A New Routing Protocol Based on OLSR Designed for UANET Maritime Search and Rescue

Energy-Awareness Gray-Coding OLSR (EAGC-OLSR) protocol for UAV Ad-Hoc Network (UANET) maritime search and rescue is proposed. To feed back the position of targets for urgent rescue, these are great challenges to transmit images rapidly with low BER and extend the network lifetime because of the limited energy of UAVs. These challenges can be solved by EAGC-OLSR, which includes applying Gray code in channel coding, transmitting the decoded results of physical layer to network layer through cross-layer mechanism, and designing a dynamic bit error threshold mechanism to judge the quality of channel. An improved MPR (Multi Point Relay) selection algorithm taking channel quality and energy of UAV nodes into consideration is also proposed to change the ‘Willingness’ of nodes adaptively so as to select the best channel and the UAV nodes to transmit images. Simulation results show that EAGC-OLSR protocol can meet the requirements of rapid and accurate image transmission applications in UANET and the network lifetime can be extended. Moreover, the device with EAGC-OLSR has characters of light weight and low power consumption.