An Overview of Decision Techniques for Vertical Handoff Across Wireless Heterogeneous Networks

Future wireless communication networks popularly known as beyond third generation (B3G) or Fourth generation (4G) networks will likely consist of heterogeneous wireless networks which will be IP-Centric based. These networks will offer a wide range of high data multimedia services to mobile users. To achieve this, Vertical Handoff (VHO) is considered as the method of realization and it is defined as the process by which users will seamlessly roam amongst these heterogeneous networks while communicating. To realize VHO, effective and efficient algorithms for accurate VHO decision are of utmost importance and hence form an area of current research focus. In this regards, several efforts have been made and it is the specific objective of this paper to provide an overview of efforts made thus far while discussing related VHO concepts. Specifically, handoff types, handoff process and classification of vertical handoff, metrics required, and existing works are presented. We seek to provide a concise background for not just VHO decision algorithms but also for understanding the basic concept of VHO.