1. PERA PER sonal A ssistance Engin Deveci Computer Engineering Department Bogazici University devecien@boun.edu.tr Can Komar Computer Engineering Department Bogazici University komar@cmpe.boun.edu.tr

2. PERA OVERALL PICTURE

3. PERA OVERALL PICTURE Location Manager Session Manager PERsonal Assistance – PERA PERA web component – PERAw

4. PERA

5. Presence Location Based Services – LBS Voice Video Session Initiation and negotiation via SIP Instant Messaging - IM

6. PERA SIP API Provides –Abstraction of SIP Signalling –Easy to Use API –Efficient and Reliable –Compatible With SIP RFC 3261 Features –Registration –Multiple Voice Call –Instant Messaging –Presence

7. PERA SIP API Architecture –Event Driven –Blocking / Non-Blocking use –Implementation in C/C++ Example –SIPPlaceCall(sip_context, “Altug Simsek”,“altugsi”,“o2.com.tr”, “Engin Deveci”,“enginde”,“o2.com.tr”, local_sdp );

8. PERA SESSION MANAGER Registrar Redirect Proxy

9. PERA SESSION MANAGER FEATURES –Registration –Voice Call –Instant Messaging –Presence ARCHITECTURE –RFC 3261 –C/C++

10. PERA Performance of SM SM is on :  256MB Ram  PIII 866  Win2K Prof SP2  100 Mbps LAN Simulators are on:  256MB Ram  PIII 800  Win2K Prof SP3  100 Mbps LAN

11. PERA Location Manager WLAN Tracker is a server-client system that is implemented in a combination of Java and C It is designed to track the users in different physical areas in a multithreaded manner and provide location based services (messages etc.) to them

12. PERA Location Manager Implemented in software, no extra hardware is used Components of the system –Server: Collects and evaluates data –Client: Sniffs the wireless medium and informs the server –WAP: IEEE 802.11 compliant access points Basic Idea –Every point on a surface has a different combination of signal levels received from different WAPs. Using this information a radio map of a surface can be prepared. Server is implemented in pure Java thus platform independent. Client is implemented in C and Java due to driver dependency.

13. PERA Location Manager Off-Tracking: In this phase, the radio map is prepared. (Data Collection phase.) On-Tracking: In this phase, the clients transmit information to the server and the server tries to estimate their location and show on a map.

14. PERA Location Manager Uses the data collected in the previous phase. Tries to estimate the location according to the data sent by the client. Data is sent via UDP datagrams. Centralized server structure, the server displays all available maps and manages them in separate threads. The configuration and precollected radiomap data are read from text files. Clients are tracked according to IP address. If configured, the clients that have static IP can be configured to have distinct labels.

15. PERA Location Manager ETA 1 st, 2 nd and 3 rd floors 4 WAPs. At most 3 WAPs at a time. 30 equally separated measurement points per floor.

16. PERA Location Manager An average of ~3m error in estimation Multiple floor problem generally can be solved with signal power filter Effects of history filter and number of WAPs are being studied.

17. PERA Client and LM Communication Via XML Mac Number Strength of Signal

18. PERA Client and LM Communication Via SIP Presence Packets LM will SUBSCRIBE to the SM for each client it wanted to track. Each NOTIFY packet will contain an extended XML body including the MAC address of the WAP and signal strength.

19. PERA Client and SM Communication SIP based. INVITE for session initiation (VOICE, VIDEO). RFC 3261 SUBSCRIBE/NOTIFY for presence. IETF simple-presence draft. MESSAGE for instant messaging. IETF sip- message draft.

20. PERA Client to Client Communication RTP for voice and video G711, G723 for voice H263,... for video.

21. PERA Client Architecture

22. PERA SM Architecture

23. PERA Q&A Thank You