An Asynchronous Multi-Beam MAC Protocol for Multi-Hop Wireless Networks

TL;DR

This paper introduces an asynchronous multi-beam MAC protocol that enhances throughput and reduces interference issues in multi-hop wireless networks with multi-beam antennas.

Contribution

It proposes novel mechanisms for asynchronous communication, reducing deafness and capture problems, and improving resource utilization in multi-beam MAC protocols.

Findings

Achieves higher throughput in simulations.

Reduces node deafness and hidden terminal problems.

Improves resource efficiency and fairness.

Abstract

A node equipped with a multi-beam antenna can achieve a throughput of up to m times as compared to a single-beam antenna, by simultaneously communicating on its m non-interfering beams. However, the existing multi-beam medium access control (MAC) schemes can achieve concurrent data communication only when the transmitter nodes are locally synchronized. Asynchronous packet arrival at a multi-beam receiver node would increase the node deafness and MAC layer capture problems, and thereby limit the data throughput. This paper presents an asynchronous multi-beam MAC protocol for multi-hop wireless networks, which makes the following enhancements to the existing multi-beam MAC schemes (i) A windowing mechanism to achieve concurrent communication when the packet arrival is asynchronous, (ii) A smart packet processing mechanism which reduces the node deafness, hidden terminals and MAC-layer capture problems, and (iii) A channel access mechanism which decreases resource wastage and node starvation. Our proposed protocol also works in heterogeneous networks that deploy the nodes equipped with single-beam as well as multi-beam antennas. Simulation results demonstrate a superior performance of our proposed protocol.