Research Of Forwarding Algorithm And Replica Management Strategy Based On Congestion Control In DTN

With the rapid development of wireless network technology and frequent upgrades of thehand-held electronic equipment, the end-to-end communication pattern based on the full path insome environment apparently has no way to meet some special requirements. In this case, a newnetwork system arises at the historic moment. The delay tolerant network (DTN) has theproperties which are applicable to mobile nodes and network connection gap. Since the DTNarchitectures were born in2003, DTN routing has become an independent research field after10years of development. Later, people find that the social characteristic of delay tolerant networkhas important practical value.Sociologists, professor of psychology at Harvard first proposed the theory of six degrees ofseparation: every social member in the world only needs a few intermediaries to establishcontact with the others in daily life. Accordingly, most of the information sent by the user onlyneeds less hops to be delivered in DTN with social characteristic. Besides, communicationamong mobile intelligent phone users follows rules. Because users frequently travel between thework and living places, information is mostly propagated among a certain relationship such ascolleagues, friends and family members.Through the study of social characteristic of delay tolerant network, we put forward a newalgorithm based on congestion awareness and interest replica management strategy. Thealgorithm is based on sociality and considers buffer and delay characteristics of the node and egonetwork. The utilities based on these characteristics cover a wide range, consider thoroughly, andare very suitable for delay tolerant network. In addition, the algorithm also adopts the replicamanagement strategy based on interest tags. Interest tags have great pertinence, avoid copyingirrelevant information and only receive interested information. So this method can not only saveresources, but also can control the number of copies in the network and relieve effectivelycongestion condition. This paper uses the ONE simulator to simulate experiment and compareswith three classical algorithms over buffer availability, delay and delivery rate. Experimentalresults show the proposed algorithm is excellent and has certain significance to informationtransmission in DTN. In general, congestion awareness algorithm can play a very good role toalleviate the network congestion, improve the delivery rate of messages and reduce delay.The main work includes the following aspects:1. Introduce the background and characteristics of delay tolerant network, analyze someclassic algorithms and new algorithms with social characteristics and list a few examples ofalgorithms in the aspect of congestion control and replica management strategy.2. Put forward a new algorithm based on congestion awareness and interest replicamanagement strategy according to social characteristic of delay tolerant network. Congestionaware forward algorithm combines a variety of different utility metrics, while replicamanagement strategy uses interest tags to manage replica. Compare the algorithm with three classical algorithms through experiment data. The results show that the algorithm has certainutility.3. Make a summary of the whole work and propose the emphases of the next step.