Gateway Multipoint Relays-an MPR-Based Broadcast Algorithm for Ad Hoc Networks

Broadcast is an essential part of ad hoc network routing protocols. An efficient broadcast algorithm can greatly reduce the number of retransmissions in a network, thus decreasing the number of packet collisions and overall power consumption. In this paper, we propose the gateway multipoint relays (GMPR) broadcast algorithm, which combines the multipoint relay (MPR) and the maximal independent set (MIS) concepts to calculate a connected dominating set (CDS) in the network. Our algorithm, which is fully localized and distributed, can significantly reduce the redundant broadcasting in the network while keeping the cost of computation low. The GMPR constructs a CDS in two phases. In the first phase, an MIS is established where nodes in the MIS are referred to as dominators, and they form the gateways in the network. In the second phase, each gateway generates some connectors to connect other gateways based on the original MPR algorithm. Then, a self-pruning procedure is applied to each gateway to eliminate redundant gateways after the CDS construction. In this paper, we show that our algorithm has O(Delta²) time complexity and O(n) message complexity, where Delta is the maximum node degree and n is the total number of nodes in the network. Simulation is conducted to compare our new algorithm with two leading MPR-based CDS broadcast algorithms. The results show that our algorithm performs better than those algorithms in terms of the size of the generated CDS