Research On Statistical Priority-based Multiple Access Protocol For UAV Network

The rapid development of Unmanned Aerial Vehicle technology make it play an extremely important role in the field of military or civilian in recent years.Compared with manned aircraft,it has many advantages such as small volume,low cost,convenient application.Faced with the disadvantages of the single UAV exposed under the complicated task conditions,many unmanned aerial vehicles have been paid much attention.The design of the UAV Data Link network system is the precondition to ensure the reliable communication between the UAV.In network communication,multiple access protocol is an important research direction to realize effective and reliable communication.The access protocol provides a mechanism to control and allocate the channel resources and finally realizes the efficient and reasonable sharing of the same channel resources by multiple nodes.Especially in military communication,low time delay and high transmission success rate are always the goals that people pursue.The latest generation of data link Tactical Targeting Network Technology(TTNT),claimed to have to attack the fast moving target and accurate positioning,realize the ability of “Find and Kill”.Based on the disclosed technology of TTNT,the implementation details of Statistical Priority-based Mutiple Access(SPMA)are explored.The UAV network system based on statistical priority multiple access protocol will be studied and designed from two aspects of physical layer and data link layer in this paper.First,this paper introduces the basic theory of unmanned aerial vehical network,including network structure,the node into the network solutions and network protocol stack.Then,according to the TTNT data link in terms of throughput and delay of advantage,summarize and analyze its main parameters and technical indicators,the design is based on statistics of multiple access protocol priority network system of unmanned aerial network.The physical layer using jump frequency hopping and pulse transmission technology,designed the overall frame structure and classify the pulse.Then based on the truncated type prime sequence constructor frequency hopping sequences design,finally will frequency hopping sequence according to time slot allocation algorithm to separate on time.The MATLAB simulation results show that the node shall be carried out in accordance with the design sent can greatly reduce the collision probability.Secondly,based on the design and distribution of frequency hopping patterns in the physical layer,a multi-access protocol scheme based on statistical priority is designed and a method of channel state judgment is proposed.The pattern assigns four sets of patterns to each node in the network according to the way of fixed allocation,so that the node has the communication ability of “one sending and four receiving”.By comparing the channel load statistics value and priority threshold value,different priority packets are sent,and the higher the priority is,the larger the threshold value is.Channel load statistics is based on the transmission pattern.Each node relies on the physical layer carrier detection ability to detect the free and busy degree of frequency point occupied in the transmission pattern frame by frame.Finally,a network simulation model is built on Omnet++,including node model,nework model,radio medium etc.A complete and nearly real network with low delay,high transmission success probability and high throughput is built.Among them,the node model is based on TCP/IP protocol,which is the stack structure.The 16 node network is built on the Omnet++ simulation platform.From the simulation results,it can be seen that high priority services than low priority services have some improvement in throughput and end-to-end delay.