Data transmission method and equipment

Abstract

The invention discloses a data transmission method and data transmission equipment. The method comprises that: network side equipment determines the downlink air interface rate of user equipment; the network side equipment computes the size of a buffer according to the downlink air interface rate, wherein the buffer is used for caching data transmitted to the user equipment; and the network side equipment transmits the data cached in the buffer to the user equipment. In the embodiment of the invention, when enabling a transmission control protocol (TCP) agent function, a radio network controller (RNC) estimates the downlink air interface rate of the user equipment (UE), and the rational size of the RNC buffer is computed based on the downlink air interface rate; and before the relocation of the UE in a cell of which the TCP agent function is enabled, the data in the RNC buffer can be completely transmitted to ensure that the rate can be recovered normally after the relocation of the UE.

Description

technical field [0001] The present invention relates to the field of communication technology, in particular to a data transmission method and equipment. Background technique [0002] After many field tests and verifications, the TCP (Transmission Control Protocol, Transmission Control Protocol) optimization function has obvious effects, especially for services such as data downloading and web browsing, and performance indicators such as delay and speed have been significantly improved. improved user perception. [0003] Based on the TCP optimization function, the air interface transmission between UE (User Equipment, user equipment) and the base station (such as NodB) has problems such as long delay, deterioration of the wireless transmission environment, and packet loss caused by handover, which will trigger TCP congestion control. As a result, TCP performance is low. Therefore, it is necessary to add a TCP proxy function on the RNC (Radio Network Controller, wireless net...

AI Technical Summary

Problems solved by technology

TCP can only detect errors, and cannot detect the nature of errors when data packets are discarded; for errors that occur during transmission, TCP assumes that packet loss is caused by network congestion. Since the BER of the wired network is very low, This assumption is basically true; but in the wireless network environment, there are many reasons for packet loss that are not related to congestion (such as sudden errors in the wireless channel, UE is in the process of handover, channel attenuation, etc.), TCP will Packet loss is due to the occurrence of network congestion, and the wrong attribute cannot be detected

[0007] (2) Lack of effective error recovery mechanism

If packet loss is due to high BER of the wireless network or UE handover, rather than packet loss due to network congestion, this error recovery mechanism of TCP will lead to protocol performance degradation, including a decrease in throughput and an increase in latency

[0008] (3) In a wireless environment, the available bandwidth of the UE is often low, so that the sending rate of the TCP source is limited, so that it uses a smaller congestion window to send data; in this case, once a packet is lost, the TCP source The end will not receive enough duplicate acknowledgment packets to trigger fast retransmission and can only be recovered through a timeout mechanism, thus reducing the efficiency of the use of available bandwidth and increasing latency

[0009] (4) Due to the lack of an effective error detection and recovery mechanism, the energy efficiency of TCP in a wireless environment is not high

[0014] (1) The larger RNC buffer size has the following problems: After the UE relocates to the target cell, the data in the original RNC buffer cannot be sent completely, resulting in the original services that cannot be restored after relocation

[0015] When the UE is relocated, the RSCP (Received Signal Code Power) of the original cell is already very weak (the quality of the air interface is very poor), the downlink rate of the air interface cannot be guaranteed, and it is difficult to complete the data transmission in the buffer in a short time of

In order to ensure that the UE relocation is successful and does not go offline, the original RNC will not wait until all the buffer data is sent before triggering relocation, so after relocation to the target cell, the data in the originally maintained TCP connection will be lost; For a long time, the rate (service) will not be restored, which will greatly affect user perception

[0016] (2) The smaller RNC buffer size has the following problems: the rate of the IU port (the interface between the access network and the core network) is much lower than the rate of the air interface, resulting in an insufficient rate of the air interface (the RNC buffer does not have enough data to send, and the UE It is manifested as service rate jitter, not full), which affects user perception

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