Delay/disruption tolerant network routing calculation method based on low-earth-orbit satellite network

Abstract

The invention discloses a delay / disruption tolerant network (DTN) routing calculation method based on a low-earth-orbit (LEO) satellite network, including the following steps: constructing a satellite DTN network system model; calculating the link delay under the influence of queuing delay; calculating the contact residual capacity; and calculating the routing. The influence of queuing delay in routing calculation is considered. A queue element is defined, and a queue scheduling mechanism is put forward. In order to avoid the problem that a path selected cannot forward a message, the influence of contact capacity is considered. By designing a message path update factor, a routing update strategy is put forward to break the balance between real-time transmission update and resource consumption. The number of redundant message copies in the network can be reduced, and the average transmission delay of messages and the network load rate can be reduced. The residual capacity is sufficient for transmitting messages. The path with the lowest delay is taken as a reference path. Thus, the method better adapts to some sudden faults in the process of communication.

Description

technical field [0001] The invention relates to a routing strategy of a low-orbit satellite network, in particular to a delay-tolerant / break-tolerant network routing calculation method based on a low-orbit satellite network. Background technique [0002] Satellite networks have the characteristics of limited transmission energy, fast mobility, frequent switching, sparse node density, frequent equipment failures, and time-varying topology. Satellite networks are intermittently in contact, making them form a typical delay / Delay / Disruption Tolerant Network (DTN). Such as figure 1 As shown, the core idea of ​​the DTN protocol system is to introduce the so-called "package layer" as an overlay layer connecting different restricted networks. Nodes using this overlay rely on sending asynchronous messages called "packages" to communicate, so the DTN protocol architecture It is a "delay-tolerant, message-oriented overlay architecture" for constrained networks. The overlay layer me...

AI Technical Summary

Problems solved by technology

This type of algorithm reduces network redundancy, but because it uses source routing and does not consider the storage space status of intermediate nodes and the status of messages in the system when calculating the path, it cannot adapt well to the high dynamics of satellite networks, which brings large ③ The routing algorithm based on the connection graph, CGR routing algorithm, this kind of routing algorithm makes full use of the predictability and periodicity of the contact between satellite nodes. The node's contact information recalculates the forwarding path, which can well adapt to the dynamics of the network

However, since the queuing delay of the message is not considered in the routing calculation, the message may miss the currently available contact opportunity, which reduces the average transmission delay and delay network load rate to a certain extent

Images