MAC Protocol Based On Joint Trasmission Time And Power Optimization For Underwater Acoustic Network

With the continuous development of the ocean,the underwater acoustic communication has become a hot research in underwater communication.Compared with terrestrial radio communication,the underwater acoustic communication can not directly use mature terrestrial communication technology due to some issues such as narrow bandwidth,large delay,large Doppler frequency shift and serious multipath effect.The underwater acoustic communication network extends the underwater communication from point-to-point communication to networked communication,thus improving the communication efficiency greatly.In the underwater acoustic communication network,it is necessary to consider the communication quality,the energy consumption of the sensor nodes and the problem of network transmission efficiency and so on.This paper proposes a kind of underwater acoustic network MAC protocol based on joint transmission time and power optimization to reduce the energy consumption of nodes and improves the transmission efficiency.The main contents of this paper are as follows:(1)The characteristics of underwater acoustic communication are summarized and analyzed with the characteristics of underwater acoustic channel.Meanwhile,the hierarchical structure and topology of underwater acoustic communication network are described macroscopically.(2)The main purpose of the important MAC protocol in the underwater acoustic communication network and the problems to be solved are analyzed in this paper.At the same time,the solutions with regard to time delay and energy consumption proposed in existing literature are studied.(3)Aiming at the problem of the transmission efficiency and energy limitation of underwater acoustic communication,this paper proposes an underwater acoustic network MAC protocol(TTPO-MAC protocol)based on joint transmission time and power optimization.The protocol controls the transmission power of nodes by power control to reduce the energy consumption and the interference with nodes.Based on the relationship within nodes,different sub-networks are divided,through which data can be transmitted in parallel.Meanwhile,with a reasonable arrangement of node data transmission time and under the condition of no conflict of receiving data,the sub-network makes full use of the propagation delay to allow the node to send data in advance,which improves the efficiency of the entire network transmission.(4)The TTPO-MAC protocol is simulated on the NS2 simulation platform and compared with the existing MAC protocols of the underwater acoustic communication network.The simulation results show that the TTPO-MAC protocol can effectively reduce the energy consumption and improve the transmission efficiency(increase the throughput and decrease the delay)in the case of multi-node simultaneous communication.