Design And Realization Of MAC Protocol For Underwater Acoustic Networks Of Regional Data Acquisition

Based on the viewpoint of practical project application,this paper is to design and realize MAC protocol of underwater acoustic network(UAN)for regional data acquisition.Depending on national 863 key project “Nodes and key networking techniques of underwater acoustic network”,sea trail is conducted to verify functionality and stability of MAC protocol.Details are as follows:Analyze the design requirements of UAN each layer's protocol that is suitable for regional data acquisition.Through comparing the workflow between ALOHA and MACAW,the research on MAC protocol in Data Link Layer is concentrated.According to the former design requirements proposed,a new MAC protocol that combines ALOHA and MACAW in compatibility is designed.Then the error control protocol and flow control protocol in Data Link Layer are selected.Corresponding with ALOHA and MACAW,node states and states converting are defined.Then the back-off algorithm and silence algorithm and timeout algorithm are determined.According to converting flow diagram,the designed UAN MAC protocol for regional data acquisition is realized.Framework of control frame and data frame is designed,and then brief fixed routing protocol is realized.Developing a data management platform of underwater acoustic modem based on ARM6410 that supporting the basic functions of underwater networking.The data management platform mainly includes the network module to communicate with upper computer,serial port module to communicate with DSP and 430 and external sensors,file storage module to record nodes information and operation information,timer module to actively trigger timing information,and network synchronization and application program updating module.Sea trial on the realized UAN for regional data acquisition is conducted in Sanya of the South China Sea.In the trial,through transmitting the acquiring data on time and retransmitting data and responding to the commands from gateway node,the performance of the designed UAN MAC protocol is tested.Moreover,according to the data that sent back to ashore station in a long period,the stability and reliability is verified.