Implementation of Vertical Handoff Algorithm between IEEE 802.11 WLAN & CDMA Cellular Network

Wireless communications is the fastest growing segment of the communications industry. Everyone wants the quality of services anytime & anywhere. Wireless networks can integrate various heterogeneous radio access technologies as GSM, WLAN, Wimax etc. WiMAX is an IP based, wireless broadband access technology that provides performance similar to 802.11/Wi-Fi networks with the coverage and QOS (quality of service) of cellular networks. WiMAX is also an acronym meaning "Worldwide Interoperability for Microwave Access (WiMAX). The main promise of interconnecting these heterogeneous networks is to provide high performance in achieving a high data rate and support real time applications. These services require various networks (such as CDMA2000 and Wireless LAN) to be integrated into IP-based networks, which further require a seamless vertical handoff to 4 generation wireless networks. When a mobile host (MH) changes its point of attachment, its IP address gets changed. MH should be able to maintain all the existing connections using the new IP address. This process of changing a connection from one IP address to another one in IP network is called handoff. Vertical handoff is switching from one network to another while maintaining the session. Vertical Handoff (VHO) is a major concern for different heterogeneous networks. VHO can be user requested or based on some criteria already designed by the researcher of that particular algorithm. The main objective is to implement efficient & effective handoff scheme between two heterogeneous network ie. 802.11 WLAN & CDMA.