Method for optimizing terminal control protocol (TCP) under wireless environment

Abstract

The invention relates to the technical field of wireless communication. The invention discloses a method for optimizing a terminal control protocol (TCP) under a wireless environment. The invention comprises the following steps of: comprehensively analyzing physical layer (PHY) channel condition information and hybrid automatic requestor (HARQ) information, multi-access computer (MAC) layer scheduling information, radio link control (RLC) layer automatic repeat quest (ARQ) information, and packet data convergence protocol PDCP switching information through the cross-layer information, judging whether loss of a TCP layer message is caused by router congestion at a core network side or the loss of a data message of a wireless chain side, therefore, misleading of starting congestion of a TCP layer is avoided, user sending speed influenced by an algorithm is avoided, retransmission competition between the TCP and an ARQ / HARQ caused by misleading the TCP to start a quick retransmission algorithm is avoided simultaneously, and a performance of the TCP protocol under the wireless environment is optimized. A layer-cross structure provided by the invention keeps an interface and a port between middle layers of a long term evolution (LTE) layering protocol framework unchanged; furthermore, running efficiency of the TCP protocol under the wireless environment is improved on the basis of keeping interconnection and intercommunication with an original network.

Description

technical field [0001] The invention relates to the technical field of the wireless communication field, in particular to a method for optimizing a TCP protocol in a wireless environment based on a cross-layer architecture. Background technique [0002] The Transmission Control Protocol (TCP) was originally designed for wired networks with a bit error rate of less than 10-8. The TCP protocol assumes that the main cause of packet loss is network congestion. Wired internet is extremely rare. The above assumptions are reasonable for wired networks, but in wireless networks, the above assumptions are difficult to hold. Because in a wireless network, it is sometimes difficult to provide a wireless channel with a bit error rate of 10-6, let alone a bit error rate of less than 10-8. Below, from the three algorithms of TCP congestion control and flow control, we analyze the problems existing between the application of TCP congestion control and the Long Term Evolution (LTE) system...

AI Technical Summary

Problems solved by technology

At this time, the LTE RLC layer ARQ protocol or HARQ protocol may also retransmit the same data packet, that is, both may recover the same lost segment at the same time

Therefore, the TCP fast retransmission mechanism may lead to multi-ARQ retransmission competition between the TCP protocol and the ARQ / HARQ protocol, resulting in a large amount of redundant data in the network and reducing the effective throughput of the system.

[0006] Among the existing methods for improving the performance of the wireless TCP protocol, the end-to-end improvement method and the method of splitting the connection are essentially to enable the TCP sender to effectively distinguish between the loss of congested packets and the loss of errored packets, so that it can only The congestion control mechanism is invoked when the packet is lost, and the mechanism is not invoked when the error message is lost, so that the rate of data transmission will not be reduced. However, the end-to-end improvement method needs to improve the existing TCP protocol stack, and the method of splitting the connection destroys the end-to-end end-to-end semantics; the essence of the link-layer ARQ-based solution is to recover most of the link-layer errors through the ARQ protocol and reduce the packet errors that TCP can perceive. However, while this method greatly reduces the bit error rate, it also It will increase the TCP end-to-end delay, and may cause TCP timeout in severe cases, affecting system performance

In addition, none of these solutions can solve the retransmission contention of HARQ / ARQ and TCP layer, which will seriously degrade the system performance

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