Vertical Handoff Decision Schemes for Heteregeneous Wireless Networks: An Overview

Abstract

The next generation wireless networks are expected to support different applications within a heterogeneous network environment. In such networks, mobile users can use the advantage of diverse networks by switching between them. The most challenging issue in heterogeneous wireless networks is the Always Best Connected (ABC) concept in order to support best connectivity to mobile users at anywhere anytime from any network. Recently, many vertical handoff decision schemes have been proposed in the literature in order to provide solution to ABC. As traditional handoff decision is mainly based on received signal strength (RSS), vertical handoff decision must take into account other factors like user mobility, network conditions, pricing issues of diverse networks, and user preferences in addition to RSS. In this paper, we first outline the main characteristics needed for vertical handoff decision, and then we present an overview of the most recent and interesting vertical handoff decision schemes. We classify these strategies and present their main characteristics.