Reducing location management costs in hierarchical-based model of mobile and wireless computing systems

With the rapid growth in mobile and wireless computing technology, location management techniques become more challenging. Future Personal Communication Systems (PCS) will support a huge user population and a network spanning a large geographical area. In such systems, the signaling traffic and processing overhead for locating mobile users is expected to increase dramatically. In a mobile computing environment, mobile hosts move from one place to another and need to access the information without interruption, regardless of their location. This is the reason why location management is one of the important issues in mobile computing environments. Several techniques have been proposed in order to optimally manage the location of mobile hosts. In this paper, we introduce a probability-based location management (PBLM) algorithm which is based on two previously introduced algorithms to locate a user optimally: FBFind and FVLF. The basic idea of using PBLM algorithm is to reduce the Signaling System No. 7 (SS7) message traffic and database access traffic by maintaining a local database, which is called Location Information Database (LID) and is to reuse the information of mobile hosts' mobility patterns. We evaluate this algorithm and identify its optimal conditions as well as limitations. Results indicate that reusing mobile hosts' mobility information in local databases can save great deal of the updating costs.