CN115119259A

CN115119259A - Congestion control method and device

Info

Publication number: CN115119259A
Application number: CN202110286524.1A
Authority: CN
Inventors: 姜金涛; 柳剑飞; 李莹
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-03-17
Filing date: 2021-03-17
Publication date: 2022-09-27

Abstract

The application provides a congestion control method and a congestion control device, wherein the congestion control method comprises the following steps: the STA receives a congestion control instruction from the AP, wherein the congestion control instruction is used for instructing the STA to carry out congestion control; based on the congestion control instruction, the STA discards at least one data packet in a buffer queue of the MAC layer; and the STA adjusts the size of the TCP sending window under the condition that the at least one data packet is detected not to be received, so that the byte number of the data sent to the AP through the TCP sending window is reduced. Because the AP informs the STA to carry out congestion control when detecting network congestion, the data transmission quantity can be controlled in time, and the AP does not need to wait until the queue at the STA side overflows to carry out congestion control. In addition, the size of the TCP sending window is adjusted in time, so that the data transmission quantity is reduced, the congestion can be relieved in a short time, and the system can be prevented from being trapped in resource deadlock.

Description

Congestion control method and device

Technical Field

The present application relates to the field of communications, and in particular, to a congestion control method and apparatus.

Background

Currently, wireless fidelity (WiFi) has become a standard interface for home terminal equipment. As more and more terminal devices are connected to WiFi, the data transmission amount of WiFi is gradually increased. For an Access Point (AP), if the transmission rate of an air interface is greater than the transmission rate of a Passive Optical Network (PON) port, a data packet that is sent may be temporarily stored in a cache queue of the AP in time. However, the network has limited resources, and as the queue depth of the buffer queue increases, the uplink transmission path between a Station (STA) and the AP is congested. Congestion has a major hazard to the network. For example, transmission delays may be increased, causing retransmissions and, in turn, the system to crash in a resource deadlock.

It is therefore desirable to provide a method that can control congestion in a timely manner, and avoid resource deadlocks as much as possible.

Disclosure of Invention

The application provides a congestion control method and a congestion control device, which are used for controlling congestion in time and avoiding a system from being trapped in resource deadlock.

In a first aspect, the present application provides a congestion control method, which may be executed by an STA, or may be executed by a component configured in the STA, such as a chip, a chip system, or another functional module capable of invoking a program and executing the program, and the present application is not limited thereto.

Illustratively, the method comprises: the STA receives a congestion control instruction from the AP, wherein the congestion control instruction is used for instructing the STA to carry out congestion control; based on the congestion control instruction, the STA discards at least one data packet in a buffer queue of a Medium Access Control (MAC) layer; when detecting that the at least one data packet is not received, the STA adjusts a size of a Transmission Control Protocol (TCP) transmission window so that a number of bytes of data transmitted to the AP through the TCP transmission window is reduced.

When the AP detects the network congestion, the AP informs the STA of carrying out congestion control. And the STA discards at least one data packet based on the congestion control instruction sent by the AP, and the packet loss can trigger the STA to adjust the size of the TCP sending window and reduce the number of bytes of data transmitted to the AP by the STA. Therefore, the data transmission amount can be controlled from the STA as the transmitting end in time, and congestion control is not required to be performed until the STA side queue overflows. In addition, the size of the TCP sending window is adjusted in time, so that the data transmission quantity is reduced, the congestion can be relieved in a short time, and the system can be prevented from being trapped in resource deadlock.

With reference to the first aspect, in some possible implementations of the first aspect, the at least one data packet includes one data packet in a buffer queue.

In view of the problem that dropping a plurality of packets may cause excessive throughput reduction, the above-mentioned dropping at least one packet in the buffer queue of the MAC layer may specifically be to drop one of the packets, where the packet may be a head-of-queue packet, a tail-of-queue packet, or any one of the packets.

Further, the one data packet is a first data packet in the buffer queue.

In order to enable the TCP layer to detect packet loss as soon as possible and further trigger the adjustment of the TCP sending window, the STA may discard the first data packet in the cache alignment, so as to shorten the congestion control time to a greater extent. And only the first data packet is discarded, and the throughput can be reduced to the greatest extent.

With reference to the first aspect, in some possible implementations of the first aspect, the receiving, by the STA, a congestion control instruction from an AP includes: the STA receives a Block Acknowledgement (BA) frame from the AP, the BA frame carrying the congestion control instruction.

Optionally, the congestion control instruction is carried in a reserved field (or reserved bits) or an added field (or added bits) in a BA control field in the BA frame.

With reference to the first aspect, in some possible implementations of the first aspect, before the STA receives the congestion control instruction from the AP, the method further includes: the STA sends first cache information to the AP, wherein the first cache information is used for indicating the queue depth in the STA, and the queue depth is used for indicating the number of data packets to be sent in a cache queue of the MAC layer.

With reference to the first aspect, in some possible implementation manners of the first aspect, the sending, by the STA, the first cache information to the AP specifically includes: the STA sends a data frame to the AP, wherein a quality of service (QoS) control field in the data frame carries the first cache information.

With reference to the first aspect, in some possible implementations of the first aspect, before the STA receives the congestion control instruction from the AP, the method further includes: the STA receives first indication information from the AP, wherein the first indication information is used for indicating that the AP has congestion control capability, and the AP with the congestion control capability can determine whether the STA is required to perform congestion control and can send the congestion control instruction to the STA; and the STA sends second indication information to the AP, wherein the second indication information is used for indicating that the STA has the congestion control capability, and the STA with the congestion control capability can identify the congestion control instruction and can perform congestion control based on the congestion control instruction.

It should be understood that by performing differentiated management on the situations with and without congestion control capability, the computational overhead can be reduced, and at the same time, by interactively confirming that the STA and the AP have congestion control capability, the AP can avoid the waste of transmission resources caused by notifying the STA of congestion control in the case that the AP or the STA does not have congestion control capability.

One possible implementation is that the AP may actively transmit the first indication information to the STA through the beacon frame, and the STA may thereafter transmit the second indication information to the AP through the association request frame. Alternatively, the STA may transmit the second indication information to the AP in a case where the AP has the congestion control capability.

Another possible implementation manner is that the STA actively sends the second indication information to the AP through the association request frame, and the AP may then send the first indication information to the STA through the association response frame. Alternatively, the AP may send the first indication information to the STA if the STA is capable of congestion control.

Optionally, the receiving, by the STA, first indication information from the AP includes: the STA receives a beacon (beacon) frame from the AP, wherein the beacon frame comprises the first indication information.

Further, the first indication information is carried in a reserved field or an added field in the beacon frame, and may specifically be in a reserved field (or reserved bits) or an added field (or added bits) in a capability information (capability information) field in the beacon frame.

Optionally, the receiving, by the STA, first indication information from the AP includes: the STA receives an association response (association response) frame from the AP, wherein the association response frame comprises the first indication information.

Further, the first indication information is carried in a reserved field or a newly added field in the association response frame, and may specifically be in a reserved field (or reserved bits) or a newly added field (or newly added bits) in a performance information field in the association response frame.

Optionally, the STA sends second indication information to the AP, including: the STA sends an association request (association request) frame to the AP, where the association request frame includes the second indication information.

Further, the second indication information is carried in a reserved field or an added field in the association request frame, and may specifically be a reserved field (or reserved bits) or an added field (or added bits) in the performance information field.

In a second aspect, the present application provides a congestion control method, which may be performed by an AP, or may be performed by a component configured in the AP, such as a chip, a system-on-chip, or another functional module capable of calling and executing a program, and the present application is not limited thereto.

Illustratively, the method comprises: the AP determines that the uplink transmission path between the AP and the STA is congested; and the AP sends a congestion control instruction to the STA, wherein the congestion control instruction is used for indicating the STA to carry out congestion control.

The congestion of an uplink transmission path between the STA and the AP is determined by the AP, and the congestion control instruction is sent to the STA, so that the STA is instructed to carry out congestion control, namely the STA discards at least one data packet, and the packet loss can trigger the STA to adjust the size of a TCP (transmission control protocol) sending window, so that the number of bytes of data transmitted to the AP by the STA is reduced. Therefore, the data transmission amount can be controlled from the STA as the transmitting end in time, and congestion control is not required to be performed until the STA side queue overflows. In addition, the size of the TCP sending window is adjusted in time, so that the data transmission quantity is reduced, the congestion can be relieved in a short time, and the system can be prevented from being trapped in resource deadlock.

With reference to the second aspect, in some possible implementations of the second aspect, the sending, by the AP, a congestion control instruction to the station STA includes: and the AP sends a Block Acknowledgement (BA) frame to the STA, wherein the BA frame carries the congestion control instruction.

With reference to the second aspect, in some possible implementations of the second aspect, the congestion control instruction is carried in a reserved field (or reserved bits) or an added field (or added bits) in a BA control field in the BA frame.

With reference to the second aspect, in some possible implementations of the second aspect, the determining, by the AP, that an uplink transmission path between the AP and the STA is congested includes: the AP calculates network time delay according to first cache information, second cache information and an uplink forwarding rate of the AP, wherein the first cache information is used for indicating the queue depth in the STA, the second cache information is used for indicating the queue depth in the AP, and the queue depth is used for indicating the number of data packets to be sent in a cache queue; and the AP determines that congestion exists in an uplink transmission path between the AP and the STA under the condition that the network delay is greater than a preset threshold.

It should be appreciated that the congestion status may be evaluated by the AP as to whether there is congestion in the uplink transmission between the STA and the AP, thereby informing the STA to perform congestion control if it is determined that congestion exists. The network time delay is calculated according to the cache information at the two sides of the AP and the STA, and whether the congestion exists or not is judged without depending on whether the cache queue overflows or not, so that the congestion can be detected before the cache queue overflows, and the STA is timely informed to carry out congestion control.

With reference to the second aspect, in some possible implementations of the second aspect, the AP receives the first buffering information from the STA.

With reference to the second aspect, in some possible implementation manners of the second aspect, the receiving, by the AP, the first cache information from the STA specifically includes: and the AP receives a data frame from the STA, wherein the QoS control field in the data frame carries the first cache information.

With reference to the second aspect, in some possible implementations of the second aspect, before the AP determines that congestion exists in an uplink transmission path between the AP and the STA, the method further includes: the AP sends first indication information to the STA, wherein the first indication information is used for indicating that the AP has congestion control capability, and the AP with the congestion control capability can determine that congestion exists in an uplink transmission path between the AP and the STA and can send the congestion control instruction to the STA; and the AP receives second indication information from the STA, wherein the second indication information is used for indicating that the STA has the congestion control capability, and the STA with the congestion control capability can identify the congestion control instruction and can perform congestion control based on the congestion control instruction.

With reference to the second aspect, in some possible implementations of the second aspect, the sending, by the AP, first indication information to the STA includes: and the AP sends a beacon frame to the STA, wherein the beacon frame comprises the first indication information.

With reference to the second aspect, in some possible implementations of the second aspect, the first indication information is carried in a reserved field (or reserved bits) or an added field (or added bits) in a performance information field in the beacon frame.

With reference to the second aspect, in some possible implementations of the second aspect, the sending, by the AP, first indication information to the STA includes: and the AP sends an association response frame to the STA, wherein the association response frame comprises the first indication information.

With reference to the second aspect, in some possible implementations of the second aspect, the first indication information is carried in a reserved field (or reserved bits) or an added field (or added bits) in a performance information field in the association response frame.

With reference to the second aspect, in some possible implementations of the second aspect, the receiving, by the AP, second indication information from the STA includes: and the AP receives an association request frame from the STA, wherein the association request frame comprises the second indication information.

With reference to the second aspect, in some possible implementations of the second aspect, the second indication information is carried in a reserved field (or reserved bits) or an added field (or added bits) in a performance information field in the association request frame.

In a third aspect, a congestion control device is provided, which includes means or modules for implementing the methods in any one of the possible implementations of the first and second aspects and the first and second aspects. It should be understood that the respective modules or units may implement the respective functions by executing the computer program.

In a fourth aspect, there is provided a congestion control apparatus comprising: a memory and a processor. The memory may be used to store a computer program; the processor may be configured to invoke a computer program in the memory to cause the computing device to perform the method of any one of the possible implementations of the first and second aspects and the first and second aspects described above. Optionally, the computing device further comprises a communication interface coupled to the processor for inputting and/or outputting information, such as congestion control instructions sent by the AP to the STA.

Optionally, the number of the processors is one or more, and the number of the memories is one or more.

Alternatively, the memory may be integral to the processor or provided separately from the processor.

In a fifth aspect, there is provided a computer program product comprising: a computer program (which may also be referred to as code, or instructions), which when executed, causes a computer to perform the method of any one of the possible implementations of the first and second aspects and the first and second aspects described above.

In a sixth aspect, a computer-readable storage medium is provided that stores a computer program (also can be referred to as code, or instructions). The computer program, when executed, causes a computer to perform the method of any one of the possible implementations of the first and second aspects and the first and second aspects described above.

Drawings

Fig. 1 is a schematic diagram of a communication system suitable for a congestion control method provided in an embodiment of the present application;

fig. 2 is a schematic diagram of a network protocol stack for uplink transmission between a STA and an AP according to an embodiment of the present disclosure;

fig. 3 is a schematic flow chart of a congestion control method provided in an embodiment of the present application;

fig. 4 is a schematic diagram of a BA control field structure provided in the embodiment of the present application;

fig. 5 is a schematic diagram of a structure of a performance information field according to an embodiment of the present application;

fig. 6 is a schematic block diagram of a congestion control apparatus provided in an embodiment of the present application;

fig. 7 is another schematic block diagram of a congestion control device according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical scheme provided by the application can be applied to the fields of vehicle monitoring, remote control, remote measurement, small wireless networks, wireless meter reading, access control systems, cell paging, industrial data acquisition systems, wireless tags, identity recognition, non-contact RF smart cards, small wireless data terminals, safety fire prevention systems, wireless remote control systems, biological signal acquisition, hydrological weather monitoring, robot control, wireless 232 data communication, wireless 485/422 data communication, digital audio, digital image transmission and the like.

The technical scheme provided by the application can be applied to various communication systems, such as: a global system for mobile communications (GSM) system, a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a General Packet Radio Service (GPRS), a long term evolution (long term evolution, LTE) system, a frequency division duplex (frequency division duplex, FDD) system, a LTE time division duplex (time division duplex, UMTS) system, a long term evolution (advanced long term evolution, WiMAX-a) system, a universal mobile telecommunications system (universal mobile telecommunications system, UMTS), a universal wireless access (wireless local area network, WLAN) system, a wireless local area network (WiFi) 4, a Wireless Local Area Network (WLAN) 4, a wireless local area network (WiFi), a Wireless Local Area Network (WLAN) system, a wireless local area network (WiFi), a Wireless Local Area Network (WLAN) system, a wireless local area network, a wireless local area network, a wireless ^th generation, 4G) mobile communication system, fifth generation (5) ^th generation, 5G) mobile communication systems and future higher-level communication systems or other communication systems, etc.

In the embodiment of the present application, the AP may also be referred to as a network device. The AP may be, for example, a Base Transceiver Station (BTS) in a GSM system or a CDMA system, a base station (node B, NB) in a WCDMA system, an evolved node B (eNB or eNodeB) in an LTE system, or a wireless controller in a Cloud Radio Access Network (CRAN), or the network device may be a mobile switching center, a relay station, an access point, a vehicle-mounted device, a wearable device, a hub, a switch, a bridge, a router, a network-side device in a 5G network, or a network device in a future evolved Public Land Mobile Network (PLMN), and the like.

In the embodiment of the present application, the STA may also be referred to as a wireless terminal, a mobile terminal, or a wireless communication terminal. The STA may be, for example, a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, or a wearable device, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and the like.

Fig. 1 is a schematic diagram of a communication system suitable for a congestion control method provided in an embodiment of the present application. The communication system shown in fig. 1 is an example of a PON system. As shown in fig. 1, the communication system 100 may include: an Optical Network Terminal (ONT) 110, an AP 120, and one or more STAs 131 through 133. The STA can be connected with the AP through a wireless network, and the AP can be connected with the ONT through an optical fiber. The data transmission from the STA to the AP and from the AP to the ONT is uplink transmission, and the data transmission from the ONT to the AP and from the AP to the STA is downlink transmission.

For example, the AP may be a gateway router of a home/enterprise in a WLAN or an intranet, and the STA may be a wireless network connectable device such as a mobile phone, a tablet, and a notebook, for example, the STA 131, the STA 132, and the STA 133 in fig. 1 are only possible examples, and the application is not limited thereto.

Although not shown in fig. 1, it is understood that the communication system shown in fig. 1 may also include other numbers of ONTs, APs and STAs. The embodiments of the present application do not limit this.

It should also be understood that fig. 1 is only an example of a communication system applicable to the congestion control method provided in the embodiment of the present application, and should not constitute any limitation on a scenario to which the present application is applicable.

In addition, for convenience of understanding, fig. 2 is a schematic diagram of a network protocol stack for uplink transmission between the STA and the AP according to the present application. As illustrated in fig. 2, the network protocol stack in the STA and the AP may include an application layer, a TCP layer, an Internet Protocol (IP) layer, a MAC layer, and a physical layer.

Take uplink transmission as an example. In the STA, data of an application layer reaches a TCP layer, and a TCP message can be obtained after the data is packaged by the TCP layer. The TCP message is then sent to the IP layer, encapsulated by the IP layer and sent to the MAC layer. The MAC layer may maintain a buffer queue for buffering packets received from the TCP layer. The MAC layer may send the encapsulated data packets to the buffer queue after encapsulating the data packets from the IP layer, and may sequentially send the data packets in the buffer queue to the physical layer. The physical layer processes the data packet and sends the processed data packet to the AP via a transmission medium (e.g., air interface resources). The processing procedure of the received data packet by the AP corresponds to the processing procedure of the data packet sent by the STA, and the data packet reaches an application layer after being processed by a physical layer, an MAC layer, an IP layer and a TCP layer in sequence. For brevity, no further description is provided herein.

It should be understood that the procedure for downlink transmission is similar to that for uplink transmission. For the sake of brevity, no further details are provided here.

It should also be understood that the network protocol stack shown in fig. 2 is merely illustrated for ease of understanding, and should not be construed as limiting the present application in any way. The protocol stacks in the STA and AP may also include other protocol layers, or one or more of the protocol layers shown in the figures may be replaced with other protocol layers that may be used to implement the same or similar functionality. The embodiments of the present application do not limit this.

In the embodiment of the present application, data transmission between the STA and the AP may be data transmission based on an Institute of Electrical and Electronics Engineers (IEEE) 802.11 series standard, but the data transmission between the STA and the AP is not limited to be implemented based on a future protocol or standard.

Fig. 3 is a schematic flow chart of a congestion control method 300 provided by the embodiment of the present application, which is shown from the perspective of device interaction. The AP in fig. 3 may be, for example, the AP 120 in the communication system 100 shown in fig. 1, and the STA in fig. 3 may be, for example, any one of the STAs 131 to 133 in the communication system 100 shown in fig. 1. It is to be understood that each STA of the STAs connected to the AP may be configured to perform the congestion control method 300 shown below, and the congestion control method 300 is described herein for ease of understanding only by taking data transmission between an AP and a STA as an example.

It should also be understood that the AP of the congestion control method 300 may also be replaced by a component in the AP, such as a chip, a system-on-chip, or other functional module capable of calling and executing a program; the STA may also be replaced with a component in the STA, such as a chip, a chip system, or another functional module capable of calling and executing a program, and the execution subject of each step in the embodiment of the present application is not limited.

The method 300 shown in fig. 3 may include steps 310 through 370. The steps in fig. 3 are described in detail below with reference to the drawings.

In step 310, the AP determines that there is congestion in the uplink transmission path between the STA and the AP.

In a possible implementation manner, the AP may determine whether there is congestion in an uplink transmission path between the STA and the AP according to the buffering information of the STA side and the buffering information of the AP side.

For convenience of distinction and explanation, the cache information of the STA side is recorded as first cache information, and the cache information of the AP side is recorded as second cache information. The first buffering information is used to indicate a queue depth in the STA. The second buffering information is used to indicate a queue depth in the AP. The queue depth may specifically be used to indicate the number of packets to be sent in the buffer queue.

In particular, the possible implementation described above may correspond to step 310. Wherein the step 310 may include a step 310a and a step 310 b.

In step 310a, the STA transmits the first buffering information to the AP.

Optionally, the first buffering information may be carried in a QoS control field in the data frame, and it should be understood that substantially most of the data frame contains the QoS control field, and thus the specific frame is not limited herein.

In step 310b, the AP calculates a network delay according to the first buffer information, the second buffer information, and the uplink forwarding rate of the AP.

One possible implementation method for the AP to determine that the uplink transmission path between the STA and the AP is congested is as follows: and judging whether network congestion exists according to the network delay. In this embodiment, the network delay may be obtained by dividing the sum of the first cache information and the second cache information by the uplink forwarding rate of the AP. In the case that the network delay is relatively high, for example, higher than a first preset threshold, the AP determines that there is congestion in an uplink transmission path between the STA and the AP.

It should be understood that the first preset threshold may be a threshold of network delay, and in the case that the calculated network delay is greater than the first preset threshold, the AP determines that there is congestion in the uplink transmission path between the STA and the AP. When the calculated network delay is less than or equal to the first preset threshold, it may be considered that there is no congestion in the uplink transmission path between the STA and the AP.

Another possible implementation method for the AP to determine that the uplink transmission path between the STA and the AP is congested is as follows: and judging whether network congestion exists according to the average queue length. For example, the AP may calculate an average queue length by using a random dropping algorithm (RED) and the like, and when the average queue length is greater than a certain set threshold (for example, recorded as a second preset threshold), the AP determines that there is congestion in an uplink transmission path between the STA and the AP.

It should be understood that the uplink forwarding rate of the AP may also be referred to as the AP-to-ONT forwarding rate.

It should also be understood that the method for determining that the uplink transmission path between the STA and the AP is congested by the AP is only a possible example given for ease of understanding, and any method that can be used to determine that the uplink transmission path between the STA and the AP is congested should fall within the scope of the present application. For example, when the uplink forwarding rate of the AP is greater than the transmission rate of the STA, the AP may also determine that there is congestion in the uplink transmission path between the AP and the STA, which is not limited in this application.

In the case that the AP determines that there is congestion in the uplink transmission path between the STA and the AP, step 320 may be executed to send a congestion control instruction to the STA, where the congestion control instruction may be used to instruct the STA to perform congestion control. Accordingly, the STA receives the congestion control command from the AP.

Optionally, the congestion control instruction may be carried in a BA control field in a BA frame sent by the AP to the STA. Fig. 4 shows an example of the structure of the BA control field. As can be seen, the BA control field includes: a BA policy (policy) field, a multi-traffic identifier (multi-TID) field, a compressed bitmap field, a multicast retransmission (GCR) field, a reserved field, and a traffic identification information (TID _ information) field. The BA control field occupies 16 bits in total, and the corresponding bits of each field are shown in the figure. Wherein the BA strategy field is 0 bit, the multi-TID field is 1 bit, the compressed bitmap field is 2 bits, the GCR field is 3 bits, and each of the fields occupies 1 bit, the reserved field occupies 8 bits for 4 to 11 bits, and the TID _ INFO occupies 4 bits for 12 to 15 bits.

Specifically, the congestion control instruction may be marked in a reserved field or a newly added field in a BA control field in the BA frame. The added field may be, for example, a field added in a future protocol, and the like, which is not limited in this application.

For example, in a reserved field or a newly added field in the BA control field, 1 may be used to indicate congestion control for the STA, 0 may be used to indicate that congestion control is not performed for the STA, and the like. It should be understood that, for convenience of understanding only, a possible case of marking whether to perform congestion control on the STA in the reserved field or the added field in the BA control field in the BA frame is shown, and this should not constitute any limitation to the present application.

In this embodiment of the application, the STA may execute a packet loss operation based on the congestion control instruction, and further trigger adjustment of the TCP sending window.

Optionally, before performing step 320, the method further includes step 370, the AP calculates a packet loss probability. If the packet loss probability is greater than the third preset threshold, step 320 is executed, and the AP sends a congestion control instruction to the STA.

It should be understood that, unlike the first preset threshold, the third preset threshold is a threshold value of the packet loss probability. The threshold value may be predefined, as defined by the protocol.

The packet loss probability may be used to indicate how likely the data packet transmitted by the STA next time will be dropped, and may also be used to determine whether the STA needs to perform a packet loss operation.

Specifically, the AP may calculate a packet loss probability according to the network delay and a first preset threshold, and when the packet loss probability is higher, for example, greater than a third preset threshold, the AP may determine that the STA needs to perform a packet loss operation and then may send a congestion control instruction to the STA.

In step 330, the STA discards at least one packet in a buffer queue of the MAC layer.

Specifically, the MAC layer in the STA may discard at least one packet in the buffer queue according to the congestion control instruction.

It should be understood that the buffer queue of the MAC layer may be used to buffer a plurality of data packets to be transmitted from the TCP layer, for example, the data packets that are currently received from the TCP layer and need to be transmitted may also include data packets that are previously received from the TCP layer and have not yet been transmitted, and the like, which is not limited in this application.

In view of the problem that dropping a plurality of packets causes an excessive decrease in throughput, only one packet may be dropped in practical implementation. Optionally, step 330 specifically includes: the STA discards one data packet in a buffer queue of the MAC layer.

In the embodiment of the present application, the STA discards a packet in a buffer queue of the MAC layer, which can be understood as follows: the STA may send other packets not discarded in the buffer queue to the physical layer, and then the packets are sent out by the physical layer through the air interface resource; the dropped packets are not sent to the physical layer, i.e., are not sent out. In other words, the AP on the receiving side cannot receive the packet discarded by the STA.

It should be noted that, in the STA, the packet loss operation occurring at the MAC layer is not reported to the upper layer, i.e., the TCP layer. The TCP layer does not perceive the packet loss operation of the MAC. However, the TCP layer may determine whether a packet transmitted through the TCP transmission window is received according to an Acknowledgement (ACK) message fed back by the AP.

In step 340, the STA adjusts the size of the TCP transmission window in case it detects that at least one dropped packet in the buffer queue is not received.

It should be understood that the TCP layer in the STA may consider that a packet loss occurs in the case of detecting that a packet transmitted through the TCP transmission window is not received. Therefore, the STA detecting that the transmitted data packet is not completely received may also indicate that the STA detects the packet loss.

One possible implementation of the TCP layer in the STA detecting whether a packet sent through the TCP send window is received is: the TCP layer may determine whether a packet transmitted through the TCP transmission window is received according to the ACK message fed back by the AP. Specifically, after the TCP layer in the STA transmits a packet through the TCP transmission window, if an ACK message fed back from the AP is not received within a predetermined time, it may be considered that the packet is not received. Or after the TCP layer sends a packet, if the received ACK message fed back by the AP lacks a sequence number marking a certain packet, the packet may be considered as not received. The examples given herein are for ease of understanding only and should not be construed as limiting the present application in any way.

The TCP layer in the STA may adjust the size of the TCP send window when packet loss is detected, so that the number of bytes of data sent through the TCP send window is reduced. One possible implementation is that the TCP layer halves the TCP send window so that the number of bytes of data sent through the TCP send window is halved. If the congestion level after halving the TCP sending window does not reach the expected target, for example, the network delay calculated in the manner described above is still greater than the first preset threshold, or the average queue length calculated in the manner described above is still greater than the second preset threshold, the above steps 320 to 340 may be repeatedly performed until the congestion level reaches the expected target after adjusting the TCP window length based on the TCP layer.

In order to enable the TCP layer to detect packet loss as soon as possible and further trigger adjustment of the TCP sending window, the STA may discard the first data packet in the buffer alignment, thereby shortening the congestion control time to a certain extent. Optionally, the step 330 of the STA dropping a data packet in the buffer queue of the MAC layer specifically includes: the STA discards the first packet in the buffer queue of the MAC layer.

It should be understood that the specific implementation manner of the TCP layer adjusting the TCP sending window size is not limited to the manner provided above, and may also depend on other algorithms or protocols, which is not limited in this application.

It should also be understood that the manner in which the TCP layer is triggered to adjust the TCP send window is not limited to packet loss here. For example, in the case of protocol support, the size of the TCP send window may also be triggered by the MAC layer sending an instruction to the TCP layer. Embodiments of the present application include, but are not limited to, the foregoing. Any manner capable of triggering the TCP layer to adjust the TCP send window size should fall within the scope of the present application.

Further, considering that the capabilities of both the STA and the AP are different, the AP and the STA may also notify each other whether or not they support congestion control before performing the above steps.

Optionally, the method further comprises: step 350, the AP sends first indication information to the STA, where the first indication information is used to indicate that the AP has a congestion control capability; and step 360, the STA sends second indication information to the AP, where the second indication information is used to indicate that the STA has the congestion control capability.

Specifically, the AP having the congestion control capability means a capability of determining that congestion exists in an uplink transmission path between the AP and the STA and transmitting a congestion control command to the STA.

Specifically, the STA having the congestion control capability is a capability of recognizing a congestion control command transmitted by the AP and performing congestion control based on the congestion control command.

Optionally, in step 350, the first indication information sent by the AP to the STA may be carried in a beacon frame periodically sent by the AP.

Specifically, the first indication information may be marked in a performance information field in a beacon frame transmitted by the AP, for example, a reserved field (or a reserved bit) or an added field (or an added bit) in the performance information field.

Fig. 5 is a schematic diagram of the capability information field in the 802.11 standard. The length of the performance information field is 2 bytes, and the performance information field comprises: an Extended Service Set (ESS) field, an Independent Basic Service Set (IBSS) field, a contention free-Poll (CF-Poll) field, a contention free-Poll request (CF-Poll) field, an encryption (privacy) field, a short synchronization signal (short preamble) field, a reserved field, a spectrum management field, QoS, a short slot (short preamble) field, an automatic power saving (autosave) field, an APSD field, a radio measurement module (radio measurement) field, a reserved field, a delayed block acknowledgement (delayed block ACK) field, and an immediate block acknowledgement (immediate block ACK) field.

Optionally, in step 350, the first indication information sent by the AP to the STA may be carried in an association response frame replied to the STA by the AP.

Specifically, the first indication information may be carried in a reserved field or an added field in a performance information field in an association response frame replied to the STA by the AP.

Optionally, in step 360, the second indication information sent by the STA to the AP may be carried in an association request frame sent by the STA to the AP.

Specifically, the second indication information may be carried in a reserved field or an added field in a performance information field in an association request frame sent to the AP when the STA accesses the AP.

It should be understood that the present application is not limited to the execution sequence of the above steps 350 and 360. Step 350 may be performed before step 360 or after step 360.

In one possible implementation, the AP may mark the first indication information in a beacon frame that is periodically transmitted to the STA. When the STA accesses the AP, under the condition that the STA determines that the AP has the congestion control capability through the beacon frame, the STA sends an association response frame to the AP and marks second indication information in the association response frame. Thereby completing the process of STA and AP interactive confirmation that each other has the congestion control capability.

In another possible implementation, when the STA accesses the AP, the STA sends an association request frame to the AP and marks the second indication information therein. After receiving the association request frame sent by the STA, the AP marks first indication information in an association response frame in reply to the association request frame. Therefore, the process that the STA and the AP interactively confirm that the STA and the AP have the congestion control capability is completed, the waste of transmission resources caused by the fact that the AP or the STA does not have the congestion control capability can be further avoided, and meanwhile, the calculation overhead can be reduced by distinguishing and managing the conditions of having the congestion control capability and not having the congestion control capability.

Based on the technical scheme, when the AP detects network congestion, the AP informs the STA to carry out congestion control. And the STA discards at least one data packet based on the congestion control instruction sent by the AP, and the packet loss can trigger the STA to adjust the size of the TCP sending window and reduce the number of bytes of data transmitted to the AP by the STA. Therefore, the data transmission amount can be controlled from the STA as the transmitting end in time, and congestion control is not required to be performed until the STA side queue overflows. In addition, the size of the TCP sending window is adjusted in time, so that the data transmission quantity is reduced, the congestion can be relieved in a short time, and the system can be prevented from being trapped in resource deadlock. In addition, the AP can determine whether congestion exists according to the cache information of the AP and the STA, and can determine the congestion before the queue overflows and notify the STA to perform congestion control. Therefore, the congestion control is faster, and the influence on data transmission (such as packet loss, time delay and the like) is smaller.

Moreover, the STA discards the first data packet in the buffer queue, which can facilitate the TCP layer to quickly detect the packet loss, thereby quickly triggering the adjustment of the size of the TCP sending window, and making congestion control more timely.

It should be understood that, in the embodiments provided in the present application, the method provided in the embodiments of the present application is introduced from the perspective of interaction between the AP and the STA. In order to implement the functions in the method provided by the embodiments of the present application, the AP and the STA may include a hardware structure and/or a software module, and implement the functions in the form of a hardware structure, a software module, or a hardware structure and a software module. Whether any of the above-described functions is implemented as a hardware structure, a software module, or a hardware structure plus a software module depends upon the particular application and design constraints imposed on the technical solution.

Fig. 6 is a schematic block diagram of a congestion control apparatus 600 according to an embodiment of the present application. As shown in fig. 6, the apparatus may include: a processing module 610 and a communication module 620.

In one possible design, the congestion control device 600 may correspond to the STA in the above method embodiment, and may be, for example, an STA, or a component configured in the STA, such as a chip, a chip system, or the like.

The communication module 620 may be configured to receive a congestion control instruction from an AP, where the congestion control instruction is used to instruct the STA to perform congestion control; the processing module 610 may be configured to drop at least one data packet in a buffer queue of a medium access control MAC layer based on the congestion control instruction; and in the case that it is detected that the at least one data packet is not received, adjusting a size of a Transmission Control Protocol (TCP) transmission window so that a number of bytes of data transmitted to the AP through the TCP transmission window is reduced.

Optionally, the at least one data packet includes a first data packet in the buffer queue.

Optionally, the communication module 620 may be further configured to receive a block acknowledgement BA frame from the AP, where the BA frame carries the congestion control instruction.

Optionally, the communication module 620 may be further configured to send first buffer information to the AP, where the first buffer information is used to indicate a queue depth in the STA, and the queue depth is used to indicate a number of data packets to be sent in a buffer queue of the MAC layer.

Optionally, the communication module 620 may be further configured to receive first indication information from the AP, where the first indication information is used to indicate that the AP has a congestion control capability, and the AP having the congestion control capability may determine whether the STA is required to perform congestion control, and may send the congestion control instruction to the STA; and sending second indication information to the AP, wherein the second indication information is used for indicating that the STA has the congestion control capability, and the STA with the congestion control capability can identify the congestion control command and can perform congestion control based on the congestion control command.

Optionally, the communication module 620 may be further configured to receive a beacon frame from the AP, where the beacon frame includes the first indication information.

Optionally, the communication module 620 may be further configured to receive an association response frame from the AP, where the association response frame includes the first indication information.

Optionally, the communication module 620 may be further configured to send an association request frame to the AP, where the association request frame includes the second indication information.

In another possible design, the congestion control device 600 may correspond to the AP in the above method embodiment, and may be, for example, an AP, or a component configured in the AP, such as a chip, a chip system, or the like.

The processing module 610 may be configured to determine that there is congestion in an uplink transmission path with the station STA; the communication module 620 may be configured to send a congestion control instruction to the STA, where the congestion control instruction is used to instruct the STA to perform congestion control.

Optionally, the communication module 620 may be further configured to send a block acknowledgement BA frame to the STA, where the BA frame carries the congestion control instruction.

Optionally, the processing module 610 may be further configured to calculate a network delay according to first buffer information, second buffer information, and an uplink forwarding rate of the AP, where the first buffer information is used to indicate a queue depth in the STA, the second buffer information is used to indicate a queue depth in the AP, and the queue depth is used to indicate a number of data packets to be sent in a buffer queue; and determining that congestion exists in an uplink transmission path between the STA and the network time delay under the condition that the network time delay is greater than a preset threshold.

Optionally, the communication module 620 may be further configured to receive the first buffering information from the STA.

Optionally, the communication module 620 may be further configured to receive a data frame from the STA, where a QoS control field in the data frame carries the first buffering information.

Optionally, the communication module 620 may be further configured to send first indication information to the STA, where the first indication information is used to indicate that the AP has a congestion control capability, and the AP having the congestion control capability can determine that an uplink transmission path with the STA is congested and can send the congestion control instruction to the STA; and receiving second indication information from the STA, wherein the second indication information is used for indicating that the STA has the congestion control capability, and the STA with the congestion control capability can identify the congestion control instruction and can perform congestion control based on the congestion control instruction.

Optionally, the communication module 620 may be further configured to send a beacon frame to the STA, where the beacon frame includes the first indication information.

Optionally, the communication module 620 may be further configured to send an association response frame to the STA, where the association response frame includes the first indication information.

Optionally, the communication module 620 may be further configured to receive an association request frame from the STA, where the association request frame includes the second indication information.

It should be understood that the congestion control device may include, but is not limited to, a plurality of modules or units listed above. The modules or units shown in fig. 6 are only shown for ease of understanding, and should not limit the embodiments of the present application in any way.

It should also be understood that the division of the modules in the embodiments of the present application is illustrative, and is only one logical functional division, and in actual implementation, there may be another division manner, and in addition, each functional module in each embodiment of the present application may be integrated in one processor, or may exist alone physically, or two or more modules are integrated in one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode.

Fig. 7 is another schematic block diagram of a congestion control apparatus 700 according to an embodiment of the present application. As shown in fig. 7, the congestion control apparatus 700 may include: a processor 710, a communication interface 720, and a memory 730. The processor 710, the communication interface 720 and the memory 730 are in communication with each other through an internal connection path, the memory 730 is used for storing instructions, and the processor 710 is used for executing the instructions stored in the memory 730 to control the communication interface 720 to transmit and/or receive signals.

It should be understood that the congestion control device 700 is configured to perform the steps and/or processes of the above-described method embodiments.

Alternatively, the memory 730 may include both read-only memory and random access memory and provides instructions and data to the processor. The portion of memory may also include non-volatile random access memory. Memory 730 may be a separate device or may be integrated into processor 710. The processor 710 may be configured to execute instructions stored in the memory 730, and when the processor 710 executes instructions stored in the memory, the processor 710 is configured to perform the various steps and/or processes of the above-described method embodiments.

Alternatively, the communication interface 720 may be a transceiver, an input/output interface, a circuit, or the like having a transmitting/receiving function. The communication interface 720 may be integrated with the processor 710 and the memory 730 on the same chip or on different chips. This is not a limitation of the present application.

The specific connection medium among the processor 710, the communication interface 720 and the memory 730 is not limited in the embodiments of the present application. In the embodiment of the present application, the processor 710, the communication interface 720 and the memory 730 are connected by a bus 740 in fig. 7, the bus is represented by a thick line in fig. 7, and the connection manner between other components is merely illustrative and not limited. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 7, but this is not intended to represent only one bus or type of bus.

In the embodiments of the present application, the processor may be a general-purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic blocks disclosed in the embodiments of the present application. A general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in a processor.

In the embodiment of the present application, the memory may be a nonvolatile memory, such as a Hard Disk Drive (HDD) or a solid-state drive (SSD), and may also be a volatile memory, for example, a random-access memory (RAM). The memory is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such. The memory in the embodiments of the present application may also be circuitry or any other device capable of performing a storage function for storing program instructions and/or data.

The present application also provides a computer-readable storage medium having stored thereon a computer program (also referred to as code, or instructions). Which when executed, causes a computer to perform the method of the embodiment shown in fig. 3.

The present application further provides a computer program product comprising: a computer program (also referred to as code, or instructions), which when executed, causes a computer to perform the method of the embodiment shown in fig. 3.

The technical solutions provided in the embodiments of the present application may be wholly or partially implemented by software, hardware, firmware, or any combination thereof. When implemented in software, 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 loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, a network appliance, a terminal device or other programmable apparatus. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that includes one or more available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., Digital Video Disk (DVD)), or a semiconductor medium, among others.

In the embodiments of the present application, the embodiments may refer to each other, for example, methods and/or terms between the embodiments of the method may refer to each other, for example, functions and/or terms between the embodiments of the apparatus and the embodiments of the method may refer to each other, without logical contradiction.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method of congestion control, the method comprising:

a station STA receives a congestion control instruction from an access point AP, wherein the congestion control instruction is used for indicating the STA to carry out congestion control;

the STA discards at least one data packet in a buffer queue of a Medium Access Control (MAC) layer based on the congestion control instruction;

and the STA adjusts the size of a Transmission Control Protocol (TCP) transmission window under the condition that the at least one data packet is detected not to be received, so that the byte number of data transmitted to the AP through the TCP transmission window is reduced.

2. The method of claim 1, wherein the at least one packet comprises a first packet in the buffer queue.

3. The method of claim 1 or 2, wherein the STA receives congestion control instructions from the AP, comprising:

and the STA receives a Block Acknowledgement (BA) frame from the AP, wherein the BA frame carries the congestion control instruction.

4. The method of any of claims 1-3, wherein prior to the STA receiving congestion control instructions from an AP, the method further comprises:

the STA sends first cache information to the AP, wherein the first cache information is used for indicating the queue depth in the STA, and the queue depth is used for indicating the number of data packets to be sent in a cache queue of the MAC layer.

5. The method of claim 4, wherein the STA sends first buffering information to the AP, comprising:

and the STA sends a data frame to the AP, wherein the first cache information is carried in a QoS (quality of service) control field in the data frame.

6. The method of any of claims 1-5, wherein prior to the STA receiving congestion control instructions from an AP, the method further comprises:

the STA receives first indication information from the AP, wherein the first indication information is used for indicating that the AP has congestion control capability, and the AP with the congestion control capability can determine whether the STA is required to perform congestion control and can send the congestion control instruction to the STA;

and the STA sends second indication information to the AP, wherein the second indication information is used for indicating that the STA has the congestion control capability, and the STA with the congestion control capability can identify the congestion control instruction and can perform congestion control based on the congestion control instruction.

7. The method of claim 6, wherein the STA receives first indication information from the AP, comprising:

and the STA receives a beacon frame from the AP, wherein the beacon frame comprises the first indication information.

8. The method of claim 6, wherein the STA receives first indication information from the AP, comprising:

and the STA receives an association response frame from the AP, wherein the association response frame comprises the first indication information.

9. The method of claim 6, wherein the STA sends second indication information to the AP, comprising:

and the STA sends an association request frame to the AP, wherein the association request frame comprises the second indication information.

10. A method of congestion control, the method comprising:

the method comprises the steps that an Access Point (AP) determines that an uplink transmission path between the AP and a Station (STA) is congested;

and the AP sends a congestion control instruction to the STA, wherein the congestion control instruction is used for indicating the STA to carry out congestion control.

11. The method of claim 10, wherein the AP sends congestion control instructions to the station STA, comprising:

and the AP sends a Block Acknowledgement (BA) frame to the STA, wherein the BA frame carries the congestion control instruction.

12. The method of claim 10 or 11, wherein the AP determining that there is congestion in an uplink transmission path with the STA comprises:

the AP calculates network time delay according to first cache information, second cache information and an uplink forwarding rate of the AP, wherein the first cache information is used for indicating the queue depth in the STA, the second cache information is used for indicating the queue depth in the AP, and the queue depth is used for indicating the number of data packets to be sent in a cache queue;

and the AP determines that congestion exists in an uplink transmission path between the AP and the STA under the condition that the network delay is greater than a preset threshold.

13. The method of claim 12, wherein the method further comprises:

the AP receives the first cache information from the STA.

14. The method of claim 13, wherein the AP receives the first buffered information from the STA, comprising:

and the AP receives a data frame from the STA, wherein a service quality QoS control field in the data frame carries the first cache information.

15. The method of any of claims 10 to 14, wherein prior to the AP determining that there is congestion in an uplink transmission path with a STA, the method further comprises:

the AP sends first indication information to the STA, wherein the first indication information is used for indicating that the AP has congestion control capability, and the AP with the congestion control capability can determine that congestion exists in an uplink transmission path between the AP and the STA and can send the congestion control instruction to the STA;

and the AP receives second indication information from the STA, wherein the second indication information is used for indicating that the STA has the congestion control capability, and the STA with the congestion control capability can identify the congestion control instruction and can perform congestion control based on the congestion control instruction.

16. The method of claim 15, wherein the AP sends first indication information to the STA comprising:

and the AP sends a beacon frame to the STA, wherein the beacon frame comprises the first indication information.

17. The method of claim 15, wherein the AP sends first indication information to the STA comprising:

and the AP sends an association response frame to the STA, wherein the association response frame comprises the first indication information.

18. The method of claim 15, wherein the AP receives second indication information from the STA, comprising:

and the AP receives an association request frame from the STA, wherein the association request frame comprises the second indication information.

19. A congestion control apparatus, characterized by comprising means for implementing the method according to any one of claims 1 to 18.

20. A congestion control apparatus, comprising:

a memory for storing a computer program;

a processor for invoking a computer program in the memory to cause the apparatus to perform the method of any of claims 1-18.

21. A computer-readable storage medium comprising instructions which, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 18.

22. A computer program product comprising a computer program which, when executed, causes a computer to perform the method of any one of claims 1 to 18.