An opportunistic network congestion control method based on forwarding task migration

Abstract

The invention discloses an opportunistic network congestion control method based on forwarding task migration. The opportunistic network is composed of n mobile nodes moving in a limited area, and each mobile node maintains two data structure tables inside: an encounter list. and task hosting table. Among them, the congested node unloads some messages to the neighbor nodes with large remaining cache space in time to reduce the risk of congestion; when the managed node encounters the task node again, if the congestion level of the task node is reduced at this time, the managed node will host it. The message is returned to the task node. The present invention achieves the purpose of reducing the number of discarded messages and improving the success rate of message transmission by temporarily unloading messages with low utility value in high congestion risk nodes to other nodes with high encounter probability and low congestion risk.

Description

technical field [0001] The invention relates to the technical field of wireless sensor network communication, in particular to an opportunistic network congestion control method based on forwarding task migration. Background technique [0002] In recent years, with the application of wireless sensor technology and the popularization and development of a large number of mobile devices with short-range wireless communication capabilities, a new type of ad hoc network model—opportunistic network has emerged. Compared with the traditional mobile ad hoc network Ad Hoc , information exchange between opportunistic network nodes does not require a complete and stable end-to-end communication link. Nodes in opportunistic networks are generally composed of mobile devices or sensors installed on moving objects, such as wireless sensors on vehicles, handheld devices carried by pedestrians, etc. Such nodes have strong mobility and frequent link discontinuities. This feature makes the ne...

AI Technical Summary

Problems solved by technology

Reducing the sending rate of a node means that the node needs to have a reasonable prediction of the next hop node or the congestion state of the current network. In an opportunistic network, there are intermittent connections between nodes, and the node cannot broadcast the current state information to the network as soon as possible. the entire network, making it difficult to make accurate predictions

Moreover, the state perception of the entire network requires a large amount of data and a large amount of calculations, which will consume a lot of energy. For opportunistic networks, which are mostly used in special scenarios, energy consumption should be minimized and the survival time of nodes should be delayed.

[0006] The second is to first assign a utility function to each message. The higher the utility function, the less likely it is to be discarded. Whenever a new incoming message will cause congestion, the cache space is vacated by discarding the message to store the new message. But this will discard a lot of data

For opportunistic networks with unstable end-to-end links, data should be discarded as little as possible to increase the survival time of messages, especially for existing routing algorithms, which basically do not use flood transmission, but reasonably predict the next hop Forwarding nodes, predicting efficient delivery paths, etc. to improve the success rate of message delivery, there are often some key nodes that are prone to congestion, but the messages stored by the nodes are very important and cannot be discarded at will

[0007] To sum up, the existing opportunistic network routing decision either does not consider the congestion problem, or it is difficult to perceive the global network state, and consumes a lot of energy, or still discards a large number of messages

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