On the channel reservation schemes for ad-hoc networks utilizing directional antennas

We introduce a novel CSMA/CA-based reservation scheme that improves the multiple access throughput of wireless ad-hoc networks using switched beam antennas. First, we show the performance limitations of the omni-directional and directional reservation paradigms investigated in the literature. This is done via emphasizing the trade-off between minimizing the number of control/data packet collisions and minimizing the number of neighbors that back-off unnecessarily. Next, we propose a novel concept that balances this trade-off via sending reservation messages, that carry information about the intended direction of transmission, on all unblocked beams. The innovation in this approach is to send directional information to as many neighbors as possible in order to better assist them in deciding whether to transmit or refrain from transmission on a specific beam. Finally, the algorithm is examined via simulations and compared to the omni-directional and directional reservation approaches.