Querying user location using call locality relation in hierarchically distributed structure

Personal communications services (PCS) should support a number of users that is several times larger than that of cellular systems. Using the fact that many call patterns in PCS have the locality between the callers and callees, the proposed mobility management strategy is able to track the user locations efficiently in a hierarchically distributed fashion. In the proposed structure, the larger number of nodes per parent node shows better results. The virtually hierarchical link is used to support the call locality, which is useful especially in the long-distance roaming. The locality consideration effectively reduces the query traffic compared with non-locality consideration.