WO2020010511A1

WO2020010511A1 - Data transmission method and base station

Info

Publication number: WO2020010511A1
Application number: PCT/CN2018/095112
Authority: WO
Inventors: 惠博; 王勇麟; 梁杰雄
Original assignee: 华为技术有限公司
Priority date: 2018-07-10
Filing date: 2018-07-10
Publication date: 2020-01-16

Abstract

An embodiment of the present invention relates to a data transmission method and a base station. The method comprises: when all medium access control (MAC) protocol data units (PDUs) corresponding to a first transmission control protocol (TCP) message are correctly received by a user equipment, a base station determining that a first TCP message is correctly received by the user equipment; when uplink resources of the user equipment are limited, the base station generating a first TCP ACK of the first TCP message according to the first TCP message that is correctly received by the user equipment, the first TCP ACK being used for indicating that the first TCP message is correctly received by the user equipment; the base station sending the first TCP ACK to a server. Thus, when the user equipment cannot promptly reply to a confirmation message, the base station confirms the service on behalf of the user equipment so as to promptly perform confirmation, thereby reducing repetition caused by there being no way to promptly reply to a confirmation message, and improving the transmission efficiency of TCP messages.

Description

Data transmission method and base station

Technical field

Embodiments of the present invention relate to the field of communications technologies, and in particular, to a data transmission method and a base station.

Background technique

Transmission Control Protocol (TCP) is a connection-oriented, reliable, byte stream-based transport layer communication protocol, defined by the Internet Engineering Task Force (IETF) RFC 793. In the simplified computer network OSI model, it completes the functions specified by the fourth layer of the transmission layer. The user datagram protocol (UDP) is another important transmission protocol in the same layer. In the Internet protocol suite, the TCP layer is an intermediate layer located above the Internet protocol (IP) layer and below the application layer. The application layers of different hosts often need reliable, pipe-like connections, but the IP layer does not provide such a flow mechanism, but instead provides unreliable packet switching.

At present, data traffic on the Internet, TCP protocol data traffic accounts for more than 90%. Among them, the TCP protocol data traffic on mobile networks also accounts for the vast majority. For example, streaming media, web browsing, and email services are basically based on the TCP protocol. Peer-to-peer (P2P) and real-time Communication (instant messaging) can also be based on the TCP protocol.

During the data stream transmission of the TCP protocol, the application layer sends a data stream represented by 8-bit bytes to the TCP layer for network transmission, and then the TCP layer partitions the data stream into message segments of appropriate length to generate a result packet. The length of the segment is usually limited by the maximum transmission unit (MTU) of the data link layer of the network to which the computer is connected. The TCP layer transmits the result packet to the IP layer, and the IP layer transmits the packet to the user equipment's TCP layer through the network. For mobile networks, this process needs to be implemented by means of wireless transmission. The user equipment returns an acknowledgement (acknowledgement, ACK) for the successfully received required packet. For mobile networks, this process needs to be implemented by wireless transmission; if the server is within a reasonable round-trip time (RTT) If no acknowledgement is received, the corresponding message is assumed to be lost and will be retransmitted. In this process, the ratio of the number of uplink and downlink packets (TCP acknowledgment packets and TCP packets) of the TCP protocol based on the statistics of the current network will reach 1: 1.3, so the requirements for the uplink and downlink bandwidth are very high.

For existing wireless networks, the proportion of uplink and downlink subframes in a special time division duplex (TDD) cell is low. For example, in a common subframe configuration, the proportion of uplink and downlink subframes is 1: 4. This makes the uplink resource much smaller than the downlink resource, making the uplink resource a bottleneck that restricts the TCP transmission rate, especially in the event guarantee, such as sports events, concerts, and major festival celebrations, the problem of limited uplink capacity continues It is obvious that the TCP download service is severely limited due to the inability to respond to the uplink TCP ACK in a timely manner, which makes the wide resources in wireless communication not fully utilized and the user's TCP transmission rate is low.

A lot of research has been done on the improvement of TCP transmission performance in wireless networks, and a series of improvement measures have been proposed. One way is to increase the priority of TCP ACK transmission on the base station and user equipment side. Specifically, the user equipment that has downlink TCP service transmission is identified by the base station side, and uplink scheduling resource allocation is preferentially performed for this type of user equipment to reduce the transmission delay of TCP ACKs of this type of user equipment; and the priority of TCP ACK transmission is increased at the UE side. The user equipment groups different types of packets into priority groups. After receiving the scheduling resources of the base station, the user equipment preferentially sends a packet containing the TCP ACK packet. However, in the uplink resource limited overload scenario, the base station preferentially allocates resources for user equipment with TCP ACK to be transmitted, which will inevitably lose the experience of other service types of user equipment, such as voice users and the number of user equipment in the network. In a scenario where multiple uplink resources are limited, the gain that a user equipment can send by preferentially sending a TCP ACK is also very limited.

Summary of the invention

Embodiments of the present invention provide a data transmission method and a base station. Improved TCP message transmission efficiency.

In a first aspect, a data transmission method is provided. The method includes: when all the media access control MAC protocol data unit PDUs corresponding to the first transmission control protocol TCP message are correctly received by the user equipment, the base station determines that the first TCP message is correctly received by the user equipment; when When the uplink resources of the user equipment are limited, the base station generates a first TCP ACK of the first TCP message according to the first TCP message correctly received by the user equipment. The first TCP ACK is used for Indicating that the first TCP packet is correctly received by the user equipment; the base station sends the first TCP ACK to the server.

According to the embodiment of the present invention, the MAC layer is used to confirm the reception of TCP packets by the UE. Since the MAC layer data can be transmitted through the physical uplink control channel (PUCCH), the PUCCH adopts the code division method in Multiple UEs are multiplexed, and their available resources can be guaranteed in the LTE network. When the user equipment cannot reply to the confirmation message in time, the base station confirms the service on behalf of the user, which can timely confirm the TCP packets, reducing Retransmission caused by failure to respond to acknowledgement messages in a timely manner improves TCP packet transmission efficiency.

In an optional implementation, the method further includes: receiving, by the base station, a first TCP packet sent by a server, and determining an identifier of the first TCP packet; and the base station referring to the first TCP packet according to a wireless chain. The road layer controls the RLC protocol and the MAC protocol to obtain at least one MAC PDU, and establishes a mapping relationship between the identifier of the first TCP packet and the identifier of the at least one MAC PDU; the base station according to the hybrid automatic retransmission request automatic (request, HARQ) feedback mechanism sends the at least one MAC PDU to the user equipment; the base station determines all the corresponding to the first TCP packet according to the MAC PDU and the mapping relationship that have been correctly received at the user equipment Whether a MAC PDU is correctly received by the user equipment; when it is determined that all MAC PDUs corresponding to the first TCP message are correctly received by the user equipment, the base station determines that the first TCP message is received by the user equipment Received correctly.

Through the embodiment of the present invention, the HARQ feedback mechanism at the MAC layer is used to confirm the reception of TCP packets by the UE. Since HARQ feedback can be transmitted through the PUCCH channel, the PUCCH channel is multiplexed among multiple UEs in a code division manner. Its available resources can be guaranteed in the LTE network.

In another optional implementation, the identifier of the TCP packet includes one or more of TCP quintuple information. In the embodiment of the present invention, the base station may obtain TCP quintuple information by analyzing the TCP packet, and identify the TCP packet by using the quintuple information, so that it is possible for the proxy to reply to TCP ACk.

In another optional implementation, when it is determined that all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, the base station determines that the first TCP packet is received by the user equipment. The correct reception includes: when it is determined that all the MAC PDUs corresponding to the first TCP message are correctly received by the user equipment, the base station updates a local record of an identifier of the TCP message currently confirmed to be received by the user equipment. Is the identifier of the first TCP packet. In the embodiment of the present invention, it is only required to record the latest TCP packet acknowledged and received by the user equipment, which can reduce the amount of data maintained by the base station and improve communication efficiency.

In another optional implementation, the uplink resource limitation of the user equipment includes one or more of the following: the base station recognizes that continuous due to limited physical downlink control channel (PDCCH) resource The uplink scheduling was not allocated for the user equipment in a timely manner; the base station identified that the uplink scheduling was not allocated for the user equipment in a timely manner due to a limited physical uplink shared channel (PUSCH) resource limitation. According to the embodiment of the present invention, the base station can accurately implement a scenario in which the uplink resources of the user equipment are limited, and when the scenario is specified, the base station proxy is started to reply with a TCP ACK to ensure communication efficiency.

In another optional implementation, the TCP ACK includes a TCP acknowledgement packet ACK; the first TCP ACK is a first TCP ACK, the first TCP ACK includes a first sequence number, and the first TCP status is used to indicate TCP messages before the first sequence number are correctly received by the user equipment; the method further includes: the base station receives a second TCP ACK sent by the user equipment, and the second TCP ACK includes a second Sequence number, the second TCPACK is used to indicate that the TCP packet before the second sequence number is correctly received by the user equipment; when the second sequence number is not greater than the first sequence number, the base station will The second TCP ACK is deleted. Through the embodiments of the present invention, it is possible to avoid sending repeated TCP ACKs to the server and improve resource utilization.

In another optional implementation, the method further includes: the base station receives a TCP repeated DUP ACK sent by the user equipment; the CP DUP ACK includes a third sequence number, and when the third sequence number is not greater than At the first sequence number, the base station retransmits a TCP message corresponding to the TCP DUP ACK according to a local buffer. The embodiment of the present invention can solve the problem that the TCP packet can be correctly retransmitted when the data of the base station MAC layer and the TCP layer are inconsistently received by the user equipment or the base station, thereby ensuring that the base station can completely receive the data on the premise of improving communication efficiency. To TCP packets to ensure communication quality.

In another optional implementation, the method further includes: when the base station receives a TCP packet sent by a server, the base station performs buffering locally; after the base station receives a second TCP ACK sent by a user equipment, the The base station deletes the local buffer of the TCP packet that is correctly received by the user equipment and indicated by the second TCP ACK. Through the embodiments of the present invention, after determining that the base station receives the TCP ACK from the user equipment, the local cache can be deleted, thereby ensuring the communication quality, reducing the maintenance cost of the base station and saving the base station resources.

In a second aspect, a base station is provided. The base station includes: a first determining unit, configured to determine that the first TCP packet is received by the user equipment when all media access control MAC protocol data unit PDUs corresponding to the first Transmission Control Protocol TCP packet are correctly received by the user equipment. A user equipment receives correctly; a generating unit, configured to generate a first TCP ACK of the first TCP message according to the first TCP message correctly received by the user equipment when uplink resources of the user equipment are limited, The first TCPACK is used to indicate that the first TCP packet is correctly received by the user equipment; and a first transceiver unit is configured to send the first TCPACK to a server.

In an optional implementation, the base station includes an RLC and MAC processing unit and a PDCP processing unit; wherein the RLC and MAC processing unit includes the first determining unit, and the PDCP processing unit includes the generating unit: the The first transceiver unit is configured to receive a first TCP packet sent by the server; the PDCP processing unit further includes a second determination unit to determine an identifier of the first TCP packet; the RLC and MAC processing unit further includes processing And an establishing unit, configured to process the first TCP packet according to a radio link layer control RLC protocol and a MAC protocol to obtain at least one MAC PDU, and establish an identifier of the first TCP packet and the at least one MAC PDU The base station further includes a second transceiver unit, configured to send the at least one MAC PDU to the user equipment according to a HARQ feedback mechanism of the hybrid automatic retransmission request; the first determining unit is specifically configured to: The MAC PDU and the mapping relationship that are correctly received by the user equipment are used to determine whether all the MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment. When all TCP said first MAC PDU corresponding to the packet is correctly received by the user equipment, determining the first TCP packet is correctly received by the user equipment.

In another optional implementation, the identifier of the TCP packet includes one or more of TCP quintuple information.

In another optional implementation, the first determining unit is further configured to: when it is determined that all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, update the local record The user equipment confirms that the identifier of the received TCP packet is the identifier of the first TCP packet.

In another optional implementation, the uplink resource limitation of the user equipment includes one or more of the following: identifying that the number of consecutive prefabrication times is not allocated to the user equipment in time due to the physical downlink control channel PDCCH resource limitation Uplink scheduling; it is identified that the uplink scheduling is not allocated to the user equipment in a timely manner due to the limitation of the physical uplink shared channel PUSCH resource.

In another optional implementation, the TCP ACK includes a TCP acknowledgement packet ACK; the first TCP ACK is a first TCP ACK, the first TCP ACK includes a first sequence number, and the first TCP status is used to indicate TCP packets before the first sequence number are correctly received by the user equipment; the second transceiver unit is configured to receive a second TCP ACK sent by the user equipment, where the second TCP ACK includes a second A serial number, and the second TCP ACK is used to indicate that the TCP packet before the second serial number is correctly received by the user equipment; the PDCP processing unit further includes a deleting unit for when the second serial number is not greater than When the first sequence number is used, the second TCP ACK is deleted.

In another optional implementation, the second transceiver unit is further configured to receive a TCP repeated DUP ACK sent by the user equipment, the CP DUP ACK includes a third sequence number, and the PDCP processing unit further includes a repeater A transmitting unit, configured to retransmit the TCP packet corresponding to the TCP DUP ACK according to a local buffer when the third sequence number is not greater than the first sequence number.

In another optional implementation, the PDCP processing unit further includes a buffering unit, configured to buffer locally when receiving a TCP packet sent by the server; after receiving a second TCP ACK sent by the user equipment, The local buffer deletion of the TCP message correctly received by the user equipment indicated by the second TCP ACK is described.

According to a third aspect, a base station is provided. The base station includes a transceiver, a communication module, a processor, and a memory. The memory is used to store programs. The transceiver is used to interact with user equipment. The communication module is used to communicate with a user equipment. The server interacts, and the processor is configured to execute the program stored in the memory to control the base station to execute the method according to the first aspect.

According to a fourth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program, and the computer program implements the method described in the first aspect when executed by a processor.

In a fifth aspect, a computer program product containing instructions is provided, and when the instructions are run on a computer, the computer is caused to perform the method described in the first aspect above.

In a sixth aspect, a chip is provided. The processor includes a processor and a memory; the memory is configured to store a program; and the processor is configured to execute the program stored in the memory to perform the method described in the first aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an application scenario according to an embodiment of the present invention; FIG.

2 is a schematic diagram of signaling interaction of a data transmission method according to an embodiment of the present invention;

3 is a schematic diagram of signaling interaction of another data transmission method according to an embodiment of the present invention;

4 is a schematic structural diagram of a base station according to an embodiment of the present invention;

5 is a schematic structural diagram of another base station according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of another base station according to an embodiment of the present invention.

detailed description

The technical solutions of the present application will be described in further detail below with reference to the drawings and embodiments.

As shown in FIG. 1, the embodiment of the present invention is mainly applicable to a wireless communication system, for example, a long term evolution (LTE) network, an LTA evolution (LTE-advanced, LTE-A) network, and the like. Among them, LTE is a long-term evolution of the Universal Mobile Telecommunications System (UMTS) technology standard formulated by the 3rd Generation Partnership Project (3GPP) organization. The TCP message generated by the server is transmitted to the user equipment (UE) by the base station (evolved node B, eNB) based on wireless transmission. Specifically, the TCP message sent by the server to the user equipment is transmitted to the eNB via the core network. , And then sent to the user equipment by the eNB. Among them, the TCP packets sent by the eNB to the user equipment from the PS domain (Packet Switched) of the core network are compressed in the Packet Data Convergence Protocol (PDCP) layer (the purpose is to improve Efficiency), then submit it to the RLC layer for segmentation, concatenation, and put it into the RLC protocol data unit (PDU), and then add the MAC header field to the Media Access Control (MAC) layer to become The MAC PDU is sent to the physical layer. At the end, the physical layer needs to add a Cyclic Redundancy Check (CRC) header, encoding, and interleaving, and then convert these data into electromagnetic waves for transmission. The user equipment then recovers through the reverse operation of the above process. A TCP packet is sent out. After receiving the TCP packet sent by the eNB correctly, the user equipment returns a TCP ACK. The TCP ACK also needs to go through the above process to be sent to the server, and details are not described again.

ACK. The user equipment can send a TCP ACK or TCP Duplicate ACK (TCP Duplicate ACK) to the server through the base station to indicate the reception of TCP packets on the user equipment. Among them, TCP ACK and TCP DUP ACK are used to indicate The TCP packets received by the terminal correctly. This indication of the TCP packets received correctly by the terminal can be understood as indicating the TCP packets expected to be received, and all are received correctly before the expected TCP packets.

Through analysis, the inventor of the present application found that, by establishing a TCP proxy on the LTE eNB side, it can buffer the received downlink TCP packets, and respond to the corresponding TCP ACK packets to the server instead of the UE, and accelerate the server to quickly issue new TCP packets. Text. Then the buffered messages are sent to the terminal one by one, and the automatic repeat-request (ARQ) feedback mechanism of the LTE RLC layer is used to confirm the reception of the TCP messages by the terminal. If the ARQ feedback is ACK, It is considered that the UE has correctly received the message, and the sending window of the TCP proxy may be updated to continue to send a new message to the UE; if the ARQ feedback is NACK, the retransmission is started quickly. This technology takes advantage of the 3GPP LTE protocol's feature that RLC ARQ feedback takes precedence over other data message transmissions, so that the eNB can quickly determine the TCP of the UE when it receives only RLC ARQ feedback but does not receive a TCP ACK message. Packet reception improves TCP downlink service rate.

However, the feedback information (for example, RLC ACK or RLC NACK) in the ARQ feedback mechanism of the RLC layer is still transmitted on the physical uplink shared channel (PUSCH), that is, the eNB still needs to allocate a physical downlink control channel for the UE ( physical downlink (channel, PDCCH), and PUSCH resources, then under heavy resource constraints, it is still impossible to guarantee that a large number of UEs' RLC ARQs are sent to the eNB in a timely manner, resulting in a large accumulation of buffered packets from the TCP proxy of the eNB. And stop the proxy.

The present invention uses a hybrid automatic repeat request (HARQ) feedback mechanism at the MAC layer to confirm the reception of the TCP message by the UE. Because HARQ feedback can be transmitted through the physical uplink control channel (PUCCH) channel, and the PUCCH channel is multiplexed among multiple UEs by code division, its available resources can be guaranteed in the LTE network of.

The embodiments of the present invention are further described below with reference to the accompanying drawings.

FIG. 2 is a schematic diagram of signaling interaction of a data transmission method according to an embodiment of the present invention. As shown in FIG. 2, the method specifically includes the following steps:

S210. When all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, the base station determines that the first TCP packet is correctly received by the user equipment.

Since MAC PDUs are obtained by processing TCP packets through PDCP, RLC, and MAC protocols, there is a correspondence between MAC PDUs and TCP packets. Based on this, the mapping relationship between the TCP packet and the MAC PDU can be established in advance.

During the data transmission between the base station and the user equipment, the base station can send MAC PDUs to the user equipment according to the MAC rules. In LTE networks, the transmission of MAC PDUs is usually based on the HARQ feedback mechanism. In this HARQ feedback mechanism, the base station The PDU will correspond to the feedback information received from the MAC layer of the user equipment. The feedback information may indicate whether the MAC PDU is received correctly. When the sent MAC PDU is received correctly, it will continue to send the next MAC PDU. When the PDU is not received correctly, it needs to be retransmitted. In this process, the base station can determine whether all MAC PDUs corresponding to the TCP packets are correctly received by the user equipment based on the mapping relationship between the TCP packets and the MAC PDUs. When the base station determines that all MAC PDUs corresponding to the TCP packet are correctly received by the user identifier, it can be determined that the TCP packet is correctly received by the user equipment.

S220. When the uplink resources of the user equipment are limited, the base station generates a first TCP ACK according to the first TCP packet correctly received by the user equipment. The first TCP ACK is used to indicate that the first TCP packet is correctly received by the user equipment.

S230: The base station sends the first TCP ACK to the server.

In the embodiment of the present invention, the uplink resource limitation of the user equipment mainly means that the PDCCH resource and the PUSCH resource are limited. Whether the uplink resource of the user equipment is limited can be identified by the base station.

Specifically, the limited uplink resource of the user equipment may include one or more of the following situations:

If the base station recognizes that the uplink scheduling is not allocated to a user equipment in a timely manner due to limited physical downlink control channel PDCCH resources, it determines that the user's uplink resources are limited;

If the base station recognizes that the uplink scheduling is not allocated to a user equipment in a timely manner due to limited physical uplink shared channel PUSCH resources, it determines that the user's uplink resources are limited.

When it is determined that the uplink resources of a certain user equipment are limited, the base station determines that the user equipment currently receives the latest TCP packet correctly received by the user equipment according to the locally maintained information, and continuously receives the quintuple information such as the confirmed TCP and SN to send to PDCP The PDCP layer accordingly constructs a TCP ACK instead of the UE. The TCP ACK is used to indicate that the TCP packet is received correctly. For example, the TCP ACK may include an acknowledgement number, which may be a TCP SN. The TCP ACK is used The TCP packet before indicating the confirmation number is correctly received by the user equipment, and indicates that it is expected to receive a TCP packet with a serial number of the confirmation number next time. The base station may send the structured TCP status to the server, so that after receiving the structured TCP ACK, the server continues to send a TCP message with a sequence number to the user equipment.

After the base station sends a TCP ACK to the server instead of the user equipment, when the base station receives the TCP ACK sent by the user equipment, it can determine whether the TCP message indicated by the TCP ACK that was correctly received by the user equipment is a reply from the base station to confirm that it was received correctly. Within the scope of the message, if it is, the base station discards the TCP ACK sent by the user equipment; if not, it sends the TCP status to the server to avoid sending duplicate TCP ACKs to the server.

Based on this, in an example, when the first TCP ACK includes a first sequence number, the first TCP state is used to indicate that a TCP packet before the first sequence number is correctly received by the user equipment; the method further includes :

The base station receives a second TCP ACK sent by the user equipment, where the second TCP ACK includes a second sequence number, and the second ACK is used to indicate that the TCP packet before the second sequence number is correctly received by the user equipment;

Judging the size of the first serial number and the second serial number;

When the second sequence number is not greater than the first sequence number, the base station deletes the second TCPACK;

When the second sequence number is greater than the first sequence number, the base station sends the second TCP ACK to the server.

In addition, if the base station receives the TCP DUP ACK returned by the UE, the base station retransmits the TCP packet corresponding to the TCP ACK to the UE according to the locally buffered TCP packet, where after the base station receives the TCP packet sent by the server , The buffering may be performed locally, and after the base station receives the TCP ACK returned by the UE, deletes the local buffer of the TCP message indicated by the TCP ACK received by the UE correctly. For example, the base station ’s MAC layer received the UE ’s HARQ ACK, but the actual corresponding TCP packet was not received by the user ’s TCP layer (the TCP packet was dropped at the UE, or the eNB mistakenly decoded the HARQ NACK to ACK, etc.) , The user equipment will send a TCP DUP ACK to notify the server to retransmit. In one example, the base station has replaced the UE with a TCP ACK of SN 10, and the actual TCP packet with an SN of 8 is lost on the UE side. Then the UE will reply with a TCP SN of 8 and indicate that the server is DUPACK. TCP packets with an SN of 8 should be retransmitted. However, since the server has previously received an ACK with an SN of 10 from the base station proxy, it is considered that all the messages before the sequence SN of 10 have been correctly received by the UE. If the server receives a TCP DU with an SN of 8 later, it will consider that However, the message is an abnormal message, and the TCP DUP with the SN of 8 is discarded. In this way, the packet with the actual SN of 8 will eventually be dropped. Therefore, the base station can buffer the received TCP packets. When the base station receives the TCP DUPACK with the SN of 8 sent by the user equipment, the base station directly retransmits the packet with the SN of 8 according to the local buffer. After receiving the TCP ACK from the UE, the base station deletes the buffered TCP packet that the UE has acknowledged. For example, after the base station receives the TCP ACK with the SN of 9 from the UE, the base station deletes the packet with the SN of 8. , Or delete all messages with SN 8 and less.

Based on this, in an example, the first TCPACK includes a first sequence number, and the first TCP state is used to indicate that a TCP packet before the first sequence number is correctly received by the user equipment; the method further includes:

The base station receives a TCP DUPACK sent by the user equipment, where the TCP DUPACK includes a third sequence number, and the TCPDUPACK is used to indicate that the TCP packet before the third sequence number is correctly received by the user equipment;

When the base station receives the TCP DUPACK from the user equipment, and the third sequence number cannot be greater than the first sequence number, the base station retransmits the TCP packet corresponding to the third sequence number according to the local buffer. When the base station receives a third TCP ACK sent by the user equipment, the third ACK includes a fourth sequence number, and the fourth sequence number is greater than the first sequence number, the base station sends the third ACK to the server.

Through the embodiment of the present invention, the HARQ feedback mechanism at the MAC layer is used to confirm the reception of TCP packets by the UE. Since HARQ feedback can be transmitted through the PUCCH channel, the PUCCH channel is multiplexed among multiple UEs in a code division manner. Its available resources can be guaranteed in the LTE network, so when the user equipment cannot reply to the confirmation message in time, the base station confirms the service on behalf of the user in order to perform the confirmation in time and reduce the retransmission caused by the failure to reply to the confirmation message in time. Improve TCP packet transmission efficiency.

FIG. 3 is a schematic diagram of signaling interaction of another data transmission method according to an embodiment of the present invention. The data transmission process between the base station and the user equipment is mainly based on TCP, PDCP, RLC, and MAC protocols. As shown in FIG. 3, based on the embodiment shown in FIG. 2, the method This can also be achieved through the following steps:

S310: The base station receives the first TCP packet sent by the server, and determines an identifier of the first TCP packet.

After receiving the downlink TCP message sent by the server, the PDCP layer of the base station can parse the TCP message based on the TCP protocol to obtain the quintuple information corresponding to the TCP message. The five-tuple information can be used as the identifier of the TCP packet.

S320: The base station processes the first TCP packet to obtain at least one MAC PDU according to the RLC protocol and the MAC protocol, and establishes a mapping relationship between an identifier of the first TCP packet and the identifier of the at least one MAC PDU.

The base station performs header compression and encryption on the received TCP message sent by the server, assembles it into a PDCP PDU, and sends it to the RLC layer along with the quintuple information of the TCP message it parses. The RLC layer divides or concatenates the RLC SDU (RLC SDU is PDCP PDU) into the RLC PDU through the downlink resource allocation size allocated by the MAC layer. Finally, the MAC layer adds information such as the control element of the MAC layer to form at least one MAC. PDU. The RLC layer and the MAC layer may establish and maintain a mapping relationship between the CP packet quintuple information and the at least one MAC PDU sequence number. For example, MAC joint RLC maintains the TCP packet information contained in each MAC PDU sent, and determines all RLC segments corresponding to each TCP packet.

For example, the mapping relationship between TCP packets and MAC PDUs maintained by the base station and the transmission status are shown in Table 1.

Table 1

S330. The base station sends the at least one MAC PDU to the user equipment according to a HARQ feedback mechanism.

According to the HARQ feedback mechanism, each time the MAC layer of the eNB sends a MAC PDU, the MAC layer of the user equipment will receive HARQ feedback information after receiving it. If the feedback is HARQ ACK, it is proved that the MAC PDU has been correctly received by the user equipment. If the feedback is HARQ NACK, it is proved that the MAC PDU has not been correctly received by the user equipment, and retransmission is required.

S340: The base station determines whether all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment according to the mapping relationship between the MAC PDUs that have been correctly received at the user equipment and the identifiers of the TCP packets and the identifiers of the MAC packets.

S350. When it is determined that all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, the base station determines that the first TCP packet is correctly received by the user equipment.

After receiving the HARQ ACK, the base station can determine the TCP packet corresponding to the acknowledged MAC PDU, and confirm whether all RLC segments corresponding to the TCP packet have been sent.

When the base station determines that all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, the base station updates the local record and the identifier of the TCP packet currently confirmed to be received by the user equipment is the identifier of the first TCP packet. Based on the maintained information, the layer updates the SN of the TCP packets that are currently continuously received.

S360. When the uplink resources of the user equipment are limited, the base station generates a first TCP ACK of the first TCP message according to the first TCP message correctly received by the user equipment, where the first TCP ACK is used to indicate the first TCP message. Received correctly by user equipment.

S370: The base station sends a first TCP ACK to the server.

The base station accurately recognizes whether the uplink resources of the user equipment are limited. If a user equipment is found N consecutive times (the N times can be adjusted according to factors such as the actual network bandwidth and the number of access users) due to limited PUSCH or PDCCH resources If the uplink scheduling cannot be obtained in time, the MAC layer of the base station sends to the PDCP layer the quintuple information of the TCP packets that the user equipment has recently received continuously and is confirmed and received by the user equipment, and the PDCP layer confirms the reception by the user equipment. The quintuple information of the TCP packet instead of the user equipment constructs a TCP ACK reply to the server, prompting the server to issue a new TCP packet as soon as possible to improve the downlink throughput rate.

S380: The base station receives the second TCP ACK sent by the user equipment, and deletes the second TCP ACK.

After receiving the TCP data packet sent by the base station, the user equipment will reply with a TCP ACK to indicate that the TCP packet was received correctly. After receiving the first TCP packet, the user equipment sends the second TCP ACK using the uplink resource obtained from the base station, and the second TCP ACK user indicates that the first TCP packet is received correctly. The second TCP ACK is processed by the PDCP layer and the RLC and MAC layers to obtain a MAC PDU, and sends the MAC PDU to the MAC layer of the base station. The MAC layer of the base station also returns HARQ ACK, and the base station's MAC, RLC, and PDCP are processed in sequence. The PDCP SDU is obtained, and then the second TCP ACK is obtained by the PDCP protocol. The PDCP layer of the base station determines whether the second TCP ACK is the same as the first TCP ACK, and if it is the same, deletes (discards) the second TCP ACK.

When the PDCP layer of the base station receives the TCP ACK from the user equipment, it is found that if the acknowledgement number of the TCP ACK is less than or equal to the acknowledgement number of the TCP ACK instead of the PDCP layer, the TCP ACK returned by the user equipment is discarded to avoid giving the server Send duplicate TCP ACK. If the PDCP layer receives the TCP DUP ACK from the user device and finds that the TCP DUP ACK acknowledgement number is less than or equal to the PDCP layer instead of the reply TCP ACK acknowledgement number, the base station retransmits the The TCP message corresponding to the acknowledgement number of the TCP DUP ACK.

In addition, if the PDCP layer repeatedly receives the TCP ACK of the same acknowledgement number returned by the UE, the base station suspends the proxy to reply to the TCP ACK until it receives a TCP ACK with a new acknowledgement number sent by the user equipment.

The embodiment of the present invention does not rely on limited uplink resources to confirm the reception of downlink TCP packets by the user equipment, but uses the functions of each layer of PDCP, RLC, and MAC across layers, and finally only confirms users through HARQ feedback at the MAC layer The device receives the downlink TCP packets, and responds to the server with a TCP ACK in a timely manner to accelerate the server, expand the downlink TCP packet sending window, and increase the downlink throughput rate.

FIG. 4 is a schematic structural diagram of a base station according to an embodiment of the present invention. As shown in Figure 4, the base station includes:

A first determining unit 401, configured to determine that the first TCP packet is correctly received by the user equipment when all the media access control MAC protocol data unit PDUs corresponding to the first transmission control protocol TCP packet are received correctly by the user equipment;

The generating unit 402 is configured to generate a first TCP ACK of the first TCP packet according to the first TCP packet correctly received by the user equipment when uplink resources of the user equipment are limited, and the first TCP ACK is used to indicate the first TCP The message is correctly received by the user equipment;

The first transceiver unit 403 is configured to send a first TCP ACK to the server.

In one embodiment, the base station includes an RLC and MAC processing unit 510 and a PDCP processing unit 520; wherein the RLC and MAC processing unit 510 includes a first determination unit 401 and the PDCP processing unit 520 includes a generation unit 402. In other words, the first The function of the determining unit 401 may be implemented by the RLC and MAC processing unit 510, and the generating unit 402 may be implemented by the PDCP processing unit 520.

Furthermore, the first transceiver unit 403 is further configured to receive a first TCP packet sent by the server;

The PDCP processing unit 520 further includes a second determining unit 521, configured to determine an identifier of the first TCP packet;

The RLC and MAC processing unit 510 further includes a processing and establishment unit 511, configured to process the first TCP packet to obtain at least one MAC PDU according to the radio link layer control RLC protocol and the MAC protocol, and to establish an identifier and Mapping relationship of at least one MAC PDU identifier;

The base station further includes a second transceiver unit 530, configured to send at least one MAC PDU to the user equipment according to a hybrid automatic repeat request HARQ feedback mechanism;

The first determining unit 401 is specifically configured to determine whether all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment according to the MAC PDUs and mapping relationships that have been correctly received at the user equipment; when determining that the first TCP packet corresponds to When all the MAC PDUs are correctly received by the user equipment, it is determined that the first TCP packet is correctly received by the user equipment.

In another embodiment, the identification of the TCP packet includes one or more of the TCP quintuple information.

In another embodiment, the first determining unit 401 is further configured to: when it is determined that all MAC PDUs corresponding to the first TCP message are correctly received by the user equipment, update the locally recorded TCP message currently confirmed to be received by the user equipment The identifier of is the identifier of the first TCP packet.

In another embodiment, the uplink resource limitation of the user equipment includes one or more of the following:

It is identified that the uplink scheduling is not allocated to the user equipment in a timely manner due to the physical downlink control channel PDCCH resource limitation;

It is identified that the uplink scheduling is not allocated to the user equipment in a timely manner due to the limited physical uplink shared channel PUSCH resources.

In another embodiment, the TCP ACK includes a TCP acknowledgement packet ACK; the first TCP ACK is a first TCP ACK, the first TCP ACK includes a first sequence number, and the first TCP status is used to indicate a TCP before the first sequence number The message is correctly received by the user equipment;

A second transceiver unit 530, configured to receive a second TCP ACK sent by the user equipment, where the second TCP ACK includes a second sequence number, and the second TCP ACK is used to indicate that the TCP packet before the second sequence number is correctly received by the user equipment;

It may further include a deleting unit 522. The PDCP processing unit 520 may further include the deleting unit 522. The deleting unit 522 is configured to delete the second TCP ACK when the second sequence number is not greater than the first sequence number.

In another embodiment, the second transceiver unit 530 is further configured to receive the TCP repeated DUP ACK sent by the user equipment, and the CP DUP ACK includes a third sequence number; the PDCP processing unit 520 further includes a retransmission unit 523 for When the three sequence number is not greater than the first sequence number, the TCP message corresponding to the TCP DUP ACK is retransmitted according to the local buffer.

In another embodiment, the PDCP processing unit 520 further includes a buffer unit 524, configured to buffer locally when receiving a TCP packet sent by the server; after receiving the second TCP ACK sent by the user equipment, the second TCP The local buffer of the TCP packet indicated by the ACK that is correctly received by the user equipment is deleted.

FIG. 6 is a schematic structural diagram of another sending device according to an embodiment of the present invention. As shown in FIG. 6, the sending device specifically includes a transceiver 601, a communication module 602, a processor 603, and a memory 604. The various modules can be connected via a bus 605.

The transceiver 601 is configured to support transmitting and receiving information between the base station and the user equipment in the foregoing embodiment. For example, the transceiver 601 may include a radio frequency circuit to support wireless communication between the base station and the user equipment. The communication module 602 is configured to support sending and receiving information between the base station and the server in the foregoing embodiment. For example, the communication module 602 performs wired communication with the server. During the communication between the base station, the user equipment, and the server, the data and signaling messages are processed by the processor 603 and sent by the transceiver 601 to the user equipment or by the communication module 602 to the server. The signal from the user equipment is received via the transceiver 601 or the information from the server is received via the communication module 603, and processed by the processor 603 to obtain data and signaling sent by the user equipment or the server. The processor 603 may control the base station to perform the processing process related to the base station in FIG. 2 or FIG. 3 and / or other processes for the technology described in this application. The memory 604 is configured to store program codes and data of the terminal.

In each of the foregoing embodiments of the present invention, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions according to the embodiments of the present invention are wholly or partially generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable medium to another computer-readable medium, for example, the computer instructions may be transmitted from a website site, computer, server, or data center through a cable (Such as coaxial cable, optical fiber, Digital Subscriber Line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) for transmission to another website site, computer, server, or data center. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, a data center, or the like that includes one or more available medium integration. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (Solid State Disk, SSD)), or the like.

The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present invention. It should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

A data transmission method, comprising:

When all the medium access control MAC protocol data unit PDUs corresponding to the first transmission control protocol TCP message are correctly received by the user equipment, the base station determines that the first TCP message is correctly received by the user equipment;

When the uplink resources of the user equipment are limited, the base station generates a first TCP ACK of the first TCP message according to the first TCP message correctly received by the user equipment. Indicating that the first TCP packet is correctly received by the user equipment;

The base station sends the first TCP ACK to the server.
The method according to claim 1, further comprising:

Receiving, by the base station, a first TCP packet sent by a server, and determining an identifier of the first TCP packet;

Processing, by the base station, the first TCP message according to a wireless link layer control RLC protocol and a MAC protocol to obtain at least one MAC PDU, and establishing an identifier of the first TCP message and an identifier of the at least one MAC PDU Mapping relations;

Sending, by the base station, the at least one MAC PDU to the user equipment according to a HARQ feedback mechanism of the hybrid automatic repeat request;

Determining, by the base station, whether all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment according to the MAC PDUs that have been correctly received on the user equipment and the mapping relationship;

When it is determined that all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, the base station determines that the first TCP packet is correctly received by the user equipment.
The method according to claim 2, wherein the identifier of the TCP packet includes one or more of TCP quintuple information.
The method according to claim 2 or 3, wherein when it is determined that all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, the base station determines the first TCP packet The text was correctly received by the user equipment, including:

When it is determined that all the MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, the base station updates a local record to identify the TCP packet currently received by the user equipment and identifies the first TCP packet as the first TCP packet identifier.
The method according to any one of claims 1-4, wherein the uplink resource limitation of the user equipment includes one or more of the following:

The base station recognizes that the uplink scheduling is not allocated to the user equipment in a timely manner due to limited physical downlink control channel PDCCH resources;

The base station recognizes that the uplink scheduling is not allocated to the user equipment in a timely manner due to the limited physical uplink shared channel PUSCH resource.
The method according to any one of claims 1-5, wherein TCPACK includes a TCP acknowledgement packet ACK; the first TCPACK includes a first sequence number, and the first TCP status is used to indicate that the TCP packets before the first sequence number are correctly received by the user equipment; the method further includes:

Receiving, by the base station, a second TCP ACK sent by the user equipment, where the second TCP ACK includes a second sequence number, and the second TCP ACK is used to indicate that a TCP packet before the second sequence number is received by the User equipment receives it correctly;

When the second sequence number is not greater than the first sequence number, the base station deletes the second TCP ACK.
The method according to claim 6, further comprising:

The base station receives the TCP repeated DUP ACK sent by the user equipment; the CP DUP ACK includes a third sequence number, and when the third sequence number is not greater than the first sequence number, the base station And transmitting a TCP packet corresponding to the TCP DUP ACK.
The method according to claim 7, further comprising:

When the base station receives a TCP packet sent by a server, the base station buffers locally;

After the base station receives the second TCP ACK sent by the user equipment, the base station deletes the local buffer of the TCP packet that is correctly received by the user equipment and indicated by the second TCP ACK.
A base station, characterized in that the base station includes:

A first determining unit, configured to determine that the first TCP message is correctly received by the user equipment when all the media access control MAC protocol data unit PDUs corresponding to the first transmission control protocol TCP message are received by the user equipment correctly ;

A generating unit, configured to generate a first TCP ACK of the first TCP packet according to the first TCP packet correctly received by the user equipment when uplink resources of the user equipment are limited, and the first TCP ACK is used to indicate that the first TCP packet is correctly received by the user equipment;

A first transceiver unit, configured to send the first TCP ACK to a server.
The base station according to claim 9, wherein the base station includes an RLC and MAC processing unit and a PDCP processing unit; wherein the RLC and MAC processing unit includes the first determining unit, and the PDCP processing unit includes the Generation unit:

The first transceiver unit is configured to receive a first TCP packet sent by a server;

The PDCP processing unit further includes a second determining unit, configured to determine an identifier of the first TCP packet;

The RLC and MAC processing unit further includes a processing and establishment unit, configured to process the first TCP packet according to a radio link layer control RLC protocol and the MAC protocol to obtain at least one MAC PDU, and establish the first TCP packet. A mapping relationship between an identifier and an identifier of the at least one MAC PDU;

The base station further includes a second transceiver unit, configured to send the at least one MAC PDU to the user equipment according to a hybrid automatic repeat request HARQ feedback mechanism;

The first determining unit is specifically configured to determine whether all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment according to the MAC PDUs that have been correctly received on the user equipment and the mapping relationship; when When it is determined that all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, it is determined that the first TCP packet is correctly received by the user equipment.
The base station according to claim 10, wherein the identifier of the TCP message includes one or more of TCP quintuple information.
The base station according to claim 10 or 11, wherein the first determining unit is further configured to: when it is determined that all MAC PDUs corresponding to the first TCP packet are correctly received by the user equipment, update the local The identifier of the recorded TCP packet currently confirmed to be received by the user equipment is the identifier of the first TCP packet.
The base station according to any one of claims 9-12, wherein the uplink resource limitation of the user equipment includes one or more of the following:

It is identified that the uplink scheduling is not allocated to the user equipment in a timely manner due to limited physical downlink control channel PDCCH resources;

It is identified that the uplink scheduling is not allocated to the user equipment in a timely manner due to limited physical uplink shared channel PUSCH resources.
The base station according to any one of claims 9-13, wherein the TCPACK includes a TCP acknowledgement packet ACK; the first TCPACK includes a first sequence number, and the first TCP status is used to indicate that the The TCP packet before the first sequence number is correctly received by the user equipment;

The second transceiver unit is configured to receive a second TCP ACK sent by the user equipment, where the second TCP ACK includes a second sequence number, and the second TCP ACK is used to indicate a number before the second sequence number. The TCP packet is correctly received by the user equipment;

A deleting unit, configured to delete the second TCP ACK when the second sequence number is not greater than the first sequence number.
The base station according to claim 14, wherein the second transceiver unit is further configured to receive a TCP repeated DUP ACK sent by the user equipment, the CP DUP ACK includes a third sequence number; the PDCP processing The unit further includes a retransmission unit, configured to retransmit a TCP message corresponding to the TCP DUPACK according to a local buffer when the third sequence number is not greater than the first sequence number.
The base station according to claim 15, wherein:

The PDCP processing unit further includes a buffering unit, configured to buffer locally when receiving a TCP packet sent by the server; after receiving a second TCP ACK sent by the user equipment, the user instructed by the second TCP ACK The local cache of TCP packets received by the device is deleted.
A base station includes a transceiver, a communication module, a processor, and a memory, where the memory is used to store programs; the transceiver is used to interact with user equipment; and the communication module is used to interact with a server. The processor is configured to execute the program stored in the memory to control the base station to execute the method according to any one of claims 1-8.
A computer-readable storage medium includes computer-readable instructions, and when a computer reads and executes the computer-readable instructions, causes a computer to execute the method according to any one of claims 1-8.
A chip is characterized in that it includes a processor and a memory; the memory is used to store a program; the processor is used to execute the program stored in the memory to perform the method according to any one of claims 1-8 .