Research On Adaptive Multiple Spray And Wait Routing Algorithm Based On Social Circle In DTN

Delay tolerant network does not require a complete link:between the source node and the destination node,which is more in line with the actual demands of Ad hoc network.DTN has broad application prospects and application value in the fields of earthquake disaster emergency management,network communication in remote areas lacking infrastructure,and sensor network,and has very important research significance.Due to the lack of a stable communication path,the design of an efficient routing algorithm is the primary problem to be solved in the field of DTN.Based on the analysis of the research achievements in the field of DTN routing algorithm obtained by domestic and foreign researchers in recent years,the main research contents of this paper are given.Considering that the ability of nodes to forward messages to the destination node is significantly different,we improve the spray phase of the traditional Spray and Wait algorithm,and a spray strategy based on social circle(SC-SS)is proposed.SC-SS adopts different relay node selection strategies according to whether the node carrying the message is in the social circle of the destination node,which makes the message delivery more effective.The main research work is as follows:(1)The social attributes between nodes show long-term stability,we can make more effective routing decisions by making rational use of the social attributes between nodes.In view of the fact that nodes often show clustering phenomena in most application scenarios of delay tolerant network,a method of constructing social circles is proposed.(2)Nodes in the same social circle are more likely to successfully forward messages to each other.If the node carrying the message is in the social circle of the destination node,SC-SS will forward the message within the social circle of the destination node,and adopt a routing forwarding strategy based on delivery predictability,that is,relay nodes will be selected based on the delivery predictability to reduce the relay forwarding times with low transmission efficiency.(3)We define a metric called transmission utility of node based on geographic information to reflect the ability of node to quickly forward messages to activity range of the destination node.If the node carrying the message is not in the social circle of the destination node,SC-SS will forward the message to the nodes in the social circle of the destination node,or adopt a routing forwarding strategy based on geographical information,that is,relay nodes will be selected based on transmission utility of node to quickly deliver the message to the activity range of the destination node.(4)This paper uses the ONE simulation to create the scenario.We compare SC-SS with Epidemic,Prophet,Spray and Wait from four aspects,simulation time,time to live,buffer size,and message generation interval.The simulation results show that SC-SS has the best overall performance in terms of delivery ratio,average delay,network overhead,and average hops.Considering that the fixed initial number of copies setting in advance cannot adapt to the dynamically changing network environment,we propose an adaptive multiple spray and wait routing algorithm based on social circle(SC-AMSW)to improve the wait phase of SC-SS.SC-AMSW selectively sprays messages with one copy multiple times,and the appropriate number of redundant copies is adaptively sprayed based on delivery predictability.Then the overall performance of the routing algorithm is improved by increasing the number of message copies.The main research work is as follows:(1)In SC-AMSW,when a node is left with only one copy of a message and encounters a node with higher delivery predictability,the node will spray the message again if the probability of the node successfully delivering the message to the destination is less than the given threshold.(2)In order to reduce the number of useless redundant copies,SC-AMSW adopts the ACK acknowledgement to notify nodes in the network to delete messages that have been successfully delivered to the destination.(3)This paper uses the ONE simulation to create the scenario.We compare SC-AMSW with Spray and Wait,GBAS from four aspects,simulation time,time to live,buffer size,and message generation interval.The simulation results show that SC-AMSW has the best overall performance in terms of delivery ratio,average delay,network overhead,and average hops.