Abstract
Different from the mechanism of medium access control (MAC) for the land-based sensor networks, the underwater acoustic sensor network faces problems such as high propagation delay, spatial-temporal uncertainty and high energy consumption. Orthogonal frequency division multiple access (OFDMA) is a channel access mechanism based on OFDM multi-carriers modulation technology. In OFDMA, multiple users can make use of the orthogonality of the subchannels to simultaneously access channel for parallel transmission. For underwater multi-hop network scenario, this paper proposes a MAC protocol of the joint relay selection and power allocation (JRSPA-MAC) based on OFDMA mechanism. The proposed protocol is divided into flowing phases: Firstly, the node determines the hop distance from the sink nodes and sends the request when there are packets to be sent. Then forwarding nodes election algorithm is proposed based on the channel condition and the delay information. On this basis, the sending nodes autonomously use the particle swarm optimization (PSO) algorithm to allocate its subchannels’ power. Secondly, taking advantage of the high underwater acoustic propagation delay, the receiving node reasonably schedule the sending time, makes sure the parallel communication of multiple pairs of nodes in one handshake period. Finally, the destination nodes and the forwarding nodes acknowledge the received packets and completes this data transmission. The simulation results show that compared with the hand-shake based MAC protocols, the JRSPA-MAC reduces the probability of packet loss caused by data conflicts between nodes. In case of low power consumption, the network throughput are effectively improved, and the average end-to-end delay of the network is reduced.
Highlights
Underwater acoustic sensor network (UASN) has a wide range of application such as marine information collection, environmental monitoring, and resource survey, etc., [1]
We focus on the design problems of the traditional UASN medium access control (MAC) protocol, such as the lack of parallel communication mechanism leading to low channel utilization, and the lack of proper power allocation algorithm leading to the waste of energy
This paper, in view of the lack of parallel communication mechanism in the design of traditional medium access control protocol for UASNs, which leads to low channel utilization rate and the lack of appropriate power allocation algorithm, and causes energy waste, proposes medium access control of joint relay selection and power allocation based on the handshake mechanism in a multi-hop network
Summary
Underwater acoustic sensor network (UASN) has a wide range of application such as marine information collection, environmental monitoring, and resource survey, etc., [1]. The electromagnetic wave transmission delay can be ignored in the design of most land-based sensor MAC protocols, and the data packet conflict caused by the high delay of underwater acoustic communication has spatial-temporal uncertainty [3]. The energy of the nodes in the underwater sensor network is limited, and many traditional channel reservation based protocols usually send RTS/CTS control packets at the excessive power during the channel reservation phase, resulting in unnecessary energy waste. The one-hop forwarding node and the destination node execute the channel reservation, send the time schedule, complete the data transmission, and confirm the reception to achieve packet transmission It completes parallel communication of multiple nodes in one communication cycle, which improves the effective throughput of the network.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
