Analysis of Location Management Schemes for MANET using Synthetic Mobility Models

In the performance evaluation of a protocol for an ad hoc network, the protocol should be tested under realistic conditions including, but not limited to, a sensible transmission range, limited buffer space for the storage of messages, representative data traffic models, and realistic movements of the mobile users (i.e., a mobility model). This paper is a survey of mobility models that are used in the simulations of ad hoc networks. We describe several mobility models that represent mobile nodes whose movements are independent of each other (i.e., entity mobility models) and several mobility models that represent mobile nodes whose movements are dependent on each other (i.e., group mobility models ).The goal of this paper is to simulate the movements of mobile nodes within a network and present a number of mobility models in order to demonstrate its effect on Location management scheme for mobile ad hoc network or personal communication services networks. Specifically, to illustrate how the performance results of an ad hoc network protocol drastically change as a result of changing the mobility model simulated. Location management is a fundamental problem in personal communication services network. The current standard of location management is HLR/VLR scheme. It has been observed that the performance of any location management scheme depends on space requirements, bandwidth requirements and time requirements. To avoid certain drawbacks in HLR/VLR scheme, many approaches including hierarchical approaches have been suggested. Working set idea is chosen to analyze its performance for location management in PCS networks. Due to inadequacy of standard network simulators to provide the output in the format desired, a new location management simulator can be built. Two variants of working set idea viz. Working set scheme for HLR/VLR approach and working set scheme for hierarchical approach can be used and then compare the performance of HLR/VLR scheme and working set scheme using the results obtained by the simulator with respect to already available mobile activity traces. Working set scheme can also be analyzed for hierarchical networks. It is indicated that the results of working set idea reduces call setup time significantly at the expense of minor increase in database and link capacities in the personal communication services network from the literature survey. Keyword: Location Management, Mobility Models, Synthetic Mobility Models, Working set.