1. An Architecture for Location- Based Service Mobility Using the SIP Event Model Ron Shacham, Henning Schulzrinne Columbia University Wolfgang Kellerer, Srisakul Thakolsri Docomo Euro-Labs Mobisys 2004, Workshop on Context Awareness Boston, MA

2. Overview Motivation: In the future, people will use many communication devices, both personal (PDA, desk phone) and public (eg. workplace, hotel), that may be personalized Examples of personalization  SIP Proxy and authorization settings  Call logs  Emergency numbers We present a SIP event-based architecture that configures and de-configures devices based on a user’s location and other context information

3. Architectural Elements SIP Events are used by devices to access, update, and receive updates about user profiles  SUBSCRIBE to profiles, and receive entire profiles and updates in NOTIFY messages  PUBLISH is used to push local updates User location is determined and updated  Location of user is determined by many sources (eg. swipe-card readers and mobile devices)  Rooms have SIP URIs, and SIP REGISTER is used to update “room presence”

4. Architectural Elements Enhanced “Soft Phones” receive room updates and user profiles to provide users their personalized services Hardware devices are handled by Device Controllers which:  Track user locations  Access profile data  Maintain an up-to-date view of device locations (SLP)  Translate into native device format

5. Architecture Room Presence SLP Directory Agent Device Controller (DC) Scripts SIP Proxy/ Registrar SLP Service Agent SLP Service Agent REGISTER (Room Presence Updates) REGISTER (Room Presence Updates) SrvReg SrvReqSrvRply TFTPHTTP Room User Profiles Soft phone SUB/NOTIFY/ Updates Room SUB/NOTIFY/Updates

6. Context-based Configuration Device configuration based on  User location  Time and calendar info  Type of location update Users specify policies through scripts that are executed upon user’s entrance into any room

7. Summary SIP Events are used to provide user profiles on any device, whether private or public Configuration is based on user location and other context information, and may be controlled by the user A wide range of devices are supported

8. Example Use Conference Room Lab

9. Conference Room Lab

10. Conference Room Lab Configured

11. Conference Room Lab Configured

12. Conference Room Lab Configured I am in lab

13. Example Conference Room Lab Default

14. Example Conference Room Lab Redial