DOA-ALOHA: slotted ALOHA for ad hoc networking using smart antennas

This paper develops a novel slotted ALOHA protocol (direction-of-arrival ALOHA) for use in ad hoc networks where nodes are equipped with smart antennas. The protocol relies on the ability of the antenna and DOA algorithms to identify the direction of the desired signal and the direction of the interferers to maximize SINR (signal to interference and noise ratio) at the receiver. The performance of the protocol is evaluated using joint simulation in OPNET and Matlab. We compare the performance of our new protocol against recent directional MAC (medium access control) [R.R. Choudhury, et al., Sept. 2002] protocol. We show that DOA-ALOHA achieves significantly higher throughput than R.R. Choudhury, et al. (Sept. 2002) despite its simplicity. The impact of using different number of antenna elements is also studied for this environment.