Directional medium access control for ad hoc networks: A cooperation-based approach

In this paper, we describe a cooperation-based approach to design directional medium access control protocol (DMAC) and propose Cooperative Asynchronous DMAC (CA-DMAC) to explore the benefit of directional transmission for the asynchronous ad hoc networks. Currently existing DMAC designs employ extra hardware or network-wide synchronization to overcome the hidden terminal problem. In the proposed CA-DMAC, the neighboring nodes around the negotiating pair actively participate in the link establishment procedure to eliminate hidden terminals. Further, since most of the previous DMAC studies employ ideal antenna model without minor-lobes, their performance may not be guaranteed in practice. In this paper, we also take the minor-lobe interference of directional antennas into consideration. The detail of the CA-DMAC is presented in the paper and the protocol´s performance is validated via simulations in NS2. The results demonstrate that CA-DMAC can provide good spatial sharing gain and excellent performance in terms of throughput and data packet transmission ratio.