UKF based aerospace DTN network bundle transmission delay estimation algorithm

Abstract

The invention relates to the technical field of data transmission of a DTN network, and particularly to a UKF (Unscented Kalman Filter) based aerospace DTN network bundle transmission delay estimation algorithm. The UKF based aerospace DTN network bundle transmission delay estimation algorithm provided by the invention comprises the steps of A, describing real-time change of link parameters; B, analyzing composition of bundle RTT (Round Trip Time; C, building a UKF based RTT estimation model; and D, working out a retransmission timer RTO setting strategy. As point-to-point bundle RTT of a BP-layer storing-forwarding mechanism in the aerospace DTN network is analyzed, the time-changing composition is tracked by utilizing the UKF, a random sudden delay is regarded as noise filtration and an exact retransmission timer is set on the basis, the bundle on a node can be released rapidly, rapid transmission of the bundle is facilitated, and transmission delay of documents is improved.

Description

technical field [0001] The invention relates to the technical field of data transmission of a DTN network, in particular to an estimation algorithm for bundle transmission time delay of an air-space DTN network based on an unscented Kalman filter. Background technique [0002] 1. Reliable transmission of DTN data and its delay estimation algorithm [0003] Compared with the traditional terrestrial network, the space network has the following outstanding features: the high bit error rate caused by the rapid fading of the space-space channel, resulting in a high packet loss rate; the asymmetry of the inter-satellite and satellite-ground bidirectional links may cause certain Transmission congestion; the communication distance between nodes is long, time-varying, and has a long propagation delay; sudden link interruption caused by the reliability of on-board equipment, etc. The above-mentioned characteristics lead to great challenges for data transmission in the space network. ...

AI Technical Summary

Problems solved by technology

[0006] 3. Problems in the DTN delay estimation algorithm

[0008] 4. The problem of setting the retransmission timer

[0009] For the setting of the space network retransmission timer, the previous algorithms only considered the possible packet loss, and did not consider that the packet loss rate itself will change in real time; more importantly, the inter-satellite propagation delay is not as large as that of the deep space link. The propagation delay cannot be used as the only factor for setting the dynamic change of the retransmission timer, and the influence of other delays such as link queuing delay and burst delay should also be fully considered

Therefore, for such a highly dynamic communication link, if the real-time network status cannot be tracked in real time, the retransmission timer cannot be accurately predicted

In particular, DTN has an asymmetric two-way link, which is likely to cause congestion of confirmation signals and introduce queuing delay. The round-trip delay will increase linearly with the increase of queuing delay.

If a static retransmission timer is set, it is almost impossible to accurately predict the arrival time of each bundle's custody confirmation signal

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