Low Collision Random Access in Underwater Acoustic Sensor Network for Harbor Surveillance

This paper proposes a low collision random access method that statistically determines the participation in random access for multiple sub-channels in harbor surveillance. The proposed method estimates a distance between a sensor node (SN) and an enemy unmanned undersea vehicle (UUV), and calculates the number of SNs who may detect the UUV, and statistically selects sub-channels with a larger channel gain while keeping a low collision probability. The proposed method reduces the collision and increases channel utilization and throughput. Computer simulations show that the channel utilization and the throughput of the proposed method are greater than those of conventional method.