Soft handover for nonuniformly-loaded mobile multimedia cellular networks

Most existing works on handover for mobile cellular networks are based on the assumption that the network traffic is uniformly-loaded for every cell, i.e., all cells in the network are equally loaded. In this paper, we present a handover initiation scheme using a fuzzy logic system (FLS) for nonuniformly loaded mobile cellular networks. Bandwidth utilization is combined into the handover decision making. The linguistic knowledge of handover based on bandwidth utilization and signal strength is obtained from a group of network experts. The FLS rules are set up based on the linguistic knowledge, and the number of rules is reduced from 81 to 18 using union-rule configuration. The output of the FLS provides a four-dimension handover possibility surface which is used to make a hard decision. We compared our scheme against the relative signal strength with hysteresis method.