Research On Routing Algorithm And Congestion Control Strategy In Mobile Opportunity Networks

Mobile opportunistic network is a new mobile ad hoc network MANETs.In this network,the network topology changes frequently,the link between nodes is intermittent,the contact between nodes is unpredictable,and the complete path between the end to end of the source node and the destination node exists rarely at the same time.In the network,the nodes transfer messages by using the principle of "storage-carry-forward",After the nodes receive the message,the message is stored in the local cache,until the next node is met,and then the message is passed to the meeting node until the final node is met,and the message transmission is completed.As a new type of network architecture,mobile opportunistic networks can better adapt to communication needs in certain special scenarios,such as location services,media services,data offloading,intelligent traffic prediction,emergency warning and so on.It has wide application space.In the process of node carrying messages,how to select the appropriate nodes for message forwarding is always the key content of the research.At the same time,because of the limited bandwidth and limited cache,too much message or forwarding can easily lead to network congestion.How to control the degree of network congestion and save the node cache is also a key research topic while ensuring the transmission of the message as far as possible.Based on the research of existing routing algorithms and congestion control,this paper proposes a strategy to use the social attributes of nodes to route messages.At the same time,a congestion control algorithm based on message coverage in a multi replica environment is proposed.The specific work is as follows:Firstly,an opportunistic routing algorithm based on node social attribute of nodes is proposed.By redefining the global ejection utility of nodes and the forwarding utility based on intimacy between nodes,the deficiency of traditional Spray&Wait algorithm is improved.In the injection stage,by dynamically distributing the replica numbers by using global node ejection utility,the message copy can be spread as fast as possible in the network.In forwarding stage,nodes do not use direct wait strategy,but transmit messages to nodes that transmit messages to the destination node for greater utility.The improved algorithm is better than the Spray&Wait algorithm in terms of message delivery rate and average delay.Secondly,put forward a congestion control strategy based on message coverage in multi replica environment.By calculating the message coverage rate,the diffusion of messages in the network is estimated dynamically,and then the message is controlled in the transmission,storage and discarding stages of the network according to the diffusion condition.Compared with the traditional caching based DF,DO algorithm and the MaxProp algorithm based on scheduling,the algorithm has obvious advantages in message delivery rate and network overhead.