MAC Protocol for Smart-Antenna Used Ad Hoc Networks With RTS/CTS Overhead Reduction
This paper proposes a MAC protocol for ad hoc networks with smart antennas. In the proposed protocol, pulse/tone exchange mechanism is applied to smart-antenna networks. The mechanism significantly reduces collisions caused by the hidden-node problem. Further throughput enhancement is achieved because of the compatibility between the pulse/tone exchange and the smart-antenna networks. The directional hidden-node problem is mitigated by the pulse/tone exchange. Additionally, the number of exposed nodes due to pulse/tone exchanges is limited because of the smart-antenna usage. Therefore, it is unnecessary to use RTS/CTS handshakes after pulse/tone exchanges, while RTS/CTS handshakes are necessary for omni-directional antenna system.