An efficient communication scheme for solving merge conflicts in maritime transportation

Abstract

In researches and applications on maritime transportation, the information is collected by maritime vessels and Underwater Wireless Sensor Networks (UWSNs). The reliable wireless links among maritime vessels are needed to keep the communications efficiency and security. The movements of maritime vessels bring challenges to the reliable and real-time information transmissions, which require proper MAC layer supports of Ship Ad-hoc NETwork (SANET). An improved multi-channel VeMAC protocol based on TDMA, named I-VeMAC, is proposed to meet the transmission requirement on MAC layer. I-VeMAC reduces the time cost of the transmission of service information. In the control channel, time slots are occupied by relay nodes and conflict nodes. In order to solve the merge conflicts in service channels and optimize the transmissions in the control channel, I-VeMAC analyzes the relative positions of time slots. Meanwhile, the service providers provide slot information of nodes within 2 hops to conflict nodes, and recalculate the time slot allocation. It is proved that the hidden terminal problem will be solved without the nearby nodes announcing the time slot information within 2 hops. The simulation results show that the improved method reduces the time cost of solving merge conflict in VeMAC and the transmission delay. I-VeMAC improves the throughput, and it can be used in real-time transmission in SANET for UWSNs data harvesting.