Power saving ADHOC: a MAC protocol for multihop wireless ad hoc networks

We propose a new version of a recently proposed MAC protocol for ad hoc network communications: the ADHOC MAC (Borgonovo, F. et al., IEEE Wireless Commun. and Networking, vol.2, p.965, 2003). Our version of the protocol, PS-ADHOC (power saving ADHOC) MAC, is suited for ad hoc networks where power consumption is effectively an issue. The operation of both protocols is based on the fact that any node distributes to neighboring nodes information about the channel state as it is perceived from its location, through a frame information (FI), a string of values identifying the stations, which is piggybacked into the MAC header of each packet. By gathering FIs from neighbors, any node is able to run the scheduling algorithm, resolve contentions and receive acknowledgments from recipients of successful transmissions. In PS-ADHOC MAC, only those stations that have to transmit, relay or acknowledge successful reception of a packet send FIs through the channel, while in ADHOC MAC any node sends FI even if it has no packet to transmit. Some basic performance figures are discussed to prove the effectiveness of this protocol; in the scenarios we have considered, PS-ADHOC MAC enables approximately 90% savings in transmission power consumption related to that of ADHOC MAC.