Transcript 投影片 1
Integration of 802.11 and Third-Generation Wireless Data Networks • 1.Introduction • 2.Service scenario in Integrated 802.11&3G • 3.Two architecture for 802.11 & 3G integration • 4.The IOTA 802.11 gateway • 5.IOTA client software • 6.Experimental results • 7.Conclusion Speaker :林家彬 1.Introduction 802.11 vs. 3G(roughly) Data Cover Areas Rate 802. 11b 11M ~54M bps 3G 64kbps Wider area of ~2Mbps coverage that enables ubiquitous connectivity Small areas, suitable for hot-spot application in hotels and airports.(1km^2) 1.1 Why is it the challenging task to integrate them? • Environment enterprise and home networks VS. global areas • Capability 1.WLAN lack AAA and billing mechanisms 2.CDMA2000 or UMTS and their extension to 802.11 • QOS • POLICY 1.2Research Contributions 2. Service Scenario in integrated 802.11 and 3G networks: problem statement • Issues on John’s case: 1.Security association 2.Switching occurs when John is on sessions. 3.User profile obtained (AAA server) 4.Revenue sharing 3.Two architecture for 802.11 and 3G integration • A. Tightly-coupled Interworking -The rationale:802.11 as another 3G access network. • B. Loosely-coupled Interworking – It completely separates the data paths in 802.11 and 3G networks A. Tightly-coupled Interworking Disadvantages of tightly-coupled Interworking • 1.Traffic engineering -Operator must own both the 802.11 and 3G parts of the network. -setup of the entire network should be remodified because traffic load increased 25~100 times . • 2.The configuration of the client devices -built-in USIM,R-UIM slots or external cards must bi plugged separately in to the subscriber devices . B. Loosely-coupled Interworking Advantages to the looselycoupled integration • 1.Independent deployment and traffic engineering of 802.11 and 3G • 2.Roaming agreements with many partners can result in widespread coverage. • 3.No longer establish separate accounts • 4.Allows WISP to provide its own hot-spot 4.The IOTA 802.11 Gateway • 1. Integration of two access technologies (IOTA) • 2. Allows the mobile node to access the network. • 3. IOTA integrates RADIUS server, Mobile-IP, dynamic firewall, QOS module and accounting module. • 4. IOTA building blocks are implemented as software modules ,and run on Linux. • A.RADIUS server -It enables roaming agreements between 3G and 802.11 -provides authentication services to the 802.11 cloud. • B. Mobile-IP agent -supports the roles of both home and foreign agents (HA,FA) • C. Dynamic firewall -implemented using the Linux IP filter architecture. Obtained from the subscriber’s home AAA. D.QOS module -750Kbps for Gold. -250Kbps for Silver . -125 Kbps for Bronze. E. Accounting module -share revenue F. Integrated web cache • G. Simple-IP operation -offers integrated authentication and billing. -Does not support seamless mobility, and requires manual user intervention to switch network access. • H. Integration with UMTS -The current UMTS standards do not include support for the I ET F AAA and Mobile –IP protocol -It is expected that the definition of usage for AAA and Mobile-IP within UMTS will soon become standardized. 5.IOTA client software • Support mobility across several kinds of physical interfaces. • Seamless: -A user doesn’t see any changes in his connections. • Selection of interface to use dependent on user preference: • The GUI allows the user to configure, monitor, and control the state of the client. A. Interface Selection Algorithm • A novel interface-selection algorithm that uses the current signal strength and the priority of the interfaces to select the active interface. • Goal—introduce a hysteresis effect and let the client stay with the current interface to prevent data loss. • 6. Experimental result • A. Performance of Mobile-IP agents • First-registration delay= AAA authentication + setting up packet filter+ creating tunnels • Re-registration delay= AAA authentication • Switching-registration delay=AAA authentication + creating tunnels B. Performance of QOS mechanisms (two scenarios) • The first scenario illustrates restricting per-user traffic to 3.5Mbps The second scenario :class-based with Gold ,Silver and Bronze. 7.Conclusion • 1.Two architectural choices for the integration: tightly & loosely • 2.Described in detail our realization of the loosely-coupled architecture in the form of the IOTA gateway • 3.Described client software . • 4.Sample experimental results .