The Research On MAC Protocol Based On Reservation And Scheduling In UWSN

In recent years,the Underwater Acoustic Sensor Networks have been gradually attracted researchers' attention.But a series of problems such as long propagation,limited bandwidth,difficulty of energy supply for node,make the Medium Access Control protocols facing huge challenges in the design.Facing these challenges,the underwater MAC protocols based on reservation and scheduling have been proposed in recent years.These protocols allocate the channels by collecting information such as location,channel condition and communication requests.However,due to the rapid signal attenuation in the underwater environment,the single center protocol has the problems of excessive power consumption and long broadcast time.Clustering and other methods are used for solving the problems.But there is still room for further optimization of fairness and throughput.In the reservation and scheduling based clustering MAC protocol,the problem of fairness is mainly reflected in the different difficulty of getting access.And the problem of throughput is that there is still room for scheduling optimization.Based on the research on these challenges,this paper proposes ACS-MAC protocol by optimizing the existing protocols.The main work of this paper can be divided into three points: 1.Scheduling optimization.Based on mathematical analysis and experimental verification,different transmission order leads to different propagation overlap.And it will lead to different network throughput.2.The use of location-based clustering.It improves the throughput and the fairness of nodes in the network.3.Use MIMO cancellation to increase the tolerance of collision.This technology can obtain more relaxed constraints in conflict-free scheduling and increase the throughput.This paper verifies the effectiveness of these methods through experiments and analyses.Comparing with other protocols,this paper proves that ACS-MAC has better performance in multi-hop network with dense nodes.