Location n-based Services Henning Schulzrinne Columbia University
Overview Time + space Getting location information Using location information Privacy issues
Getting location Universal inform mation anywhere in the world independent of network connectivity Non-proprietary Energy efficient Accurate to 10 m/r room level
determination meth hods GPS 802.11 L2 10m 20-100m protocols cell tower man L2, L3, L7 room-level, AP 100 m-2 km room or A privacy global accurate simple to implement reasonably accurate room-level accuracy no surveying needed no infrastructure cost client privacy no infras privacy mostly outdoors requires survey only works in urban areas requires Internet connectivity mapping IP address to switch port? low accuracy cell coverage stationar doesn t s Enterprise & home LANs Enterprise & home LANs DSL, cable backup for other methods enter home
Location delivery yprotocols Method LLDP-MED DHCP HELD layer L2 L3 L7 (HTTP) accuracy room-level, AP room-level, AP room-level, AP advantages simple to implement built into switch direct port/room mapping simple to implement network locality traverses NATs can be operated by L2 provider problems may be hard to automate for large enterprises mapping MAC address to location? mapping IP address to switch port? use Enterprise & home LANs Enterprise & home LANs Some ISPs DSL, cable ISPs
indoor routing services direction s car park assistance traffic management ing ing Tracking Navigation Emergency em au as rist w Information Advertising ba location- based services Billing ro er Games facility Infrastru g es are ling Communications buddy finder Leisuree Management custom relation instant messaging security flee (schedu environm
Location-based services Finding services based on location physical services (stores, restaurants, ATMs,...) electronic services (hot spots, prin nters,...) Using location to improve (network) services incoming or outgoing g communicat cations adapts to location o 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 Location-aware inbound serv vices 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 emerg routing gency call center send delivery@pizza.c i com to nearest branch location-based events subscribe to locations, not people
consum mer app) the city in true realtime: how busy is the city & where is everyone going, rig ed: all anonymous destination activity it Green: only unusual destination ac Press 1 to see the #1 hottest destination, then 1 again to see the restaurants and bars there, e Now available in San Francisco, more cities rolling out in beta version. PS n
Minimum Volume Embedding ine learning algorithm that determine s behavior and clusters from anonymo aggregate movement from all pairs of corners in the city. Obtains behavioral map of city (vs. geographical map) Restaurants s Work Nightlife Residential
Platforms missing network connectivity missing navigation
IETF GEOPRIV and SIMPLE archite ectures DHCP rule XCAP (rules) maker et publication interface location server notification interface location recipient GEOPR ntity PUBLISH presence agent SUBSCRIBE watcher SIP presen
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 y (e.g., nearest gas station ) rivacy reveal identity + location to LBS (friend finder service) reveal to (friend, other) individual
Presence and privacy: PIDF LO 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 <tuple id="sg89ae"> <status> t <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> p </gp:usage-rules> </gp:geopriv> </status> <timestamp>2003-06-22t20:57:29z</timestamp> 06 22T20:57:29Z </tuple>
GEOPRIV privacy 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 rul es User gets maximum of permissions across all matching rules privacy-safe compositio removal of a rule can on reduce privileges Extendable to new presence data rich presence biological i l sensors mood sensors
Open technical and standard ds issues Universal APIs As simple as getti meofday() Not specific to metho od or vendor Crowd-sourcing Integration between presence and location presence as universal third party interface? Clear privacy rules
Deployme ent issues ISPs need to make location available to their customers for in-door use location as a chargeable service? LAN-based location f APs and ports enterprise for room-level location