A Novel Multi-channel MAC Protocol for Directional Antennas in Ad Hoc Networks

Abstract

In recent years, the employment of directional antennas in ad hoc networks has increased significantly. In this paper, we propose a multi-channel MAC protocol for directional antennas (MCMDA) for IEEE 802.11 based ad hoc networks. To improve the network performance, the so-called hidden terminals and deafness should be decreased as much as possible. In MCMDA, not only multiple channels are effectively utilized but also vertically opposite clear-to-send is employed to minimize the effects of hidden terminals and deafness. Each node is equipped with multiple interfaces for multiple directional antennas such that concurrent transmissions and receptions take place in a node at the same time, resulting in further improvement of the network capacity. The performance study based on extensive computer simulation shows that the proposed MCMDA achieves significant performance improvement in comparison to the conventional directional MAC as well as IEEE 802.11 distributed coordination function in terms of network throughput and end-to-end delay.

Network for hypersonic UCAV swarms

“…(1) Using multiple control frames [117]. The approaches using multiple control frames try to solve the deafness problem by disclosing the transmission information to all the neighboring nodes.…”

Directional Medium Access Control (MAC) Protocols in Wireless Ad Hoc and Sensor Networks: A Survey

“…Reference [80] is a multi-channel MAC protocol for directional antennas (MCMDA) in ad hoc networks. It is a non-control-channel-based multi-channel non-circular DMAC protocol.…”

A Directional Cognitive-Radio-Aware MAC Protocol for Cognitive Radio Sensor Networks

“…If any one or both of the two nodes are in omni-directional mode and out of range, then they both may fall within the range which might cause collision when they beam-form towards each other [21]. In Figure 1, two nodes X and Y are communicating directionally with gain G d towards each other.…”

“…This scheme introduces head of line (HoL) blocking problem for the protocols using directional antennas. If a packet at the top of the queue is blocked because the medium is not free in that direction, then other packets which are in the queue with some other directions are also blocked [21]. For example, we can see in Figure 4 that node P has packets for Q, R and S. S and T are in communication with each other.…”

“…The information about the location of neighbours is vital in case of directional antennas to enhance the link quality. This information helps the transmitting nodes to beam-form in the direction of the receiver so that the gain is maximized [21]. Exact location information reduces the effect of interference from other nodes to a large extent.…”