A unified framework for topology management multi-rate ad hoc networks

Finite battery energy and limited bandwidth resources are the two major constraints in ad hoc networks. Therefore, researchers have persistently sought for optimization algorithms to reduce the control overhead and to increase bandwidth utilization efficiency, using mechanisms such as topology control and management, multi-rate adaptation etc. to cut down the energy expenditure in ad hoc networks. However, the energy conservation and network throughput improvement are handled separately in many cases. In this paper, we propose a unified framework that combines the multi-rate adaptation and clustering mechanisms so as to provide the optimal network throughput under very low control overhead. The framework incorporates two control mechanisms into the networking stack. The first mechanism is based on a novel clustering algorithm, called PATM (priority-based adaptive topology management), that constructs the backbone of the network topology for routing protocols. The second mechanism is a medium access control protocol, called RMAC (relay-based MAC), that provides high data transmission rates between adjacent backbone nodes. The efficiency of the unified framework is evaluated using theoretical analysis and extensive simulations with DSR (dynamic source routing) as the underlying routing protocol. We demonstrate that our solution not only significantly reduces the routing control overhead, but also substantially improves the network throughput.