Research On Network Coding-based Data Dissemination Techniques For DTN Network In Sea Battlefield

As the central nervous system of the information battlefield,the sea battlefield information network has played an important role in guaranteeing the battlefield reliable information interaction in surveillance,early warning,navigation,and command and control,and it's also important to improve combat efficiency.At the same time,with harsh climate and communication environment in the sea battlefield,the suppression of electronic warfare and electromagnetic weapons,the mobile deployment of combat units,and the interference between shipboard weapons,the sea battlefield information network suffers more and more serious interference of electromagnetic and the environment,which is brought about to be of dynamical network topology,intermittent connectivity,unreliable data transmission,large delay or even interrupt of the data transmission.So the sea battlefield information network is a typical Delay/disruption Tolerant Network(DTN).However,the special environment and requirement of sea battlefield information network ask the communication system to assure the optimal data delivery performance in the delay/disruption tolerant network.In order to provide high-efficiency information interaction capacity of the sea battlefield information networks,especially the effective information interaction capacity in the sea battlefield delay/disruption tolerant network environment,it is necessary to research on data dissemination technology in delay/disruption tolerant network,and to solve data transmission problem where end-to-end connection can not be guaranteed,intermittent connectivity and large transmission delay exists,so as to guarantee the effectiveness of information interaction.Aiming at the present situations in the sea battlefield,such as nodes distributed in a large area and moving in a wide range with bad communication environment,which result in a sea battlefield network that is intermittently connected,of dynamic topology,with limited bandwidth,and delay tolerant,a data dissemination mechanism based on network coding is proposed in this dissertation.The sea battlefield node mobility model,dynamic random network coding,congestion control,and data dissemination method based on network coding in sea battlefield delay/disruption tolerant network were researched,to improve the data transmission and data delivery performance in sea battlefield abominable communication environment;to solve the problem of lower channel utilization rate,inefficiency of data transmission,and insufficient communication ability in traditional communication method and routing mechanism;and to support the design of delay/disruption tolerant network communication system.The following is the main contribution and innovation:(1)A dynamic random network coding transmission method in DTN network environment is proposed.According to the receive data states of nodes,it first obtains the transmit speeds of every network channel,and then constructs the network flow graphic with channel capacities and calculates the network multicast capacity.Moreover,the random network coding scenario is extended and tailored according to the multicast capacity to transmit data packages under DTN environments.Based on this method,it can increase the delivery probability and reduce the average latency of data packages.(2)A mobility model detection method based on birth and death model in DTN environment is proposed.It first constructs the three-dimension time varying intercommunication metrics,which is composed of channel capacity between local node and other nodes.Based on these,the connection birth and death mode of nodes based on connected edges is constructed,and then the birth and death features of the connected nodes are analyzed to detect the mobility model,whose connection features are used to improve the data retransmission process and congestion control strategy during the package delivery process in DTN environment.(3)A congestion control strategy based on the data delivery probability is proposed.Considering the node mobility model,data delivery probability and data congestion degree,the data delivery probability model is constructed.And then the congestion control strategy is proposed,which includes two aspects,i.e.on the one hand,by the means of adjusting the packet forwarding process,it equilibriums the data packet delivery to avoid node congestion caused by too many packets received;and on the other hand,through the design of efficient discarding strategy,it reduces the impact of packet loss caused by congestion.(4)Combined with network coding and the publish/subscribe mechanism,it puts forward a data dissemination mechanism with network coding based on ant colony algorithm.The topic data is published and subscribed by using dynamic network coding method.Transferred with network coding method,the data multicast process can take full advantage of the network capacity,so as to improve the security and efficiency of the transfer process.At the same time,to solve the problem of large data redundancy and vast invalid delivery time in the coded package broadcast process,a coded package routing scheme based on ant colony algorithm is brought up to guide the package delivery to the destinations with direction,which will reduce the data redundancy of coded package broadcasting process and cut down the data delivery latency.