The 802.11g relaying MAC that saves energy

In this paper we focus on energy efficient opportunistic relaying in WLANs. We propose and examine an extension to IEEE 802.11g MAC protocol that enables self-enforced relaying, where the main idea behind the relaying is to decrease overall energy expenses in WLANs. Since frame transmission and reception require spending some energy by wireless nodes as well as access points, it is desirable for every node in a wireless system to get access to the channel as fast as possible and occupy it for a reasonably short period. In our proposal the protocol extension uses RTS/CTS mechanisms to precede every transmission and employs intermediate nodes which may serve as relays. Potential relays in the network are self-motivated to perform as helpers since remaining in idle mode or waiting for channel access also requires energy. Therefore, by helping other ongoing transmissions, relays may decrease total transmission time and increase their possibility of being awarded faster access to wireless medium, which eventually yields decrease in energy consumptions. Experimentation results prove that opportunistic relaying provides energy savings in 802.11g-based WLANs.