A calculation method for soft handoff rate in cellular systems

Handoffs in a mobile cellular communications environment will become an increasingly important issue as cell sizes shrink to accommodate the ever-growing service load demanded. When handoffs occur at the overlapping area of the cells in a cellular system, a mobile station (MS) must communicate with two different base stations (BS) for some period of time. In this case, an MS in the handoff area connects with two BS even though the MS does not move from the current cell to the other cell. The channel efficiency may increase to overcome this situation. Thus, analysis of handoff rate is the key to understanding and increasing channel efficiency. A simple and straightforward mathematical function for obtaining direction-based soft handoff rate in cellular systems is proposed.