Practical application of physical energy detection to recognize starvation in 802.11 wireless networks

In order to prevent a wireless node from corrupting other on-going transmissions, IEEE 802.11 medium access control (MAC) allows the node to access the channel only if the medium is determined to be idle. However, this rule sometimes can lead to extremely low transmission opportunities (i.e. starvation) of nodes owing to unfair carrier sensing induced by complex properties of wireless communication such as hidden/exposed-node topologies, asymmetric channel conditions, and other environmental factors. To share the wireless resource fairly, thus it is necessary for 802.11 nodes to detect the starvation and mitigate it. In this paper we propose a novel starvation detection technique that can identify whether the node is in the flow-in-the-middle (FIM) state by exploiting the physical energy detection mechanism implemented basically in 802.11 devices. In addition, we present a simple strategy that can mitigate the starvation. We show the effectiveness of our scheme via extensive simulations. The results demonstrate that our scheme recognizes the starvation and alleviates it effectively.