An adaptive location management strategy for mobile IP

Mobile intemetworking revolves around the premise that a mobile host (MH) will frequently attach to and detach from the Intemet, thus changing its addressfrequently. Location management in mobile intemetworking refers to the process of keeping track of the current addresses of MHs in the Intemet. Protocols proposedfor mobile intemetworking rely on a combination of searchesand updates for location management. Adrawback of these protocols is that they arenot uniformly efficient over all possible call-to-mobility ratios (i.e., the relative frequency of searchesascompared to updates). Unimportant issue, therefore, ishowthe overall costs of location management can be reduced, regardless of the call-to-mobility ratio. The aim of this work is to explore a new and practical scheme for location management, with emphasis on network cost reduction. We makethe keyobservation thatwhile thepotential setof sources forthe MHmaybelmge, tiesetofsources thatagiven MH communicates most frequently with is very small. Based on this, we develop the concept of a working set o~hosts for the MH (similar to the working set concept in operating systems). An adaptive scheme of location management is proposed, that enables an MH to dynamically determine its working set, and trade-off routing and update costs in order to reduce the total cost. Comparative analysis of the proposed scheme, using simulation, shows its efficiency over a wide range of call-to-mobility ratios.