Data control frame interval in a wireless communication system

Abstract

To improve reliability and reduce latency in multi-access point coordination.SOLUTION: The present subject matter relates to a method for determining a set of interfering apparatuses configured to access a communication channel of a wireless communication system using a communication link between the apparatuses, the method comprising: Determining a transmission schedule indicating, for each communication link, a data control frame interval between a data frame and a corresponding control frame, the data control frame interval enabling a reduction of delay in transmission of data frames by the set of apparatuses, and controlling the set of apparatuses to transmit data frames and control frames in the communication channel according to the transmission schedule.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] Various exemplary embodiments relate to telecommunications systems, and more particularly to an apparatus for transmitting data in a communication channel using a data control frame interval. [Background technology]

[0002] Multi-access point coordination (MAPC) is expected to play a key role in improving reliability and reducing latency in the upcoming IEEE 802.11bn standard (Wi-Fi 8). It allows access points (APs) from different networks to more effectively utilize spectrum resources within an overlapping basic service set (OBSS). New mechanisms for implementing MAPC have been developed, including multi-AP transmit opportunity (TXOP) sharing, cooperative spatial reuse, cooperative time division multiple access (TDMA), and cooperative beamforming. However, further improvements are still needed. Summary of the Invention [Problem to be solved by the invention]

[0003] An exemplary embodiment provides an apparatus (referred to as the first apparatus) comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least the steps of: determining a set of interfering devices that access a communication channel of a wireless communication system using communication links between the set of interfering devices, the set of interfering devices comprising a first apparatus; determining, for each communication link, a transmission schedule indicating a data control frame interval between a data frame and a corresponding control frame, the data control frame interval enabling reduced delay in transmission of the data frames by the set of devices; and controlling the set of interfering devices to transmit the data frames and the control frames on the communication channel in accordance with the transmission schedule.

[0004] An exemplary embodiment provides a method comprising the steps of determining a set of interfering devices that access a communication channel of a wireless communication system using communication links between the set of interfering devices; determining, for each communication link, a transmission schedule indicating a data control frame interval between a data frame and a corresponding control frame, wherein the data control frame interval enables reduced delay in transmission of data frames by the set of interfering devices; and controlling the set of interfering devices to transmit the data frames and the control frames on the communication channel according to the transmission schedule.

[0005] An exemplary embodiment provides a computer program comprising instructions that cause a device to perform at least the steps of: determining a set of interfering devices that access a communication channel of a wireless communication system using communication links between the set of interfering devices, the set of interfering devices comprising devices; determining, for each communication link, a transmission schedule indicating a data control frame interval between a data frame and a corresponding control frame, the data control frame interval enabling reduced delay in transmission of data frames by the set of devices; and controlling the set of devices to transmit the data frames and the control frames on the communication channel according to the transmission schedule.

[0006] An exemplary embodiment provides a non-transitory computer-readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least a method.

[0007] As used herein, "first," "second," etc. are used as labels for the preceding nouns and do not necessarily imply any type of ordering (e.g., spatial, temporal, logical), unless explicitly defined as such.

[0008] The accompanying drawings are included to provide a further understanding of the examples, and are incorporated in and constitute a part of this specification. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a flowchart of a method for transmitting data in a communication channel using data control frame intervals according to an example of the present subject matter. [Figure 2] FIG. 2 is a flowchart of a method for determining a set of interfering devices according to an example of the present subject matter. [Figure 3] FIG. 3 illustrates an exemplary wireless communication system in which the present subject matter may be implemented, by way of example. [Figure 4] FIG. 4 shows a signaling diagram illustrating a method for data transmission by a set of devices using the same communication channel of a wireless communication system, according to an example of the present subject matter. [Figure 5A] FIG. 5A is a signaling diagram illustrating an example of control or management frame transmission coordination for the operational phase of a Cooperative ACK (C-ACK) transmission method utilizing the MAPC protocol as the coordination framework, according to an example of the present subject matter. [Figure 5B] FIG. 5B illustrates access to a communication channel by a set of devices according to the C-ACK transmission method. [Figure 6A] FIG. 6A is a signaling diagram illustrating the operational steps of a C-ACK transmission method utilizing a multi-AP TXOP sharing protocol as a coordination framework, according to one example of the present subject matter. [Figure 6B] FIG. 6B illustrates access to a communication channel by a set of devices using a C-ACK transmission method with one TXOP. [Figure 6C] FIG. 6C illustrates access to a communication channel by a set of devices using the C-ACK transmission method with multiple TXOPs. [Figure 7A]FIG. 7A illustrates a signaling diagram showing the operational steps of a C-ACK transmission method utilizing the Block Acknowledgment (BACK) protocol as a coordination framework according to one example of the present subject matter. [Figure 7B] FIG. 7B illustrates access to a communication channel by a set of devices according to the C-ACK transmission method and the BACK protocol. [Figure 8] FIG. 8 is a block diagram illustrating an example of an apparatus according to an example of the present subject matter. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular architectures, interfaces, techniques, etc., in order to provide a thorough understanding of the examples. However, it will be apparent to those skilled in the art that the disclosed subject matter may be practiced in other illustrative embodiments that depart from these specific details. In some instances, detailed descriptions of well-known devices and / or methods are omitted so as not to obscure the description with unnecessary detail.

[0011] It may be necessary to enable simultaneous access for transmissions on the same communication channel. However, coordinating this access can introduce delays due to the need to manage and synchronize multiple transmissions. These delays may result from coordination overhead, the time required to resolve contention between links, or ensuring that all devices comply with prioritization rules. For example, in wireless communication systems, associating data frames with control frames can lead to higher latency because waiting for control frames such as acknowledgment (ACK) frames before transmitting the next data frame can cause delays. While these delays may be used to maintain orderly and efficient communications, they may also adversely affect time-sensitive data transmissions, potentially affecting overall network performance and user experience. The present subject matter can address this issue by enabling a coordination mechanism that balances the need for efficient simultaneous access with minimizing transmission delays, ensuring both high performance and timely data delivery. Specifically, the present subject matter may aim to utilize the benefits of associating data frames with control frames while minimizing its drawbacks by enabling efficient transmissions in a concurrent environment, thereby reducing delays in data transmissions. Additionally, this may allow for prioritization of low latency data, allowing for more rapid transmission compared to existing data transmission protocols.

[0012] A data frame may be a data packet structure that includes a data payload along with additional information. The additional information may include, for example, a header and trailer necessary for transmission. A data frame may serve as a basic unit of communication in a wireless communication system that defines how data is formatted and transmitted over the network of the wireless communication system. For example, a data frame may comprise a header that includes metadata about the frame, such as source and destination addresses, error checking information, and control information; a payload that is the actual data being transmitted, such as a segment of a file or video stream; and a trailer that includes error detection and correction information to ensure data integrity. The structure and contents of a data frame may vary depending on the particular networking protocol used by the wireless communication system.

[0013] A control frame may not carry a data payload in the sense of user data, but may include information necessary to manage or control communications within a network. Thus, a control frame, as used herein, may also refer to a management frame. For example, the structure of a control frame may comprise a header containing control information, such as source and destination addresses and other metadata related to a particular control function, and control information that replaces the data payload. This control information may include commands or signals useful for managing network operations, such as access control, error checking, and synchronization. A control frame may be, for example, an acknowledgement (ACK) frame, a block acknowledgement (BACK) frame, a request to send (RTS) frame, a clear to send (CTS) frame, or any other control frame associated with a data frame and facilitates transmission of the data frame based on the control information contained within the control frame.

[0014] A first device may be configured to access a communication channel of a wireless communication system. This access may include transmitting data using the communication channel. The wireless communication system may include a wireless network. The communication channel may be of a first wireless network of the wireless communication system. The first device may, for example, be connected to the first wireless network. A wireless network of a wireless communication system refers to a network including network nodes, such as access points, that are capable of wireless communication with devices connected to the wireless network. However, the communication channel may not be exclusively accessible by the first device because other devices may compete with the first device to use the same communication channel. Thus, these devices, including the first device, may form a set of interfering devices. The first device may have priority for first access to the communication channel.

[0015] A set of interfering devices may comprise a pair of devices, each pair defining a communication link for exchanging data, including both data frames and control frames, over the same communication channel. As a result, these communication links are defined between the set of interfering devices. Thus, the set of interfering devices may be described as being configured to access a communication channel of the wireless communication system using the communication link between the set of interfering devices. A communication link represents a logical connection between a pair of devices in the wireless communication system. In other words, a communication link is defined by the particular pair of devices involved. A communication channel refers to a particular frequency range, and transmitting data over this communication channel involves encoding the data into signals corresponding to frequencies within that range.

[0016] A set of interfering devices may be determined by a first device. The set of interfering devices may interfere because all of its members may compete for the same communication channel, potentially causing collisions and signal interference. Such contention may lead to delays, reduced data throughput, and reduced overall network efficiency. The present subject matter can address and solve this problem.

[0017] For ease of explanation, the set of interfering devices may be referred to as a set of devices. Each device in the set of devices may be, for example, an access point of the wireless network or a wireless device configured to connect to the wireless network. The wireless device may include a mobile station, a subscriber station, a remote terminal, a wireless terminal, a receiving point, a user device, a smartphone, a tablet, a laptop, an IoT device, or any other type of equipment capable of wireless communication within the wireless network.

[0018] The communication link defined between the set of devices may be a set of two or more communication links. The set of communication links may include at least one communication link defined by each pair of devices including the first device. The first device may be configured to determine a transmission schedule for the set of devices, which may reduce transmission delays of data frames by the set of devices compared to an existing schedule. For each communication link in the set of communication links, the transmission schedule may define a data control frame interval between data frames and corresponding control frames transmitted on each communication link. This may result in a set of data control frame intervals for the set of communication links, respectively. The set of data control frame intervals is defined by the first device to enable reduced delays in transmission of data frames by the set of devices.

[0019] For example, data may be transmitted over a communication link by pairing one or more data frames with a control frame, creating what is referred to as a data control pair. Multiple data control pairs may be transmitted on the same communication link. The number of data frames paired with a control frame in a data control pair may depend on the communication protocol used by the wireless communication system. For example, a data control pair may comprise one data frame and a corresponding control frame. Alternatively, a data control pair may comprise multiple data frames and corresponding control frames. Thus, "the transmission schedule indicates, for each communication link, the data control frame spacing between a data frame and its corresponding control frame" may mean that the transmission schedule indicates the data control frame spacing between each data control pair transmitted on each communication link. The transmission of a data control pair may be referred to as a transmission instance, and a transmission cycle refers to the process in which each communication link in a set of communication links completes one transmission instance. In one example, a transmission instance may include gaining access to a communication channel to enable transmission of a data control pair.

[0020] The first device may be configured to control the set of devices to transmit data frames and corresponding control frames in the communication channel according to a transmission schedule. For example, for each communication link Lx of the set of communication links, the pair of devices defining the communication link Lx may be controlled by the first device to transmit the data control pair using the communication channel according to the data control frame interval determined for the communication link Lx. This control may also relate to the communication link including the first device.

[0021] In one example, the transmission schedule may be determined for one transmission cycle.

[0022] In another example, the transmission schedule may be determined for multiple (consecutive) transmission cycles. In this case, the transmission schedule may be configured to include one individual schedule for each transmission cycle. In one example, the set of data control frame intervals governing these transmissions may be applied consistently across each of the individual schedules. Thus, in each transmission cycle, a set of devices may simultaneously access the communication channel.

[0023] For example, for each communication link Lx of the set of communication links, transmission of a data control pair may be performed as follows. For example, one or more transmission instances may be performed on the communication link Lx. The one or more transmission instances may be performed consecutively, one transmission instance after the other. A current transmission instance on the communication link Lx may include transmission of a data frame by one of a pair of devices defining the communication link Lx and transmission of a corresponding control frame by that device or the other of the pair. This transmission instance is performed such that the period from the end of reception of the data frame until the control frame is transmitted is a data control frame interval associated with the communication link Lx.

[0024] For simplicity, consider three wireless networks each including three communication links L1, L2, and L3. Each communication link is defined by an access point of the wireless network and a wireless device connected to the wireless network. For example, one transmission instance may be performed on each communication link. The transmission instance on communication link L1 may include a data frame df1 and a corresponding control frame cf1. The transmission instance on communication link L2 may include a data frame df2 and a corresponding control frame cf2. The transmission instance on communication link L3 may include a data frame df3 and a corresponding control frame cf3. For example, according to the cooperative framework, communication link L1 may have access to the communication channel first, followed by communication link L2, which may then be followed by communication link L3. A transmission schedule defined for the three communication links may indicate that df1 is transmitted first, followed by df2, and then df3. Then, control frames cf1, cf2, and cf3 may be transmitted only after the data frame has been transmitted, with the time interval between each data frame and its corresponding control frame being defined by the corresponding data-control frame interval. This may mean that transmission of control frames cf1 and cf2 is postponed until all data frames have been transmitted. This may speed up the transmission process of data frames df2 and df3 and reduce the delay in transmitting data frames by the set of devices for which communication links L1, L2, and L3 are defined. Alternatively, the transmission schedule defined for the three communication links may indicate that df1 is transmitted first, followed by df2, and then df3. Then, only control frame cf3 is postponed until after the data frame has been transmitted, with the time interval between each data frame and its corresponding control frame being defined by the corresponding data-control frame interval. This may speed up the transmission process of data frame df2 and reduce the delay in transmitting data frames by the set of devices for which communication links L1, L2, and L3 are defined.

[0025] The present subject matter may provide different types of associations between data frames and control frames. In one example, a control frame may be associated with a later data frame, meaning that after a data frame of a data control pair is transmitted, the corresponding control frame of the data control pair is transmitted to confirm its successful reception. This method can ensure data integrity and reliability by providing a mechanism for error detection and retransmission as needed. Conversely, a control frame of a data control pair may be transmitted a priori before the corresponding data frame of the data control pair to manage channel access and prevent collisions by ensuring that the communication link is clear before transmitting data. Thus, the present subject matter may utilize data-control frame spacing for different types of control frames. In one example, the present subject matter can advantageously use control frames as acknowledgment frames. In this approach, control frames involved in transmission scheduling will serve as acknowledgment frames or block acknowledgment frames. That is, the control frames can be ACK frames or BACK frames. This can be particularly beneficial because acknowledgment frames directly affect the delay between transmission instances, helping to optimize timing and reduce latency.

[0026] According to one example, the duration of a transmission instance includes transmitting a data frame, transmitting a control frame, and a data-control frame interval on the communication link. For example, the duration of a transmission instance includes transmitting the data frame and control frame of a data-control pair and the data-control frame interval on the communication link. The data-control frame interval indicates the point in time to transmit a control frame after transmitting the corresponding data frame, which occurs before the next transmission instance on the communication link. In this example, the transmission of the control frame may be postponed, but the postponement remains within certain limits to ensure that it does not extend beyond the duration of the current transmission instance and into the start of the next transmission instance.

[0027] "The duration of a transmission instance includes transmitting a data frame, transmitting a control frame, and a data control frame interval" may mean that the total time of a transmission instance encompasses the time required to transmit a data frame, the time required to transmit a control frame, and the data control frame interval between the data frame and the control frame. The time required to transmit a data frame (or a control frame) may be the time required to transmit the data frame from a source device to a destination device using a wireless signal. This time may include the generation of a signal for the data frame, the actual transmission of the signal, and any additional time required for processing and accessing a communication channel.

[0028] Sending a control frame before the transmission of the next transmission instance may ensure reliable communication. It may, for example, allow the transmitter to verify that the previous data frame was received successfully and without error, and allow for error detection and correction as necessary. This process may help manage the flow of data, prevent the transmitter from overwhelming the receiver, and ensure that each data frame is processed before the next data frame is sent.

[0029] According to one example, the data control frame interval of each communication link of the set of communication links may last for at least one of the duration of one or more transmission instances on each other communication link of the set of communication links, one or more default Arbitration Inter-Frame Spaces (AIFS), the transmission time of a BACK request, or the time to gain access to the communication channel.

[0030] Gaining access to a communication channel may include determining that the communication channel is free by listening to the communication channel and waiting for a suitable time slot, where, for example, the time slot may include a duration counted by a backoff timer for performing a data transmission on the communication channel.

[0031] One or more transmission instances on each other communication link of the set of communication links may belong to the same transmission cycle, i.e., the transmission instance used to define the data control frame interval for a particular transmission instance may belong to the same transmission cycle as that particular transmission instance.

[0032] To simplify the explanation of this example, consider an example of three wireless networks each including three communication links L1, L2, and L3. For example, the data control frame interval of communication link L1 may last the duration of one transmission instance on communication link L2, the duration of one transmission instance on communication link L3, and one or more AIFSs, the data control frame interval of communication link L2 may last the duration of one transmission instance and one or more AIFSs on communication link L3, and the data control frame interval of communication link L3 may last one AIFS because the transmission instances on L1 and L2 occurred before the transmission instance on L3.

[0033] Providing different types of timing intervals to be involved in each transmission cycle may allow the first device to flexibly determine the most appropriate data control frame interval for each communication link, ensuring that in each transmission cycle: a) each communication link is utilized for its transmission instance; and b) delays in transmitting data frames are minimized. The timing intervals may be determined based on the particular communication protocol employed by the wireless communication system.

[0034] According to one example, a wireless communication system includes a neighboring wireless network comprising a group of devices including a set of devices. A first device may be configured to determine the set of devices by collecting information indicative of capabilities of at least a subset of the group of devices of the wireless network and using the collected information to select a set of interfering devices. The subset of devices may be referred to as an initial group of devices.

[0035] This example may enable dynamic cooperation to effectively manage dense environments and overlapping networks. The decision to involve all devices or only a subgroup may depend on the network architecture and specific objectives, such as reducing interference or optimizing spectrum usage in a particular area. Collecting information from a subgroup of devices may allow cooperation to be focused on specific devices, such as those with adjacent or overlapping coverage areas. This targeted approach may streamline the process and reduce cooperation overhead. However, collecting information from an entire group of devices may help avoid missing any relevant interfering devices. The collected information for a given device may include the capabilities of the given device, such as supported frequency bands, channel width, transmit power levels, antenna configuration, quality of service (QoS) capabilities, support for specific protocols, and processing and buffering capacity. This information may help optimize network performance by leveraging the strengths and addressing limitations of the initial group of queried devices.

[0036] For device set selection, the initial group of devices can be refined. To that end, collected information can be used to initially determine a candidate set of interfering devices configured to access the communication channel. Refining the initial group into a candidate set of interfering devices can enable more targeted and efficient cooperation, focusing on devices with overlapping coverage or proximity. In this example, at least a first device, by gaining access to the communication channel and performing a selection operation, performs a selection of a set of interfering devices from a candidate set of interfering devices configured based on capabilities from among the candidate interfering devices for selection. The selection includes transmitting a trigger message to a subset of the candidate set of devices for triggering transmission according to the determined transmission schedule, receiving confirmation messages from at least some of the devices in response to transmitting the trigger message, and using the devices that provided the confirmation messages to select a set of interfering devices based on the confirmation messages. The selection of the set of interfering devices can be performed using the received confirmation messages. For example, the set of interfering devices may be the devices that provided the confirmation messages. In another example, if the device that provided the confirmation message is an access point, the set of interfering devices may include the access point and wireless devices served by the access point.

[0037] A subset of the candidate set of devices may be selected from the candidate set of devices, for example, based on selection criteria, which may involve, for example, random selection or preferential selection based on certain parameters such as performance, availability, or other predefined factors.

[0038] According to one example, the subset of devices may be access points. Furthermore, the first device may be an access point. This may be advantageous because the access point may act as a central control point in the wireless communication system and manage overall communications, resource allocation, and interference. This centralized approach may ensure consistent and reliable management of network resources. In this example, the set of interfering devices may be the subset of access points and wireless devices served by the access points.

[0039] The coordination mechanism according to the present subject matter can use a coordination framework defined, for example, by the Multi-AP TXOP Sharing protocol, the MAPC protocol, or the BACK protocol. The Multi-AP TXOP Sharing (TXS) protocol may provide a coordination framework for managing channel access by allowing devices to exclusively use a channel for a set period of time, enabling efficient data transmission. The MAPC protocol may establish coordination among multiple access points to optimize spectrum usage and reduce interference. The BACK protocol provides a coordination framework for efficiently acknowledging multiple data frames in a single message, which can reduce overhead. Thus, the present subject matter can operate smoothly and efficiently using these protocols for managing the access, coordination, and acknowledgment processes.

[0040] According to one example, a set of devices are controlled to perform their respective transmission instances during a shared transmit opportunity (TXOP). For example, a first device may have priority for first access to a communication channel, and a TXOP may be a time interval during which the first device has priority access to the communication channel. Sharing a TXOP may allow this opportunity to be divided among a set of devices, allowing the devices to transmit within the same TXOP. This approach can be used to improve efficiency and further reduce delays in the transmission of data frames by a set of devices. This is because the TXOP already configured by the first device can be fully utilized, thereby bypassing the steps that each device typically must take to establish its own TXOP. Examples of these individual steps include the time required to prepare and access the communication channel. For example, a transmission schedule can be determined for one transmission cycle occurring within the shared TXOP.

[0041] According to one example, the trigger message comprises one or more multi-user request-to-send (MU-RTS) TXS control frames for scheduling one or more devices within the same TXOP and querying information for determining transmission schedules, and the acknowledgement message comprises one or more clear-to-send (CTS) frames. The MU-RTS TXS and CTS frames are examples of frames used to extend TXOP sharing capabilities to support multi-AP TXOP sharing. The MU-RTS TXS control frame can be obtained by extending the MU-RTS frame to provide the ability to trigger other APs from other BSSs in upcoming shared TXOPs.

[0042] According to one example, a set of devices is configured to share one or more transmission opportunities for performing transmission of data frames by the set of devices, and a data control frame interval lasts within a single transmission opportunity or extends across two or more transmission opportunities.

[0043] According to one example, a wireless communication system is configured according to a MAPC protocol. A set of devices is controlled to transmit data frames and control frames according to a transmission schedule during a MAPC session established between the set of devices. For example, the sequence in which data frames and control frames are transmitted by each device of the set of devices may be determined according to the MAPC protocol, and data control frame intervals between data frames and control frames may be defined according to the transmission schedule. That is, once a set of devices is identified, the devices may be controlled to communicate according to the MAPC protocol with the additional constraint of adhering to a specified transmission schedule. In one example, a MAPC session may include the set of devices and other devices of a subset of devices or a candidate set of interfering devices.

[0044] Additionally, the first device can utilize existing signaling mechanisms defined for establishing and terminating a MAPC session to identify the set of devices, determine the transmission schedule, and terminate the use of the transmission schedule. According to one example, the wireless communication system is configured according to a MAPC protocol. The first device may be configured to perform the selection operation as part of establishing a MAPC session between the set of devices, wherein the trigger message comprises a MAPC coordination frame and the confirmation message comprises a MAPC adjustment frame.

[0045] According to one example, the MAPC coordination frame received from each device includes a delay metric, and the first device can be configured to determine a transmission schedule using the received delay metric.

[0046] In the MAPC protocol, the candidate set of interference devices refined from the initial group may be a MAPC group, i.e., the collected information may be used to determine the MAPC group using the MAPC protocol.

[0047] According to one example, a wireless communication system is configured according to a BACK protocol, where a set of devices are controlled to transmit data frames and control frames according to a transmission schedule during a BACK session established between the set of devices.

[0048] According to one example, a wireless communication system is configured according to a BACK protocol. A first device may be configured to perform a selection operation as part of establishing a BACK session between a set of devices. The trigger message includes an Addition Block Acknowledgment (ADDBA) request, and the confirmation message includes an ADDBA response. In one example, the BACK session may include the set of devices and other devices of a subset of devices or a candidate set of interfering devices.

[0049] According to one example, the data control frame interval includes the time during which the BACK request is executed. For example, the data control frame interval can be configured such that the time during which the BACK request is transmitted falls within the data control frame interval and the control frame is transmitted within a BACK block associated with the BACK request. The BACK request can be transmitted by any device in a set of devices of a given communication link and can be detected by a transmitter of each communication link in a set of communication links different from the given communication link.

[0050] According to an example, the first device may be configured to control the set of devices to terminate transmissions according to a transmission schedule.

[0051] Once a particular need for coordination between a set of devices is resolved, terminating the use of transmission schedules can optimize performance, minimize unnecessary complexity, and ensure that the wireless communications system operates efficiently and flexibly.

[0052] According to an example, a first device may be configured to modify a transmission schedule and control a set of devices to transmit data frames and control frames according to the modified transmission schedule.

[0053] Modifying transmission schedules instead of terminating them can enable dynamic adaptation to changing conditions while maintaining the benefits of cooperation. The network can continue to optimize performance in response to new traffic patterns, user densities, or interference levels. This flexibility ensures that the network remains efficient and effective without having to fully restart the cooperation process, thereby reducing downtime and maintaining seamless connectivity for users.

[0054] According to one example, the set of devices comprises access points and wireless devices of adjacent wireless networks of a wireless communication system.

[0055] The present subject matter can be seamlessly integrated into existing wireless communication systems, such as Wi-Fi systems. A wireless communication system according to the present subject matter can be a Wi-Fi system, but is not limited to Wi-Fi. It can also be adapted for use in other wireless communication systems, such as cellular networks, and any other protocol that involves managing access to a shared communication channel.

[0056] According to one example, the wireless communication system comprises a basic service set (BSS), and the set of devices comprises an access point and stations of an interfering BSS.

[0057] According to one example, determining the set of devices is performed by sensing inter-BSS transmissions to identify the presence of overlapping BSSs that may be used to form the set of devices.

[0058] Using BSS and control frames as acknowledgement frames (ACKs) can enable a cooperative mechanism for coordinating ACK transmissions. This concept is sometimes called cooperative ACK (C-ACK) transmission. Furthermore, this method not only covers intra-BSS transmissions, but also applies to inter-BSS transmissions.

[0059] 1 is a flowchart of a method for transmitting data in a communication channel of a wireless communication system according to an example of the present subject matter. The method of FIG. 1 may be performed by, for example, a first device such as the device of FIG.

[0060] In step 101, a set of interfering devices (a set of devices) configured to access the communication channel can be determined. The set of devices can be configured to access the communication channel using a communication link between the set of devices. The set of devices comprises a first device.

[0061] In step 103, a transmission schedule may be determined. The transmission schedule indicates or specifies, for each of the communication links, a data control frame interval between a data frame and a corresponding control frame. The data control frame interval enables reduced delay in transmitting data frames by the set of devices.

[0062] The set of devices may be controlled in step 105 to transmit data frames and control frames on the communication channel according to a transmission schedule.

[0063] 2 is a flowchart of a method for determining a set of interfering devices configured to access a communication channel of a wireless communication system according to an example of the present subject matter. The wireless communication system includes a neighboring wireless network comprising a group of devices. The method of FIG. 2 may be performed, for example, by a first device, such as the device of FIG. 8.

[0064] Information indicative of the overall capabilities of a group or subgroup of devices in a wireless network may be collected in step 201 .

[0065] The collected information may be used to select or choose a candidate set of interfering devices from the devices for which information was collected, step 203 .

[0066] The first device may gain access to a communication channel in step 205 .

[0067] In step 207, a trigger message may be transmitted to a subset of the candidate set of devices to trigger transmission according to the determined transmission schedule.

[0068] In response to transmitting the trigger message, confirmation messages may be received in step 209 from at least some of the devices that received the trigger message.

[0069] The device that provided the confirmation message may be used to select a set of interfering devices in step 211 based on the confirmation message.

[0070] 3 is a diagram illustrating an exemplary wireless communication system in which the present subject matter may be implemented according to one example. Wireless communication system 300 is a Wi-Fi system that includes two adjacent BSSs, BSS1 and BSS2. BSS1 includes access point AP1 and station STA1, and BSS2 similarly includes access point AP2 and station STA2.

[0071] As shown in Figure 3, in BSS1, an access point AP1 and a station STA1 are a pair of devices that define a communication link L1 via a communication channel, with one device functioning as a transmitter and the other device functioning as a receiver. In BSS2, an access point AP2 and a station STA2 are a pair of devices that define a communication link L2 via a communication channel, with one device functioning as a transmitter and the other device functioning as a receiver.

[0072] To perform transmissions on the two communication links L1 and L2 using the same communication channel, a prioritization mechanism such as the MAPC protocol may be used, which allows simultaneous access to the communication channel. However, this cooperative simultaneous access may result in delays due to the need to effectively manage and synchronize multiple transmissions. To address this issue, a transmission schedule may be determined for access points AP1 and AP2 and stations STA1 and STA2 in accordance with the present subject matter. For example, the method of FIG. 1 may be used to achieve this, where the first device may be access point AP1, and the set of devices may be access points AP1 and AP2 and stations STA1 and STA2. In the following description of the figure, APx may be referred to as access point APx or device APs. Similarly, STAx may be referred to as station STAx or device STAx.

[0073] For simplicity, only two wireless networks are shown, each consisting of one access point and one station, however, this configuration is not limited as it can be expanded to include multiple networks and multiple access points and stations within each network depending on specific requirements or use cases.

[0074] 4 is a signaling diagram illustrating a method for data transmission by a set of devices using the same communication channel of a wireless communication system according to an example of the present subject matter. The wireless communication system may be, for example, the wireless communication system 300 of FIG. 3. The method of FIG. 4 may be referred to as a cooperative ACK (C-ACK) transmission method. The C-ACK transmission method may be, for example, an exemplary embodiment of the method of FIG. 1.

[0075] As shown in FIG. 4 (400), a set of devices AP1, AP2, STA1, and STA2 may be obtained or selected according to a cooperation framework. The involved APs may be assumed to be in a cooperation agreement that allows them to exchange signaling messages, for example, to emphasize the transmission of ACKs and BACKs. This may allow some trust to be established between the BSSs, BSS1 and BSS2. The method may include three phases: a setup phase 401A, an operation phase 401B, and a termination or modification phase 401C. In this example, access point AP1 may gain access to the communication channel first, potentially due to an assigned priority.

[0076] In the setup phase 401A, the access point AP1 may begin the process by sending a discovery and setup request to the access point AP2 (402A). In response, the access point AP2 may reply with a discovery and setup response (402B). This may trigger the access point AP2 to send a discovery and setup request to the station STA2 (404A). In response, the station STA2 may reply with a discovery and setup response (404B). The access point AP1 may send a discovery and setup request to the station STA1 (403A). In response, the access point AP2 may reply with a discovery and setup response (403B).

[0077] Thus, the setup phase 401A may, for example, enable APs and their associated STAs to discover each other's capabilities and agree on terms for the cooperative ACK transmission method. The cooperative ACK transmission method may be implemented on devices configured with the cooperative ACK transmission function. For cooperative ACK capability discovery, cooperative access points AP1 and AP2 exchange frames to indicate support for features and potentially other information (e.g., traffic type). Based on the signaled information, the access points may trigger mechanisms during the access point's operation phase. Capabilities may be advertised in different ways depending on the cooperation framework used. Some examples of method advertisement or discovery are via beacons, MAPC-specific setup signaling, or the transmission or exchange of ADDBA frames. For cooperative ACK transmission method discovery and setup, each access point may also check whether its associated STAs support the feature. Capabilities can be advertised, for example, through beacons or association / reassociation frames, while setup can be performed through specific signaling (e.g., MAPC-specific frames, extended ADDBA request / response frames) that include C-ACK information such as the mode to be used, timeouts, etc.

[0078] In the operation phase 401B, the access point AP1 can initiate the operation phase by sending a C-ACK transmission trigger to the access point AP2 in step 405A. In response, the access point AP2 can respond with a C-ACK transmission response in step 405B. The sets of devices AP1, AP2, STA1, and STA2 can then exchange data according to the transmission schedule of the C-ACK transmission method. Specifically, the access point AP1 can transmit one or more data frames 406A. Upon transmitting these one or more data frames 406A, the access point AP1 can receive an ACK message 406B from the station STA1. If multiple data frames are transmitted under the BACK protocol, the ACK message 406B can be a BACK response. Similarly, the access point AP2 can transmit one or more data frames 407A. Upon transmission, the access point AP2 can receive an ACK message 407B from the station STA2, which can also be a BACK response if multiple frames are transmitted within the BACK protocol. The transmission schedule can be determined by the access point AP1. The transmission schedule may indicate how ACK frames may be deferred on communication links L1 and L2. To that end, the transmission schedule may define a data control frame interval 409A that indicates when ACK message 406B is transmitted. The transmission schedule may further define a data control frame interval 409B that indicates when ACK message 407B is transmitted. Data control frame interval 409A may, for example, enable ACK deferral for ACK message 406B, and data control frame interval 409B may, for example, enable ACK deferral for ACK message 407B.

[0079] Thus, once the setup phase 401A has taken place, immediately after accessing the communication channel, an access point AP1 (called a sharing device) that implements the C-ACK transmission function can trigger other devices (called shared devices) to coordinate their ACK / BACK frame transmissions. The other devices that receive the trigger can respond by indicating their willingness to coordinate ACK / BACK transmissions. From that point on, the transmission of data frames and ACK frames is performed as agreed upon. The sharing device and the shared device can agree on how ACK transmissions will be coordinated (e.g., in the same shared TXOP, separate TXOPs). For this purpose, several mechanisms are possible, and their specific implementation depends on the specific protocol used. MAPC coordination frames can, for example, be employed to first agree on the execution of the feature and then agree on the scheduling of the transmission of different types of frames (e.g., data and ACK frames). Within multi-AP TXOP sharing, such information can be carried by MU-RTS TXS and CTS frames. Alternatively, within TXOP sharing, a Block ACK Request (BAR) can be used to trigger ACK / BACK transmissions at the desired time. From the perspective of the receiver of the data transmission, the receiver may be aware of the ACK deferral procedure, which may signal the possibility of postponing the sending or receiving of the ACK, and the time when the ACK frame needs to be sent or received. This procedure may incur additional signaling, either for new frames or new fields.

[0080] In this example, the subset of devices queried during the setup phase by the first device, access point AP1, to select a set of devices includes access point AP2, but may also include other access points. For example, the signaling between access point AP1 and access point AP2 shown in the setup phase may be performed by access point AP1 with other access points in the subset. Furthermore, the setup phase may result in selecting a set of devices shown to include AP1, AP2, STA1, and STA2 for simplicity, but may comprise additional access points and associated stations in the subset. In this case, the operation schedule may indicate operations to be performed by access points AP1 and AP2 as well as the other access points and associated stations.

[0081] In the termination or modification phase 401C, the access point AP1 may initiate this phase by sending a termination or modification instruction to the access point AP2 (410A). In response, the access point AP2 may respond with a termination or modification response (410B). The access point AP2 may then send a termination or modification instruction to the station STA2 (412A). In response, the station STA2 may respond with a termination or modification response (412B). The access point AP1 may send a termination or modification instruction to the station STA1 (411A). In response, the station STA2 may respond with a termination or modification response (411B).

[0082] Thus, the termination or modification of the operation can be performed by each involved device. For such purpose, a control frame is used to indicate the finalization of the coordination, which triggers the modification / deletion of the associated buffers on both the AP and STA sides. Upon receiving the termination / modification request, the device acknowledges it by sending another message. The termination / modification of the C-ACK transmission method, as well as the configuration and operation of the C-ACK transmission method, differs depending on the embodiment. For example, MAPC signaling is used for modification and teardown, while specific signaling such as DELBA frames should be used within the BACK extension. For multi-AP TXOP sharing, given the dynamic approach where decisions are made independently for each shared TXOP, termination / modification may not be required.

[0083] As described with reference to Figure 4, the stages of the C-ACK transmission method may be implemented depending on the type of cooperation framework used. Figure 5A is a signaling diagram illustrating the operational stages of the C-ACK transmission method utilizing the MAPC protocol as the cooperation framework according to one example of the present subject matter. For simplicity, only the signaling between access points AP1 and AP2 is shown in the diagram.

[0084] The access point AP1 that has priority access to the communication channel according to the MAPC protocol may be referred to as a sharing device, and other contenders, such as access point AP2, may be referred to as shared devices. The procedure begins with access point AP1 accessing the communication channel in step 501, followed by sending a MAPC coordination frame (e.g., supporting both TXOP sharing and cooperative ACK transmission) to a potential shared AP, such as access point AP2, in step 502A. The MAPC coordination frame is a message that allows AP1 to search for other compatible APs (e.g., APs in the same MAPC group that implement the C-ACK function) to perform ACK deferral. Upon receiving the MAPC coordination frame, access point AP2 may respond to it by indicating its willingness to participate in ACK deferral in step 502B. At this point, low latency requirements (e.g., by indicating buffer status and current delay metrics) may be indicated by access point AP2 to access point AP1. Based on the received input, the access point AP1 then determines the moment when the ACK will be transmitted (e.g., at the end of the data transmission from the two APs) and communicates a scheduling decision to the involved devices STA1, STA2, and AP2, i.e., including the receiver of the transmission, in step 502C. The scheduling decision may indicate an ACK deferral for each communication link.

[0085] Thus, steps 503 to 507 may be performed based on a scheduling decision. In step 503, the access point AP1 transmits a data frame to the device STA1. The ACK message by the device STA1 may be postponed according to the scheduling decision, so that the access point AP2 may access the communication channel in step 504 to transmit the data frame to the device STA2 in step 505. According to the scheduling decision, the device STA2 may transmit an ACK frame with an ACK postponement in step 506, which may be equal to the gap time defined by the cooperation framework for transmitting the ACK message. According to the scheduling decision, the device STA1 may transmit an ACK frame with an ACK postponement to the access point AP1 in step 507 after the transmission instance between the access point AP2 and the device STA2 has ended. This may be done after the access point AP1 detects that the transmission on the communication link L2 has ended.

[0086] FIG. 5B illustrates access to a communication channel by a set of devices AP1, AP2, STA1, and STA2 according to the C-ACK transmission method. Each device in the set is associated with a timeline outlining the operations it performs according to the transmission schedule. The timeline defines the specific timing intervals involved in the device's transmission. For simplicity, the timing interval for the transmission of a frame may be the same as the timing interval for its reception, where the frame may be a data frame or a control frame. Additionally, the size of certain periods, such as AIFSs, is shown differently in the figure for simplicity, even if they are the same. The reference numerals 1, 2, 3, and 4 in the figure represent the countdown values ​​of backoff timers used to perform random backoff before accessing the communication channel. The backoff timer expires, for example, when it reaches zero.

[0087] After the backoff timer expires and the access point AP1 accesses the communication channel, the access point AP1 may perform actions according to the MAPC protocol during timing interval 511A before transmitting a data frame to the device STA1 during timing interval 511B. For example, during timing interval 511A, the access point AP1 may transmit a MAPC frame to the access point AP2. The device STA1 may receive the data frame during timing interval 512A. Receipt of an acknowledgment of receipt of the data frame by the device STA1 may be delayed by timing interval 511C, which may be the period between end 512B1 of receipt of the data frame and time 512B2 at which the device STA1 transmits the acknowledgment. Because the timing interval for transmission of a frame may be the same as the timing interval for its reception, the timing interval for postponing transmission of the acknowledgment 512B may be equal to the timing interval for postponing receipt of the acknowledgment 511C.

[0088] For example, access point AP2 may perform actions according to the MAPC protocol during timing interval 513A while attempting to access the communication channel. This is indicated by the start of timing interval 513A, which represents the status of a back-off timer for accessing the communication channel. For example, during timing interval 513A, the access point may receive a MAPC frame from access point AP1 and send a response (R). Access point AP2 may continue to gain access to the communication channel after access point AP1 completes transmission of its data frame, and this access gain lasts for timing interval 513C. For simplicity of illustration, timing interval 513B, during which the channel was busy, may correspond to timing interval 512A required to receive a data frame at device STA1. Thereafter, access point AP2 may transmit a data frame to device STA2 during timing interval 513D. Device STA2 may receive the data frame during timing interval 514A. Acknowledgment of receipt of the data frame by device STA2 may be postponed for timing interval 514B (which may be equal to timing interval 513E). Timing interval 514B may be equivalent to one AIFS. Access point AP2 may receive an acknowledgement frame from device STA2 during timing interval 513F.

[0089] The timing interval 512B for ACK deferral on communication link L1 involving access point AP1 and station STA1 may be defined according to the timing intervals for transmission on communication link L2 involving access point AP2 and station STA2, as shown in FIG. 5B, where the timing interval 512B for ACK deferral may be the sum of timing intervals 513C, 513D, 513E, 513F and one AIFS.

[0090] Timing intervals 512B and 514B may be examples of a set of data control intervals defined for communication links L1 and L2, respectively.

[0091] 6A is a signaling diagram illustrating the operational steps of a C-ACK transmission method utilizing a multi-AP TXOP sharing protocol as a cooperative framework, according to one example of the present subject matter. For simplicity, only signaling between access points AP1 and AP2 is shown in the diagram.

[0092] The procedure begins with access point AP1 accessing the communication channel in step 601, which then transmits a MU-RTS TXS control frame in step 602A to find candidates, such as access point AP2, for cooperation. Other APs, such as access point AP2, can then respond with a CTS frame in step 602B, which schedules a deferral of the ACK, thereby enabling access point AP2 to transmit low-latency data before the ACK from AP1's transmission. Based on the received input, access point AP1 then determines the moment at which the ACK will be transmitted (e.g., at the end of data transmission from the two APs) and communicates a scheduling decision to the participating devices STA1, STA2, and AP2, i.e., including the receiver of the transmission, in step 602C. The scheduling decision may indicate an ACK deferral for each communication link. As shown in Figures 6B and 6C, the operation steps (and the transmission of the deferred ACK) can occur within the same shared TXOP or different shared TXOPs, respectively.

[0093] Thus, steps 603 to 606 may be performed based on the scheduling decision. In step 603, the access point AP1 transmits a data frame to the device STA1. The ACK message by the device STA1 may be postponed according to the scheduling decision, and thus the access point AP2 may transmit a data frame to the device STA2 in step 604. According to the scheduling decision, the device STA2 may transmit an ACK frame with an ACK postponement, which may be equal to the gap time defined by the cooperation framework for transmitting the ACK message, in step 605. According to the scheduling decision, the device STA1 may transmit an ACK frame with an ACK postponement to the access point AP1 after the transmission instance between the access point AP2 and the device STA2 has ended in step 606.

[0094] FIG. 6B illustrates access to a communication channel by a set of devices AP1, AP2, STA1, and STA2 using the C-ACK transmission method. Each device in the set is associated with a timeline outlining the operations it performs according to a transmission schedule. The timeline defines the specific timing intervals involved in the device's transmission. For simplicity, the timing interval for a frame's transmission may be the same as the timing interval for its reception, where the frame may be a data frame or a control frame. Additionally, the size of certain periods, such as AIFSs, is shown differently in the diagram for simplicity, even if they are the same. The reference numerals 1, 2, 3, and 4 in the diagram represent the countdown values ​​of backoff timers used to perform random backoff before accessing the communication channel. The backoff timer expires, for example, when it reaches zero.

[0095] After the backoff timer expires and the access point AP1 accesses the communication channel, the access point AP1 may perform actions according to the multi-AP TXOP sharing protocol during timing interval 611A before transmitting a data frame to the device STA1 during timing interval 611B. During timing interval 611A, the access point AP1 may transmit an MU-RTS TXS frame to the access point AP2 and receive a CTS control frame from the access point AP2. The device STA1 may receive the data frame during timing interval 612A. Receipt of an acknowledgment of receipt of the data frame by the device STA1 may be delayed by timing interval 611C, which may be the period between end of reception of the data frame 612B1 and the time STA1 transmits the acknowledgment 612B2. Because the timing interval for transmission of a frame may be the same as the timing interval for its reception, this may mean that the timing interval for postponing transmission of the acknowledgment 612B may be equal to the timing interval for postponing reception of the acknowledgment 611C.

[0096] For example, the access point AP2 may perform actions according to the TXOP protocol during timing interval 613A while attempting to access the communication channel. This is indicated by the start of timing interval 613A, which represents the status of a backoff timer for accessing the communication channel. For example, during timing interval 613A, the access point AP2 may receive an MU-RTS TXS control frame from the access point AP1 and transmit a CTS control frame to the access point AP1. The access point AP2 may transmit a data frame to the device STA2 during timing interval 613B. The device STA2 may receive the data frame during timing interval 614A. An acknowledgment of receipt of the data frame by the device STA2 may be delayed during timing interval 614B (which may be equal to timing interval 613C). The timing interval 614B may be equal to one AIFS. The access point AP2 may receive an acknowledgment frame from the device STA2 during timing interval 613D.

[0097] The timing interval 612B for ACK deferral in communication link L1 involving access point AP1 and station STA1 may be defined according to the timing intervals involved in transmissions on communication link L2 involving access point AP2 and station STA2. This is shown in FIG. 6B, where the timing interval 612B for ACK deferral may be the sum of one AIFS, timing intervals 613B, 613C, and 613D, and another AIFS.

[0098] Timing intervals 612B and 614B may be examples of a set of data control intervals defined for communication links L1 and L2, respectively.

[0099] 6C illustrates the access of a communication channel by a set of devices AP1, AP2, STA1, and STA2 according to different C-ACK transmission methods with shared TXOP. The reference numerals 1, 2, 3, and 4 in the figure represent the countdown values ​​of backoff timers used to perform random backoff before accessing the communication channel. The backoff timer expires, for example, when it reaches zero.

[0100] The first shared TXOP (TXOP1) is used to transmit a data frame on the communication link L1. After the backoff timer expires and the access point AP1 accesses the communication channel, the access point AP1 may perform actions according to the multi-AP TXOP sharing protocol during timing interval 621A before transmitting a data frame to the device STA1 during timing interval 621B. The device STA1 may receive the data frame during timing interval 622A. Receipt of an acknowledgment of receipt of the data frame by the device STA1 may be delayed by timing interval 621C, which may be the period between end 622B1 of receipt of the data frame and time 622B2 when STA1 transmits the acknowledgment. Because the timing interval for transmission of a frame may be the same as the timing interval for its reception, the timing interval 622B for postponing transmission of the acknowledgment may be equal to timing interval 621C.

[0101] For example, access point AP2 may perform actions according to the multi-AP TXOP sharing protocol prior to timing interval 623A, during which access point AP2 gains access to the communication channel and thus may have a second TXOP (TXOP2). Access point AP2 transmits a data frame to device STA2 in timing interval 623B. Device STA2 may receive the data frame during timing interval 624A. Acknowledgment of receipt of the data frame by STA2 may be delayed for timing interval 624B (which may be equal to timing interval 623C). Timing interval 624B may be equivalent to one AIFS. Access point AP2 may receive an acknowledgment frame from device STA2 during timing interval 623D.

[0102] The timing interval 622B for ACK deferral in communication link L1 involving access point AP1 and station STA1 may be defined according to the timing intervals involved in transmissions on communication link L2 involving access point AP2 and station STA2. This is shown in FIG. 6C, where the timing interval 622B for ACK deferral may be the sum of timing intervals 623A, 623B, 623C, and 623D plus one AIFS. Thus, the timing interval 622B for deferring transmission of an acknowledgment extends over two transmission opportunities.

[0103] In this example of FIG. 6C, the receiver portion on communication link L2 is aware of the end of the transmission on communication link L1 (e.g., by overhearing the transmission of L1 or by being triggered by the transmitter, e.g., its own AP) and can therefore send an ACK at the correct time.

[0104] Timing intervals 622B and 624B may be examples of a set of data control intervals defined for communication links L1 and L2, respectively.

[0105] 7A is a signaling diagram illustrating the operational steps of a C-ACK transmission method utilizing the BACK protocol as a cooperation framework, according to an example of the present subject matter. For simplicity, only signaling between access points AP1 and AP2 is shown in the diagram.

[0106] The procedure begins with the access point AP1 accessing the communication channel in step 701. Then, in step 702A, the access point AP1 transmits an ADDBA request, which may include information for negotiating a C-ACK, such as information indicating whether a delayed or immediate method can be used for the ACK, the device responsible for triggering the BACK request, and the like, in addition to frame aggregation-related information. Upon receiving the ADDBA request, the access point AP2 may respond to it in step 702B, for example, by indicating its intention to be part of the ACK postponement. The access point AP1 determines a scheduling decision indicating the moment when the ACK is transmitted by the device STA1 (e.g., at the end of data transmission from the two APs). The scheduling decision may indicate an ACK postponement for each communication link. For example, the task of transmitting the BACK request may be offloaded to the access point AP2. To that end, a schedule may be agreed upon first, and the transmission of the ACK to the device STA1 may occur when the transmission from the access point AP2 ends, followed by the BACK request. For example, the scheduling decision may be communicated to access point AP2 in steps 702A and / or 702B. After transmitting or receiving data, access point AP2 may transmit a BACK request (not shown) that should be understood by both devices STA1 and STA2. Devices STA1 and STA2 then transmit BACK based on some timing reference. The timing reference may, for example, require one or more AIFS before transmitting BACK.

[0107] Thus, steps 703 to 707 may be performed based on a scheduling decision. In step 703, the access point AP1 transmits a data frame to the device STA1. The ACK message by the device STA1 may be postponed according to the scheduling decision, so that the access point AP2 can access the communication channel in step 704 to transmit a data frame to the device STA2 in step 705. According to the scheduling decision, the device STA2 may transmit an ACK frame with an ACK postponement, which may be equal to the gap time defined by the cooperation framework for transmitting the ACK message, in step 706. According to the scheduling decision, the device STA1 may transmit an ACK frame with an ACK postponement to the access point AP1 in step 707 after the transmission instance between the access point AP2 and the device STA2 has ended. This may be performed after detecting that a BACK request is provided on the communication link L2, as shown by the dashed line in FIG. 7A.

[0108] FIG. 7B illustrates access to a communication channel by sets of devices AP1, AP2, STA1, and STA2 according to the C-ACK transmission method. Each of the sets of devices is associated with a timeline outlining the operations it performs according to a transmission schedule. The timeline defines the specific timing intervals involved in the device's transmissions. For simplicity, the timing interval for the transmission of a frame may be the same as the timing interval for its reception, where the frame may be a data frame or a control frame. Additionally, the size of certain periods, such as AIFS, is shown differently in the drawing for simplicity, even if they are the same.

[0109] When timing interval 711A ends, the backoff timer expires, allowing access point AP1 to access the communication channel, and access point AP1 can transmit at least one data frame to device STA1 during timing interval 711B. Device STA1 may receive the data frame during timing interval 712A. Receipt of an acknowledgment of receipt of the data frame by device STA1 may be delayed by timing interval 711C, which may be the period between end of reception of the data frame 712B1 and time STA1 transmits the acknowledgment 712B2. Because the timing interval for transmission of a frame may be the same as the timing interval for its reception, timing interval 712B for postponing transmission acknowledgment may be equal to timing interval 711C. As shown in FIG. 7B , timing interval 712B for postponing transmission acknowledgment should end until the end of a predetermined period after device STA1 receives a BAR request from access point AP2, which may include, for example, one AIFS, the time required for access point AP2 to transmit or receive the acknowledgment, and additional AIFS.

[0110] For example, the access point AP2 may operate periodically and wait until the transmission between the access point AP1 and the device STA1 ends. For example, the end of this transmission may be detected automatically (e.g., no signaling is required for detection), and then, during timing interval 713A, the access point AP2 may perform one AIFS and backoff the remainder. From that point on, the access point AP2 may transmit data and, at some arbitrary point in time (which may be immediate or delayed based on the BACK nomenclature), transmit a BACK request (BAR), in this case intended for both STA1 and STA2. Thus, the access point AP2 may transmit at least one data frame to the device STA2 during timing interval 713B. The device STA2 may receive the data frame during timing interval 714A. An acknowledgment of the receipt of the data frame by the device STA2 may be delayed during timing interval 714B (which may be equal to timing interval 713C). The timing interval 714B may correspond to two AIFS and an RX BAR time. Access point AP2 may receive an acknowledgment frame from device STA2 during timing interval 713D.

[0111] The timing interval 712B for ACK deferral in communication link L1 involving access point AP1 and station STA1 may be defined according to the timing intervals involved in transmissions on communication link L2 involving access point AP2 and station STA2. This is shown in Figure 7B, where the timing interval 712B for ACK deferral may be the sum of timing intervals 713A, 713B, 713C, 713D and one AIFS.

[0112] Timing intervals 712B and 714B may be examples of a set of data control intervals defined for communication links L1 and L2, respectively.

[0113] For example, in the BACK protocol, a control frame transmission may occur where, at some point, one of the transmitters sends a BACK request that not only triggers a corresponding ACK / BACK transmission, but also triggers the transmission of delayed ACK / BACKs from other devices participating in the C-ACK transmission method. Figure 7A describes the case where the ACK trigger is sent by a single device but is interpreted by all participating receivers, including inter-BSS (e.g., non-associated) devices. Nevertheless, other triggering mechanisms are possible.

[0114] Therefore, in the present subject matter, the BACK feature is extended to enable ACK coordination of multiple devices, not necessarily within the same BSS. According to this approach, ACK transmissions from multiple transmitters are coordinated through an extended Block ACK request, which is proposed to trigger the transmission of ACKs from multiple devices at some agreed-upon time in the future, using either a default delay or a predefined extended delay. ACK multiplexing can be achieved in different ways, including a single trigger from a given device that schedules the transmission of different ACKs by multiplexing them into specific time / frequency resources, or through the ordered transmission of individual triggers transmitted by each transmitting source. The first approach may require inter-BSS communication capabilities (e.g., an AP or STA should be able to communicate with APs or STAs in other BSSs). In the second approach, only transmitters (e.g., APs) may be required to communicate with each other, but receivers would not rely on this process (they would only expect to receive ACK triggers from their transmitter counterparts). Figure 7B illustrates the case where a single trigger / BAR (transmitted by AP2) is used to initiate the transmission of different ACKs.

[0115] FIG. 8 shows a block circuit diagram illustrating a configuration of an apparatus 1070 configured to implement at least a portion of the present subject matter. The apparatus may be user equipment or an access point for wireless communication. It should be noted that the apparatus 1070 shown in FIG. 8 may include additional elements or functions in addition to those described below, which are not essential for understanding and are therefore omitted for brevity. Furthermore, the apparatus may also be another device having similar functionality, such as a chipset, chip, or module, which may also be part of the apparatus or attached to the apparatus 1070 as a separate element. The apparatus 1070 may include a processing function such as a central processing unit (CPU) or a processor or controller 1071 that executes instructions provided by a program associated with a flow control mechanism, for example. The processor 1071 may include one or more processing units dedicated to specific processing, as described below, or the processing may be performed within a single processor. The parts for performing such specific processing may also be provided as discrete elements or within one or more additional processors or processing parts, e.g., within one physical processor such as a CPU, or within several physical entities. Reference numeral 1072 denotes a transceiver or input / output (I / O) unit (interface) connected to the processor 1071. The I / O unit 1072 may be used to communicate with one or more other network elements, entities, terminals, etc. The I / O unit 1072 may be a composite unit comprising communication equipment for several network elements or may comprise a distributed structure with multiple different interfaces for different network elements. Reference numeral 1073 denotes a memory usable for storing data and instructions, e.g., programs executed by the processor 1071, and / or as working storage for the processor 1071.

[0116] The processor 1071 is configured to perform processing related to the subject matter described above. In particular, the device 1070 may be configured to perform a method such as that described in relation to FIG.

[0117] For example, the processor 1071 is configured to perform the steps of: determining a set of interfering devices configured to access a communication channel of the wireless communication system using communication links between the devices, the set of devices comprising devices; determining, for each communication link, a transmission schedule indicating a data control frame interval between a data frame and a corresponding control frame, the data control frame interval enabling reduced delay in transmission of the data frames by the set of devices; and controlling the set of devices to transmit the data frames and the control frames on the communication channel according to the transmission schedule.

[0118] As will be appreciated by those skilled in the art, aspects of the present invention may be embodied as an apparatus, a method, a computer program, or a computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, all of which may be referred to generally herein as a "circuit," "module," or "system." Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer-readable medium(s) having computer-executable code embodied therein. A computer program comprises computer-executable code or "program instructions."

[0119] Any combination of one or more computer-readable media may be utilized. A computer-readable medium may be a computer-readable storage medium. As used herein, "computer-readable storage medium" encompasses any tangible storage medium capable of storing instructions executable by a processor of a computing device. A computer-readable storage medium may also be referred to as a computer-readable non-transitory storage medium. A computer-readable storage medium may also be referred to as a tangible computer-readable medium. In some embodiments, a computer-readable storage medium may also be capable of storing data that can be accessed by a processor of a computing device.

[0120] "Computer memory" or "memory" is an example of a computer-readable storage medium. Computer memory is any memory that is directly accessible to a processor. "Computer storage" or "storage" is a further example of a computer-readable storage medium. Computer storage is any non-volatile computer-readable storage medium. In some embodiments, computer storage may also be computer memory, or vice versa.

[0121] As used herein, a "processor" encompasses an electronic component capable of executing a program or machine-executable instructions or computer-executable code. Reference to a computing device comprising a "processor" should be interpreted as including, in some cases, multiple processors or processing cores. A processor may be, for example, a multi-core processor. A processor may also refer to a collection of processors within a single computer system or distributed among multiple computer systems. The term computing device should also be interpreted as referring, in some cases, to a collection or network of computing devices, each comprising one or more processors. Computer-executable code may be executed by multiple processors, which may be within the same computing device or distributed across multiple computing devices.

[0122] Computer-executable code may include machine-executable instructions or programs that cause a processor to perform aspects of the present invention. Computer-executable code for performing operations for aspects of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages, such as the "C" programming language or similar programming languages, and compiled into machine-executable instructions. In some cases, the computer-executable code may be in the form of a high-level language or in pre-compiled form and may be used in conjunction with an interpreter that generates machine-executable instructions on the fly.

[0123] Generally, program instructions can be executed on one processor or several processors. In the case of multiple processors, they can be distributed across several different entities. Each processor can execute some of the instructions intended for that entity. Thus, when referring to a system or process involving multiple entities, it is understood that the computer program or program instructions are adapted to be executed by processors associated with or related to the respective entities.

Claims

1. at least one processor; at least one memory that stores instructions that, when executed by the at least one processor, at least, determining a set of interfering devices having access to a communication channel of a wireless communication system using communication links between the set of interfering devices, the set of interfering devices comprising the device; determining, for each communication link, a transmission schedule indicating a data control frame interval between a data frame and a corresponding control frame, the data control frame interval enabling a reduction in delay in transmission of data frames by the set of interfering devices; and controlling the set of interfering devices to transmit data frames and control frames on the communication channel according to the transmission schedule.

2. 2. The apparatus of claim 1, wherein the control frame comprises an acknowledgement frame.

3. 2. The apparatus of claim 1, wherein the transmission of the data frame and the corresponding control frame is referred to as a transmission instance, the duration of the transmission instance including transmitting the data frame, transmitting the control frame, and the data control frame interval on the communication link, the data control frame interval indicating a time point for transmitting the control frame after transmitting a corresponding data frame, the time point occurring before a next transmission instance on the communication link.

4. 2. The apparatus of claim 1, wherein the transmission of the data frame and corresponding control frame is referred to as a transmission instance, the duration of the transmission instance including transmitting the data frame, transmitting the control frame, and the data control frame interval on the communication link, the data control frame interval following at least one of the duration of one or more of the transmission instances on each other communication link, one or more default arbitration interframe spaces (AIFS), a time for transmission of a block acknowledgement (BACK) request, or a time for gaining access to the communication channel.

5. 2. The apparatus of claim 1, wherein a transmission of a data frame and a corresponding control frame is referred to as a transmission instance, and the set of interfering devices is controlled to perform each transmission instance during a shared transmission opportunity (TXOP).

6. 2. The device of claim 1 , wherein the wireless communication system follows a Multi-Access Point Coordination (MAPC) protocol, and the set of interfering devices are controlled to transmit the data frames and control frames according to the transmission schedule during a MAPC session established between the set of interfering devices.

7. 10. The apparatus of claim 1, wherein the wireless communication system follows a block acknowledgement (BACK) protocol, and the set of interfering devices are controlled to transmit the data frames and control frames according to the transmission schedule during a BACK session established between the set of interfering devices.

8. The wireless communication system comprises a neighboring wireless network comprising a group of devices including the set of interfering devices, and the instructions, when executed by at least one of the processors, further comprise: at least, collecting information indicative of the overall capabilities of the group or subgroup of devices of the wireless network; 2. The apparatus of claim 1, wherein the step of determining the interfering devices is performed by the apparatus by using the collected information to select the set of interfering devices.

9. The instructions, when executed by at least one of the processors, at least, gaining access to said communication channel; performing a selection operation to select the set of interfering devices from the candidate set based on capabilities; The step of performing the selection operation includes: transmitting a trigger message to a subset of the candidate set of devices for triggering transmission according to the determined transmission schedule; receiving confirmation messages from at least some of the devices in response to sending the trigger message; 10. The apparatus of claim 8, further comprising: using the device that provided the confirmation message to select the set of interfering devices based on the confirmation message.

10. 10. The apparatus of claim 1, wherein the instructions, when executed by at least one of the processors, further cause the apparatus to perform the step of controlling the set of interfering devices to terminate transmissions according to the transmission schedule.

11. 10. The apparatus of claim 1, wherein the instructions, when executed by at least one of the processors, further cause the apparatus to perform the steps of modifying the transmission schedule and controlling the set of interfering devices to transmit data frames and control frames in accordance with the modified transmission schedule.

12. 10. The apparatus of claim 1, wherein the set of interfering devices comprises access points and wireless devices of neighboring wireless networks of the wireless communication system.

13. The wireless communication system includes:

13. The apparatus of any preceding claim, comprising a Basic Service Set (BSS), wherein the set of interfering devices comprises access points and stations of the interfering BSS.

14. determining a set of interfering devices that access a communication channel of the wireless communication system using a communication link between the set of interfering devices; determining, for each communication link, a transmission schedule indicating a data control frame interval between a data frame and a corresponding control frame, the data control frame interval enabling a reduction in delay in transmission of data frames by the set of interfering devices; and controlling the set of interfering devices to transmit data frames and control frames on the communication channel according to the transmission schedule.

15. at least, determining a set of interfering devices that have access to a communication channel of a wireless communication system using communication links between the set of interfering devices, the set of interfering devices comprising devices; determining, for each communication link, a transmission schedule indicating a data control frame interval between a data frame and a corresponding control frame, the data control frame interval enabling a reduction in delay in transmission of data frames by the set of interfering devices; and controlling the set of interfering devices to transmit data frames and control frames on the communication channel according to the transmission schedule.

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