Design And Simulation Of GPSR Routing Protocol Based On Fishing VHF Ad Hoc Network

Ultrashort wave communication refers to using the band radio waves of 30 ~ 300 MHZ to transmit information. The length of its wave ranges from one to ten meters, and its transmission is mainly relying on ground wave and space wave. The band width of ultrashort wave is 270 MHZ, which is 10 times of the width of the short wave band. Because of the wide frequency band, it is widely used in TV, FM radio, radar, mobile communications, military communications and other fields.Marine ultrashort wave communication refers to the use of 27.5 ~ 39.5 MHz band radio waves to communicate between fishing boats. Its wavelength is between 10.91 and 7.59 meters. This band is shortwave of high and low segment of ultrashort wave, which is China’s fishing boats valuable spectrum communication. Countries have(offshore) ultrashort wave communication network construction. It is comprised of 78 seat unattended station and remote communication control center and offshore slipway, providing communication services for more than 170000 fishing boats.At present, the main problems of the fishing boats ultrashort wave communication mainly includes: one is a large number of fishing boats gathered homework, for each fishing boat, users are assigned a separate channel network congestion signal, the communication information can’t communicate, communication quality is severely affected. The other one is except a few province stations can communicate with other province. Other stations not only cannot manage different ground to the base station, but also cannot use different base stations and sea fishing boats for ultrashort wave communication.The core technology to solve the problem is to establish suitable for offshore fishing vessels of ultrashort wave wireless ad hoc network. Ad Hoc network is composed of many wireless mobile nodes, nodes can organize network at any time. When two nodes cannot communicate directly, the other nodes can relay. Ad Hoc for the establishment of fishing ultrashort self-organizing network to solve the above problems provide a good theoretical basis and technical reference.Ad Hoc network technology and VHF communication network are combined to establish a proper communication of VHF Ad Hoc network. This network not only can make up for the faults which VHF cannot be used in long distance communicate on the sea, but also can improve the quality of network communication. It is the sea fishing vessel safety communication and a new direction of development.VHF Ad Hoc network is a self-organizing, dynamic topology, no center structure network, nodes must have the ability of packet routing and forwarding, therefore, the selection and design of routing protocol is the core technology not only affects the entire network performance of self- organized fishing ultrashort wave, but also the key of the construction of marine Ad Hoc network.Because the fishing wireless communication has small bandwidth and communication shortcomings is instability, a type of ad hoc network routing protocol of ultrashort wave is designed. VHF Ad Hoc network, improve the fishing vessel safety communication, a key technology in the existing fishing vessels is particularly important. In order to protect the safety of fishing vessels, fishing vessels cash are equipped with GPS positioning system, geographic location information using GPS positioning system obtaining the position information of each search at sea fishing. The favorable factors based on the GPSR routing protocol based on location information as the research object. Fishing communication has randomness, instability of routing is able to quickly establish communication quality, higher requirements. This paper designs GPSR routing protocol base on the traditional, by using MATLAB and OPNET to verify the improved protocol performance.The paper presents two kinds of improved protocol, the first kind of protocol put forward an improved clustering protocol GPSR based on clustering the network. Based on the residual energy information and link information to the most residual energy as the basis of choosing cluster head selection in cluster. Second improved protocol is proposed based on the left(right) hand rule GPSR protocol, rollback mechanism optimized greedy algorithm mainly use the protocol, using the left and right hand rule to optimize the routing path, so as to improve the reliability and stability of communication, reduce the communication delay. The paper compares the two kinds of improved protocol, and draw the following conclusions: GPSR protocol based on cluster is suitable for network which node energy is limited, GPSR protocol based on the left(right) hand rule is suitable for network which high stability, small network delay. Because of fishing communication physical conditions, the paper selects GPSR protocol based on the left(right) technique to simulate systematic. By using OPNET simulation software, the paper simulate the environment of fishing work, the simulation of the communication vessels among different network scale, observes the performance of GPSR protocol, analyzes the simulation results. The simulation results shows that when the fishing fleet of about 20 ships, and the running speed in the range of 5m/s-15m/s,the GPSR routing protocol performances well.