A Study Of Routing And Congestion Control Technology In Delay Tolerant Networks

Delay tolerant network is a new kind of network architecture，the typical applicationsinclude Inter-planet networks, wireless sensor networks, and vehicular networks. Thenetwork topology of delay tolerant network suffers from frequently partition and change,the continuous end-to-end connect may not exist and the delay of transmission is alwayslarge. These network characteristics could not satisfy the assumption that make traditionalTCP/IP protocol work efficiently. The routing schemes and congestion control methodswhich fit with the special characteristics of network are needed.Hierarchical geographical tags based routing proposed in this paper is a combinationof singer-copy scheme and multi-copies scheme. In this method the network territory ispartitioned level-by-level into many sub-regions, node make a region it most frequentlyexists as its home location. Messages are greedily transmitted towards the home locationof the destination node, when messages reach the home location of the destination, amulti-copies transmitting method is adopted to accelerate the forwarding in the regionwith a high probability to finish the final delivery. The geographic information is used tohelp improve the delivery ratio. To solve problem of network congestion, this paperproposes a congestion control methods based on message migration. When the node bufferis used up, congestion node chooses a neighbor node which has a smallest migration costto migrate part of message stored in buffer. The storage resources are redistributed in thelocal area of network through this solution, achieve the goals of remitting the nodecongestion, and make network works effectively.The performance of the routing scheme proposed in this paper is evaluated bysimulation. We compare our method with several other routing protocols in delay tolerantnetwork, and simulation results show that our proposed solution provides higher deliveryratio compare to those well-known protocols, and incurs acceptable extra overhead.