1. Internet Standards for Geolocation Richard L. Barnes BBN Technologies IETF GEOPRIV & XCON Co-Chair Emergency Services Workshop Co-Chair 8 February 2010

2. Opinions expressed here are those of the presenter, and do not necessarily represent the consensus views of the IETF, the GEOPRIV or ECRIT WGs, or any other body. NOTE WELL

3. Agenda n Location supply and demand l Current and emerging location-based applications l Current and emerging sources of location information n The quest for a Grand Unified Theory

4. Supply and Demand

5. Demand, part 1: Commercial Applications n Since time immemorial: Web site localization l Relatively coarse precision requirements l Incorrect geolocation has low impact n Mobile applications have started from the opposite direction l High-precision location available (GPS / cellular / wifi) l Applications critically depend on highly precise location n Demand for highly-precise, highly-accurate location is increasing l Mobile applications moving to the desktop l Location-based advertising and market analysis

6. Demand, part 2: VoIP Emergency Calling n Calling for help is a critical function of the telephone network, so as more voice is over IP, there’s a desire to replicate that function n Critical requirement is context resolution l Where is the caller? l What are the appropriate emergency resources for that location? n The ECRIT architecture thus enables emergency calls by having the caller do two additional steps: l Figure out where it is l Request contact information for the responsible Public Safety Answering Point (PSAP)

7. Geolocation in the ECRIT Architecture CallerPSAP Location Provider Contact Info DB 1. Request Location4. Update Location 3. Send Location in Call Signaling 2. Request Contact Info using Location

8. Geolocation in the ECRIT Architecture n Location is needed for two purposes: l Routing calls to the correct PSAP l Dispatching emergency responders to the location of the emergency n Architecture doesn’t specify how location is determined, just standard interface for client n General idea that location information is provided by the local IP network to which a caller is connected l Physical connection to caller facilitates geolocation l Bootstrap off of DHCP to discover local location server

9. Demand: Summary n Commercial and emerging regulatory forces driving interest in location information about Internet hosts n Commercial applications are increasingly driving market demand for high-quality geolocation l User-facing applications: Mapping, social networking, augmented reality, etc. l Infrastructural applications: Advertising, market analysis, network coverage analysis n Enabling VoIP emergency calling will require geolocation at two levels l Provided to user for call routing l Provided to PSAP for emergency response

10. Supply: Geolocation Techniques n Autonomous: GNSS n Network-Assisted: l Wireless: Trilateration from endpoint-provided measurements l Wireline: Wiremap with endpoint-provided connectivity info n Network-based: l Wireless: Trilateration based on network measurements l Wireline: Wiremap with SNMP / DHCP info n Third-party: l Topology estimation l A-GPS

11. Supply: An Attempt at Taxonomy GlobalLocal Authoritative Observed Latency-based EnterpriseISP Wiremap Cellular E9-1-1 Skyhook / Google GNSSA-GNSS Target Network3 rd Party n Positioning mechanisms vary along several dimensions l Source of information l Scope of coverage l Entities involved n These factors impact the usability of the positioning mechanism in question l Precision l Accuracy l Timeliness l Protocol requirements

12. The Quest for a Grand Unified Theory

13. Interoperability n General Internet engineering principles have special importance due to the inherent limitations of geolocation services l Dynamic discovery: Applications should be able to find the best location service for the circumstances l Interoperability: Applications need to be able to talk to multiple different location services n Starting to see some movement toward common platforms for Internet geolocation and location-based applications l W3C Geolocation WG: Javascript API for web location l IETF GEOPRIV WG u Internet geolocation protocols in general u Privacy protections for geolocation

14. W3C Geolocation Working Group n Javascript API that allows web pages to request geolocation l navigator.geolocation.getCurrentPosition(…); n How the browser gets location information is unspecified l Firefox uses the Google Gears service (wifi) l Safari Mobile uses CoreLocation (wifi + GPS) n Web apps are beginning to take advantage of the API l Google maps, Flickr mobile, et al. Browser Javascript Location Provider

15. IETF GEOPRIV Working Group n GEOPRIV produces protocols and data formats to support geolocation and privacy n Interoperable data formats l Location Object (PIDF-LO) l Privacy Rules n Protocols for “location configuration” l Internet-general  goal to support many positioning systems l Generalization to third-party requests for location

16. Location Objects n Geodetic location information l Geospatial Markup Language l Simplified GML profile n Civic location information l XML type/value pairs n Basic privacy rules l How long the object can be retained l Whether the recipient can retransmit the object l Reference to additional rules <presence entity="pres:sample@example.com"> 48.14 16.94 250 AT Wien yes 2010-02-07T21:02:00Z 2008-08-19T19:42:55Z

17. Privacy Rules n Presence systems and geolocation systems both require rules for managing access to information, so GEOPRIV worked with the SIMPLE WG to develop a rules syntax n “Common-policy”: General framework for access control permissions l Conditions: Who can have access to the controlled information l Transformations: What version of the information they should get n “Geopriv-policy”: Geolocation-specific privacy features [draft-ietf- geopriv-policy] l Conditions: Grant access based on location l Transformations: Control granularity of location

18. Location Configuration Protocols n “Location configuration” is the process by which a host learns its location from an Internet location provider n DHCP options allow configuration alongside network parameters l Geodetic information in an ad-hoc binary format l Civic information in a binary type/value format (same as PIDF-LO) l Location URIs n HELD is an XML/HTTP protocol that support more advanced scenarios

19. Basic HELD (with discovery, identifiers) n Endpoint gets local access domain name from DHCP n Endpoint queries DNS for NAPTR service “LIS:HELD” n Endpoint sends HTTP POST request to URI from NAPTR n Server returns PIDF-LO and/or location URI access-net.example.org IN NAPTR 100 10 "u" "LIS:HELD" ( ; service "!*.!https://lis.example.org:4802/?c=ex!" ; regex. ; replacement ) POST /?c=ex HTTP/1.1 Host: lis.example.org:4802 Content-Type: application/held+xml geo locationURI 3105551212 HTTP/1.1 200 OK Content-Type: application/held+xml http://lis.example.org:4802/?d=12345

20. GEOPRIV Status and Directions n Completed work: l PIDF-LO Location Object format l DHCP Location options l Privacy rules formats l Basic HELD and LIS Discovery, HELD identifiers n Next steps: l HELD measurements l Indoor / relative location

21. Advanced HELD n HELD is intended to be extensible to support more advanced geolocation use cases n Third-party requests l Extensions to add identifiers (IP/MAC address, IMSI/MSISDN) l LIS Discovery records can be re-used for third-party location service discovery (e.g., by including in the reverse-DNS tree) n Positioning using network information l Wifi, Cellular, et al. POST /?c=ex HTTP/1.1 Host: lis.example.org:4802 Content-Type: application/held+xml 192.0.2.5 A0-12-34-56-78-90 11235550123 00:17:df:aa:37:37 -40 4723 15892 12

22. Indoor Location n Request from 802.11v to define an indoor location format n Shape relative to a reference point l Circular area on 4 th floor, 25m west of main elevator l Normal CRS (e.g., WGS84) to get to reference point l For offset, Cartesian CRS relative to reference point l May allow CRS to rotate according to orientation of “container” n Design team work converging on XML (PIDF-LO) and binary encodings

23. Summary n There is increasing diversity in the Internet geolocation arena l Many different applications are using geolocation, with different communications requirements and quality trade-offs l An increasing number of positioning techniques are being applied to Internet hosts n Things are beginning to move toward interoperability l Web standard for distributing location to web applications l Internet standards for location formats and protocols u Common location and privacy rule formats u DHCP configuration for basic network location delivery u HELD for dynamic discovery and advanced use cases

24. References n For IETF documents, use: http://tools.ietf.org/html/ n IETF ECRIT WG: http://tools.ietf.org/wg/ecrit/ l draft-ietf-ecrit-phonebcp l draft-ietf-ecrit-framework l draft-ietf-ecrit-rough-loc n Emergency services architectures l US: NENA i3 architecture l Canada: Canadian i2 l UK: NICC architecture still in progress; presentation to emergency services workshop here: n W3C Geolocation WG: http://www.w3.org/2008/geolocation/ n IETF GEOPRIV WG: http://tools.ietf.org/wg/geopriv/ n PIDF-LO: RFC3693, RFC 4119, RFC 5491 n Privacy rules: RFC4745, draft-ietf-geopriv-policy n DHCP Location: RFC 3825, RFC 4776, draft-ietf-geopriv-rfc3825bis, draft-ietf-geopriv-dhcp- lbyr-uri-option n HELD: draft-ietf-geopriv-http-location-delivery l draft-ietf-geopriv-lis-discovery l draft-ietf-geopriv-held-identity-extensions l draft-thomson-geopriv-held-measurements