QoS-based Vertical Handoff between IEEE802.11 WLAN and GPRS Cellular Network
Date Issued
2004
Date
2004
Author(s)
Chen, Li-Ming
DOI
zh-TW
Abstract
With the rising and flourishing development of mobile communication markets, many international organizations and research groups have promoted B3G (3G and Beyond) research and standard actively. The vision of B3G is expected to integrate all kinds of wireless technologies and create a heterogeneous multi-access network which provides wireless users with convenient global information access capabilities and multimedia wireless communication services.
In the heterogeneous multi-access network, vertical handoff had been proposed to achieve seamless handoff between different kinds of wireless technologies. In addition to the mobility management, we propose that the vertical handoff is also a good way to avoid degrading QoS due to wireless channel interference or network overload. Instead of RSS, the proposed algorithm uses measured bandwidth as the criterion for handoff decision.
In this paper, a QoS-based vertical handoff scheme is proposed. The vertical handoff process is divided into two phases. In the handoff trigger phase, access network selection and handoff time decision is made by the vertical handoff algorithm. In order to maintain the QoS, the handoff algorithm will guide mobile device to switch between IEEE802.11 WLAN and mobile cellular networks by comparing their transport capacity and the user service requirements. In the handoff execution phase, a smooth (seamless) vertical handoff procedure is involved. We design a loosely coupled WLAN and GPRS network with mobile IP. In order to reduce the registration latency, an enhancement of mobile IP is also proposed. In this paper, we will simulate the vertical handoff process in the NS2 to verify the design.
Subjects
垂直換手
IEEE802.11無線區域網路
GPRS
服務品質
IEEE802.11 WLAN
Vertical Handoff
mobi
QoS
Type
thesis