Adaptive network congestion control method based on SCPS-TP

Abstract

The invention discloses an adaptive network congestion control method based on SCPS-TP, comprising the following steps: a SCPS-TP gateway source end receives a data packet and forwards the data packet to a destination end; whether there is new data acknowledged is judged according to parsed packet information; if there is no new data acknowledged, the window size growth mode is changed to a linear adaptive mode when a repeated ACK counter increases to a certain value; if there is new data acknowledged, congestion control is in an exponential growth mode, and after the window size is increased, Diff is greater than a set threshold, and the congestion control mode is changed to a linear adaptive mode; if congestion control is in a linear adaptive mode, the window size is adjusted according to Diff; and the SCPS-TP gateway source end sends data in a packet loss buffer region to the destination end, and sends new data according to the size of the congestion window. Network congestion and serious packet loss due to a too long intermediate router queue are avoided, and bandwidth can be fully utilized. A network transmission acceleration function can be achieved when the method is applied to a satellite network with high transmission delay and high link error rate.

Description

technical field [0001] The invention relates to a network reliable transmission method, in particular to an adaptive network congestion control method based on SCPS-TP. Background technique [0002] At present, due to the advantages of wide coverage, fast and flexible networking, and no geographical restrictions, satellite communication has formed a complementary and competitive trend with ground communication in recent years; it is widely used in satellite telephones, navigation and positioning, emergency rescue and disaster relief Applied communications, national defense systems and other economic and military fields. [0003] Satellite communication uses artificial earth satellites as relay stations to forward radio waves, thereby realizing communication between two or more earth stations; because the transmission distance of radio signals in satellite communication is very long, the transmission delay is huge; for example, it is mostly used for navigation and positioning...

AI Technical Summary

Problems solved by technology

[0003] Satellite communication uses artificial earth satellites as relay stations to forward radio waves, thereby realizing communication between two or more earth stations; because the radio signal transmission distance of satellite communication is very long, the transmission delay is huge; for example, it is mostly used for navigation and positioning and The geostationary satellite communication distance for data relay is about 36,000 kilometers, and the transmission delay can reach 500ms to 800ms; the long transmission distance will also cause great attenuation of the signal, and the signal-to-noise ratio of the received signal is extremely low and unstable The space environment leads to a high link bit error rate; in practical applications, the bit error rate of space communication can reach 10 -3 , while the BER of terrestrial transmission is only 10 -10 ; High delay and high bit error rate of the link pose challenges to traditional communication methods

[0004] At present, a series of solutions have been proposed to solve the impact of adverse factors such as high transmission delay, high bit error rate, and uplink and downlink channel asymmetry in space communication on the transmission protocol; for example, the TCP Westwood protocol is based on the traditional TCP protocol, adding The bandwidth measurement mechanism is used for the adjustment strategy of the congestion window, thereby eliminating the influence of high bit error rate, but because the slow start and congestion avoidance phase still use the TCP traditional strategy, the protocol is greatly affected by the delay and cannot be well The use of bandwidth; the XCP protocol monitors the network traffic status in the intermediate router, and feeds back the network status to the sender by modifying the packet header field, but the protocol requires a dedicated router to support the protocol; the TCP-Peach protocol sends dummy packets This article is used to test the congestion of the network. At the same time, it uses the sudden start and fast recovery mechanism, which can quickly recover and occupy bandwidth after connection establishment and packet loss. It is suitable for networks with high delay and high bit error rate, but the protocol requires intermediate routers to support Priority strategy, otherwise the dummy will put pressure on the link; the Delay Tolerant Networks (DTN) architecture uses a copy / flood packet copy strategy throughout the network, although this can increase the transmission probability and reduce the transmission Delay, but too many redundant copies cause a great waste of network resources, and DTN requires intermediate nodes to store all received packets in the buffer before the received packets are successfully forwarded, which will consume a lot of satellite network resources ;Space Communications Protocol Specification-Transport Protocol (SCPS-TP) is a space communication environment-oriented transmission protocol proposed by the Consultative Committee for Space Data Systems (CCSDS), based on traditional ground communication transmission The protocol is expanded. The protocol adopts a larger window size, adds a Selective Negative Acknowledgment (SNACK) mechanism, header compression function, and data rate control function, so that the protocol can adapt to large bandwidth delay products and high bit error rates. The satellite network is currently the most widely used network transmission protocol, but there is still a phenomenon that the intermediate router queue is too long, causing serious packet loss due to network congestion, and the bandwidth cannot be fully utilized according to the actual network situation.

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