Queue-driven cut-through medium access in wireless ad hoc networks

Abstract

In multihop ad hoc networks the IEEE 802.11 MAC protocol, in its distributed version, dramatically degrades the performance in terms of throughput and delay. This is due to a protocol property, which tries to provide equal probability of channel access to all nodes. But in multihop ad hoc network a more frequent channel access might be necessary at certain nodes that are intermediate hops and forward other nodes' data. This paper proposes a modification to the protocol that leads to a higher throughput and lower delay by combining the ACK for one packet with the channel access procedure for another, queued-to-be-sent packet. Hence, nodes receiving many packets, probably forwarder, have a higher chance of accessing the channel. Additionally, these changes provide a scheme of packet forwarding more robust to different layouts than original IEEE 802.11, where performance can heavily deteriorate in certain configurations.