DA-MAC: A Duty-Cycled, Directional Adaptive MAC Protocol for Airborne Mobile Sensor Network

Airborne mobile wireless sensor network, which is composed of lots of sensor nodes installed on vehicles, is introduced into many aerial tasks, such as environmental surveillance, airborne enemy target tracking, disaster warning. However, due to the intrinsic motion characteristics, most of the existing MAC protocols perform poorly in end-to-end delivery latency and energy consumption caused by high retransmission rate, especially in multi-hop and requiring high real-time responding airbornemobile wireless sensor networks. We present DA-MAC-a novel duty-cycled, directional adaptive MAC protocol. It utilizes: (I) a stochastic wake-up schedule, anycast MAC scheme minimizes collisions and reducing coordination overheads, (II) adaptive duty-cycles based on the local network connectivity and topology to locally reduce idle listening, (III) directional adaptive forwarder sets selection mechanism, each sensor node can transmit message to the one-hop neighbor node with the optimal properties. In the end then converges gradually from route-suboptimal anycast with unsynchronized duty cycling to route-optimal unicast with synchronized scheduling. DA-MAC fully considers the adverse impact of movement, and chooses node with the optimal properties as forwarders, achieves good endto- end latency. Our simulation results by NS-2 show DA-MAC performs well in end-to-end delivery latency and energy savings in mobile wireless sensor networks.