Study On The Centralized Resource Scheduling Algorithms For Underwater Acoustic-Optical Communication Networks

As the underwater communication technology is becoming more and more important role in ocean engineering,the research of underwater communication technology has attracted the attention of various countries in the world and has been developed rapidly.At present,the underwater communication technology is main underwater acoustic communication technology,but the propagation delay of acoustic signal is high and the bandwidth is narrow,which make it questionable in applications of large data transmission such as video.Researchers tried to use visible light communication as a supplement to underwater communications,with blue and green visible light communications to achieve high-speed underwater data transmission.However,the blue and green visible light communication is only suitable for short distance communication because of serious channel transmission loss.Underwater acoustic-optical communication networks combine underwater acoustic communication and underwater optical communication to give full play to the advantages of the two communication modes,thus improving the overall performance of the networks.The throughput and reliability of underwater wireless communication networks are closely related to resource scheduling algorithms,and the underwater network resources are valuable.Therefore,it is particularly important to study the corresponding network resource scheduling algorithms.At present,most resource scheduling algorithms for underwater communication network are designed for underwater acoustic communication networks.Unlike traditional underwater acoustic communication networks,network nodes in new underwater acoustic-optical communication networks can select underwater acoustic communication or underwater optical communication according to the communication environment conditions.Therefore,existing resource scheduling algorithms cannot be directly applied underwater acoustic-optical communication networks.In conclusion,the research on the resource scheduling algorithm of underwater acoustic-optical communication network is of great significance.In this paper,firstly,relevant knowledge of underwater communication networks and centralized resources scheduling algorithms are researched.Secondly,the characteristics of underwater acoustic channel and underwater optical channel are studied,and both underwater acoustic communication and underwater optical communication module in network simulation software NS2 are built,in addition,the correctness of the modules are verified.Thirdly,the multi-interface support module is added to the underwater wireless nodes in the NS2 software so that it can support both underwater acoustic communication and underwater optical communication,which provides the research foundation for resources scheduling algorithms of underwater acoustic-optical communication networks.Finally,aiming at the existing shortages of the centralized resources scheduling algorithms for underwater acoustic-optical communication networks,these two proposed resources scheduling algorithms that based on the star topology structure,a network throughput-maximizing scheduling algorithm is first proposed to maximize channel utilization by using the characteristics of the networks.Second,in order to ensure the fairness of data sent by nodes,a fair scheduling algorithm is proposed on the basis of ensuring the maximum throughput.The simulation results in the simulation software NS2 show the effectiveness of the proposed scheduling algorithms.