 A wifi element is made up of one or more access points, and an 674 optional "nicType" element. Each access point is described using the 675 "ap" element, which is comprised of the following fields: 677 bssid: The basic service set identifier. In an Infrastructure BSS 678 network, the bssid is the 48 bit MAC address of the access point. 680 The "verified" attribute of this element describes whether the 681 device has verified the MAC address or it authenticated the access 682 point or the network operating the access point (for example, a 683 captive portal accessed through the access point has been 684 authenticated). This attributes defaults to a value of "false" 685 when omitted. 687 ssid: The service set identifier (SSID) for the wireless network 688 served by the access point. 690 The SSID is a 32-octet identifier that is commonly represented as 691 a ASCII [RFC0020] or UTF-8 [RFC3629] encoded string. To represent 692 octets that cannot be directly included in an XML element, 693 escaping is used. Sequences of octets that do not represent a 694 valid UTF-8 encoding can be escaped using a backslash ('\') 695 followed by two case-insensitive hexadecimal digits representing 696 the value of a single octet. 698 The canonical or value-space form of an SSID is a sequence of up 699 to 32 octets that is produced from the concatenation of UTF-8 700 encoded sequences of unescaped characters and octets derived from 701 escaped components. 703 channel: The channel number (frequency) that the access point 704 operates on. 706 location: The location of the access point, as reported by the 707 access point. This element contains any valid location, using the 708 rules for a "location-info" element, as described in [RFC5491]. 710 type: The network type for the network access. This element 711 includes the alphabetic suffix of the 802.11 specification that 712 introducted the radio interface, or PHY; e.g. "a", "b", "g", or 713 "n". 715 band: The frequency band for the radio, in gigahertz (GHz). 802.11 716 [IEEE.80211] specifies PHY layers that use 2.4, 3.7 and 5 717 gigahertz frequency bands. 719 regclass: The regulatory domain and class. The "country" attribute 720 optionally includes the applicable two character country 721 identifier (dot11CountryString), which can be followed by an 'O', 722 'I' or 'X'. The element text content includes the value of the 723 regulatory class: an 8-bit integer in decimal form. 725 antenna: The antenna identifier for the antenna that the access 726 point is using to transmit the measured signals. 728 flightTime: Flight time is the difference between the time of 729 departure (TOD) of signal from a transmitting station and time of 730 arrival (TOA) of signal at a receiving station, as defined in 731 [IEEE.80211V]. Measurement of this value requires that stations 732 synchronize their clocks. This value can be measured by access 733 point or Device; because the flight time is assumed to be the same 734 in either direction - aside from measurement errors - only a 735 single element is provided. This element includes optional 736 "rmsError" and "samples" attributes. RMS error might be derived 737 from the reported RMS error in TOD and TOA. 739 apSignal: Measurement information for the signal transmitted by the 740 access point, as observed by the Device. Some of these values are 741 derived from 802.11v [IEEE.80211V] messages exchanged between 742 Device and access point. The contents of this element include: 744 transmit: The transmit power reported by the access point, in dB. 746 gain: The gain of the access point antenna reported by the access 747 point, in dB. 749 rcpi: The received channel power indicator for the access point 750 signal, as measured by the Device. This value SHOULD be in 751 units of dBm (with RMS error in dB). If power is measured in a 752 different fashion, the "dBm" attribute MUST be set to "false". 753 Signal strength reporting on current hardware uses a range of 754 different mechanisms; therefore, the value of the "nicType" 755 element SHOULD be included if the units are not known to be in 756 dBm and the value reported by the hardware should be included 757 without modification. This element includes optional 758 "rmsError" and "samples" attributes. 760 rsni: The received signal to noise indicator in dBm. This 761 element includes optional "rmsError" and "samples" attributes. 763 deviceSignal: Measurement information for the signal transmitted by 764 the device, as reported by the access point. This element 765 contains the same child elements as the "ap" element, with the 766 access point and Device roles reversed. 768 All elements are optional except for "bssid". 770 The "nicType" element is used to specify the make and model of the 771 wireless network interface in the Device. Different 802.11 chipsets 772 report measurements in different ways, so knowing the network 773 interface type aids the LIS in determining how to use the provided 774 measurement data. The content of this field is unconstrained and no 775 mechanisms are specified to ensure uniqueness. 777 5.3.1. Wifi Measurement Requests 779 Two elements are defined for requesting WiFi measurements in a 780 measurement request: 782 type: The "type" element identifies the desired type (or types that 783 are requested. 785 parameter: The "parameter" element identifies an optional 786 measurements are requested for each measured access point. An 787 element is identified by its qualified name. The optional 788 "context" parameter can be used to specify if an element is 789 included as a child of the "ap" or "device" elements; omission 790 indicates that it applies to both. 792 Multiple types or parameters can be requested by repeating either 793 element. 795 5.4. Cellular Measurements 797 Cellular Devices are common throughout the world and base station 798 identifiers can provide a good source of coarse location information. 799 This information can be provided to a LIS run by the cellar operator, 800 or may be provided to an alternative LIS operator that has access to 801 one of several global cell-id to location mapping databases. 803 A number of advanced location determination methods have been 804 developed for cellular networks. For these methods a range of 805 measurement parameters can be collected by the network, Device, or 806 both in cooperation. This document includes a basic identifier for 807 the wireless transmitter only; future efforts might define additional 808 parameters that enable more accurate methods of location 809 determination. 811 The cellular measurement set allows a Device to report to a LIS any 812 LTE (Figure 7), UMTS (Figure 8), GSM (Figure 9) or CDMA (Figure 10) 813 cells that it is able to observe. Cells are reported using their 814 global identifiers. All 3GPP cells are identified by public land 815 mobile network (PLMN), which is formed of mobile country code (MCC) 816 and mobile network code (MNC); specific fields are added for each 817 network type. 819 Formats for 3GPP cell identifiers are described in [TS.3GPP.23.003]. 820 Bit-level formats for CDMA cell identifiers are described in 821 [TIA-2000.5]; decimal representations are used. 823 MCC and MNC are provided as digit sequences; a leading zero in an MCC 824 or MNC is significant. All other values are decimal integers. 826 828 829 830 4652080936424 831 832 833 4650610736789 834 835 836 838 Long term evolution (LTE) cells are identified by a 28-bit cell 839 identifier (eucid). 841 Figure 7: Example LTE Cellular Measurement 843 845 846 847 46520 848 200065000 849 850 851 46506 852 1638332767 853 854 855 857 Universal mobile telephony service (UMTS) cells are identified by 16- 858 bit radio network controller (rnc) id and a 16-bit cell id (cid). 860 Figure 8: Example UMTS Cellular Measurement 861 863 864 865 46506 866 1638332767 867 868 869 871 Global System for Mobile communication (GSM) cells are identified by 872 a 16-bit location area code (lac) and 16-bit cell id (cid). 874 Figure 9: Example GSM Cellular Measurement 876 878 879 880 15892472312 881 882 883 15892472313 884 885 886 888 Code division multiple access (CDMA) cells are not identified by 889 PLMN, instead these usea 15-bit system id (sid), a 16-bit network id 890 (nid) and a 16-bit base station id (baseid). 892 Figure 10: Example CDMA Cellular Measurement 894 In general a cellular Device will be attached to the cellular network 895 and so the notion of a serving cell exists. Cellular network also 896 provide overlap between neighbouring sites, so a mobile Device can 897 hear more than one cell. The measurement schema supports sending 898 both the serving cell and any other cells that the mobile might be 899 able to hear. In some cases, the Device may simply be listening to 900 cell information without actually attaching to the network, mobiles 901 without a SIM are an example of this. In this case the Device may 902 simply report cells it can hear without flagging one as a serving 903 cell. An example of this is shown in Figure 11. 905 907 908 909 46520 910 200065000 911 912 913 46506 914 1638332767 915 916 917 919 Figure 11: Example Observed Cellular Measurement 921 5.4.1. Cellular Measurement Requests 923 Two elements can be used in measurement requests for cellular 924 measurements: 926 type: A label indicating the type of identifier to provide: one of 927 "gsm", "umts", "lte", or "cdma". 929 network: The network portion of the cell identifier. For 3GPP 930 networks, this is the combination of MCC and MNC; for CDMA, this 931 is the network identifier. 933 Multiple identifier types or networks can be identified by repeating 934 either element. 936 5.5. GNSS Measurements 938 GNSS use orbiting satellites to transmit signals. A Device with a 939 GNSS receiver is able to take measurements from the satellite 940 signals. The results of these measurements can be used to determine 941 time and the location of the Device. 943 Determining location and time in autonomous GNSS receivers follows 944 three steps: 946 Signal acquisition: During the signal acquisition stage, the 947 receiver searches for the repeating code that is sent by each GNSS 948 satellite. Successful operation typically requires measurement 949 data for a minimum of 5 satellites. At this stage, measurement 950 data is available to the Device. 952 Navigation message decode: Once the signal has been acquired, the 953 receiver then receives information about the configuration of the 954 satellite constellation. This information is broadcast by each 955 satellite and is modulated with the base signal at a low rate; for 956 instance, GPS sends this information at about 50 bits per second. 958 Calculation: The measurement data is combined with the data on the 959 satellite constellation to determine the location of the receiver 960 and the current time. 962 A Device that uses a GNSS receiver is able to report measurements 963 after the first stage of this process. A LIS can use the results of 964 these measurements to determine a location. In the case where there 965 are fewer results available than the optimal minimum, the LIS might 966 be able to use other sources of measurement information and combine 967 these with the available measurement data to determine a position. 969 Note: The use of different sets of GNSS _assistance data_ can 970 reduce the amount of time required for the signal acquisition 971 stage and obviate the need for the receiver to extract data on the 972 satellite constellation. Provision of assistance data is outside 973 the scope of this document. 975 Figure 12 shows an example of GNSS measurement data. The measurement 976 shown is for the GPS system and includes measurement data for three 977 satellites only. 979 981 983 984 499.9395 985 0.87595747 986 45 987 988 989 378.2657 990 0.56639479 991 52 992 993 994 -633.0309 995 0.57016835 996 48 997 998 999 1001 Figure 12: Example GNSS Measurement 1003 Each "gnss" element represents a single set of GNSS measurement data, 1004 taken at a single point in time. Measurements taken at different 1005 times can be included in different "gnss" elements to enable 1006 iterative refinement of results. 1008 GNSS measurement parameters are described in more detail in the 1009 following sections. 1011 5.5.1. GNSS System and Signal 1013 The GNSS measurement structure is designed to be generic and to apply 1014 to different GNSS types. Different signals within those systems are 1015 also accounted for and can be measured separately. 1017 The GNSS type determines the time system that is used. An indication 1018 of the type of system and signal can ensure that the LIS is able to 1019 correctly use measurements. 1021 Measurements for multiple GNSS types and signals can be included by 1022 repeating the "gnss" element. 1024 This document creates an IANA registry for GNSS types. Two satellite 1025 systems are registered by this document: GPS [GPS.ICD] and Galileo 1026 [Galileo.ICD]. Details for the registry are included in Section 9.1. 1028 5.5.2. Time 1030 Each set of GNSS measurements is taken at a specific point in time. 1031 The "time" attribute is used to indicate the time that the 1032 measurement was acquired, if the receiver knows how the time system 1033 used by the GNSS relates to UTC time. 1035 Alternative to (or in addition to) the measurement time, the 1036 "gnssTime" element MAY be included. The "gnssTime" element includes 1037 a relative time in milliseconds using the time system native to the 1038 satellite system. For the GPS satellite system, the "gnssTime" 1039 element includes the time of week in milliseconds. For the Galileo 1040 system, the "gnssTime" element includes the time of day in 1041 milliseconds. 1043 The accuracy of the time measurement provided is critical in 1044 determining the accuracy of the location information derived from 1045 GNSS measurements. The receiver SHOULD indicate an estimated time 1046 error for any time that is provided. An RMS error can be included 1047 for the "gnssTime" element, with a value in milliseconds. 1049 5.5.3. Per-Satellite Measurement Data 1051 Multiple satellites are included in each set of GNSS measurements 1052 using the "sat" element. Each satellite is identified by a number in 1053 the "num" attribute. The satellite number is consistent with the 1054 identifier used in the given GNSS. 1056 Both the GPS and Galileo systems use satellite numbers between 1 and 1057 64. 1059 The GNSS receiver measures the following parameters for each 1060 satellite: 1062 doppler: The observed Doppler shift of the satellite signal, 1063 measured in meters per second. This is converted from a value in 1064 Hertz by the receiver to allow the measurement to be used without 1065 knowledge of the carrier frequency of the satellite system. This 1066 value includes an optional RMS error attribute, also measured in 1067 meters per second. 1069 codephase: The observed code phase for the satellite signal, 1070 measured in milliseconds. This is converted the system-specific 1071 value of chips or wavelengths into a system independent value. 1072 Larger values indicate larger distances from satellite to 1073 receiver. This value includes an optional RMS error attribute, 1074 also measured in milliseconds. 1076 cn0: The signal to noise ratio for the satellite signal, measured in 1077 decibel-Hertz (dB-Hz). The expected range is between 20 and 50 1078 dB-Hz. 1080 mp: An estimation of the amount of error that multipath signals 1081 contribute in metres. This parameter is optional. 1083 cq: An indication of the carrier quality. Two attributes are 1084 included: "continuous" may be either "true" or "false"; direct may 1085 be either "direct" or "inverted". This parameter is optional. 1087 adr: The accumulated Doppler range, measured in metres. This 1088 parameter is optional and is not useful unless multiple sets of 1089 GNSS measurements are provided or differential positioning is 1090 being performed. 1092 All values are converted from measures native to the satellite system 1093 to generic measures to ensure consistency of interpretation. Unless 1094 necessary, the schema does not constrain these values. 1096 5.5.4. GNSS Measurement Requests 1098 Measurement requests can include a "gnss" element, which includes the 1099 "system" and "signal" attributes. Multiple elements can be included 1100 to indicate a requests for GNSS measurements from multiple systems or 1101 signals. 1103 5.6. DSL Measurements 1105 Digital Subscriber Line (DSL) networks rely on a range of network 1106 technology. DSL deployments regularly require cooperation between 1107 multiple organizations. These fall into two broad categories: 1108 infrastructure providers and Internet service providers (ISPs). 1109 Infrastructure providers manage the bulk of the physical 1110 infrastructure including cabling. End users obtain their service 1111 from an ISP, which manages all aspects visible to the end user 1112 including IP address allocation and operation of a LIS. See 1113 [DSL.TR025] and [DSL.TR101] for further information on DSL network 1114 deployments and the parameters that are available. 1116 Exchange of measurement information between these organizations is 1117 necessary for location information to be correctly generated. The 1118 ISP LIS needs to acquire location information from the infrastructure 1119 provider. However, the infrastructure provider has no knowledge of 1120 Device identifiers, it can only identify a stream of data that is 1121 sent to the ISP. This is resolved by passing measurement data 1122 relating to the Device to a LIS operated by the infrastructure 1123 provider. 1125 5.6.1. L2TP Measurements 1127 Layer 2 Tunneling Protocol (L2TP) is a common means of linking the 1128 infrastructure provider and the ISP. The infrastructure provider LIS 1129 requires measurement data that identifies a single L2TP tunnel, from 1130 which it can generate location information. Figure 13 shows an 1131 example L2TP measurement. 1133 1135 1136 1137 192.0.2.10 1138 192.0.2.61 1139 528 1140 1141 1142 1144 Figure 13: Example DSL L2TP Measurement 1146 5.6.2. RADIUS Measurements 1148 When authenticating network access, the infrastructure provider might 1149 employ a RADIUS [RFC2865] proxy at the DSL Access Module (DSLAM) or 1150 Access Node (AN). These messages provide the ISP RADIUS server with 1151 an identifier for the DSLAM or AN, plus the slot and port that the 1152 Device is attached on. These data can be provided as a measurement, 1153 which allows the infrastructure provider LIS to generate location 1154 information. 1156 The format of the AN, slot and port identifiers are not defined in 1157 the RADIUS protocol. Slot and port together identify a circuit on 1158 the AN, analogous to the circuit identifier in [RFC3046]. These 1159 items are provided directly, as they were in the RADIUS message. An 1160 example is shown in Figure 14. 1162 1164 1165 AN-7692 1166 3 1167 06 1168 1169 1171 Figure 14: Example DSL RADIUS Measurement 1172 5.6.3. Ethernet VLAN Tag Measurements 1174 For Ethernet-based DSL access networks, the DSL Access Module (DSLAM) 1175 or Access Node (AN) provide two VLAN tags on packets. A C-TAG is 1176 used to identify the incoming residential circuit, while the S-TAG is 1177 used to identify the DSLAM or AN. The C-TAG and S-TAG together can 1178 be used to identify a single point of network attachment. An example 1179 is shown in Figure 15. 1181 1183 1184 613 1185 1097 1186 1187 1189 Figure 15: Example DSL VLAN Tag Measurement 1191 Alternatively, the C-TAG can be replaced by data on the slot and port 1192 that the Device is attached to. This information might be included 1193 in RADIUS requests that are proxied from the infrastructure provider 1194 to the ISP RADIUS server. 1196 5.6.4. ATM Virtual Circuit Measurements 1198 An ATM virtual circuit can be employed between the ISP and 1199 infrastructure provider. Providing the virtual port ID (VPI) and 1200 virtual circuit ID (VCI) for the virtual circuit gives the 1201 infrastructure provider LIS the ability to identify a single data 1202 stream. A sample measurement is shown in Figure 16. 1204 1206 1207 55 1208 6323 1209 1210 1212 Figure 16: Example DSL ATM Measurement 1214 6. Privacy Considerations 1216 Location-related measurement data can be as privacy sensitive as 1217 location information. 1219 Measurement data is effectively equivalent to location information if 1220 the contextual knowledge necessary to generate one from the other is 1221 readily accessible. Even where contextual knowledge is difficult to 1222 acquire, there can be no assurance that an authorized recipient of 1223 the contextual knowledge is also authorized to receive location 1224 information. 1226 In order to protect the privacy of the subject of location-related 1227 measurement data, this implies that measurement data is protected 1228 with the same degree of protection as location information. 1230 6.1. Measurement Data Privacy Model 1232 It is less desirable to distribute measurement data in the same 1233 fashion as location information. Measurement data is less useful to 1234 location recipients than location information. Therefore, a simple 1235 distribution model is desirable. 1237 In this simple model, the Device is the only entity that is able to 1238 distribute measurement data. To use an analogy from the GEOPRIV 1239 architecture, the Device - as the Location Generator (or the 1240 Measurement Data Generator) - is the sole entity that can assume the 1241 roles of Rule Maker and Location Server. 1243 No entity is permitted to redistribute measurement data. The Device 1244 directs other entities in how measurement data is used and retained. 1246 6.2. LIS Privacy Requirements 1248 A LIS MUST NOT reveal location-related measurement data or location 1249 information based on measurement data to any other entity unless 1250 directed to do so by the Device. 1252 By adding measurement data to a request for location information, the 1253 Device implicitly grants permission for the LIS to generate the 1254 requested location information using the measurement data. 1255 Permission to use this data for any other purpose is not implied. 1257 As long as measurement data is only used in serving the request that 1258 contains it, rules regarding data retention are not necessary. A LIS 1259 MUST discard location-related measurement data after servicing a 1260 request, unless the Device grants permission to use that information 1261 for other purposes. 1263 6.3. Measurement Data and Location URIs 1265 A LIS MAY use measurement data provided by the Device to serve 1266 requests to location URIs, if the Device permits it. A Device 1267 permits this by including measurement data in a request that 1268 explcitly requests a location URI. By requesting a location URI, the 1269 Device grants permission for the LIS to use the measurement data in 1270 serving requests to that URI. 1272 Note: In HELD, the "any" type is not an explicit request for a 1273 location URI, though a location URI might be provided. 1275 The usefulness of measurement data that is provided in this fashion 1276 is limited. The measurement data is only valid at the time that it 1277 was acquired by the Device. At the time that a request is made to a 1278 location URI, the Device might have moved, rendering the measurement 1279 data incorrect. 1281 A Device is able to explicitly limit the time that a LIS retains 1282 measurement data by adding an expiry time to the measurement data, 1283 see Section 4.1.2. 1285 6.4. Third-Party-Provided Measurement Data 1287 An authorized third-party request for the location of a Device (see 1288 [I-D.ietf-geopriv-held-identity-extensions]) can include location- 1289 related measurement data. This is possible where the third-party is 1290 able to make observations about the Device. 1292 A third-party that provides measurement data MUST be authorized to 1293 provide the specific measurement for the identified device. A third- 1294 party MUST either be trusted by the LIS for the purposes of providing 1295 measurement data of the provided type, or the measurement data MUST 1296 be validated (see Section 7.2.1) before being used. 1298 How a third-party authenticates its identity or gains authorization 1299 to use measurement data is not covered by this document. 1301 7. Security Considerations 1303 Use of location-related measurement data has privacy considerations 1304 that are discussed in Section 6. 1306 7.1. Threat Model 1308 The threat model for location-related measurement data concentrates 1309 on the Device providing falsified, stolen or incorrect measurement 1310 data. 1312 A Device that provides location location-related measurement data 1313 might use data to: 1315 o acquire the location of another Device, without authorization; 1317 o extract information about network topology; or 1319 o coerce the LIS into providing falsified location information based 1320 on the measurement data. 1322 Location-related measurement data describes the physical environment 1323 or network attachment of a Device. A third party adversary in the 1324 proximity of the Device might be able to alter the physical 1325 environment such that the Device provides measurement data that is 1326 controlled by the third party. This might be used to indirectly 1327 control the location information that is derived from measurement 1328 data. 1330 7.1.1. Acquiring Location Information Without Authorization 1332 Requiring authorization for location requests is an important part of 1333 privacy protections of a location protocol. A location configuration 1334 protocol usually operates under a restricted policy that allows a 1335 requester to obtain their own location. HELD identity extensions 1336 [I-D.ietf-geopriv-held-identity-extensions] allows other entities to 1337 be authorized, conditional on a Rule Maker providing sufficient 1338 authorization. 1340 The intent of these protections is to ensure that a location 1341 recipient is authorized to acquire location information. Location- 1342 related measurement data could be used by an attacker to circumvent 1343 such authorization checks if the association between measurement data 1344 and Target Device is not validated by a LIS. 1346 A LIS can be coerced into providing location information for a Device 1347 that a location recipient is not authorized to receive. A request 1348 identifies one Device (implicitly or explicitly), but measurement 1349 data is provided for another Device. If the LIS does not check that 1350 the measurement data is for the identified Device, it could 1351 incorrectly authorize the request. 1353 By using unvalidated measurement data to generate a response, the LIS 1354 provides information about a Device without appropriate 1355 authorization. 1357 The feasibility of this attack depends on the availability of 1358 information that links a Device with measurement data. In some 1359 cases, measurement data that is correlated with a target is readily 1360 available. For instance, LLDP measurements (Section 5.1) are 1361 broadcast to all nodes on the same network segment. An attacker on 1362 that network segment can easily gain measurement data that relates a 1363 Device with measurements. 1365 For some types of measurement data, it's necessary for an attacker to 1366 know the location of the target in order to determine what 1367 measurements to use. This attack is meaningless for types of 1368 measurement data that require that the attacker first know the 1369 location of the target before measurement data can be acquired or 1370 fabricated. GNSS measurements (Section 5.5) share this trait with 1371 many wireless location determination methods. 1373 7.1.2. Extracting Network Topology Data 1375 Allowing requests with measurements might be used to collect 1376 information about a network topology. This is possible if requests 1377 containing measurements are permitted. 1379 Network topology can be considered sensitive information by a network 1380 operator for commercial or security reasons. While it is impossible 1381 to completely prevent a Device from acquiring some knowledge of 1382 network topology if a location service is provided, a network 1383 operator might desire to limit how much of this information is made 1384 available. 1386 Mapping a network topology does not require that an attacker be able 1387 to associate measurement data with a particular Device. If a 1388 requester is able to try a number of measurements, it is possible to 1389 acquire information about network topology. 1391 It is not even necessary that the measurements are valid; random 1392 guesses are sufficient, provided that there is no penalty or cost 1393 associated with attempting to use the measurements. 1395 7.1.3. Lying By Proxy 1397 Location information is a function of its inputs, which includes 1398 measurement data. Thus, falsified measurement data can be used to 1399 alter the location information that is provided by a LIS. 1401 Some types of measurement data are relatively easy to falsify in a 1402 way that the resulting location information to be selected with 1403 little or no error. For instance, GNSS measurements are easy to use 1404 for this purpose because all the contextual information necessary to 1405 calculate a position using measurements is broadcast by the 1406 satellites [HARPER]. 1408 An attacker that falsifies measurement data gains little if they are 1409 the only recipients of the result. The attacker knows that the 1410 location information is bad. The attacker only gains if the 1411 information can somehow be attributed to the LIS by another location 1412 recipient. 1414 A recipient might evaluate the trustworthiness of the location 1415 information based on the credibility of its source. By coercing the 1416 LIS into providing falsified location information, any credibility 1417 that the LIS might have - that the attacker does not - is gained by 1418 the attacker. 1420 A third-party that is reliant on the integrity of the location 1421 information might base an evaluation of the credibility of the 1422 information on the source of the information. If that third party is 1423 able to attribute location information to the LIS, then an attacker 1424 might gain. 1426 Location information that is provided to the Device without any means 1427 to identify the LIS as its source is not subject to this attack. The 1428 Device is identified as the source of the data when it distributes 1429 the location information to location recipients. 1431 An attacker gains if they are able to coerce the LIS into providing 1432 location information based on falsified measurement data and that 1433 information can be attributed to the LIS. 1435 Location information is attributed to the LIS either through the use 1436 of digital signatures or by having the location recipient directly 1437 interact with the LIS. A LIS that digitally signs location 1438 information becomes identifiable as the source of the data. 1439 Similarly, the LIS is identified as a source of data if a location 1440 recipient acquires information directly from a LIS using a location 1441 URI. 1443 7.1.4. Measurement Replay 1445 The value of some measured properties do not change over time for a 1446 single location. This allows for simple replay attacks, where an 1447 attacker acquires measurements that can later be used without being 1448 detected as being invalid. 1450 Measurement data is frequently an observation of an time-invariant 1451 property of the environment at the subject location. For 1452 measurements of this nature, nothing in the measurement itself is 1453 sufficient proof that the Device is present at the resulting 1454 location. Measurement data might have been previously acquired and 1455 reused. 1457 For instance, the identity of a radio transmitter, if broadcast by 1458 that transmitter, can be collected and stored. An attacker that 1459 wishes it known that they exist at a particular location, can claim 1460 to observe this transmitter at any time. Nothing inherent in the 1461 claim reveals it to be false. 1463 For properties of a network, time-invariance is often directly as a 1464 result of the practicalities of operating the network. Limiting the 1465 changes to a network ensures greater consistency of service. A 1466 largely static network also greatly simplifies the data management 1467 tasks involved with providing a location service. 1469 7.1.5. Environment Spoofing 1471 Some types of measurement data can be altered or influenced by a 1472 third party so that a Device. If it is possible for a third party to 1473 alter the measured phenomenon, then any location information that is 1474 derived from this data can be indirectly influenced. 1476 Altering the environment in this fashion might not require 1477 involvement with either Device or LIS. Measurement that is passive - 1478 where the Device observes a signal or other phenomenon without direct 1479 interaction - are most susceptible to alteration by third parties. 1481 Measurement of radio signal characteristics is especially vulnerable 1482 since an adversary need only be in the general vicinity of the Device 1483 and be able to transmit a signal. For instance, a GNSS spoofer is 1484 able to produce fake signals that claim to be transmitted by any 1485 satellite or set of satellites (see [GPS.SPOOF]). 1487 Measurements that require direct interaction increases the complexity 1488 of the attack. For measurements relating to the communication 1489 medium, a third party cannot avoid direct interaction, they need only 1490 be on the comminications path (that is, man in the middle). 1492 Even if the entity that is interacted with is authenticated, this 1493 does not provide any assurance about the integrity of measurement 1494 data. For instance, the Device might authenticate the identity of a 1495 radio transmitter through the use of cryptographic means and obtain 1496 signal strength measurements for that transmitter. Radio signal 1497 strength is trivial for an attacker to increase simply by receiving 1498 and amplifying the raw signal; it is not necessary for the attacker 1499 to be able to understand the signal content. 1501 Note: This particular "attack" is more often completely legitimate. 1502 Radio repeaters are commonplace mechanism used to increase radio 1503 coverage. 1505 Attacks that rely on altering the observed environment of a Device 1506 require countermeasures that affect the measurement process. For 1507 radio signals, countermeasures could include the use of authenticated 1508 signals, altered receiver design. In general, countermeasures are 1509 highly specific to the individual measurement process. An exhaustive 1510 discussion of these issues is left to the relevant literature for 1511 each measurement technology. 1513 A Device that provides measurement data is assumed to be responsible 1514 for applying appropriate countermeasures against this type of attack. 1516 For a Device that is the ultimate recipient of location information 1517 derived from measurement data, a LIS might choose to provide location 1518 information without any validation. The responsibility for ensuring 1519 the veracity of the measurement data lies with the Device. 1521 Measurement data that is susceptible to this sort of influence MUST 1522 be treated as though it were produced by an untrusted Device for 1523 those cases where a location recipient might attribute the location 1524 information to the LIS. Such measurement data MUST be subjected to 1525 the same validation as for other types of attacks that rely on 1526 measurement falsification. 1528 Note: Altered measurement data might be provided by a Device that 1529 has no knowledge of the alteration. Thus, an otherwise trusted 1530 Device might still be an unreliable source of measurement data. 1532 7.2. Mitigation 1534 The following measures can be applied to limit or prevent attacks. 1535 The effectiveness of each depends on the type of measurement data and 1536 how that measurement data is acquired. 1538 Two general approaches are identified for dealing with untrusted 1539 measurement data: 1541 1. Require independent validation of measurement data or the 1542 location information that is produced. 1544 2. Identify the types of sources that provided the measurement data 1545 that location information was derived from. 1547 This section goes into more detail on the different forms of 1548 validation in Section 7.2.1, Section 7.2.2, and Section 7.2.3. The 1549 impact of attributing location information to sources is discussed in 1550 more detail in Section 7.2.4. 1552 7.2.1. Measurement Validation 1554 Detecting that measurement data has been falsified is difficult in 1555 the absence of integrity mechanisms. 1557 Independent confirmation of the veracity of measurement data ensures 1558 that the measurement is accurate and that it applies to the correct 1559 Device. By gathering the same measurement data from a trusted and 1560 independent source, the LIS is able to check that the measurement 1561 data is correct. 1563 Measurement information might contain no inherent indication that it 1564 is falsified. On the contrary, it can be difficult to obtain 1565 information that would provide any degree of assurance that the 1566 measurement device is physically at any particular location. 1567 Measurements that are difficult to verify require other forms of 1568 assurance before they can be used. 1570 7.2.1.1. Effectiveness 1572 Measurement validation MUST be used if measurement data for a 1573 particular Device can be easily acquired by unauthorized location 1574 recipients, as described in Section 7.1.1. This prevents 1575 unauthorized access to location information using measurement data. 1577 Validation of measurement data can be significantly more effective 1578 than independent acquisition of the same. For instance, a Device in 1579 a large Ethernet network could provide a measurement indicating its 1580 point of attachment using LLDP measurements. For a LIS, acquiring 1581 the same measurement data might require a request to all switches in 1582 that network. With the measurement data, validation can target the 1583 identified switch with a specific query. 1585 Validation is effective in identifying falsified measurement data 1586 (Section 7.1.3), including attacks involving replay of measurement 1587 data (Section 7.1.4). Validation also limits the amount of network 1588 topology information (Section 7.1.2) made available to Devices to 1589 that portion of the network topology that they are directly attached. 1591 Measurement validation has no effect if the underlying effect is 1592 being spoofed (Section 7.1.5). 1594 7.2.1.2. Limitations (Unique Observer) 1596 A Device is often in a unique position to make a measurement. It 1597 alone occupies the point in space-time that the location 1598 determination process seeks to determine. The Device becomes a 1599 unique observer for a particular property. 1601 The ability of the Device to become a unique observer makes the 1602 Device invaluable to the location determination process. As a unique 1603 observer, it also makes the claims of a Device difficult to validate 1604 and easily to spoof. 1606 As long as no other entity is capable of making the same 1607 measurements, there is also no other entity that can independently 1608 check that the measurements are correct and applicable to the Device. 1609 A LIS might be unable to validate all or part of the measurement data 1610 it receives from a unique observer. For instance, a signal strength 1611 measurement of the signal from a radio tower cannot be validated 1612 directly. 1614 Some portion of the measurement data might still be independently 1615 verified, even if all information cannot. In the previous example, 1616 the radio tower might be able to provide verification that the Device 1617 is present if it is able to observe a radio signal sent by the 1618 Device. 1620 If measurement data can only be partially validated, the extent to 1621 which it can be validated determines the effectiveness of validation 1622 against these attacks. 1624 The advantage of having the Device as a unique observer is that it 1625 makes it difficult for an attacker to acquire measurements without 1626 the assistance of the Device. Attempts to use measurements to gain 1627 unauthorized access to measurement data (Section 7.1.1) are largely 1628 ineffectual against a unique observer. 1630 7.2.2. Location Validation 1632 Location information that is derived from location-related 1633 measurement data can also be verified against trusted location 1634 information. Rather than validating inputs to the location 1635 determination process, suspect locations are identified at the output 1636 of the process. 1638 Trusted location information is acquired using sources of measurement 1639 data that are trusted. Untrusted location information is acquired 1640 using measurement data provided from untrusted sources, which might 1641 include the Device. These two locations are compared. If the 1642 untrusted location agrees with the trusted location, the untrusted 1643 location information is used. 1645 Algorithms for the comparison of location information are not 1646 included in this document. However, a simple comparison for 1647 agreement might require that the untrusted location be entirely 1648 contained within the uncertainty region of the trusted location. 1650 There is little point in using a less accurate, less trusted 1651 location. Untrusted location information that has worse accuracy 1652 than trusted information can be immediately discarded. There are 1653 multiple factors that affect accuracy, uncertainty and currency being 1654 the most important. How location information is compared for 1655 accuracy is not defined in this document. 1657 7.2.2.1. Effectiveness 1659 Location validation limits the extent to which falsified - or 1660 erroneous - measurement data can cause an incorrect location to be 1661 reported. 1663 Location validation can be more efficient than validation of inputs, 1664 particularly for a unique observer (Section 7.2.1.2). 1666 Validating location ensures that the Device is at or near the 1667 resulting location. Location validation can be used to limit or 1668 prevent all of the attacks identified in this document. 1670 7.2.2.2. Limitations 1672 The trusted location that is used for validation is always less 1673 accurate than the location that is being checked. The amount by 1674 which the untrusted location is more accurate, is the same amount 1675 that an attacker can exploit. 1677 For example, a trusted location might indicate a five kilometer 1678 radius uncertainty region. An untrusted location that describes a 1679 100 meter uncertainty within the larger region might be accepted as 1680 more accurate. An attacker might still falsify measurement data to 1681 select any location within the larger uncertainty region. While the 1682 100 meter uncertainty that is reported seems more accurate, a 1683 falsified location could be anywhere in the five kilometer region. 1685 Where measurement data might have been falsified, the actual 1686 uncertainty is effectively much higher. Local policy might allow 1687 differing degrees of trust to location information derived from 1688 untrusted measurement data. This might not be a boolean operation 1689 with only two possible outcomes: untrusted location information might 1690 be used entirely or not at all, or it could be combined with trusted 1691 location information with the degree to which each contributes based 1692 on a value set in local policy. 1694 7.2.3. Supporting Observations 1696 Replay attacks using previously acquired measurement data are 1697 particularly hard to detect without independent validation. Rather 1698 than validate the measurement data directly, supplementary data might 1699 be used to validate measurements or the location information derived 1700 from those measurements. 1702 These supporting observations could be used to convey information 1703 that provides additional assurance that the Device was acquired at a 1704 specific time and place. In effect, the Device is requested to 1705 provide proof of its presence at the resulting location. 1707 For instance, a Device that measures attributes of a radio signal 1708 could also be asked to provide a sample of the measured radio signal. 1709 If the LIS is able to observe the same signal, the two observations 1710 could be compared. Providing that the signal cannot be predicted in 1711 advance by the Device, this could be used to support the claim that 1712 the Device is able to receive the signal. Thus, the Device is likely 1713 to be within the range that the signal is transmitted. A LIS could 1714 use this to attribute a higher level of trust in the associated 1715 measurement data or resulting location. 1717 7.2.3.1. Effectiveness 1719 The use of supporting observations is limited by the ability of the 1720 LIS to acquire and validate these observations. The advantage of 1721 selecting observations independent of measurement data is that 1722 observations can be selected based on how readily available the data 1723 is for both LIS and Device. The amount and quality of the data can 1724 be selected based on the degree of assurance that is desired. 1726 Use of supporting observations is similar to both measurement 1727 validation and location validation. All three methods rely on 1728 independent validation of one or more properties. Applicability of 1729 each method is similar. 1731 Use of supporting observations can be used to limit or prevent all of 1732 the attacks identified in this document. 1734 7.2.3.2. Limitations 1736 The effectiveness of the validation method depends on the quality of 1737 the supporting observation: how hard it is to obtain at a different 1738 time or place, how difficult it is to guess and what other costs 1739 might be involved in acquiring this data. 1741 In the example of an observed radio signal, requesting a sample of 1742 the signal only provides an assurance that the Device is able to 1743 receive the signal transmitted by the measured radio transmitter. 1744 This only provides some assurance that the Device is within range of 1745 the transmitter. 1747 As with location validation, a Device might still be able to provide 1748 falsified measurements that could alter the value of the location 1749 information as long as the result is within this region. 1751 Requesting additional supporting observations can reduce the size of 1752 the region over which location information can be altered by an 1753 attacker, or increase trust in the result, but each additional has a 1754 cost. Supporting observations contribute little or nothing toward 1755 the primary goal of determining the location of the Device. Any 1756 costs in acquiring supporting observations are balanced against the 1757 degree of integrity desired of the resulting location information. 1759 7.2.4. Attribution 1761 Lying by proxy (Section 7.1.3) relies on the location recipient being 1762 able to attribute location information to a LIS. The effectiveness 1763 of this attack is negated if location information is explicitly 1764 attributed to a particular source. 1766 This requires an extension to the location object that explicitly 1767 identifies the source (or sources) of each item of location 1768 information. 1770 Rather than relying on a process that seeks to ensure that location 1771 information is accurate, this approach instead provides a location 1772 recipient with the information necessary to reach their own 1773 conclusion about the trustworthiness of the location information. 1775 Including an authenticated identity for all sources of measurement 1776 data is presents a number of technical and operational challenges. 1777 It is possible that the LIS has a transient relationship with a 1778 Device. A Device is not expected to share authentication information 1779 with a LIS. There is no assurance that Device identification is 1780 usable by a potential location recipient. Privacy concerns might 1781 also prevent the sharing identification information, even if it were 1782 available and usable. 1784 Identifying the type of measurement source allows a location 1785 recipient to make a decision about the trustworthiness of location 1786 information without depending on having authenticated identity 1787 information for each source. An element for this purpose is defined 1788 in Section 4.4. 1790 When including location information that is based on measurement data 1791 from sources that might be untrusted, a LIS SHOULD include 1792 alternative location information that is derived from trusted sources 1793 of measurement data. Each item of location information can then be 1794 labelled with the source of that data. 1796 A location recipient that is able to identify a specific source of 1797 measurement data (whether it be LIS or Device) can use this 1798 information to attribute location information to either or both 1799 entity. The location recipient is then better able to make decisions 1800 about trustworthiness based on the source of the data. 1802 A location recipient that does not understand the "source" element is 1803 unable to make this distinction. When constructing a PIDF-LO 1804 document, trusted location information MUST be placed in the PIDF-LO 1805 so that it is given higher priority to any untrusted location 1806 information according to Rule #8 of [RFC5491]. 1808 Attribution of information does nothing to address attacks that alter 1809 the observed parameters that are used in location determination 1810 (Section 7.1.5). 1812 7.2.5. Stateful Correlation of Location Requests 1814 Stateful examination of requests can be used to prevent a Device from 1815 attempting to map network topology using requests for location 1816 information (Section 7.1.2). 1818 Simply limiting the rate of requests from a single Device reduces the 1819 amount of data that a Device can acquire about network topology. 1821 8. Measurement Schemas 1823 The schema are broken up into their respective functions. There is a 1824 base container schema into which all measurements are placed, plus 1825 definitions for a measurement request (Section 8.1). A PIDF-LO 1826 extension is defined in a separate schema (Section 8.2). There is a 1827 basic types schema, that contains various base type definitions for 1828 things such as the "rmsError" and "samples" attributes IPv4, IPv6 and 1829 MAC addresses (Section 8.3). Then each of the specific measurement 1830 types is defined in its own schema. 1832 8.1. Measurement Container Schema 1834 1835 1843 1844 1846 1847 1848 1850 This schema defines a framework for location measurements. 1851 1852 1854 1856 1857 1858 1859 1860 1861 1863 1864 1865 1866 1867 1868 1869 1870 1871 1873 1875 1876 1877 1878 1879 1881 1883 1884 1885 1886 1888 1889 1890 1892 1893 1894 1896 1897 1898 1899 1900 1901 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1918 Measurement Container Schema 1919 8.2. Measurement Source Schema 1921 1922 1929 1930 1932 1933 1934 1936 This schema defines an extension to PIDF-LO that indicates the 1937 type of source that produced the measurement data used in 1938 generating the associated location information. 1939 1940 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1956 Measurement Source PIDF-LO Extension Schema 1958 8.3. Base Type Schema 1960 Note that the pattern rules in the following schema wrap due to 1961 length constraints. None of the patterns contain whitespace. 1963 1964 1971 1972 1974 1975 1976 1978 This schema defines a set of base type elements. 1979 1980 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2022 2023 2024 2026 2027 2028 2029 2030 An IP version 6 address, based on RFC 4291. 2031 2032 2033 2034 2035 2036 2037 2038 2039 2041 2043 2045 2047 2049 2051 2052 2053 2054 2062 2063 2064 2065 2067 2068 2069 2070 2074 2075 2077 2078 2079 2080 2082 2083 2085 2087 Base Type Schema 2089 8.4. LLDP Measurement Schema 2091 2092 2100 2101 2103 2104 2105 2107 This schema defines a set of LLDP location measurements. 2108 2109 2110 2112 2113 2114 2115 2116 2117 2118 2119 2121 2122 2123 2124 2125 2127 2128 2129 2130 2132 2133 2134 2136 2137 2138 2139 2140 2141 2143 2145 LLDP measurement schema 2147 8.5. DHCP Measurement Schema 2149 2150 2158 2159 2161 2162 2163 2165 This schema defines a set of DHCP location measurements. 2166 2167 2169 2171 2172 2173 2174 2175 2176 2177 2178 2180 2182 2184 2186 2187 2188 2189 2190 2192 2193 2194 2195 2197 2198 2199 2201 2203 DHCP measurement schema 2205 8.6. WiFi Measurement Schema 2206 2207 2216 2217 2219 802.11 location measurements 2220 2221 2222 2224 This schema defines a basic set of 802.11 location measurements. 2225 2226 2228 2229 2231 2233 2234 2235 2236 2237 2239 2241 2242 2243 2244 2245 2247 2248 2249 2250 2251 2252 2254 2256 2258 2260 2262 2264 2266 2268 2270 2272 2273 2275 2276 2277 2278 2280 2281 2282 2283 2285 2286 2287 2289 2291 2292 2293 2294 2295 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2316 2317 2318 2319 2320 2322 2323 2324 2325 2326 2328 2329 2331 2333 2335 2336 2337 2338 2340 2341 2342 2343 2344 2345 2346 2348 2349 2350 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2367 2369 WiFi measurement schema 2371 8.7. Cellular Measurement Schema 2373 2374 2381 2382 2384 2385 2386 2388 This schema defines a set of cellular location measurements. 2389 2390 2392 2394 2395 2396 2397 2398 2399 2400 2401 2402 2404 2405 2406 2407 2408 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2429 2430 2431 2432 2433 2434 2436 2437 2439 2440 2441 2442 2444 2445 2447 2448 2449 2451 2452 2453 2454 2455 2457 2458 2459 2460 2461 2463 2465 2466 2467 2468 2469 2470 2471 2472 2473 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2490 2492 Cellular measurement schema 2494 8.8. GNSS Measurement Schema 2495 2496 2504 2505 2507 2508 2509 2511 This schema defines a set of GNSS location measurements 2512 2513 2515 2517 2518 2519 2520 2521 2522 2523 2525 2526 2527 2528 2529 2531 2533 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2549 2550 2552 2554 2555 2556 2558 2559 2560 2562 2563 2564 2565 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2580 GNSS measurement Schema 2582 8.9. DSL Measurement Schema 2584 2585 2593 2594 2596 DSL measurement definitions 2597 2598 2599 2601 This schema defines a basic set of DSL location measurements. 2602 2603 2605 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2663 2665 DSL measurement schema 2667 9. IANA Considerations 2669 This section creates a registry for GNSS types (Section 5.5) and 2670 registers the namespaces and schema defined in Section 8. 2672 9.1. IANA Registry for GNSS Types 2674 This document establishes a new IANA registry for Global Navigation 2675 Satellite System (GNSS) types. The registry includes tokens for the 2676 GNSS type and for each of the signals within that type. Referring to 2677 [RFC5226], this registry operates under "Specification Required" 2678 rules. The IESG will appoint an Expert Reviewer who will advise IANA 2679 promptly on each request for a new or updated GNSS type. 2681 Each entry in the registry requires the following information: 2683 GNSS name: the name and a brief description of the GNSS 2685 Brief description: the name and a brief description of the GNSS 2687 GNSS token: a token that can be used to identify the GNSS 2689 Signals: a set of tokens that represent each of the signals that the 2690 system provides 2692 Documentation reference: a reference to one or more stable, public 2693 specifications that outline usage of the GNSS, including (but not 2694 limited to) signal specifications and time systems 2696 The registry initially includes two registrations: 2698 GNSS name: Global Positioning System (GPS) 2700 Brief description: a system of satellites that use spread-spectrum 2701 transmission, operated by the US military for commercial and 2702 military applications 2704 GNSS token: gps 2706 Signals: L1, L2, L1C, L2C, L5 2708 Documentation reference: Navstar GPS Space Segment/Navigation User 2709 Interface [GPS.ICD] 2711 GNSS name: Galileo 2713 Brief description: a system of satellites that operate in the same 2714 spectrum as GPS, operated by the European Union for commercial 2715 applications 2717 GNSS Token: galileo 2719 Signals: L1, E5A, E5B, E5A+B, E6 2721 Documentation Reference: Galileo Open Service Signal In Space 2722 Interface Control Document (SIS ICD) [Galileo.ICD] 2724 9.2. URN Sub-Namespace Registration for 2725 urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc 2727 This section registers a new XML namespace, 2728 "urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc", as per the guidelines 2729 in [RFC3688]. 2731 URI: urn:ietf:params:xml:ns:pidf:geopriv10:lmsrc 2733 Registrant Contact: IETF, GEOPRIV working group, 2734 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2736 XML: 2738 BEGIN 2739 2740 2742 2743 2744 Measurement Source for PIDF-LO 2745 2746 2747

Namespace for Location Measurement Source

2748

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

2749 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2750 with the RFC number for this specification.]] 2751

See RFCXXXX.

2752 2753 2754 END 2756 9.3. URN Sub-Namespace Registration for 2757 urn:ietf:params:xml:ns:geopriv:lm 2759 This section registers a new XML namespace, 2760 "urn:ietf:params:xml:ns:geopriv:lm", as per the guidelines in 2761 [RFC3688]. 2763 URI: urn:ietf:params:xml:ns:geopriv:lm 2765 Registrant Contact: IETF, GEOPRIV working group, 2766 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2768 XML: 2770 BEGIN 2771 2772 2774 2775 2776 Measurement Container 2777 2778 2779

Namespace for Location Measurement Container

2780

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

2781 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2782 with the RFC number for this specification.]] 2783

See RFCXXXX.

2784 2785 2786 END 2788 9.4. URN Sub-Namespace Registration for 2789 urn:ietf:params:xml:ns:geopriv:lm:basetypes 2791 This section registers a new XML namespace, 2792 "urn:ietf:params:xml:ns:geopriv:lm:basetypes", as per the guidelines 2793 in [RFC3688]. 2795 URI: urn:ietf:params:xml:ns:geopriv:lm:basetypes 2797 Registrant Contact: IETF, GEOPRIV working group, 2798 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2800 XML: 2802 BEGIN 2803 2804 2806 2807 2808 Base Device Types 2809 2810 2811

Namespace for Base Types

2812

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

2813 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2814 with the RFC number for this specification.]] 2815

See RFCXXXX.

2816 2817 2818 END 2820 9.5. URN Sub-Namespace Registration for 2821 urn:ietf:params:xml:ns:geopriv:lm:lldp 2823 This section registers a new XML namespace, 2824 "urn:ietf:params:xml:ns:geopriv:lm:lldp", as per the guidelines in 2825 [RFC3688]. 2827 URI: urn:ietf:params:xml:ns:geopriv:lm:lldp 2829 Registrant Contact: IETF, GEOPRIV working group, 2830 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2832 XML: 2834 BEGIN 2835 2836 2838 2839 2840 LLDP Measurement Set 2841 2842 2843

Namespace for LLDP Measurement Set

2844

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

2845 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2846 with the RFC number for this specification.]] 2847

See RFCXXXX.

2848 2849 2850 END 2852 9.6. URN Sub-Namespace Registration for 2853 urn:ietf:params:xml:ns:geopriv:lm:dhcp 2855 This section registers a new XML namespace, 2856 "urn:ietf:params:xml:ns:geopriv:lm:dhcp", as per the guidelines in 2857 [RFC3688]. 2859 URI: urn:ietf:params:xml:ns:geopriv:lm:dhcp 2861 Registrant Contact: IETF, GEOPRIV working group, 2862 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2864 XML: 2866 BEGIN 2867 2868 2870 2871 2872 DHCP Measurement Set 2873 2874 2875

Namespace for DHCP Measurement Set

2876

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

2877 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2878 with the RFC number for this specification.]] 2879

See RFCXXXX.

2880 2881 2882 END 2884 9.7. URN Sub-Namespace Registration for 2885 urn:ietf:params:xml:ns:geopriv:lm:wifi 2887 This section registers a new XML namespace, 2888 "urn:ietf:params:xml:ns:geopriv:lm:wifi", as per the guidelines in 2889 [RFC3688]. 2891 URI: urn:ietf:params:xml:ns:geopriv:lm:wifi 2893 Registrant Contact: IETF, GEOPRIV working group, 2894 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2896 XML: 2898 BEGIN 2899 2900 2902 2903 2904 WiFi Measurement Set 2905 2906 2907

Namespace for WiFi Measurement Set

2908

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

2909 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2910 with the RFC number for this specification.]] 2911

See RFCXXXX.

2912 2913 2914 END 2916 9.8. URN Sub-Namespace Registration for 2917 urn:ietf:params:xml:ns:geopriv:lm:cell 2919 This section registers a new XML namespace, 2920 "urn:ietf:params:xml:ns:geopriv:lm:cell", as per the guidelines in 2921 [RFC3688]. 2923 URI: urn:ietf:params:xml:ns:geopriv:lm:cell 2925 Registrant Contact: IETF, GEOPRIV working group, 2926 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2928 XML: 2930 BEGIN 2931 2932 2934 2935 2936 Cellular Measurement Set 2937 2938 2939

Namespace for Cellular Measurement Set

2940

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

2941 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2942 with the RFC number for this specification.]] 2943

See RFCXXXX.

2944 2945 2946 END 2948 9.9. URN Sub-Namespace Registration for 2949 urn:ietf:params:xml:ns:geopriv:lm:gnss 2951 This section registers a new XML namespace, 2952 "urn:ietf:params:xml:ns:geopriv:lm:gnss", as per the guidelines in 2953 [RFC3688]. 2955 URI: urn:ietf:params:xml:ns:geopriv:lm:gnss 2957 Registrant Contact: IETF, GEOPRIV working group, 2958 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2960 XML: 2962 BEGIN 2963 2964 2966 2967 2968 GNSS Measurement Set 2969 2970 2971

Namespace for GNSS Measurement Set

2972

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

2973 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 2974 with the RFC number for this specification.]] 2975

See RFCXXXX.

2976 2977 2978 END 2980 9.10. URN Sub-Namespace Registration for 2981 urn:ietf:params:xml:ns:geopriv:lm:dsl 2983 This section registers a new XML namespace, 2984 "urn:ietf:params:xml:ns:geopriv:lm:dsl", as per the guidelines in 2985 [RFC3688]. 2987 URI: urn:ietf:params:xml:ns:geopriv:lm:dsl 2989 Registrant Contact: IETF, GEOPRIV working group, 2990 (geopriv@ietf.org), Martin Thomson (martin.thomson@andrew.com). 2992 XML: 2994 BEGIN 2995 2996 2998 2999 3000 DSL Measurement Set 3001 3002 3003

Namespace for DSL Measurement Set

3004

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

3005 [[NOTE TO IANA/RFC-EDITOR: Please update RFC URL and replace XXXX 3006 with the RFC number for this specification.]] 3007

See RFCXXXX.

3008 3009 3010 END 3012 9.11. XML Schema Registration for Measurement Source Schema 3014 This section registers an XML schema as per the guidelines in 3015 [RFC3688]. 3017 URI: urn:ietf:params:xml:schema:pidf:geopriv10:lmsrc 3019 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3020 Martin Thomson (martin.thomson@andrew.com). 3022 Schema: The XML for this schema can be found in Section 8.2 of this 3023 document. 3025 9.12. XML Schema Registration for Measurement Container Schema 3027 This section registers an XML schema as per the guidelines in 3028 [RFC3688]. 3030 URI: urn:ietf:params:xml:schema:lm 3032 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3033 Martin Thomson (martin.thomson@andrew.com). 3035 Schema: The XML for this schema can be found in Section 8.1 of this 3036 document. 3038 9.13. XML Schema Registration for Base Types Schema 3040 This section registers an XML schema as per the guidelines in 3041 [RFC3688]. 3043 URI: urn:ietf:params:xml:schema:lm:basetypes 3045 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3046 Martin Thomson (martin.thomson@andrew.com). 3048 Schema: The XML for this schema can be found in Section 8.3 of this 3049 document. 3051 9.14. XML Schema Registration for LLDP Schema 3053 This section registers an XML schema as per the guidelines in 3054 [RFC3688]. 3056 URI: urn:ietf:params:xml:schema:lm:lldp 3058 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3059 Martin Thomson (martin.thomson@andrew.com). 3061 Schema: The XML for this schema can be found in Section 8.4 of this 3062 document. 3064 9.15. XML Schema Registration for DHCP Schema 3066 This section registers an XML schema as per the guidelines in 3067 [RFC3688]. 3069 URI: urn:ietf:params:xml:schema:lm:dhcp 3071 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3072 Martin Thomson (martin.thomson@andrew.com). 3074 Schema: The XML for this schema can be found in Section 8.5 of this 3075 document. 3077 9.16. XML Schema Registration for WiFi Schema 3079 This section registers an XML schema as per the guidelines in 3080 [RFC3688]. 3082 URI: urn:ietf:params:xml:schema:lm:wifi 3084 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3085 Martin Thomson (martin.thomson@andrew.com). 3087 Schema: The XML for this schema can be found in Section 8.6 of this 3088 document. 3090 9.17. XML Schema Registration for Cellular Schema 3092 This section registers an XML schema as per the guidelines in 3093 [RFC3688]. 3095 URI: urn:ietf:params:xml:schema:lm:cellular 3097 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3098 Martin Thomson (martin.thomson@andrew.com). 3100 Schema: The XML for this schema can be found in Section 8.7 of this 3101 document. 3103 9.18. XML Schema Registration for GNSS Schema 3105 This section registers an XML schema as per the guidelines in 3106 [RFC3688]. 3108 URI: urn:ietf:params:xml:schema:lm:gnss 3110 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3111 Martin Thomson (martin.thomson@andrew.com). 3113 Schema: The XML for this schema can be found in Section 8.8 of this 3114 document. 3116 9.19. XML Schema Registration for DSL Schema 3118 This section registers an XML schema as per the guidelines in 3119 [RFC3688]. 3121 URI: urn:ietf:params:xml:schema:lm:dsl 3123 Registrant Contact: IETF, GEOPRIV working group, (geopriv@ietf.org), 3124 Martin Thomson (martin.thomson@andrew.com). 3126 Schema: The XML for this schema can be found in Section 8.9 of this 3127 document. 3129 10. Acknowledgements 3131 Thanks go to Simon Cox for his comments relating to terminology that 3132 have helped ensure that this document is aligns with ongoing work in 3133 the Open Geospatial Consortium (OGC). Thanks to Neil Harper for his 3134 review and comments on the GNSS sections of this document. Thanks to 3135 Noor-E-Gagan Singh, Gabor Bajko and Russell Priebe for their 3136 significant input to and suggestions for improving the 802.11 3137 measurements. Thanks to Cullen Jennings for feedback and 3138 suggestions. Bernard Aboba provided review and feedback on a range 3139 of measurement data definitions. Mary Barnes provided a review and 3140 corrections. David Waitzman and John Bressler both noted 3141 shortcomings with 802.11 measurements. 3143 11. References 3145 11.1. Normative References 3147 [DSL.TR025] 3148 Wang, R., "Core Network Architecture Recommendations for 3149 Access to Legacy Data Networks over ADSL", September 1999. 3151 [DSL.TR101] 3152 Cohen, A. and E. Shrum, "Migration to Ethernet-Based DSL 3153 Aggregation", April 2006. 3155 [GPS.ICD] "Navstar GPS Space Segment/Navigation User Interface", 3156 ICD GPS-200, Apr 2000. 3158 [Galileo.ICD] 3159 GJU, "Galileo Open Service Signal In Space Interface 3160 Control Document (SIS ICD)", May 2006. 3162 [RFC0020] Cerf, V., "ASCII format for network interchange", RFC 20, 3163 October 1969. 3165 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 3166 Requirement Levels", BCP 14, RFC 2119, March 1997. 3168 [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 3169 10646", STD 63, RFC 3629, November 2003. 3171 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 3172 Resource Identifier (URI): Generic Syntax", STD 66, 3173 RFC 3986, January 2005. 3175 [RFC4119] Peterson, J., "A Presence-based GEOPRIV Location Object 3176 Format", RFC 4119, December 2005. 3178 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 3179 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 3180 May 2008. 3182 [RFC5491] Winterbottom, J., Thomson, M., and H. Tschofenig, "GEOPRIV 3183 Presence Information Data Format Location Object (PIDF-LO) 3184 Usage Clarification, Considerations, and Recommendations", 3185 RFC 5491, March 2009. 3187 [RFC5985] Barnes, M., "HTTP-Enabled Location Delivery (HELD)", 3188 RFC 5985, September 2010. 3190 [TIA-2000.5] 3191 TIA/EIA, "Upper Layer (Layer 3) Signaling Standard for 3192 cdma2000(R) Spread Spectrum Systems", TIA-2000.5-D, 3193 March 2004. 3195 [TS.3GPP.23.003] 3196 3GPP, "Numbering, addressing and identification", 3GPP 3197 TS 23.003 9.4.0, September 2010. 3199 11.2. Informative References 3201 [ANSI-TIA-1057] 3202 ANSI/TIA, "Link Layer Discovery Protocol for Media 3203 Endpoint Devices", TIA 1057, April 2006. 3205 [GPS.SPOOF] 3206 Scott, L., "Anti-Spoofing and Authenticated Signal 3207 Architectures for Civil Navigation Signals", ION- 3208 GNSS Portland, Oregon, 2003. 3210 [HARPER] Harper, N., Dawson, M., and D. Evans, "Server-side 3211 spoofing and detection for Assisted-GPS", Proceedings of 3212 International Global Navigation Satellite Systems Society 3213 (IGNSS) Symposium 2009 16, December 2009, 3214 . 3216 [I-D.ietf-geopriv-held-identity-extensions] 3217 Winterbottom, J., Thomson, M., Tschofenig, H., and R. 3218 Barnes, "Use of Device Identity in HTTP-Enabled Location 3219 Delivery (HELD)", 3220 draft-ietf-geopriv-held-identity-extensions-06 (work in 3221 progress), November 2010. 3223 [I-D.thomson-geopriv-uncertainty] 3224 Thomson, M. and J. Winterbottom, "Representation of 3225 Uncertainty and Confidence in PIDF-LO", 3226 draft-thomson-geopriv-uncertainty-06 (work in progress), 3227 March 2011. 3229 [IANA.enterprise] 3230 IANA, "Private Enterprise Numbers", 2011, 3231 . 3233 [IEEE.80211] 3234 IEEE, "Wireless LAN Medium Access Control (MAC) and 3235 Physical Layer (PHY) specifications - IEEE 802.11 Wireless 3236 Network Management", IEEE Std 802.11-2007, June 2007. 3238 [IEEE.80211V] 3239 IEEE, "Wireless LAN Medium Access Control (MAC) and 3240 Physical Layer (PHY) specifications - IEEE 802.11 Wireless 3241 Network Management (Draft)", P802.11v D12.0, June 2010. 3243 [IEEE.8021AB] 3244 IEEE, "IEEE Standard for Local and Metropolitan area 3245 networks, Station and Media Access Control Connectivity 3246 Discovery", 802.1AB, June 2005. 3248 [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, 3249 "Remote Authentication Dial In User Service (RADIUS)", 3250 RFC 2865, June 2000. 3252 [RFC3046] Patrick, M., "DHCP Relay Agent Information Option", 3253 RFC 3046, January 2001. 3255 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, 3256 January 2004. 3258 [RFC3693] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and 3259 J. Polk, "Geopriv Requirements", RFC 3693, February 2004. 3261 [RFC3993] Johnson, R., Palaniappan, T., and M. Stapp, "Subscriber-ID 3262 Suboption for the Dynamic Host Configuration Protocol 3263 (DHCP) Relay Agent Option", RFC 3993, March 2005. 3265 [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing 3266 Architecture", RFC 4291, February 2006. 3268 [RFC4580] Volz, B., "Dynamic Host Configuration Protocol for IPv6 3269 (DHCPv6) Relay Agent Subscriber-ID Option", RFC 4580, 3270 June 2006. 3272 [RFC4649] Volz, B., "Dynamic Host Configuration Protocol for IPv6 3273 (DHCPv6) Relay Agent Remote-ID Option", RFC 4649, 3274 August 2006. 3276 [RFC5808] Marshall, R., "Requirements for a Location-by-Reference 3277 Mechanism", RFC 5808, May 2010. 3279 Authors' Addresses 3281 Martin Thomson 3282 Andrew 3283 Andrew Building (39) 3284 University of Wollongong 3285 Northfields Avenue 3286 Wollongong, NSW 2522 3287 AU 3289 Phone: +61 2 4221 2915 3290 Email: martin.thomson@andrew.com 3291 URI: http://www.andrew.com/ 3293 James Winterbottom 3294 Andrew 3295 Andrew Building (39) 3296 University of Wollongong 3297 Northfields Avenue 3298 NSW 2522 3299 AU 3301 Phone: +61 2 4221 2938 3302 Email: james.winterbottom@andrew.com 3303 URI: http://www.andrew.com/