Effects of Mobility in Hierarchical Mobile Ad Hoc Networks

In this paper, we study the effects of mobility on network parameters in hierarchical ad hoc networks. Several mobility models have been designed and studied to mimic the behavior of real world mobility in networks. They have been successful in modeling the movement of mobile nodes in simulations. However, in this work, we show that several mobility models fall short of extending the same result to hierarchical networks. Most mobility models can only predict the movement of nodes in a single cell or cluster. When mobile nodes start moving into adjacent clusters, the time required for handoff and other protocol overhead issues alter the throughput. This leads to drastic drop in throughput and increased latency in packet delivery. Also, commonly used routing protocols do not adequately support handling high mobility and frequent route discovery issues. We evaluate the performances of various routing protocols and mobility models in a highly mobile hierarchical ad hoc network using NS2 simulation.