A Hybrid Power-Saving Protocol by Dual-Channel and Dual-Transmission-Range Clustering in IEEE 802.11 MANETs*

There are two types of power saving protocols for IEEE 802.11-based MANETs: synchronous and asynchronous. IEEE 802.11 has defined a synchronous power-saving (PS) protocol for single-hop (full connected) MANETs based on periodical transmission of beacons by accurate clock synchronization. There are some quorum-based asynchronous PS protocols proposed. The protocols need no synchronized clocks; however, they usually consume more energy than the synchronous ones. In this paper, we proposed a hybrid PS protocol, which combines the advantages of synchronous and asynchronous ones for an IEEE 802.11 MANETs. The protocol utilizes the concept of dual channel and dual transmission-range clustering. It divides all the hosts into clusters. Each cluster has a head and all the heads are organized as a virtual backbone to help route data. The synchronous PS protocol can be operated in an individual cluster, and the quorum-based asynchronous PS protocol is applied among cluster heads. As we will show the proposed protocol is power efficient, scalable and adaptive to topology changing.