Introduction to LBS Fall 2004 CS644 Advanced Topics in Networking Sue B. Moon Division of Computer Science Dept. of EECS KAIST

2 Location Based Services Services that integrate a mobile device's location or position with other information so as to provide added value to a user

3 Taxonomy Person-oriented –e.g. friend finder –M-commerce Device-oriented –e.g. car tracking for theft recovery Push services –e.g. subscription-based service Pull services –e.g. where to find the nearest cinema?

4 Location Determination Technologies Network-based –Cell-ID trace mechanism 단점 : –Accuracy: up to 2km urban, 30km rural –CI-TA (Cell-ID with Time Advance) Calculate delay between handset and base station –AOA (Angle of Arrival) Use multiple antennas at base station Triangulation of location based on angles of signal reception –TDOA (Time Difference Of Arrival) Exploit relative difference between two base stations

5 Location Determination Technologies Handset-based –GPS (Global Positioning System) Need a view of 3 satellites out of 24 of US Gov't 단점 : –Long Time-to-First-Fix (TTFF) Hybrid –GPS-DR (Dead reckoning) –Wireless-Assisted GPS (WAG)

6 General LBS Comm Model GIS Application Middleware Layer Positioning Layer

7 OSFi (Open Srouce Gateway Initiative) Java-based S/W Architecture Application OSGi Core and Optional Services Device Mgr, HTTP service, User Admin, etc. Hardward Platform S/W Platform Real-Time OS Network Drivers TCP/IP, 802, Bluetooth, etc. Native Code VR, TTS Application OSGi Framework Core APIs for applications to share JavaVM: life cycle mgmt, security, Java 2 Micro Edition (JVM)

8 AMI-C (Automotive Multimedia Interface Collaboration) Standard Platform API Middleware OS Hardware Car NavitaionContentsInternetTheft Prevention Audio Other Device S/W Platform Standard H/W Platform Standard

9 Telematics Telematics = telecommunication + informatics

10 References "Location-Based Services" by Jochen Schiller and Agnes Voisard, Morgan Kaufmann 텔레매틱스 개론 by 송준화 외 다수, 홍릉과학출판사