This Life

AN OPTIMIZED VERTICAL HANDOFF DECISION STRATEGY

IN HETEROGENEOUS WIRELESS NETWORKS: A CASE FOR ARTIFICIAL NEURAL NETWORKS AND ANT COLONY OPTIMIZATION

1.0 INTRODUCTION

1.1 BACKGROUND

A heterogeneous (or hybrid) network can be defined as a network, which comprises of two or more different access network technologies (VANET, WLAN, UMTS, CDMA, MANET) to provide ubiquitous coverage. The emergence and development of mobile devices continues to expand and reshape our living standards. In the recent years, advances in miniaturization, low-power circuit design, and development in radio access technologies and increase in user demand for high speed internet access are the main aspects leading to the deployment of a wide array of wireless and mobile networks. The varying wireless technologies are driving today’s wireless networks to become heterogeneous and provide a variety of new applications (such as multimedia) that eases and smoothes the transition across multiple wireless network interfaces. Fourth generation wireless communication system is the promising solution for heterogeneous wireless networks. The 4G wireless systems have the potential to provide high data transfer rates, effective user control, and seamless mobility. Many internetworking mechanisms have been proposed [1]- [4] to combine different wireless technologies. Two main architectures (a) Tightly coupled (b) Loosely-coupled have been proposed for describing internetworking of heterogeneous networks. However, roaming across the heterogeneous networks creates many challenges such as mobility management and vertical handoff, resource management, location management, providing QoS, security and pricing etc. In this kind of environment, mobility management is the essential issue that supports the roaming of users from one network to another. One of the mobility management component called as handoff management, controls the change of the mobile terminal’s point of attachment during active...