End-to-end performance improvements for multi-hop ad-hoc wireless networks

In this paper, we make MAC protocol improvements for performance enhancement of multihop ad-hoc wireless networks. A node in ad-hoc wireless networks can transmit a packet only when the medium is available, and while a packet is being transmitted, no other node is allowed to transmit a packet if they are in carrier sensing range. Carrier sensing range can be divided into two disjoint areas of transmission range and carrier sensing zone, and we address the importance of the protocol procedure when a node is in carrier sensing zone. The characteristic of the carrier sensing zone is that a node can not know when the remaining time of the ongoing transmission session expires or exactly when the media becomes available. Current MAC protocol does not behave in much different way between when a node is in transmission range and in carrier sensing zone. We have conducted a comprehensive simulation to study the performance improvements. The simulation results indicate that the performance is increased and the number of dropped packets due to collision is significantly reduced as much as a half.