Comparison between vertical handoff algorithms for heterogeneous wireless networks

In heterogeneous Wireless communication network, transferring of data between moving nodes can be handled by well designed mobility management system, in which handover is a important factor in maintaining space connection to base station even in high speed. During handover (i.e. mobile node moving from one base station area to another base station area), there is a need to change initial point of connection to a new base station area towards which the mobile node is moving. Currently, in our world all mobile equipment is moving so mobility of equipment becomes necessary, so to overcome this mobility issue there is a method known as handover. Horizontal Handover (HHO) is a symmetric process and occurs within the same technology e.g between different Wi-Fi scenarios. If it is executed between different technologies, for example, UMTS to WLan, then it is called vertical HO. conventionally a mobile user may roam and accomplish the vertical HO using single criteria, such as received signal strength (RSS). Single criteria vertical handover decision, however, may cause inefficient handoff, unbalanced network load, and service interruption. This paper anticipated a suitable method among the various vertical handover decision algorithms in the environment of three network interfaces: (i) wireless local area network (WLAN), (ii) wideband code division multiple access (WCDMA), and (iii) worldwide interoperability for microwave access (WiMAX) and also some of the vertical handoff decision algorithms are compared with the usual method (RSS).