Method and system for selecting DTN network routing path of low-orbit satellite

Abstract

The embodiment of the invention provides a low earth orbit satellite DTN network routing path selection method and system, and the method comprises the steps: generating a contact plan for each node according to contact information and distance information, and generating a contact graph of each node through the contact plan; obtaining a neighbor node set based on the sending node and a receivingnode in the contact plan; calculating the total time delay based on the link state and throughput between the local node and each neighbor node in the neighbor node set, and generating a forwards nodeset; and arranging the total time delay in the nodes in the forwardable node set in a descending order, selecting the path with the minimum total time delay as the optimal path to perform data transmission, and selecting the path with the second minimum total time delay as the backup path. According to the scheme, the state of the link and the queuing delay are fully considered, node congestion or network congestion cannot be caused, and the influence of the queuing delay on the whole network performance can be effectively reduced on the basis of ensuring the service volume.

Description

Technical field[0001]The invention relates to a method and system for selecting a routing path of a low-orbit satellite DTN network, belonging to the technical field of network routing.Background technique[0002]In recent years, China's low-orbit mobile communication satellite system has developed rapidly, and low-orbit satellite communication systems such as "Hongyun" and "Hongyan" have been proposed successively. However, the networking technology currently adopted by these satellite systems is still based on terrestrial IP networking technology. Delay / Disruption Tolerant Networks (DTN) networks have the characteristics of intermittent connectivity, large delays, and insufficient node processing capabilities, which makes DTN widely used in spatial information networks.[0003]The successful application of DTN in space information networks proves that DTN can also be applied to low-orbit satellite networks. In recent years, the application of DTN to low-orbit satellite networks has gr...

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Problems solved by technology

However, because DTN is directly applied, there are a series of problems, especially in terms of routing. Existing DTN routing methods are designed according to special scenarios; key factors (links or nodes) and network traffic in the network are not considered, so there are The following technical problems: drastic changes in network topology lead to frequent interruption of links; limited storage capacity and computing capacity of nodes; most of the existing DTN routes are single-path transmission, which is easy to cause congestion and queuing, low transmission efficiency and poor reliability

[0010] 1. The dynamics of low-orbit satellite nodes are very high, and the connection stability between nodes is poor, which will eventually lead to inconsistencies between the connection plan and the actual network topology, poor transmission reliability, resulting in unreliable connection plans, and the final calculated path may be invalid At this time, the data packets are temporarily stored in the satellite nodes, which greatly increases the queuing delay of the data packets, and at the same time increases the possibility of satellite node congestion

[0011] 2. The calculation of CGR routing does not fully consider the link status and queuing delay. In some special cases, it may cause excessive transmission delay or even buffer overflow to cause packet loss.

[0012] 3. In the low-orbit satellite DTN network, there will be some "important" nodes. These nodes exist on many paths and will receive many data packets at the same time. Under limited processing conditions, a lot of data will be cached in the nodes packets, not only increases the queuing delay of data packets, but also easily causes node congestion

[0013] 4. CGR routing is a satellite routing method based on a single copy. There is only one transmission path for data transmission between the source end and the destination end. This transmission mode has limited transmission capacity and cannot make full use of network resources, especially in low-orbit satellite networks. Node resources are limited, once business conflicts, it is likely to cause network congestion, or even partial paralysis

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