Simulation Research Of Tactical Data Link Link11

In modern warfare,sharing the information between combat units to achieve the synchronization of fighting actions is the key to win a war.Intelligence in formation exchange between multiple platforms can be carried out by Tactical Data Link.Building of Tactical Data Link is one of the important indicators of the development of information warfare.Application of Tactical Data Link determines the level and ability of information warfare in great significance.Tactical Data Information Link A(TADIL A)Link11 is a kind of tactical digital information links which applies network communication technology and standard information formats for digital information exchange,and is widely used for information exchange among the American army airplanes,terrestrial and the naval vessels.Therefore simulation and analysis of Link11 is an important task for military communication networks.In this thesis,the communication protocol of Link11 is investigated.Two policies for different traffic based on traditional Link11 are proposed,and a new mode for Link11 network constitution is given.The QualNet simulation platform is utilized to do simulations and to analyze the system performances.In the traditional Link11,Data Network Control Station(DNCS) polls each Participating Unit(PU),and distributes up-link slots to each PU.The polled PU is allowed to send data to DNCS.In this scheme, each PU has the same opportunity to send its data.When a PU has large amount of traffic to send,obviously it does not benefit this kind of PU, so a new scheme which is aware of heavy traffic is proposed.When it learns a PU has a large amount of traffic to send,DNCS changes its polling list dynamically,and distributes double or more up-link slots for this PU.In this way,it promotes transmission speed for the PU than that of traditional Link11,shortens the transmission delay and also improves the network transmission efficiency.When a PU has a kind of traffic with high real-time desire(such as voice traffic,military control command),it needs a fast response from DNCS.Therefore,in this thesis,a polling scheme based on fast response is proposed.As the DNCS checks a PU which has this kind of traffic,it changes polling list and puts its ID of PU in the front of the list.Therefore,the DNCS can poll the PU fist in the next polling period. This will satisfy the requirement of tactical network with high real-time demand.One DNCS controls each PU in tradition Link11,as the numberof nodes increases and battlefield being extended,the load of DNCS will increases.And due to the limitation of the transmission field of DNCS, the quality of the network will be decreased.Therefore,a hierarchy Link11scheme for network constitution is proposed.In this scheme, each PU can be polled by primary DNCS and secondary DNCS,the secondary DNCS with function of forwarding data lightens the load of DNCS.More nodes being separated in the smaller sub-networks guarantees the communication quality.From the simulation results, performances like network throughput and successful transmission rate are improved in the hierarchy Link11scheme than that in traditional Link11.The hierarchy Link11scheme is fit for large scale military network because it can contain larger number of nodes.