A cooperative vertical and horizontal handoff for enhancing qos in wimax wlan overlay network

Abstract

In the past few years, the installation of IEEE 802.11 newlineWLAN increased all over the world due to easy installation, higher newlinebandwidth, and low cost. The latest 802.11 standard (802.11n) provides the newlinemaximum data speed of about 600 Mbps which makes it an accepted newlinebenchmark for deploying WLANs. The IEEE 802.11n is backward newlinecompatible and the new features of 802.11n may not be achieved fully if the newlineIEEE 802.11n WLAN contains one or more legacy 802.11a/b/g clients. newlineFurthermore, the WLAN without a legacy client is not possible today since newlinethe WLAN users have a tendency to upgrade their devices gradually. One of newlinethe drawbacks in WLAN is its small cell size, which is not suitable for newlinedevices with high velocity. The alternate network technology for IEEE 802.11 newlineWLAN with almost identical bandwidth and QoS support with longer cell newlinesize is IEEE 802.16 WiMAX, which is one of the quickest growing network newlinetechnologies throughout the world. Hence, the integration of WLAN and newlineWiMAX is considered to be an excellent approach in 4G networks. newlineThe proposed work has explored the WiMAX/WLAN integration newlinearchitectures such as openly coupling, loosely coupling, and tightly coupling newlinealong with the background details. The tightly coupling architecture is newlineidentified as the best integration architecture for integrating the WiMAX and newlineWLAN networks for getting the benefits such as better resource management, newlinelow latency vertical handoff, network implementation cost, low signaling newlineoverhead, and performance via the literature survey. Further, the proposed newlinework presents a network condition estimation scheme which computes the newlinecondition of both the IEEE 802.11 WLAN and IEEE newline newline