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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 t
he 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) TH1WLAN > TH2WLAN
Only WLAN subnet is scanned and connected TH1WLAN > SNR > TH2WLAN
The interface may be attached to GPRS TH2WLAN < SNR
The policy Interfaces follow (1/3)
MN
Interface1
Active
Interface2
Standby
SNR > TH1wlan
TH1wlan > SNR > TH2wlan
Interface2
OFF
WLAN2
WLAN1
The policy Interfaces follow (2/3)
MN
SNR > TH2wlan
SNR < TH2wlan
Interface1
Active
Interface2
Ready
Interface2
OFF
WLANGPRS
The policy Interfaces follow (3/3)
MN
SNR > THGPRS
SNR < THGPRS
Interface1
Ready
Interface2
Ready
Interface2
OFF
GPRS1
GPRS2
Horizontal Handoff between WLANs
MN
Interface1
Active
SNR > TH1wlan
TH1wlan > SNR > TH2wlan
Interface2
OFF
Interface2
Standby
Interface1
Standby
Interface2
Active
Interface1
Idle
WLAN1
WLAN2
Vertical Handoff from WLAN to GPRS
MN
SNR > TH2wlan
SNR < TH2wlan
Interface1
Active
Interface2
Standby
Interface2
OFF
Interface1
Standby
Interface1
Idle
Interface2
Ready
WLANGPRS
Vertical Handoff from GPRS to WLAN
MN
SNR > TH2wlan
Interface1
Off
Interface2
Active
Interface2
Standby
Interface1
Standby
Interface1
Active
Interface2
Off
WLANGPRS
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 networksInayat, R. Aibara, R. Nishimura, K.Advanced Information Networking and Applications, 2004. AINA 2004. 18th International Conference on 2004 IEEE
