Retransmission control method and transmission equipment

Abstract

The present invention relates to the communication field and discloses a retransmission controlling method and transmission device. In the present invention, a TCP data package from the transmitting terminal is received and is divided into son data packages to be transmitted to the receiving terminal and at least part of the link transmitting son packages is wireless link. If the TCP data package is arrived in the pre-estimated receiving time, the affirming message ACK which indicates that the TCP data package is received from the receiving terminal is not received and the son packages divided by the TCP data package have been all transmitted to the receiving terminal, then the TCP data package is retransmitted, making the retransmission of the TCP data package more timely. After the son packages divided by the TCP data package are transmitted on the wireless link, if the message NAK which indicates a failure in receiving the son packages from the receiving terminal is received, then the TCP data package is retransmitted. RTO similar computing is not necessary to be adopted and the ACK receiving time is pre-estimated directly according to the history value of the time needed for receiving ACK, which is very simple to be realized.

Description

technical field [0001] The invention relates to the communication field, in particular to retransmission control technology. Background technique [0002] Transmission Control Protocol (Transmission Control Protocol, referred to as "TCP") is the most basic communication protocol used by the Internet and interconnected networks. It has now become a de facto standard for network communication. The main content of TCP is to provide an inter-process communication mechanism and ensure the reliability of data transmission. Reliability includes confirming the receipt of data packets (packets), marking the sequence information of packets, ensuring the integrity of packets, etc., and also including the control of errors, for example, the confirmation signaling is not received, the packets do not arrive in order, the packets are lost or Handling rules for situations such as miscasting, etc. [0003] Since the original design of TCP only considers the application in the wired commun...

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Problems solved by technology

[0005] However, the inventors of the present invention have found that all current optimization techniques are unable to detect packet loss in a timely manner, either it is necessary to receive repeated acknowledgment signaling (Acknowledgment, referred to as "ACK"), or it is necessary to wait for a timeout before judging packet loss , to retransmit, so that the retransmission of TCP data packets is not timely enough

Moreover, the existing TCP optimization technology does not solve the essential problem of wireless link and wired link transmission: the detection of the cause of packet loss, that is, how to detect the cause of packet loss on the wireless side and how to use it to control transmission

Obviously, if the packet is lost due to a bit error, the TCP sender should perform immediate retransmission to avoid affecting the transmission rate; but if the packet is lost due to congestion, then simply using the fast retransmission mechanism on the BS side will only aggravate the congestion. Causes more packet loss and greatly affects TCP performance

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