1. WLAN-GPRS Integration For Next-Generation Mobile Data Networks Wireless Communications IEEE 2002 報告者：陳崇凱

2. Authors Apostolis K. Salkintzis, Motorola Chad Fors, Motorola Rajesh Pazhyannur, Motorola

3. Outline Integrated WLAN and cellular data networks Interworking architecture Current standardization activities A tight coupling architecture A loosely coupled architecture Conclusion

4. Integrated WLAN and Cellular Data Networks Roaming  Between WLANs and cellular system Session mobility  Session : a flow of IP packets between the end user and an external entity Enhanced mobile applications  Ex : mobile email application

6. Interworking Architecture Loose coupling and Tight coupling. With loose coupling the WLAN bypasses the GPRS network and provides direct data access to the external packet data networks (PDNs). With tight coupling the WLAN data traffic goes through the GPRS core network before reaching the external PDNs.

8. Current Standardization Activities Scenario 1 — Common billing and customer care Scenario 2 — 3GPP system-based access control and charging Scenario 3 — Access to 3GPP GPRS-based services Scenario 4 — Service continuity Scenario 5 — Seamless services Scenario 6 — Access to 3GPP circuit-switched services

9. A Tight Coupling Architecture Providing a novel solution for interworking between 802.11 WLANs and GPRS. System description Protocol architecture WLAN adaptation function GIF/RAI discovery procedure

10. A Tight Coupling Architecture BENEFITS  Seamless service continuation across WLAN and GPRS.  Reuse of GPRS AAA.  Reuse of GPRS infrastructure and protection of cellular operator’s investment.  Support of lawful interception for WLAN subscribers.  Increased security.  Common provisioning and customer care.  Access to core GPRS services

16. A Loosely Coupled Architecture authentication encryption billing session mobility

20. Conclusion The recent evolution and successful deployment of WLAN systems worldwide has fueled the need for interworking mechanisms between WLANs and cellular data networks such as GPRS. Comparison : tight coupling vs. loose coupling