Congestion control in wireless networks

Abstract

A destination station (STA) in a wireless network, comprising: a memory; and a processor coupled to the memory, the processor configured to: receive a plurality of packets from a source STA via a router, the router located between the destination STA and the source STA; determine a congestion prediction for the source STA based on a packet arrival time of the plurality of packets; compare the congestion prediction to a first threshold; generate a congestion prediction signal based on the comparison, wherein the congestion prediction signal indicates an operating mode of the source STA; and transmit the congestion prediction signal to the source STA via the router.

Description

Technical Field

[0001] This disclosure generally relates to wireless communication systems, and more specifically, to congestion control in, for example, but not limited to, wireless networks. Background Technology

[0002] Since the late 1990s, Wireless Local Area Network (WLAN) technology has evolved towards increasing data rates and continues to grow in various markets such as homes, businesses, and hotspots. WLAN allows devices to access the Internet in the 2.4 GHz, 5 GHz, 6 GHz, or 60 GHz frequency bands. WLAN is based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. The IEEE 802.11 standard family aims to improve speed and reliability and extend the operational range of wireless networks.

[0003] WLAN devices increasingly need to support a variety of latency-sensitive or real-time applications, such as augmented reality (AR), robotics, artificial intelligence (AI), cloud computing, and autonomous vehicles. To achieve the extremely low latency and extremely high throughput required for such applications, Multi-Link Operation (MLO) has been proposed for WLANs. A WLAN is formed by WLAN devices within a limited area such as a home, school, apartment, or office building. Each WLAN device can have one or more Stations (STAs), such as Access Point (AP) STAs and Non-Access Point (Non-AP) STAs.

[0004] MLO enables non-AP multi-link devices (MLDs) to establish multiple links with AP MLDs. Each of these links can independently enable channel access and frame switching between the non-AP MLD and the AP MLD, which can reduce latency and increase throughput.

[0005] The descriptions set forth in the Background section should not be assumed to be prior art simply because they are set forth in the Background section. The Background section may describe aspects or embodiments of this disclosure. Summary of the Invention

[0006] Solution to the problem

[0007] One aspect of this disclosure provides a destination station (STA) in a wireless network, including: a memory; and a processor coupled to the memory. The processor is configured to receive multiple packets from a source STA via a router located between the destination STA and the source STA. The processor is configured to determine a congestion prediction for the source STA based on the packet arrival times of the multiple packets. The processor is configured to compare the congestion prediction with the first threshold. The processor is configured to generate a congestion prediction signal based on the comparison, wherein the congestion prediction signal indicates an operating mode of the source STA. The processor is configured to transmit the congestion prediction signal to the source STA via the router.

[0008] In some embodiments, packet arrival time is associated with either the delay in the buffer at the router or the propagation delay between the destination STA and the source STA.

[0009] In some embodiments, the processor is further configured to, during a first time window: determine that the congestion prediction is less than a first threshold; and generate a congestion prediction signal indicating that the source STA operates in a single-link operation mode using the main link or that the source STA maintains a first operation mode of packet transmission rate from the source STA to the destination STA.

[0010] In some embodiments, the processor is further configured to, during a second time window: determine that the congestion prediction is greater than a first threshold; and generate a congestion prediction signal indicating a second operating mode in which the source STA operates in a multi-link operating mode using a primary link and one or more secondary links or reduces the packet transmission rate from the source STA to the destination STA.

[0011] In some embodiments, the processor is further configured to, during a third time window: determine that the congestion prediction is less than a second threshold, wherein the second threshold is less than a first threshold; and generate a congestion prediction signal indicating that the source STA returns to operating in the first operating mode.

[0012] In some embodiments, the processor is also configured to estimate a set of autoregressive coefficients that model congestion from the time the packets arrive at the packets.

[0013] In some embodiments, the processor is also configured to perform training on samples within a training interval to estimate the set of autoregressive coefficients.

[0014] In some embodiments, the processor is further configured to: receive a congestion notification signal from the router indicating congestion at the router; and perform logical operations based on the received congestion notification signal and the congestion prediction signal to generate a congestion prediction signal.

[0015] One aspect of this disclosure provides a source station (STA) in a wireless network, including: a memory and a processor coupled to the memory. The processor is configured to receive, via a router located between the source and destination STAs, a congestion prediction signal indicating an operating mode of the source STA. The processor is configured to send packets to the destination STA based on the operating mode indicated by the congestion prediction signal.

[0016] In some embodiments, the processor is further configured to, during a first time window: operate in a first operating mode such that, based on a congestion prediction signal indicating the first operating mode, the source STA operates in a single-link operating mode using the primary link or the source STA maintains the packet transmission rate from the source STA to the destination STA.

[0017] In some embodiments, the processor is further configured to operate in a second operating mode during a second time window, such that, based on a congestion prediction signal indicating the second operating mode, the source STA operates in a multi-link operating mode using a primary link and one or more secondary links, or the source STA reduces the packet transmission rate from the source STA to the destination STA.

[0018] In some embodiments, the processor is also configured to, during a third time window, return to operating in the first operating mode based on a congestion prediction signal indicating the first operating mode. Attached Figure Description

[0019] Figure 1 An example of a wireless network according to an embodiment is shown.

[0020] Figure 2A shows an example of an AP according to an embodiment.

[0021] Figure 2B shows an example of a STA according to an embodiment.

[0022] Figure 3 An example of multi-link communication operation according to an embodiment is shown.

[0023] Figure 4 A system model according to an embodiment is shown.

[0024] Figure 5 The use of timestamps for congestion control according to an embodiment is illustrated.

[0025] Figure 6 A system for congestion prediction according to an embodiment is shown.

[0026] Figure 7 The congestion prediction based on a Kalman filter without explicit congestion notification (ECN) is shown according to an embodiment.

[0027] Figure 8 A state diagram for dynamic switching for congestion control according to an embodiment is shown.

[0028] Figure 9 A graph showing the soft handover according to an embodiment is shown.

[0029] Figure 10 A state diagram illustrating dynamic switching for congestion control using different transmission rates, according to an embodiment, is shown.

[0030] Figure 11 A graph showing a soft handover according to an embodiment is provided, where only single-link operation (SLO) is available.

[0031] Figure 12 A state diagram illustrating dynamic switching when Multi-Link Operation (MLO) has more than two links, according to an embodiment, is shown.

[0032] Figure 13 The congestion prediction based on a Kalman filter with ECN according to an embodiment is shown.

[0033] Figure 14 A process with an early ECN tag is shown according to an embodiment.

[0034] In one or more embodiments, not all components depicted in each figure are necessary, and one or more embodiments may include additional components not shown in the figures. Variations in the arrangement and type of components may be made without departing from the scope of this subject matter disclosure. Additional components, different components, or fewer components may be utilized within the scope of this subject matter disclosure. Detailed Implementation

[0035] The detailed description set forth below in conjunction with the accompanying drawings is intended to describe various embodiments and is not intended to represent the only embodiments in which the subject matter can be practiced. Rather, this detailed description includes specific details to provide a thorough understanding of the subject matter of the invention. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the scope of this disclosure. Therefore, the drawings and description are to be considered illustrative rather than restrictive in nature. The same reference numerals denote the same elements.

[0036] The following description pertains to certain implementations for the purpose of describing the innovative aspects of this disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in a variety of different ways. The examples in this disclosure are based on WLAN communication in accordance with the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, including the IEEE 802.11be standard and any future revisions to the IEEE 802.11 standard. However, the described embodiments can be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals according to the IEEE 802.11 standard, Bluetooth standard, Global System for Mobile Communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunking Radio (TETRA), Wideband CDMA (W-CDMA), Evolved Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High-Speed ​​Packet Access (HSPA), High-Speed ​​Downlink Packet Access (HSDPA), High-Speed ​​Uplink Packet Access (HSUPA), Evolved High-Speed ​​Packet Access (HSPA+), Long Term Evolution (LTE), 5G NR (New Radio), AMPS, or other known signals for communicating within wireless, cellular, or Internet of Things (IoT) networks, such as systems utilizing 3G, 4G, 5G, 6G, or further implementations thereof.

[0037] Depending on the network type, other well-known terms may be used instead of "access point" or "AP," such as "router" or "gateway." For convenience, the term "AP" is used in this disclosure to refer to a network infrastructure component that provides wireless access to remote terminals. In a WLAN, assuming that the AP also contends for the wireless channel, the AP may also be referred to as a STA. Furthermore, depending on the network type, other well-known terms may be used instead of "station" or "STA," such as "mobile station," "subscriber station," "remote terminal," "user equipment," "wireless terminal," or "user device." For convenience, the terms "station" and "STA" are used in this disclosure to refer to a remote wireless device that wirelessly accesses an AP or contends for a wireless channel in a WLAN, whether the STA is a mobile device (such as a mobile phone or smartphone) or is generally considered a fixed device (such as a desktop computer, AP, media player, fixed sensor, television, etc.).

[0038] Multilink Operation (MLO) is a key feature that standards bodies are currently developing for next-generation Ultra High Throughput (EHT) Wi-Fi systems in IEEE 802.11be. Wi-Fi devices that support MLO are called Multilink Devices (MLDs). Using MLO, a non-AP MLD can discover, authenticate, associate, and establish multiple links with an AP MLD. Channel access and frame switching are possible on each link between the AP MLD and non-AP MLDs.

[0039] Figure 1 An example of a wireless network 100 according to an embodiment is shown. Figure 1 The illustrated embodiment of the wireless network 100 is for illustrative purposes only. Other embodiments of the wireless network 100 may be used without departing from the scope of this disclosure.

[0040] like Figure 1 As shown, wireless network 100 may include multiple wireless communication devices. Each wireless communication device may include one or more stations (STAs). An STA may be a logical entity that is a separate addressable instance of an interface to the Media Access Control (MAC) layer and Physical (PHY) layer of the wireless medium. STAs may be classified as Access Point (AP) STAs and Non-Access Point (Non-AP) STAs. An AP STA may be an entity that provides access to a distribution system service to an associated STA via the wireless medium. A Non-AP STA may be a STA that is not included within an AP-STA. For simplicity, an AP STA may be referred to as an AP, and a Non-AP STA may be referred to as a STA. Figure 1 In the example, APs 101 and 103 are wireless communication devices, each of which may include one or more AP STAs. In such an embodiment, APs 101 and 103 may be AP multilink devices (MLDs). Similarly, STAs 111-114 are wireless communication devices, each of which may include one or more non-AP STAs. In such an embodiment, STAs 111-114 may be non-AP MLDs.

[0041] APs 101 and 103 communicate with at least one network 130, such as the Internet, a proprietary Internet Protocol (IP) network, or other data network. AP 101 provides wireless access to network 130 to multiple stations 111-114 in the coverage area 120 of AP 101. APs 101 and 103 can communicate with each other and with STAs using Wi-Fi or other WLAN communication technologies.

[0042] Depending on the network type, other well-known terms may be used instead of "access point" or "AP," such as "router" or "gateway." For convenience, the term "AP" is used in this disclosure to refer to a network infrastructure component that provides wireless access to remote terminals. In a WLAN, assuming that the AP also contends for the wireless channel, the AP may also be referred to as a STA. Furthermore, depending on the network type, other well-known terms may be used instead of "station" or "STA," such as "mobile station," "subscriber station," "remote terminal," "user equipment," "wireless terminal," or "user device." For convenience, the terms "station" and "STA" are used in this disclosure to refer to a remote wireless device that wirelessly accesses an AP or contends for a wireless channel in a WLAN, whether the STA is a mobile device (such as a mobile phone or smartphone) or is generally considered a fixed device (such as a desktop computer, AP, media player, fixed sensor, television, etc.).

[0043] exist Figure 1 In the diagram, the dashed lines indicate the approximate extent of the coverage areas 120 and 125 of APs 101 and 103, which are shown as approximately circular for illustrative and explanatory purposes. It should be clearly understood that, depending on the configuration of the APs, the coverage areas associated with the APs (such as coverage areas 120 and 125) may have other shapes, including irregular shapes.

[0044] As described in more detail below, one or more of the APs may include circuitry and / or procedures for managing MU-MIMO and OFDMA channel detection in a WLAN. Although Figure 1 An example of a wireless network 100 is shown, but more details can be found on other wireless networks. Figure 1 Various modifications can be made. For example, wireless network 100 can include any number of APs and any number of STAs in any suitable arrangement. Furthermore, AP 101 can communicate directly with any number of STAs and provide them with wireless broadband access to network 130. Similarly, each AP 101 and 103 can communicate directly with network 130 and provide STAs with direct wireless broadband access to network 130. Additionally, AP 101 and / or 103 can provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0045] Figure 2A illustrates an example of AP 101 according to an embodiment. The embodiment of AP 101 shown in Figure 2A is for illustrative purposes, and Figure 1 AP 103 may have the same or similar configuration. However, APs have a wide variety of configurations, and Figure 2A does not limit the scope of this disclosure to any particular implementation of the AP.

[0046] As shown in Figure 2A, AP 101 may include multiple antennas 204a-204n, multiple radio frequency (RF) transceivers 209a-209n, transmit (TX) processing circuitry 214, and receive (RX) processing circuitry 219. AP 101 may also include a controller / processor 224, a memory 229, and a backhaul or network interface 234. RF transceivers 209a-209n receive incoming RF signals from antennas 204a-204n, such as signals transmitted by STAs in network 100. RF transceivers 209a-209n down-convert the incoming RF signals to generate intermediate (IF) or baseband signals. The IF or baseband signals are sent to RX processing circuitry 219, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 219 sends the processed baseband signals to controller / processor 224 for further processing.

[0047] TX processing circuit 214 receives analog or digital data (such as voice data, network data, email, or interactive video game data) from controller / processor 224. TX processing circuit 214 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 209a-209n receive the processed baseband or IF signal from TX processing circuit 214 and up-convert the baseband or IF signal into an RF signal transmitted via antennas 204a-204n.

[0048] The controller / processor 224 may include one or more processors or other processing devices that control the overall operation of the AP 101. For example, the controller / processor 224 may control the RF transceivers 209a-209n, the RX processing circuitry 219, and the TX processing circuitry 214 to receive uplink signals and transmit downlink signals, based on well-known principles. The controller / processor 224 may also support additional functions, such as more advanced wireless communication capabilities. For example, the controller / processor 224 may support beamforming or directional routing operations, where outgoing signals from multiple antennas 204a-204n are weighted differently to effectively direct outgoing signals in a desired direction. The controller / processor 224 may also support OFDMA operations, where outgoing signals are assigned to different subsets of subcarriers from different receivers (e.g., different STAs 111-114). The controller / processor 224 may support a variety of other functions in the AP 101, including combining DLMU-MIMO and OFDMA in the same transmission opportunity. In some embodiments, the controller / processor 224 may include at least one microprocessor or microcontroller. The controller / processor 224 is also capable of executing programs and other processes, such as an operating system, residing in the memory 229. The controller / processor 224 can move data into or out of the memory 229 as needed for the execution process.

[0049] Controller / processor 224 is also coupled to backhaul or network interface 234. Backhaul or network interface 234 allows AP 101 to communicate with other devices or systems via a backhaul connection or over a network. Interface 234 can support communication via any suitable wired or wireless connection. For example, interface 234 can allow AP 101 to communicate with a larger network (such as the Internet) via a wired or wireless local area network or via a wired or wireless connection. Interface 234 can include any suitable structure supporting communication via a wired or wireless connection, such as Ethernet or an RF transceiver. Memory 229 is coupled to controller / processor 224. A portion of memory 229 can include RAM, and another portion of memory 229 can include RAM or other ROM.

[0050] As described in more detail below, AP 101 may include circuitry and / or procedures for managing the channel probing process in a WLAN. Although Figure 2A shows an example of AP 101, various changes can be made to Figure 2A. For example, AP 101 may include any number of each of the components shown in Figure 2A. As a particular example, the AP may include multiple interfaces 234, and the controller / processor 224 may support routing functionality to route data between different network addresses. As another example, although shown as a single instance including TX processing circuitry 214 and a single instance including RX processing circuitry 219, AP 101 may include multiple instances of each (such as one per RF transceiver). Alternatively, only one antenna and RF transceiver path may be included, as in a conventional AP. Furthermore, the various components in Figure 2A may be combined, further subdivided, or omitted, and additional components may be added as needed.

[0051] As shown in Figure 2A, in some embodiments, AP 101 may be an AP MLD comprising multiple APs 202a-202n. Each AP 202a-202n is attached to AP MLD 101 and includes multiple antennas 204a-204n, multiple radio frequency (RF) transceivers 209a-209n, transmit (TX) processing circuitry 214, and receive (RX) processing circuitry 219. Each AP 202a-202n can communicate independently with the controller / processor 224 and other components of AP MLD 101. Figure 2A illustrates that each AP 202a-202n has separate multiple antennas, but each AP 202a-202n can share multiple antennas 204a-204n without requiring separate multiple antennas. Each AP 202a-202n can represent the physical (PHY) layer and a lower media access control (MAC) layer.

[0052] Figure 2B illustrates an example of STA 111 according to an embodiment. The embodiment of STA 111 shown in Figure 2B is for illustrative purposes, and Figure 1 STAs 111-114 may have the same or similar configurations. However, STAs appear in a wide variety of configurations, and Figure 2B does not limit the scope of this disclosure to any particular implementation of the STA.

[0053] As shown in Figure 2B, STA 111 may include an antenna 205, an RF transceiver 210, a TX processing circuit 215, a microphone 220, and an RX processing circuit 225. STA 111 may also include a speaker 230, a controller / processor 240, an input / output (I / O) interface (IF) 245, a touchscreen 250, a display 255, and a memory 260. The memory 260 may include an operating system (OS) 261 and one or more applications 262.

[0054] RF transceiver 210 receives incoming RF signals transmitted by the AP of network 100 from antenna 205. RF transceiver 210 down-converts the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are sent to RX processing circuitry 225, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. RX processing circuitry 225 sends the processed baseband signals to speaker 230 (e.g., for voice data) or to controller / processor 240 for further processing (e.g., for web browsing data).

[0055] TX processing circuitry 215 receives analog or digital voice data from microphone 220, or other outgoing baseband data (such as web data, email, or interactive video game data) from controller / processor 240. TX processing circuitry 215 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. RF transceiver 210 receives the processed outgoing baseband or IF signal from TX processing circuitry 215 and up-converts the baseband or IF signal into an RF signal transmitted via antenna 205.

[0056] The controller / processor 240 may include one or more processors and executes a basic OS program 261 stored in memory 260 to control the overall operation of STA 111. In one such operation, the controller / processor 240 controls the RF transceiver 210, RX processing circuitry 225, and TX processing circuitry 215 to receive downlink signals and transmit uplink signals according to well-known principles. The controller / processor 240 may also include processing circuitry configured to provide management of the channel detection process in the WLAN. In some embodiments, the controller / processor 240 may include at least one microprocessor or microcontroller.

[0057] The controller / processor 240 is also capable of executing other processes and programs residing in the memory 260, such as operations for managing channel sensing processes in the WLAN. The controller / processor 240 can move data into or out of the memory 260 as needed for the execution of the process. In some embodiments, the controller / processor 240 is configured to execute multiple applications 262, such as applications for channel sensing, including feedback calculations based on received Null Data Packet Advertisements (NDPA) and Null Data Packets (NDP), and sending beamforming feedback reports in response to trigger frames (TF). The controller / processor 240 can operate the multiple applications 262 based on the OS program 261 or in response to signals received from the AP. The controller / processor 240 is also coupled to an I / O interface 245, which provides the STA 111 with the ability to connect to other devices such as laptops and handheld computers. The I / O interface 245 is the communication path between these accessories and the main controller / processor 240.

[0058] The controller / processor 240 is also coupled to input 250 (such as a touchscreen) and display 255. An operator of STA 111 can use input 250 to input data into STA 111. Display 255 may be a liquid crystal display, a light-emitting diode display, or other display capable of displaying text and / or at least limited graphics (such as from a website). Memory 260 is coupled to the controller / processor 240. A portion of memory 260 may include random access memory (RAM), and another portion of memory 260 may include RAM or other read-only memory (ROM).

[0059] Although Figure 2B shows an example of STA 111, various changes can be made to Figure 2B. For example, the various components in Figure 2B can be combined, further subdivided, or omitted, and additional components can be added as needed. In a particular example, STA 111 may include any number of antennas 205 for MIMO communication with AP 101. In another example, STA 111 may not include voice communication, or the controller / processor 240 may be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, while Figure 2B shows STA 111 configured as a mobile phone or smartphone, the STA can be configured to operate as other types of mobile or fixed devices.

[0060] As shown in Figure 2B, in some embodiments, STA 111 may be a non-AP MLD comprising multiple STAs 203a-203n. Each STA 203a-203n is attached to the non-AP MLD 111 and includes an antenna 205, an RF transceiver 210, TX processing circuitry 215, and RX processing circuitry 225. Each STA 203a-203n can independently communicate with the controller / processor 240 and other components of the non-AP MLD 111. Figure 2B shows each STA 203a-203n having a separate antenna, but each STA 203a-203n can share antenna 205 without requiring a separate antenna. Each STA 203a-203n can represent the physical (PHY) layer and a lower media access control (MAC) layer.

[0061] Figure 3 An example of multi-link communication operation according to an embodiment is shown. Multi-link communication operation can be used in the IEEE 802.11be standard and any future revisions of the IEEE 802.11 standard. Figure 3 In the middle, AP MLD 310 can be Figure 1 Wireless communication devices 101 and 103 are included, and the non-AP MLD 220 can be... Figure 1 One of the wireless communication devices 111-114 in the series.

[0062] like Figure 3 As shown, AP MLD 310 may include multiple affiliated APs, such as AP 1, AP 2, and AP 3. Each affiliated AP may include a PHY interface to the wireless medium (Link 1, Link 2, or Link 3). AP MLD 310 may include a single MAC Service Access Point (SAP) 318 through which the affiliated APs of AP MLD 310 communicate with higher layers (Layer 3 or network layer). Each affiliated AP of AP MLD 310 may have a different MAC address (lower MAC address) than any other affiliated AP of AP MLD 310. AP MLD 310 may have an MLD MAC address (upper MAC address), and the affiliated APs share the single MAC SAP 318 to Layer 3. Therefore, the affiliated APs share a single IP address, and Layer 3 identifies AP MLD 310 by assigning a single IP address.

[0063] A non-AP MLD 320 may include multiple affiliated STAs, such as STA 1, STA 2, and STA 3. Each affiliated STA may include a PHY interface to the wireless medium (Link 1, Link 2, or Link 3). A non-AP MLD 320 may include a single MAC SAP 328, through which affiliated STAs communicate with higher layers (Layer 3 or network layer). Each affiliated STA of a non-AP MLD 320 may have a different MAC address (lower MAC address) than any other affiliated STA of the non-AP MLD 320. A non-AP MLD 320 may have an MLD MAC address (upper MAC address), and the affiliated STAs share the single MAC SAP 328 to Layer 3. Therefore, affiliated STAs share a single IP address, and Layer 3 identifies the non-AP MLD 320 by assigning this single IP address.

[0064] AP MLD 310 and non-AP MLD 320 can establish multiple links between their associated APs and STAs. In this example, AP 1 and STA 1 can establish Link 1, operating in the 2.4 GHz band. Similarly, AP 2 and STA 2 can establish Link 2, operating in the 5 GHz band, and AP 3 and STA 3 can establish Link 3, operating in the 6 GHz band. Each link can independently enable channel access and frame switching between AP MLD 310 and non-AP MLD 320, which can increase data throughput and reduce latency. When associated with an AP MLD on a set of links (link establishment), each non-AP device is assigned a unique Association Identifier (AID).

[0065] In some embodiments, congestion control (CC) can be used to manage network resources efficiently to prevent network outages and provide resource sharing across competing traffic flows. Therefore, CC can minimize packet loss, thereby improving the reliability of traffic flows. In some embodiments, latency-based CC methods can be optimized for efficient use in high-speed networks, allowing for rapid integration into end-to-end utilization without burdening the network.

[0066] Transmission Control Protocol (TCP), primarily focused on reliability, may be insufficient for handling real-time traffic streams, partly due to the use of retransmission and acknowledgment within the TCP protocol. While User Datagram Protocol (UDP) may be more satisfactory for handling real-time traffic streams, the CC mechanism is not available for UDP. Therefore, in some embodiments, the CC mechanism can be integrated at the application layer for real-time traffic streams. In some embodiments, when the input rate exceeds the output rate, a buffer in the bottleneck can be used to absorb bursty traffic. However, when the sending rate consistently exceeds the output rate, a queue may be established in the buffer. Furthermore, when the number of waiting packets in the buffer begins to exceed the maximum size of the buffer, packets can be dropped. That is, packets can be queued until they are dropped.

[0067] In some embodiments, the size of the buffer and / or the link speed of the bottleneck can be dynamically changed (e.g., increased or decreased) to alleviate congestion. In some embodiments, the source of network traffic can reduce network load by sending data to the destination more slowly. In some embodiments, CC can be designed by pre-reserving fixed bandwidth in the network and / or adaptively allocating bandwidth in response to congestion indication signals fed back by the destination. In some embodiments, open-loop CC control may be preferred for dynamic real-time traffic processing based on available hardware resources.

[0068] In some embodiments, for congestion indication signals, the destination can use an explicit congestion notification (ECN), where a device (e.g., a router, switch, etc.) can tag packets based on queue occupancy. For example, a router can tag packets with an indication that the packet may encounter congestion along its path. After receiving the ECN, the destination can notify the source of the congestion. For example, the buffer in the router is reaching its maximum storage capacity among other factors that may cause congestion. In some embodiments, implicit congestion indications (such as packet loss and packet delay, among other factors) can be used to determine the congestion state within the network. Specifically, the round-trip time (RTT) of packet transmission can increase as packets are queued in the buffer, making the RTT relevant to congestion. Therefore, since ECNs may not always be available for determining congestion, the destination may need to use other characteristics to determine the congestion state and provide feedback to the source.

[0069] In some embodiments, for the adaptive rate approximation of Single Link Operation (SLO), the source may need to smooth traffic by reducing the transmission rate when signaling congestion. In some embodiments, Multi-Link Operation (MLO) may also use one or more secondary helper links in addition to the primary link, such that when congestion is signaled, MLO-MAC can switch from SLO to MLO instead of smoothing traffic as in a traditional SLO.

[0070] Figure 4 A system for congestion prediction according to an embodiment is shown. Specifically, Figure 4 A system 400 is illustrated, comprising a source (S) 410 communicating with a router (R) 420 via link 411. As shown, router 420 includes queues. Router 420 communicates with a destination (D) 430 via link 421. As shown, source (S) 410 may need to understand the congestion status on links 411 and 421, which connect to router (R) 420 and destination (D) 430. In some embodiments, router (R) 420 may not tag packets via explicit congestion notification (ECN). In some embodiments, destination (D) 430 may not be able to access the timestamps of packet transmissions recorded at source (S) 410. Therefore, it may be necessary to find implicit characteristics at destination (D) 430 to indicate the congestion status on links 411 and 421. In some embodiments, the corresponding congestion indication or signal may be used by an MLO-MAC residing in source (S) 410 to dynamically switch between SLO and MLO to reduce congestion on the primary link of SLO.

[0071] Figure 5 This illustrates congestion control using timestamps according to an embodiment. Specifically, Figure 5 The diagram shows the timestamps recorded at source (S) 410, router (R) 420, and destination (D) 430. Destination (D) 430 may need to use available timestamps, such as the packet arrival time at D, 430, for example... and However, the packet departure time recorded at source (S) 410 is unknown, for example... and Furthermore, target characteristics may require queuing delays (such as those experienced by buffers or queues deployed at the router(R)420) and ) and the propagation delay experienced on links 411 and 421 respectively. and Related. According to embodiments of this disclosure, congestion can be predicted based on target characteristics, and corresponding indications or signals can be provided to source (S) 410. In some embodiments, when more than one link is available, MLO-MAC (e.g., source 410) can dynamically use the primary link and one or more secondary links (e.g., helper links) to reduce congestion on the primary link. In some embodiments, when only the primary link is available, MLO-MAC (e.g., source 410) can adaptively change the transmission rate.

[0072] Figure 6A system for congestion prediction using implicit features according to an embodiment is illustrated. Specifically, the inter-arrival packet time 601 can be input to a congestion prediction 600 that can output a congestion prediction signal 660. In some embodiments, the inter-arrival packet time can be used as a feature of the congestion prediction signal. In some embodiments, the delay-based CC method can provide low-latency data transmission by controlling network congestion once a bottleneck begins to occur. In some embodiments, when packet sizes are the same in the target flow, clocks can be quasi-synchronized between the source S, router R, and destination D. Furthermore, assuming no path rerouting occurs during transmission of the target flow, the propagation delay can be nearly constant on the target flow. (Reference) Figure 5 It shows three consecutive arrival timestamps, and and The data are recorded as shown in equations (1) to (3):

[0073]

[0074] Then, refer to Figure 5 and Figure 6 The one-way arrival interval 601 measured between two consecutive groups is given by equations (4) and (5), respectively:

[0075]

[0076] By calculating the difference between the times of two consecutive one-way arrival packets, common unknown propagation delays can be eliminated from the expression for the one-way arrival packet interval. and Furthermore, equations (4) and (5) show and Separately with the departure time of the groups 510, 511, and 512, and respectively related to queuing delays. 530, 531, and 532 are related. Based on equations (4) and (5), we can further obtain equation (6):

[0077]

[0078] It is from The beginning The mean of a sliding window consisting of consecutive one-way arrival times. Equation (6) shows that by... The average of the arrival times of consecutive one-way groups is calculated. Expressed by two one-way arrival times; (i) the initial one-way arrival time. (ii) and the last one-way arrival time of the group This reduces the difference between them, thus decreasing the sliding window size. Similarly, the queuing delay difference occurring at router R 420 also decreases. Therefore, in In the calculation, a smoothing filter can be applied to each step of the sliding window. In some embodiments, the Kalman filter can be used to predict congestion states.

[0079] Figure 7 The diagram illustrates congestion prediction without ECN based on a Kalman filter, according to an embodiment. In some embodiments, it is based on an available set of measurements. The key problem to be solved may be predicting the upcoming congestion state. For this purpose, filters, such as a third-order Kalman filter 740, can be used according to some embodiments of this disclosure, the dynamics and measurement equations of which are given by equations (7) and (8):

[0080]

[0081] The coefficients of the Kalman filter are { } Determine the dynamic model to predict congestion according to the sliding window 770. Kalman filter autoregressive (AR) coefficients { The AR coefficients may be unknown and depend on the incoming traffic, and should be pre-computed or trained. Some embodiments estimate the AR coefficients from samples within the training interval. In some embodiments, Burg's maximum entropy-based method can be used for estimation.

[0082] In some embodiments, { } represents the set of congestion states described by the Kalman filter estimation. Furthermore, { Let} represent the set of process noise, which indicates the degree of correlation between the uncertainty in the state estimation of the Kalman filter and the error between the state estimates. In some embodiments, it is assumed that... It is independent and has zero mean and The variance is Gaussian. In some embodiments, 740 and 741 are from the first Measurements obtained from a sliding window, where Indicates measurement noise. In some embodiments, due to the use of a sliding window, a Lag between two consecutive operations at the destination.

[0083] This paper discloses Burg's maximum entropy-based method according to some embodiments. Since it may not be easy to find a reliable dynamic model of congestion for heterogeneous traffic, i.e., to find the dynamic coefficients of the Kalman filter { Therefore, some embodiments can apply Burg's maximum entropy-based method. For 711 sliding windows, each of which is composed of Composed of consecutive one-way arrival packet intervals 701, Burg provides { based on the maximum entropy method 712. The estimation of}, that is, it can be done using parameters. Determine the dynamic equation of congestion according to the sliding window.

[0084] In some embodiments, the test interval 720 begins after the learning interval 710, during which the Kalman coefficients are calculated. That is, the Kalman filter is ready for prediction. A test interval 720 may consist of: i) an initial filling interval for performing an initial sliding window 721 and operation 722 to sequentially calculate the mean of the sliding window 723, for example... 740 and 741;ii) Kalman filter operation for initial prediction And measurements, and generate Kalman predictions. and ; and iii) soft handover 750, regarding the two thresholds and The Kalman prediction is processed, and then congestion prediction signals 760 and 761 for the first two sliding windows are generated. These operations are performed on each of the sliding windows 770.

[0085] Figure 8 A state diagram for dynamic switching for congestion control according to an embodiment is shown. Figure 9 A graph illustrating soft handover according to an embodiment is shown. (Reference) Figure 8 and Figure 9 The state diagram for dynamic switching used for congestion control is specified by 800, where two key states, SLO and MLO, determine the dynamic MLO-MAC switching operation from single-link operation (SLO) to multi-link operation (MLO) using two or more available links (e.g., a primary link and one or more auxiliary links). Specifically, Figure 8 The transitions between different states (including state zero (St=0) 810, state three (St=3) 830 and state four (St=4) 840) are shown via various state transitions (including (St=2) 815 from state zero (St=0) 810 to state four (St=4) 840, and (St=1) 825 from state three (St=3) 830 back to state zero (St=0) 810).

[0086] In some embodiments, state zero (St=0) 810 corresponds to MLO-MAC in the SLO utilizing the primary link, which can be the default mode. When the destination (e.g., destination D 430) predicts that congestion will begin to occur on the primary link, MLO-MAC transitions to state four 840 via state transition 815, thereby allowing the source (e.g., source S 410) to use one or more secondary auxiliary links to reduce the bottleneck on the primary link. Therefore, MLO-MAC switches from state zero (St=0) 810 to MLO state four (St=4) 840 via state transition (St=2) 815.

[0087] refer to Figure 9 And the soft handover provided in 900 and Kalman prediction 831, when the Kalman prediction 831 of the second sliding window (i.e., (greater than) At 910, the MLO-MAC switches from state zero (St=0) 810 to MLO with state four (St=4) 840. For the... A sliding window, MLO-MAC will and Compare 910. If Kalman predicts 831 is not greater than... 910, then the MLO-MAC control source (S) uses only the main link. Specifically, the MLO-MAC maintains the SLO in a state of zero (St=0) 810 via state transition 811.

[0088] When MLO-MAC is in an MLO with state four (St=4) 840, when Kalman prediction 831 (i.e., (less than) At 911, MLO-MAC switches back to SLO state zero (St=0) 810 via state transition (St=1) 825.

[0089] Under conditions Below, an additional third state is added as an MLO with state three (St=3) 830. By adding the third state (St=3) 830, MLO-MAC can be achieved via state transition 821, even though... Less than 910 and greater than After 911, control (S) is maintained using both the primary link and the secondary auxiliary link. Therefore, a lag during handover 920 may result in an additional third state (St=3) 830 to avoid a rapid handover from MLO to SLO.

[0090] In some embodiments, the dynamic transmission rate change of SLO can be used for CC. In some embodiments, when only SLO mode is available, i.e., when the source (S) can only access the main link, the dynamic switching algorithm causes MLO-MAC to change the transmission rate of the source (S) in response to congestion indication or signal.

[0091] Figure 10 A state diagram showing the dynamic switching of congestion control using different transmission rates is presented. Figure 11 A graph illustrating soft handover according to an embodiment when only SLO is available is shown. (Reference) Figure 10 and Figure 11 The state diagram for dynamic switching used for congestion control is specified by 1000, where SLOs with different transmission rates determine the dynamic MLO-MAC switching operation 1100. Specifically, Figure 10 The transitions between different states (including state zero (St=0) 1010, state three (St=3) 1030 and state four (St=4) 1040) are shown via various state transitions (including (St=2) 1015 from state zero (St=0) to state four (St=4), and (St=1) 1025 from state three (St=3) back to state zero (St=0).

[0092] In MLO-MAC, when the source (S) is in a state of SLO with state zero (St=0) 1010, the MLO-MAC control source (S) is greater than Kalman prediction 1131. At 1110, the state transition (St=2) 1015 is used to enter SLO with state four (St=4) 1040 to reduce the transmission rate of S, as shown by equation (9):

[0093]

[0094] Even if SLO is in state four (ST=4) 1040 or state three (ST=3) 1030, MLO-MAC updates the transmission rate of source (S) according to equation (9) via state transition 1021.

[0095] When Kalman predicts 1131 is less than At 1111, the congestion state transitions to SL0 with state zero (St=0) 1010 via state transition (St=1) 1025. In state zero (St=0) 1010, MLO-MAC maintains the increased transmission rate of the source (S), as shown in equation (10):

[0096]

[0097] Kalman prediction is less than Within interval 1110, the state transition is represented by 1011. Some embodiments can use dynamic link adaptation for MLO.

[0098] Figure 12 A state diagram illustrating dynamic switching when the MLO has more than two links, according to an embodiment, is shown. In some embodiments, for MLO establishment where more than two links are available for the MLO-MAC 1200, dynamic link adaptation of the MLO is possible. Specifically, Figure 12 The transitions between different states (including state zero (St=0) 1210, state three (St=3) 1230 and state four (St=4) 1240) are shown via various state transitions (including (St=2) 1215 from state zero (St=0) to state four (St=4), and (St=1) 1225 from state three (St=3) back to state zero (St=0).

[0099] As shown in the figure, an MLO with state zero (ST=0) 1210 is in a state where no additional links are needed to avoid congestion between the deployed link sets. However, when congestion begins to occur, a state transition (St=2) 1215 is performed to avoid congestion between the deployed link sets. Therefore, based on... The Kalman prediction for comparison indicates that the congestion state switches to MLO with state four (St=4) 1240. In state four (St=4), an additional link can be used as a helper link. In some embodiments, depending on the... and In comparison, the congestion state can remain in an MLO with state four (St=4) 1240, represented by state transition (St=1) 1221, or an MLO with state three (St=3) 1230. However, when the Kalman prediction is less than... At that time, in state four (St=4) 1240 or state three (St=3) 1230, the congestion state is switched to MLO with state zero (St=0) 1225 via state transition (St=1) 1225. In some embodiments, dynamic SLO-MLO switching with ECN input can be used for congestion control.

[0100] Figure 13A Kalman filter-based congestion prediction with an ECN is illustrated according to an embodiment. As shown, an arrival interval 1303 is provided to a Kalman filter-based congestion prediction 1301 without an ECN, which outputs a first congestion prediction signal 1305. As shown, when an ECN 1310 is provided by the router as a congestion notification 1310, the dynamic SLO-MLO switch 1300 can use the congestion prediction signal 1310 and the output 1305 of the Kalman filter-based congestion prediction as additional indication signals to output a final congestion prediction signal 1330. Logical operations (logical AND or logical OR) can be performed in block 1320. In some embodiments, for a more restrictive congestion prediction signal, a logical AND can be performed on two different congestion intervals determined by 1310 and 1320. In some embodiments, a logical OR operation can be performed to cover more congestion time intervals.

[0101] In some embodiments, adaptive changes to the learning interval for AR coefficient estimation can be used in CC. Depending on the application profile, the learning interval for AR coefficient estimation (e.g., Figure 7 The learning interval 710 for AR coefficient estimation can be adaptive. In some embodiments, early ECN tags used for adjustment based on congestion detected at the destination can be used for CC.

[0102] Figure 14 A process with an early ECN marker is illustrated according to an embodiment. Although one or more operations are described or illustrated in a specific order, in other embodiments, the operations may be rearranged in a different order, which may include performing multiple operations in at least partially overlapping time periods.

[0103] In Operation 1401, a congestion predictor can be assigned to a traffic flow that has ECN enabled (e.g., ECT bits set to 01, 10 in the IP header).

[0104] In operation 1403, if the congestion predictor detects congestion in the flow, but the ECN bit has not yet been marked (e.g., due to the queue having more lenient restrictions on queue delay), the congestion predictor can then classify the packet in operation 1405 before forwarding it to the application.

[0105] Embodiments of this disclosure can provide congestion control (CC) to efficiently manage network resources, prevent network outages, and provide resource sharing across contention flows, which can prevent packet loss and thus improve communication on wireless networks.

[0106] Unless otherwise specified, references to singular elements are not intended to indicate one and only one, but rather one or more. For example, a “one” module can refer to one or more modules. In the absence of further constraints, elements preceded by “a,” “an,” “the,” or “the” do not preclude the presence of additional identical elements.

[0107] Titles and subtitles (if any) are used for convenience only and do not limit the invention. The terms "exemplary" are used to indicate that they are intended as examples or illustrations. Within the scope of the use of terms such as "comprising," "having," etc., such terms are intended to be inclusive in a manner similar to the term "comprising," as "comprising" is interpreted when used as a transitional word in the claims. Relational terms such as "first" and "second" may be used to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between these entities or actions.

[0108] Phrases such as aspect, that aspect, on the other hand, some aspects, one or more aspects, implementation, that implementation, another implementation, some implementations, one or more implementations, embodiment, that embodiment, another embodiment, some embodiments, one or more embodiments, configuration, that configuration, another configuration, some configurations, one or more configurations, subject matter, disclosure, this disclosure, other variations thereof, etc., are used for convenience and do not imply that disclosures associated with such phrases are essential to the subject matter, or that such disclosures apply to all configurations of the subject matter. Disclosures associated with such phrases may apply to all configurations or one or more configurations. Disclosures associated with such phrases may provide one or more examples. Phrases such as aspect or some aspects may refer to one or more aspects, and vice versa, and this similarly applies to other foregoing phrases.

[0109] The phrase "at least one" following a series of items, along with the terms "and" or "or" used to separate any items, modifies the list as a whole, not each member of the list. The phrase "at least one of..." does not require the selection of at least one item; rather, it allows for the inclusion of at least one of any one item, and / or at least one of any combination of items, and / or at least one of each item. For example, each of the phrases "at least one of A, B, and C" or "at least one of A, B, or C" refers to only A, only B, or only C; any combination of A, B, and C; and / or at least one of each of A, B, and C.

[0110] It should be understood that the specific order or hierarchy of the disclosed steps, operations, or processes is an explanation of exemplary methods. Unless otherwise expressly stated, it should be understood that the specific order or hierarchy of steps, operations, or processes may be performed in a different order. Some steps, operations, or processes may be performed simultaneously, or may be performed as part of one or more other steps, operations, or processes. The appended method claims (if any) present elements of various steps, operations, or processes in a sample order, but this does not imply limitation to the specific order or hierarchy presented. These may be performed serially, linearly, in parallel, or in different orders. It should be understood that the described instructions, operations, and systems can generally be integrated together in a single software / hardware product or packaged into multiple software / hardware products.

[0111] This disclosure is provided to enable any person skilled in the art to practice the various aspects described herein. In some cases, well-known structures and components are shown in block diagram form to avoid obscuring the concept of the subject matter. This disclosure provides various examples of the subject matter, and the subject matter is not limited to these examples. Various modifications to these aspects will be apparent to those skilled in the art, and the principles described herein can be applied to other aspects.

[0112] All structural and functional equivalents of the various aspects described herein, whether now or hereafter known to a person skilled in the art, are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is explicitly stated in the claims. No claim element is to be interpreted pursuant to paragraph 6 of 35 USC §112 unless it is expressly stated using the phrase “means for…” or, in the case of a method claim, using the phrase “steps for…”.

[0113] The title, background art, description of the drawings, abstract, and drawings are incorporated herein by reference and are provided as illustrative examples rather than as limiting descriptions. It should be understood at the time of filing that they are not intended to limit the scope or meaning of the claims. Furthermore, in the detailed description, it will be apparent that the description provides illustrative examples and that various features are combined in various embodiments for the purpose of simplifying the disclosure. The approach of this disclosure should not be construed as reflecting an intention to require more features than expressly recited in each claim. Rather, as reflected in the following claims, the inventive subject matter lies in all features of fewer than those in a single disclosure configuration or operation. The appended claims are incorporated herein by reference, wherein each claim is independently claimed as a separate subject matter.

[0114] The claims are not intended to be limited to the aspects described herein, but rather to conform to the full scope consistent with the language claims and to include all legal equivalents. Nevertheless, no claim is intended to include subject matter that does not meet the requirements of applicable patent law, nor should they be interpreted in this manner.

Claims

1. A destination station (STA) in a wireless network, comprising: Memory; as well as A processor, coupled to a memory, is configured to: Multiple packets are received from the source STA via a router located between the destination STA and the source STA. Congestion prediction for the source STA is determined based on the arrival time of multiple packets; Compare the congestion prediction with a first threshold; A congestion prediction signal is generated based on comparison, wherein the congestion prediction signal indicates the operating mode of the source STA; and The congestion prediction signal is sent to the source STA via the router.

2. The destination STA according to claim 1, wherein, Packet arrival time is associated with either the delay in the buffer at the router or the propagation delay between the destination STA and the source STA.

3. The destination STA according to claim 1, wherein, The processor is also configured to, during the first time window: Determine that the congestion prediction is less than the first threshold; and Generate a congestion prediction signal indicating whether the source STA is operating in single-link operation mode using the main link or in first operation mode maintaining the packet transmission rate from the source STA to the destination STA.

4. The destination STA according to claim 3, wherein, The processor is also configured to, during the second time window: The congestion prediction is determined to be greater than the first threshold; and Generate a congestion prediction signal indicating whether the source STA is operating in a multi-link operation mode using the primary link and one or more secondary links, or whether the source STA is reducing the packet transmission rate from the source STA to the destination STA in a second operation mode.

5. The destination STA according to claim 4, wherein, The processor is also configured to, during the third time window: Determine that the congestion prediction is less than a second threshold, where the second threshold is less than a first threshold; and The indicator source STA returns to the congestion prediction signal operating in the first operating mode.

6. The destination STA according to claim 1, wherein, The processor is also configured to estimate a set of autoregressive coefficients that model congestion from the time the packets arrive at the packets.

7. The destination STA according to claim 6, wherein, The processor is also configured to perform training on samples within the training interval to estimate the set of autoregressive coefficients.

8. The destination STA according to claim 1, wherein, The processor is also configured to: Receive congestion notification signals from the router indicating congestion at the router; and Logical operations are performed based on the received congestion notification signals and congestion prediction signals to generate congestion prediction signals.

9. A source station (STA) in a wireless network, comprising: Memory; as well as A processor, coupled to a memory, is configured to: The router receives a congestion prediction signal indicating the operating mode of the source STA from the destination STA; the router is located between the source STA and the destination STA. Packets are sent to the destination STA based on the operating mode indicated by the congestion prediction signal.

10. The source STA according to claim 9, wherein, The processor is also configured to, during the first time window: Operating in the first operating mode enables the source STA to operate in the single-link operating mode of the primary link or maintain the packet transmission rate from the source STA to the destination STA, based on the congestion prediction signal indicating the first operating mode.

11. The source STA according to claim 10, wherein, The processor is also configured to, during the second time window: Operating in the second operating mode causes the source STA to operate in a multi-link operating mode using the primary link and one or more secondary links, or the source STA to reduce the packet transmission rate from the source STA to the destination STA, based on the congestion prediction signal indicating the second operating mode.

12. The source STA according to claim 11, wherein, The processor is also configured to, during the third time window: Based on the congestion prediction signal indicating the first operating mode, return to operating in the first operating mode.

13. A computer-implemented method for wireless communication by a destination station (STA) in a wireless network, comprising: Multiple packets are received from the source STA via a router located between the destination STA and the source STA. Congestion prediction for the source STA is determined based on the arrival time of multiple packets; Compare the congestion prediction with a first threshold; A congestion prediction signal is generated based on comparison, wherein the congestion prediction signal indicates the operating mode of the source STA; and The congestion prediction signal is sent to the source STA via the router.

14. The computer implementation method according to claim 13, wherein, Packet arrival time is associated with either the delay in the buffer at the router or the propagation delay between the destination STA and the source STA.

15. The computer implementation method according to claim 13, further comprising, during the first time window: Determine that the congestion prediction is less than the first threshold; and Generate a congestion prediction signal indicating whether the source STA is operating in single-link operation mode using the main link or in first operation mode maintaining the packet transmission rate from the source STA to the destination STA.

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