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, an opportunistic network is composed of n mobile nodes moving in a limited area, and twodata structure tables, namely an encounter list and a task hosting table, are maintained in each mobile node, wherein the congestion node timely unloads a part of messages to neighbor nodes with relatively large residual cache space so as to reduce the risk of congestion; and when the hosting node encounters the task node again, if the congestion degree of the task node is reduced at the moment, the hosting node returns the hosted message to the task node. According to the method and the device, the messages with low utility values in the nodes with high congestion risks are temporarily unloaded to other nodes with high encountering probability and low congestion risks, so that the aims of reducing the message discarding number and improving the message transmission success rate are fulfilled.

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-distance 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 can be realized without a complete and stable end-to-end communication link between opportunistic network nodes, and it has a wide range of applications in some specific fields and scenarios, such as space communication, underwater networking, vehicle network, disaster rescue, etc. Nodes in opportunistic networks are generally composed of mobile devices or sensors installed on moving obje...

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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