Introducing Handover Prioritization in Channel Borrowing Without Locking (CBWL)

In English In order to improve the offered quality of service in a cellular network, load balancing between cells with momentarily different traffic loads can be applied. This can be accomplished through channel borrowing techniques where a cell requiring extra capacity borrows a channel from a less loaded cell in the same region. However, the borrowing of a channel results in an alteration of the channel reuse pattern. To prevent channels from being locked in some of its dedicated cells due to unacceptable interference levels caused by borrowing, a method where borrowed channels are transmitted with reduced power, called Channel Borrowing Without Locking (CBWL), can be applied. In CBWL, borrowed channels are only capable of serving calls in the proximity of the base station, meaning that an intracellular handover is required if one of these calls move to the outer cell area. In this paper, different handover prioritization methods applicable to CBWL are discussed. It is shown that the efficiency of these methods are highly dependent on the CBWL parameter settings.