Probabilistic-routing-oriented DTN (delay-tolerant network) congestion avoiding method

Abstract

The invention belongs to the field of DTNs (delay-tolerant networks), and particularly relates to a probabilistic-routing-oriented DTN congestion avoiding method. The method comprises steps as follows: a source node S sends messages M to a target node D, priority division is performed on the messages with a message priority division method; for the messages with priorities determined, a copy number threshold value Q which can be produced by each single message is set with a message copy number threshold value distributing method; whether any node L forwarding messages is encountering any node N or not is judged; whether the probability from N to the target node D is larger than L or not is judged; whether the copy number K of the messages M of the node L forwarding the messages is equal to the threshold values Q or not is judged. With the adoption of the method, sizes of the messages sent by the source node, life cycles of the messages and the probability from the source node to the target node are comprehensively considered, the copy number threshold values are set for the messages, and copy numbers of messages in a network can be effectively limited, so that the phenomenon of congestion in the network is avoided.

Description

technical field [0001] The invention belongs to the field of delay-tolerant networks, and in particular relates to a probabilistic routing-oriented delay-tolerant network congestion avoidance method. Background technique [0002] Delay Tolerant Network (DTN) is a new type of network, which has the characteristics of high latency, intermittent connectivity, topology variability, and limited node resources. In order to overcome these network limitations and ensure the arrival rate of message transmission, the delay-tolerant network uses the services provided by the transport layer, uses the hop-to-hop hosting mechanism, and uses the "store-carry-forward" method to transmit messages. However, DTN has the characteristics of high latency, intermittent connectivity, topology variability, and limited node resources, which lead to the fact that managed nodes may need to store received messages for a long time to cope with possible network delays and interruptions until they receive ...

AI Technical Summary

Problems solved by technology

[0007] Based on the above analysis, for the defects of the existing congestion control methods and congestion avoidance methods: the congestion control method does not consider the number of copies of data packets in the network, and it is very likely to discard the data packets with the least number of copies in the cache, making these The data packet cannot reach the destination node, resulting in the loss of the data packet; at the same time, it only starts from deleting the cached data packet of the node, without considering that the number of copies of the new data packet received by the node in the network may be higher than the existing data packet in the node Many copies in the network

The problem with the congestion avoidance method is that it only considers network congestion without considering the success rate of data transmission. Although the traditional DTN probabilistic routing protocol guarantees the success rate of message forwarding, there are a large number of message copies in the network. With the progress of replication and forwarding, more and more message copies will be stored in the node cache. When the number of copies increases to a certain number and exceeds the limited space of the cache, the nodes in the network will be congested

Images