An Asymmetric Quorum-based Power Saving Protocol for Clustered Ad Hoc Networks

Clustering in Mobile Ad Hoc Networks (MANETs) has shown to be a promising technique to ensure the scalability and efficiency of various communication protocols. Since stations in MANETs are usually equipped with batteries as the power source, it is critical to ensure the energy efficiency of clustering schemes. The Quorum-based Power Saving (QPS) protocols render extensive energy conservation as compared with IEEE 802.11 Power Saving (PS) mode and are widely studied over the past years. However, most existing QPS protocols adopt a symmetric design where stations in the network are guaranteed to discover each other. Observing that in clustered environments there is no need to insist in all-pair neighbor discovery, we propose an Asymmetric Cyclic Quorum (ACQ) system. The ACQ system guarantees the neighbor discovery between each member node and the clusterhead in a cluster, and between clusterheads in the network. A construction scheme is presented in this work, which assembles the ACQ system in O(1) time. We show that by taxing slightly more energy consumption on the clusterhead, the average energy consumption of stations in a cluster can reduce substantially than can be achieved by traditional QPS protocols. Simulation results show that the ACQ system outperforms the previous studies up to 52% in energy efficiency, while introducing no extra worst-case latency.