Transcript ppt
A Seamless Handoff for Dual-interfaced Mobile Devices in Hybrid WLAN Speaker : Rui-Yi Chien Date : 2005 / 02 / 17 Outline Introduction Dual-Interface Handoff Mechanisms Performance Evaluation Of Handoff Conclusions Outline Introduction Dual-Interface Handoff Mechanisms Performance Evaluation Of Handoff Conclusions Introduction Today’s wireless access network consist of several overlapping tiers Provision of real time undisrupted communication to mobile users , anytime and anywhere through these heterogeneous overlay networks , is a challenge A Typical Heterogeneous Network Characteristics of the Overlay Networks The network’s service areas are overlapped Two network support different data rates The signal powers received from the BSs of the different networks are incomparable When there is a change in IP address of the MN , process may cause service disruption Outline Introduction Dual-Interface Handoff Mechanisms Performance Evaluation Of Handoff Conclusions State Model of an Interface Dual-Interface Handoff Mechanisms Use two interfaces each capable of connecting to the WLAN & GPRS networks Two different thresholds (TH1WLAN , TH2WLAN) of Signal to Noise Ratio (SNR) Only WLAN subnet is scanned and connected TH1WLAN > TH2WLAN TH1WLAN > SNR > TH2WLAN The interface may be attached to GPRS TH2WLAN < SNR The policy Interfaces follow (1/3) Interface1 Interface2 Active Standby OFF TH1wlan > SNR > TH2wlan MN WLAN2 SNR > TH1wlan WLAN1 The policy Interfaces follow (2/3) Interface1 Interface2 Active Ready OFF SNR < TH2wlan SNR > TH2wlan MN WLAN GPRS The policy Interfaces follow (3/3) Interface1 Interface2 Ready Ready OFF SNR < THGPRS MN SNR > THGPRS GPRS1 GPRS2 Horizontal Handoff between WLANs Interface1 Interface2 Standby Active Idle Standby Active OFF WLAN2 SNR > TH1wlan MN WLAN1 TH1wlan > SNR > TH2wlan Vertical Handoff from WLAN to GPRS Interface1 Interface2 Standby Active Idle Standby Ready OFF SNR < TH2wlan SNR > TH2wlan MN WLAN GPRS Vertical Handoff from GPRS to WLAN Interface1 Interface2 Standby Active Off Standby Active Off MN SNR > TH2wlan WLAN GPRS Outline Introduction Dual-Interface Handoff Mechanisms Performance Evaluation Of Handoff Conclusions Performance Evaluation (1/2) Performance Evaluation (2/2) Outline Introduction Dual-Interface Handoff Mechanisms Performance Evaluation Of Handoff Conclusions Conclusions The handoff requires that MN can control the switching of communication between two dual mode interfaces Reference A seamless handoff for dual-interfaced mobile devices in hybrid wireless access networks Inayat, R. Aibara, R. Nishimura, K. Advanced Information Networking and Applications, 2004. AINA 2004. 18th International Conference on 2004 IEEE