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Location-Based Services. Henning Schulzrinne Columbia University. Overview. Time + space Getting location information Using location information Privacy issues. Getting location information. Universal anywhere in the world independent of network connectivity Non-proprietary
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Location-Based Services • Henning Schulzrinne • Columbia University
Overview • Time + space • Getting location information • Using location information • Privacy issues
Getting location information • Universal • anywhere in the world • independent of network connectivity • Non-proprietary • Energy efficient • Accurate to 10 m/room level doesn’t exist in one system
traffic management people & vehicle tracking car park assistance mobile yellow pages travel & tourist guides instant messaging customer relationship banners & alerts automotive assistance emergency calls location-aware call handling fleet (scheduling) Information Tracking Management Emergency Billing Advertising buddy finder environmental security mobile games indoor routing travel planner directions geocaching road tolling Navigation shopping guides product tracking facility Leisure Communications Games Infrastructure location-based services Location-based services Foundations of Location-based Services (Steinger, Neun, Edwardes), modified) 6
Location-based services • Finding services based on location • physical services (stores, restaurants, ATMs, ...) • electronic services (hot spots, printers, ...) • Using location to improve (network) services • incoming or outgoing communications adapts to location • Using location to provide information • tourist guides • advertisements • Making others aware of user location • presence (individual) • popularity, movement (group) • Security • grant access based on user’s location
Location-based VoIP services • Location-aware inbound routing • do not forward call if time at callee location is [11 pm, 8 am] • only forward time-for-lunch if destination is on campus • do not ring phone if I’m in a theater • outbound call routing • contact nearest emergency call center • send delivery@pizza.com to nearest branch • location-based events • subscribe to locations, not people • Alice has entered the meeting room • subscriber may be device in room 8
Location-based security • Examples: • Garmin GPS unlocks at home • Only allow person in room to control conference room equipment via web browser • Restrict access to bank account based on user’s location • IP-address based (MaxMind, ...) • Need certified location
Modes of emergency communications emergency call information “I-am-alive” dispatch emergency alert (“inverse 911”) civic coordination 10
Components of NG911 system LoST (public) LoST (private) PSAP ESN (county, state, …) PSAP Internet 11
cluster serves VSP2 Bergen County NJ US Leonia NJ US NJ US NY US LoST: Location-to-URL Mapping VSP1 cluster serving VSP1 replicate root information 123 Broad Ave Leonia Bergen County NJ US LoST root nodes search referral sip:psap@leonianj.gov 12
G G G G G resolver T3 (.dk) (.dk) T1 (.us) T2 (.de) LoST Architecture tree guide broadcast (gossip) T1: .us T2: .de seeker 313 Westview Leonia, NJ US Leonia, NJ sip:psap@leonianj.gov 13
<findService xmlns="urn:…:lost1” recursive="true" serviceBoundary="value"> <location profile="basic-civic"> <civicAddress> <country>Germany</country> <A1>Bavaria</A1> <A3>Munich</A3> <A6>Neu Perlach</A6> <HNO>96</HNO> </civicAddress> </location> <service>urn:service:sos.police</service> </findService> LoST: Query example 14
LoST “Find Service” response/warning example <findServiceResponse xmlns="urn:ietf:params:xml:ns:lost1"> <mapping expires=“1990-12-31T23:59:60Z” lastUpdated=“2006-11-01T01:00:00Z”> <displayName xml:lang="de">München Polizei-Abteilung</displayName> <service>urn:service:sos.police</service> <serviceBoundary profile=”civic”> <civicAddress xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"> <country>Germany</country> <A1>Bavaria</A1><A3>Munich</A3><PC>81675</PC> </civicAddress> </serviceBoundary> <uri>sip:munich-police@example.com</uri> <serviceNumber>110</serviceNumber> </mapping> <path> <via source=“lost:esgw.uber-110.de.example”/> <via source=“lost:polizei.munchen.de.example”> </path> </findServiceResponse> 15
Citysense.com See the city in true realtime: how busy is the city & where is everyone going, right now?Red: all anonymous destination activity Green: only unusual destination activity Press “1” to see the #1 hottest destination, then “1” again to see the restaurants and bars there, etc. Now available in San Francisco, more cities rolling out in beta version. Aggregate GPS information
Minimum Volume Embedding Machine learning algorithm that determines behavior and clusters from anonymous aggregate movement from all pairs of corners in the city. Obtains behavioral map of city (vs. geographical map) Work Restaurants Nightlife Residential
Platforms missing location missing network connectivity time zone missing navigation BlueTooth? ZigBee?
rule maker location server presence agent location recipient target watcher presentity IETF GEOPRIV and SIMPLE architectures DHCP XCAP (rules) notification interface publication interface GEOPRIV SUBSCRIBE SIP presence PUBLISH
Privacy issues • Not all LBS are privacy-sensitive • “where is the the M125 bus?” • navigation with GPS • Problem: location + personal identity • or derivable (e.g., via home location)
Privacy threats reveal device anonymously (e.g., “nearest gas station”) reveal identity + location to LBS (friend finder service) Privacy reveal to individual (friend, other)
Presence and privacy: PIDF-LO <tuple id="sg89ae"> <status> <gp:geopriv> <gp:location-info> <gml:location> <gml:Point gml:id="point1“ srsName="epsg:4326"> <gml:coordinates>37:46:30N 122:25:10W </gml:coordinates> </gml:Point> </gml:location> </gp:location-info> <gp:usage-rules> <gp:retransmission-allowed>no </gp:retransmission-allowed> <gp:retention-expiry>2003-06-23T04:57:29Z </gp:retention-expiry> </gp:usage-rules> </gp:geopriv> </status> <timestamp>2003-06-22T20:57:29Z</timestamp> </tuple> • All presence data, particularly location, is highly sensitive • Basic location object (PIDF-LO) describes • distribution (binary) • retention duration • Policy rules for more detailed access control • who can subscribe to my presence • who can see what when 22
GEOPRIV privacy rules • User gets maximum of permissions across all matching rules • privacy-safe composition: removal of a rule can only reduce privileges • Extendable to new presence data • rich presence • biological sensors • mood sensors • Conditions • identity, sphere • time of day • current location • identity as <uri> or <domain> + <except> • Actions • watcher confirmation • Transformations • include information • reduced accuracy • e.g., only within 5 mile radius 23
Open technical and standards issues • Universal APIs • As simple as gettimeofday() • Not specific to method or vendor • Crowd-sourcing • Integration between presence and location • presence as universal third party interface? • Clear privacy rules • both technical and legal
Deployment issues • ISPs need to make location available to their customers • for in-door use • location as a chargeable service? • LAN-based location for room-level location • APs and ports • enterprise
Conclusion • Location as fundamental service building block → time & space • Improve user experience • from navigation and locating services • to automatic silent mode • Need network protocols for • conveying location • mapping location to services • describing privacy requirements