Forwarding Pointers for Eecient Location Management in Distributed Mobile Environments (preliminary Version)

Location management consists of location update and search protocols. Trade-oo in location management is between the cost of searches and the cost of updates. The goal of an \eecient" location management strategy is to reduce the search and update costs. In this paper, we show that, using forwarding pointers in addition to home location servers help in providing eecient location management. It is shown that using forwarding pointers reduces the network load during updates, however, use of forwarding pointers may increase the search cost due to long chain lengths. We present two heuristics, namely, movement-based and call-based, to limit the length of the chain of forwarding pointers. It was observed that for most of the call-mobility patterns call-based heuristic performed better than the movement-based heuristic. A search-update occurs after a successful search, when the location information corresponding to the searched mobile host is updated at some hosts. This paper proposes various strategies for search-updates. It was noticed that performing search-updates signiicantly reduced the search costs with very little cost to pay for updates (upon moves and searches).