An overheard-based relay-assisted MAC protocol using symbol level network coding in vehicular networks

Many network coding schemes have been proposed so as to enhance the communication efficiency and security of wireless networks. To further enhance the communication efficiency, an overheard-based relay-assisted MAC protocols for vehicular networks is proposed in this paper. Since the symbol level network coding (SLNC) scheme has lower error probability than the packet level network coding (PLNC) scheme, SLNC is adopted in the proposed protocol so as to improve the transmission efficiency. An overheard relay vehicle is chosen to help the avoidance of different data multiplying with the same coefficient. When the original data cannot be decoded due to the lost of some symbols, the symbol acquisition process is initiated. Simulation results have shown that the proposed protocol performs better than the traditional network coding protocol. It can reduce packet delivery delay, improve throughput and the successful probability of transmissions.