Handroff transactions strategies in wireless networks

Abstract

Mobility is the most important feature of a wireless cellular communication system. In cellular networks continuous service is achieved by supporting handoff (orhandover) from one cell to another. Handoff is the process of changing the channel associated with the current connection while a call is in progress. Handoff is a key newlineelement in wireless cellular networks in order to provide quality of service to the users and to support the user s mobility. The user s point of view, the service of handoff request is more important, as the forced termination of the ongoing call is moreannoying than the blocking of new calls. Therefore in order to support QoS in cellularnetworks it is a significant issue to allocate the communication channels efficiently because the bandwidth allocated for the cellular communication is limited.When mobile hosts move from one cell to another cell, to provide uninterrupted service, the new cell should have enough channels to support theongoing communication of the mobile hosts that moved into the cell. If channels arestatically allocated, a cell may run out of channels when large number of mobile hosts moves to a cell, thus degrading the quality of service. To overcome this problem, dynamic channel allocation approaches have been proposed which allocate channelsto cells on demand, thus increasing channel utilization and hence improving thequality of service. This scheme aimed at minimizing the effect of assigned channelson the availability of them in order to use in the interfering cells and reduce theiroverall reuse distance. The system shows better performance when the channels aredistributed uniformly/non-uniformly with queues using the frequency reuse scheme.To improve the performance of channel allocation methods, it depends on thetype of traffic and its allocation priorities. An optimal channel allocation algorithm has been proposed.