Reversing the IEEE 802.11 backoff algorithm for receiver-initiated MAC protocols

To date, a significant body of work has already been done in the design of receiver-initiated medium access control (MAC) protocols for wireless ad hoc networks. Most of these works, however, have not appropriately dealt with the fundamental issues inherently related to this class of protocols, such as the rate at which polling is triggered by a node, and the way in which nodes are selected for polling. Moreover, previous works on receiver-initiated protocols have not considered the impact of physical layer aspects on network performance. We analyze the effects of considering such aspects and then we show how to improve these issues with ideas based on the operation of the IEEE 802.11. In addition, we present an algorithm that prioritizes the transmission of polling nodes to nodes that are more likely to have a successful handshake with them. This way, we are actually improving the network overall performance. Our analytical results confirm that even when physical layer aspects are considered, receiver-initiated protocols outperforms sender-initiated protocols, but with a margin significantly lower than that obtained in previous works.