A directional MAC protocol for marine ship ad-hoc networks

In marine ship ad-hoc networks, the distance between ships is usually several kilometers. The IEEE802.11 standard designed for indoor networks is not applicable so that the use of directional antennas extends the communication range. In this case, the node cannot listen to data transmission activity outside the beam. And the asymmetric gain of the antenna can lead to hidden termination problems. This paper proposes a directional MAC protocol for ship ad-hoc networks (DMSA) by using Automatic Identification System (AIS) to obtain ship node position information. The transmitting node will send polling RTS (P-RTS) to the surrounding nodes before sending data, and the neighboring nodes around it will create a P-NAV table to record the direction of the data transmission after hearing the P-RTS frame. After completing the RTS/CTS handshake, power control is used to solve the hidden terminal problem caused by antenna gain asymmetry