Fuzzy-control-based TCP (transmission control protocol) congestion control method in vehicle-mounted communication network

Abstract

The invention discloses a fuzzy-control-based TCP congestion control method in a vehicle-mounted communication network and relates to the field of wireless communication. The method includes utilizing fuzzy control and introducing relative speed of neighboring nodes, distance between neighboring nodes, relative round-trip-delay change rate, short-term throughout change rate as the input parameters of fuzzy inference to establish a fuzzy control rule library; and determining a packet loss reason through the fuzzy inference, and improving TCP congestion control strategies and route switching strategies in combination with cross-layer schemes to take different processing countermeasures for different packet loss reasons, so that the route stability can be enhanced, the transmission interruptions caused by route switching can be reduced, and the system throughput and the average delay can be improved. The fuzzy-control-based TCP congestion control method in the vehicle-mounted communication network is used for improving the TCP transmission performance in the vehicle-mounted communication network, and is particularly applicable to conditions of high-speed node motion, frequent topological change and poor channel quality.

Description

technical field [0001] The invention mainly relates to the field of wireless communication, in particular to the problem of TCP transmission performance in the vehicle communication network. Background technique [0002] In recent years, the explosive growth of vehicles and the ubiquitous information demand have closely combined the communication network and the transportation network, and the vehicle communication network has emerged as the times require, and has become a research hotspot. The vehicle communication network is divided into two parts: RVC (Road to Vehicle Communications, road vehicle communication) and IVC (Inter-Vehicle Communication, inter-vehicle communication). RVC enables vehicles to access the Internet and obtain network resources through road infrastructure or mobile base stations; while IVC installs wireless communication equipment on vehicles to enable vehicles to form an ad hoc network through multi-hops, that is, VANET (Vehicular Ad Hoc Networks). ...

AI Technical Summary

Problems solved by technology

[0005] In the VANET environment, due to its short transmission distance and fast moving speed, link switching is very frequent, and packet loss caused by frequent routing switching is an important reason affecting TCP transmission performance.

When the node moves rapidly and the route is interrupted, multiple consecutive TCP packets will be lost. If the sender cannot receive the ACK (Acknowledgment, confirmation signal), it needs to wait for the RTO (Retransmission Time Out, timeout retransmission time) before starting the retransmission task , and may trigger unnecessary congestion control processes

It can be seen that if the packet loss caused by routing switching cannot be effectively handled, the transmission delay will increase, and unreasonable congestion control and retransmission will be brought about.

In the literature (Marc Bechler, Sven Jaap, Lars Wolf "An Optimized TCP for Internet Access of Vehicular Ad Hoc Networks" Lecture Notes in Computer Science, 2005, Volume 3462, NETWORKING2005:869-880) proposed a proxy mechanism-based VANET environment The following TCP optimization scheme: MCTP (Mobile Control Transport Protocol, mobile transmission control protocol), this scheme separates the end-to-end TCP connection by setting a proxy, and optimizes the TCP transmission performance in the proxy, but this scheme needs to increase Agent, the implementation is more complicated, and the compatibility is not good enough, and this solution does not combine the characteristics of the vehicle communication network with predictable movement trends, nor does it combine the network layer for joint optimization

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