WO2021230764A1

WO2021230764A1 - Devices and methods for a wireless multi ap network

Info

Publication number: WO2021230764A1
Application number: PCT/RU2020/000224
Authority: WO
Inventors: Andrey Vladimirovich KLIMAKOV; Jie Chen; Wensimi BAI; Dmitri Alfredovich SHMELKIN; Defu SUN
Original assignee: Huawei Technologies Co., Ltd
Priority date: 2020-05-15
Filing date: 2020-05-15
Publication date: 2021-11-18

Abstract

The present invention relates to a device (1) for operating as an access point, AP, in a wireless Multi AP network. The device (1) is configured to receive (S44) a message (3) over a wireless medium from one or more neighboring APs (2), the message (3) comprising information indicative of first traffic over the wireless medium, the first traffic being managed by the one or more neighboring APs (2). Further, the device is configured to change (S45, S46, S51, S52, S53) one or more own Enhanced Distributed Channel Access, EDCA, parameters for one or more access categories, ACs, (AC0, AC1, AC2, AC3) on the basis of the received information. The present invention further relates to a system comprising at least one such device and a method for managing a wireless communication over a wireless medium by such a device.

Description

DEVICES AND METHODS FOR A WIRELESS MULTI AP NETWORK

TECHNICAL FIELD

The present disclosure relates to devices for operating as an access point (AP) in a wireless Multi AP network, a system comprising such devices and a method for managing a wireless communication over a wireless medium by a device of such devices.

BACKGROUND

A wireless LAN, Local Area Network, system (WLAN system), such as a Wi-Fi system, uses a scheme called Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA). Examples of such a WLAN system are the WLAN system according to the industry standard IEEE 802.1 lac, also known as Wi-Fi 5, or the WLAN system according to the industry standard IEEE 802.1 lax, also known as Wi-Fi 6.

The principle of CSMA/CA is (1) ‘‘listen before you talk” and (2) if you collide by speaking at the same time as someone else, wait a random time before you try again.

Using a back-off counter as a random value in a range of [0, CW:=CWMin] for each access category (AC) and updating Contention Window Value CW:=min{2*CW, CWMax} in case of collision is called Enhanced Distributed Channel Access (EDCA), wherein CW is the Contention Window Value, CWMin is the Minimum Contention Window and CWMax is the Maximum Contention Window. That is, the initial back-off counter respectively back-off wait time is determined from an initial range, wherein CWMin is the upper limit of the initial range. After each collision, the initial range is changed by doubling CWMin after each collision (2*CW) until CWMax is reached, or until no collision and, thus, a successful transmission occurs, or until the packet is dropped by the maximum delay time. Dropping the packet by the maximum delay time allows staying in the queue policy of the WLAN system, in particular in the WLAN MAC (Media Access Control) queue policy.

An Access Point (AP) shares an own EDCA parameter set in beacon frames, and each station (client) can overwrite the own EDCA parameter set to the EDCA parameter set of the AP. Different values of the EDCA parameters, such as CWMin, CWMax and the Arbitrated Interframe Space (AIFS), for different ACs determine respectively set different probability air channel accesses for the different ACs in the whole network. The AIFS is a minimum waiting time for sending a new frame.

SUMMARY

Embodiments of the invention base also on the following considerations made by the inventors:

As shown in Figure 1, there may be four different ACs: The Voice AC labeled by the reference sign “ AC3 ”, the Video AC labeled by the reference sign “ACT”, the Best Effort AC labeled by the reference sign “ ACl ” and the Background AC labeled by the reference sign “A CO”. The priority of the Voice AC may be higher than the priority of the other three ACs. That is, a Voice AC frame is send with higher priority compared to a frame of any of the other three ACs. The priority of the Video AC may be higher than the priority of the Best Effort AC and Background AC. That is, a Video AC frame is send with higher priority compared to a frame of the Best Effort AC and Background AC. The priority of the Best Effort AC may be higher than the priority of the Background AC. That is, a Best Effort AC frame is send with higher priority compared to a frame of the Background AC.

The terms “send” and “transmit” may be used as synonyms.

As shown in Figure 1, after a busy medium (i.e. one or more frames are sent over the wireless medium in the WLAN system (the wireless network)), it is waited for a time interval called Short Interframe Space (SIFS) for sending a new frame. The AIFS is for each AC different and, thus, the four different ACs AC0, ACl, AC2 and AC3 have a different priority. The AIFS is an example of an EDCA parameter. The higher the priority of an AC the lower is the AIFS. Therefore, the AIFS [3] of the Voice AC AC3 is shortest, the AIFS [2] of the Video AC AC2 is shorter than the AIFS [1] of the Best Effort AC ACl and the AIFS [0] of the Background AC AC0 is longest.

In addition to the AIFS, the priority of the different ACs may be set/changed by the CWMin and CWMax, which are further examples of EDCA parameters. Therefore, the higher the priority of an AC the lower is the respective CWMin and CWMax of the AC. By changing CWmin and/or CWmax for the different ACs the traffic of the different ACs may be more or less prioritized for all devices (stations/clients) in a wireless network, such as a WLAN network, and the network capacity may be increased.

Adaptive EDCA management, i.e. changing one or more EDCA parameters, such as CWMin and/or CWMax, for the different ACs, with the goal of increasing network capacity (total network goodput) without decreasing Quality of Service, QoS, may be provided for one wireless network, such as WLAN network, with one Access Point (AP). For example, this may be achieved by decreasing the CWMin of the Best Effort AC and Background AC and increasing at the same time the CWMin and CWMax of the Video AC and the Voice AC, such that the QoS of the Video AC and the Voice AC is still acceptable.

However, in a wireless multi AP network, such as a WLAN multi AP network, a plurality of APs with adaptive EDCA management use the same wireless medium respectively channel. Since each AP of these APs takes decisions independently of the other APs with respect to the adaptive EDCA management of the respective traffic managed by the AP, the QoS decreases below an acceptable QoS, in particular for the higher priority ACs, such as Voice AC and Video AC, due to increasing interference and collisions between the traffics over the wireless medium managed by the different APs.

In view of the above-mentioned problems and disadvantages, embodiments of the present invention aim to propose a solution for increasing throughput for less prioritized ACs, such as the Best Effort AC and the Background AC, and total throughput in a wireless Multi AP network, without changes or with only negligible changes of the QoS with regard to more prioritized ACs, such as the Video AC and Voice AC, for neighboring APs of the wireless Multi AP network that share the same wireless medium (in particular, they may share a primary channel and optionally one or more extended channels) and are located close to each other such that they are configured to receive messages from each other. An objective is to provide a device for operating as an access point (AP) in a wireless Multi AP network that is configured to perform an adaptive EDCA management in order to increase throughput for less prioritized ACs, such as the Best Effort AC and the Background AC, and total throughput in a wireless Multi AP network, without changes or with only negligible changes of the QoS with regard to the more prioritized ACs, such as the Video AC and Voice AC. The objective is achieved by the embodiments of the invention as described in the enclosed independent claims. Advantageous implementations of the embodiments of the invention are further defined in the dependent claims.

A first aspect of the present disclosure provides a device for operating as an access point (AP) in a wireless Multi AP network. The device is configured to receive a message over a wireless medium from one or more neighboring APs, the message comprising information indicative of first traffic over the wireless medium, the first traffic being managed by the one or more neighboring APs. Further, the device is configured to change one or more own Enhanced Distributed Channel Access (EDCA) parameters for one or more access categories, ACs, on the basis of the received information.

Since the device according to the first aspect considers the information indicative of the first traffic over the wireless medium, which is managed by one or more neighboring APs, when changing one or more own EDCA parameters for performing an adaptive EDCA management, the device according to the first aspect may increase throughput for less prioritized ACs, such as the Best Effort AC and the Background AC, and total throughput in the wireless Multi AP network, without changes or with only negligible changes of the QoS with regard to more prioritized ACs, such as the Video AC and Voice AC.

The device may be referred to by the terms “transceiver device " and “ network device". Since the device is a device for operating as an AP in a wireless Multi AP network, the device is configured to operate as an AP in the wireless Multi AP network and, thus, the device may function as an AP in the wireless Multi AP network. Therefore, when the device is being used as an AP in a wireless Multi AP network, it may be referred to as an access point (AP) of the one or more APs of the wireless Multi AP network.

In particular, the device is configured to receive from each of the one or more neighboring APs a message that comprises information indicative of first traffic over the wireless medium, which is managed by the respective neighboring AP.

In an implementation form of the first aspect, the wireless Multi AP network is a wireless LAN (WLAN) network, e.g. a Wi-Fi network. In particular, the wireless Multi AP network may be a WLAN network according to the industry standard IEEE 802.1 lac, also known as Wi-Fi 5. Alternatively or additionally, the wireless Multi AP network may be a WLAN network according to the industry standard IEEE 802.1 lax, also known as Wi-Fi 6.

A wireless Multi AP network is a wireless network with two or more APs.

The one or more own EDCA parameters may comprise or correspond to one or more of the Minimum Contention Window (CWMin), the Maximum Contention Window (CWMax), the Arbitrated Interframe Space (AIFS), and the Transmit Opportunity, TXOP.

The TXOP is an interval of time, when a device (station/client) has the right to initiate transmissions towards the Access Point (AP).

In particular, the wireless medium is an air channel.

In an implementation form of the first aspect, the device is configured to change one or more own EDCA parameters for two or more ACs on the basis of the received information. In particular, the device may be configured to change one or more own EDCA parameters for one or more high priority ACs, such as the Voice AC and/or Video AC, and one or more low priority ACs, such as the Best Effort AC and/or the Background AC.

The device according to the first aspect may comprise a transmission (Tx) circuitry, a reception (Rx) circuitry and a processing circuitry which are configured to cooperate to perform the various operations and methods described herein.

The processing circuitry is configured to perform, conduct or initiate the various operations of the device described herein. The processing circuitry may comprise hardware and/or software. Alternatively or additionally, the processing circuitry may be controlled by software. The hardware may comprise analog circuitry or digital circuitry, or both analog and digital circuitry. The digital circuitry may comprise components such as application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), digital signal processors (DSPs), or multipurpose processors. The device may further comprise memory circuitry, which stores one or more instruction(s) that can be executed by the processing circuitry, in particular under control of the software. For instance, the memory circuitry may comprise a non-transitory storage medium storing executable software code which, when executed by the processing circuitry, causes the various operations of the device to be performed.

In one embodiment, the processing circuitry comprises one or more processors and a non- transitory memory connected to the one or more processors. The non-transitory memory may carry executable program code which, when executed by the one or more processors, causes the device to perform, conduct or initiate the operations or methods described herein.

The first traffic managed by one neighboring AP may refer to messages respectively frames that are communicated, in particular send/transmitted, over the wireless medium, wherein the communication of said messages respectively frames is managed by the neighboring AP. The terms “ communication traffic ” or “frame traffic” may be used as synonyms for the term “traffic". The transmission of the messages respectively frames may be prioritized according to the ACs. That is a high priority AC frame, such as a Voice AC frame (VO AC frame) or Video AC frame (VI AC frame), is transmitted with a higher priority than a low priority AC frame, such as a Best Effort AC frame (BE AC frame) or Background AC frame (BK AC frame).

The information indicative of the first traffic managed by an AP may comprise, or correspond to, information indicative of first downlink (DL) traffic over the wireless medium managed by the neighboring AP and/or information indicative of first uplink (UL) traffic over the wireless medium managed by the neighboring AP.

In particular, the downlink (DL) traffic managed by an AP corresponds to the traffic starting from the AP to one or more stations, i.e. in the direction of the one or more stations. The uplink (UL) traffic managed by an AP corresponds to the traffic starting from one or more stations to the AP, i.e. in the direction of the AP.

In an implementation form of the first aspect, the device is configured to send a message over the wireless medium to one or more neighboring APs, the message comprising information indicative of second traffic over the wireless medium, the second traffic being managed by the device itself. This has the advantage of the one or more neighboring APs being able to use the information of the second traffic managed by the device for an adaptive EDCA management, in case the one or more neighboring APs are configured for an adaptive EDCA management by changing one or more respective own EDCA parameters for one or more access categories on the basis of the received information (from the device).

In an implementation form of the first aspect, the device is configured to change one or more own EDCA parameters for one or more ACs on the basis of the received information (from the one or more neighboring APs) and the information indicative of the second traffic managed by the device itself.

A message may comprise or correspond to one or more frames.

The second traffic managed by the device may refer to messages respectively frames that are communicated, in particular send/transmitted, over the wireless medium, wherein the communication of said messages respectively frames is managed by the device. The terms “ communication traffic ” or “frame traffic” may be used as synonyms for the term “traffic”. As outlined already above, the transmission of the messages respectively frames may be prioritized according to the ACs. That is a high priority AC frame, such as a Voice AC frame (VO AC frame) or Video AC frame (VI AC frame), is transmitted with a higher priority than a low priority AC frame, such as a Best Effort AC frame (BE AC frame) or Background AC frame (BK AC frame).

The information indicative of the second traffic may comprise, or correspond to, information indicative of second downlink (DL) traffic over the wireless medium managed by the device and/or information indicative of second uplink (UL) traffic over the wireless medium managed by the device.

In particular, the downlink (DL) traffic managed by the device corresponds to the traffic starting from the device to one or more stations, i.e. in the direction of the one or more stations. The uplink (UL) traffic managed by the device corresponds to the traffic starting from one or more stations to the device, i.e. in the direction of the device. In an implementation form of the first aspect, the message of the device is a beacon frame and the device is configured to periodically broadcast the beacon frame. Alternatively or additionally the message of the one or more neighboring APs is a beacon frame that is periodically broadcasted by the one or more neighboring APs.

This has the advantage, that the information indicative of the second traffic is periodically shared with the neighboring APs. Thus, the one or more neighboring APs may base the management of the respective first traffic, in particular an adaptive EDCA management, on the basis of up-to-date information. The same applies for the message of the one or more neighboring APs being a beacon frame. Namely, this has the advantage, that the information indicative of the respective first traffic of the one or more neighboring APs is periodically shared with the device. Thus, the device may base the management of the second traffic, in particular an adaptive EDCA management by changing one or more own EDCA parameters for one or more ACs, on the basis of up-to-date information.

In an implementation form of the first aspect, the information indicative of the second traffic is stored within one or more fields of the public section of the beacon frame of the device. Alternatively or additionally, the information indicative of the first traffic is stored within one or more fields of the public section of the beacon frame that is periodically broadcasted by the one or more neighboring APs.

According to an embodiment, in a WLAN network, such as a wireless Multi AP network, each AP, in particular the device according to the first aspect and its implementation forms and/or the one or more neighboring APs, broadcasts beacon frames (e.g. each 100ms by default) with different information described in the respective WLAN (e.g. Wi-Fi) industry standard, such as IEEE 802.1 lac, also known as Wi-Fi 5, or IEEE 802.1 lax, also known as Wi-Fi 6. This different information may include Service Set Identifier (SSID), Rates, Very High Throughput (VHT), Quality of Service (QoS) parameters (e.g. Wi-Fi Multimedia (WWM), Wireless Multimedia Extensions (WME) with EDCA) and vendor specific information. The public section of a beacon frame may correspond to the fields for the vendor specific information, i.e. the fields given to vendors for their purposes. That is, said vendor fields respectively one or more fields of the public section may be used for storing the information indicative of the first traffic in case of a beacon frame from a neighboring AP or the information indicative of the second traffic in case of a beacon frame from the device. Thus, said fields may be used for AP cooperation between the APs of the Multi AP network, in particular between the device and the one or more neighboring APs, to improve QoS.

In an implementation form of the first aspect, the information of the message of the device comprises one or more Quality of Service (QoS) indicators of one or more high priority AC frames lastly transmitted and/or received by the device. Additionally or alternatively, the information of the message receivable by the device comprises one or more QoS indicators of one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs.

In other words, the information of the message of the device may comprise one or more QoS indicators of one or more high priority AC frames lastly transmitted by the device. These lastly transmitted one or more high priority AC frames are frames of the downlink (DL) traffic managed by the device. Alternatively or additionally, the information of the message of the device may comprise one or more QoS indicators of one or more high priority AC frames lastly received by the device. These lastly received one or more high priority AC frames are frames of the uplink (UL) traffic managed by the device.

The information of the message receivable by the device from each of the one or more neighboring APs may comprise one or more QoS indicators of one or more high priority AC frames lastly transmitted by the respective neighboring AP. These lastly transmitted one or more high priority AC frames are frames of the DL traffic managed by the respective neighboring AP. Alternatively or additionally, the information of the message receivable by the device from each of the one or more neighboring APs may comprise one or more QoS indicators of one or more high priority AC frames lastly received by the respective neighboring AP. These lastly received one or more high priority AC frames are frames of the UL traffic managed by the respective neighboring AP.

A high priority AC frame lastly transmitted by the device may correspond to the top frame in the respective high priority AC transmit queue of the device until the moment of the transmission. For example, in case the high priority AC frame corresponds to the Voice AC frame (VO AC frame), then the VO AC frame lastly transmitted by the device corresponds to the top frame in the Voice AC transmit queue (VO AC transmit queue) of the device until the moment of the transmission. The same applies for the neighboring APs. That is, a high priority AC frame lastly transmitted by a neighboring AP may correspond to the top frame in the respective high priority AC transmit queue of the neighboring AP until the moment of the transmission.

The " top frame " in a transmit queue may also be referred to as the frame in the front of the queue, or as the frame that is next for transmission.

In an implementation form of the first aspect, the device is configured to change the one or more own EDCA parameters on the basis of the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs.

In an implementation form of the first aspect, the device is configured to change the one or more own EDCA parameters on the basis of the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs and the device itself.

That is, the device may be configured to change the one or more own EDCA parameters on the basis of the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs and the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the device itself.

In an implementation form of the first aspect, the device is configured to decrease the Minimum Contention Window (CWMin) and/or the Maximum Contention Window (CWMax) as the one or more own EDCA parameters of one or more low priority AC frames and at the same time to increase the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames, in case the one or more QoS indicators are less or equal to a first threshold for the one or more QoS indicators. Additionally, the device is configured to rollback the change of the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames, in case the one or more QoS indicators are greater than the first threshold.

In other words, the device may be configured to decrease the CWMin and/or the CWMax of the one or more low priority AC frames and at the same time to increase the CWMin and/or CWMax of the one or more high priority AC frames, in case the one or more QoS indicators are less or equal to a first threshold for the one or more QoS indicators.

Additionally, the device is configured to rollback the change of the CWMin and/or the CWMax of the one or more low priority AC frames and the change of the CWMin and/or the CWMax of the one or more high priority AC frames, in case the one or more QoS indicators are greater than the first threshold.

In an implementation form of the first aspect, the one or more QoS indicators correspond to the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs. In another implementation form of the first aspect, the one or more QoS indicators correspond to the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs and the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the device.

By decreasing the CWMin and/or the CWMax of the one or more low priority AC frames, such as the Best Effort AC frame and/or the Background AC frame, and at the same time increasing the CWMin and/or the CWMax of the one or more high priority AC frames, such as the Voice AC frame and/or the Video AC frame, the priority of the low priority AC frames is increased. As a result, the throughput for less prioritized ACs, such as the Best Effort AC and the Background AC, and total throughput in a wireless Multi AP network is increased. The QoS with regard to more prioritized ACs, such as the Video AC and Voice AC, is not effected negatively (i.e. the effect on the QoS is negligible), because the device is configured to rollback the change of the CWMin and/or CWMax of the one or more low priority AC frames and one or more high priority AC frames, in case the one or more QoS indicators are greater than the first threshold.

In an implementation form of the first aspect, the device may be configured to decrease, starting from the respective initial value, the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more low priority AC frames, and at the same time to increase, starting from the respective initial value, the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames, in case the one or more QoS indicators are less or equal to a first threshold for the one or more QoS indicators. Additionally, according to said implementation form, the device may be configured to rollback the change of the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames such that the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames correspond to the respective initial values, in case the one or more QoS indicators are greater than the first threshold.

In another implementation form of the first aspect, the device may be configured to decrease, starting from the respective initial value, the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more low priority AC frames, and at the same time to increase, starting from the respective initial value, the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames, in case the one or more QoS indicators are less or equal to a first threshold for the one or more QoS indicators. Additionally, the device may be configured to increase the CWMin and/or the CWMax as the one or more own EDCA parameters of the one or more low priority AC frames back in the direction towards the respective initial value, and at the same time to decrease the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames back in the direction towards the respective initial value, in case one or more QoS indicators are greater than the first threshold.

In an implementation form of the first aspect, the passage “ increasing/decreasing a parameter back in the direction towards the respective initial value^’’^'' is to be understood as “ increasing/decreasing the parameter in the direction towards the respective initial value, but not setting the parameter immediately to the respective initial value”. The parameter (one or more own EDCA parameters) may be increased/decreased stepwise or continuously over a time period greater than a minimum time period.

Therefore, according to said implementation form, in case one or more QoS indicators are greater than the first threshold, the device is configured to increase the CWMin and/or the CWMax as the one or more own EDCA parameters of the one or more low priority AC frames in the direction towards the respective initial value, wherein the CWMin and/or the CWMax of the one or more low priority AC frames are not set immediately to the respective initial value, and at the same time to decrease the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames in the direction towards the respective initial value, wherein the CWMin and/or the CWMax of the one or more high priority AC frames are not set immediately to the respective initial value.

In an implementation form of the first aspect, the term “ rollback ” is to be understood as not a full rollback but a reverse type action. That is, the device may be configured to gradually increase the CWMin and/or the CWMax as the one or more own EDCA parameters of the one or more low priority AC frames back in the direction towards the respective initial value, and at the same time to gradually decrease the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames back in the direction towards the respective initial value, in case one or more QoS indicators are greater than the first threshold.

The initial values of the CWMin and CWMax of one or more low priority AC frames is higher than the initial values of the CWMin and CWMax of the one or more high priority AC frames.

In an implementation form of the first aspect, the one or more QoS indicators comprise at least one of a delay time, a queuing time, a number of packets or total size of transmit queue, a packet error rate, and a packet loss ratio of the one or more high priority AC frames.

That is the one or more QoS indicators may comprise a delay time of the one or more high priority AC frames, and/or a queuing time of the one or more high priority AC frames, and/or a number of packets in the transmit queue, or the total size of the transmit queue, in the device, and/or a packet error rate of the one or more high priority AC frames, and/or a packet loss ratio of the one or more high priority AC frames.

In particular, the one or more QoS indicators of one or more high priority AC frames lastly transmitted by the device or a neighboring AP (i.e. one or more QoS indicators of one or more high priority AC frames of a downlink (DL) traffic) may comprise at least one of a delay time, a queuing time, a number of packets or total size of transmit queue, a packet error rate, and a packet loss ratio of the one or more high priority AC frames lastly transmitted by the device respectively the neighboring AP.

The delay time of the one or more high priority AC frames lastly transmitted (i.e., the delay time of the one or more high priority AC frames of a DL traffic) may be referred to as a “preparing for transmission delay time”. The delay time of a frame lastly transmitted by the device or a neighboring AP may correspond to the delay time of the frame lastly transmitted. Alternatively, the delay time of a frame lastly transmitted by the device or a neighboring AP may correspond to the average delay time of one or more last/previous frames transmitted by the device or the neighboring AP. In particular, the delay time of a frame lastly transmitted by the device or a neighboring AP may correspond to the average delay time of one or more last/previous frames transmitted by the device or the neighboring AP that form an aggregated statistic of transmissions, collected over a time period.

The queuing time of the one or more high priority AC frames lastly transmitted (i.e. the queuing time of the one or more high priority AC frames of a DL traffic) may be referred to as a “preparing for transmission queuing time”. The queuing time of a frame lastly transmitted by the device or a neighboring AP may correspond to the queuing time of the top frame in the respective transmit queue until the moment of the transmission.

The size of the transmit queue of the one or more high priority AC frames lastly transmitted (i.e. the size of the transmit queue of the one or more high priority AC frames of a DL traffic) may be referred to as “preparing for transmission queue size”. The size of the transmit queue may be defined by the number of packets or in bytes.

The packet error rate of the one or more high priority AC frames lastly transmitted (i.e. the packet error rate of the one or more high priority AC frames of a DL traffic) may be referred to as “ transmitted packet error rate”. The transmitted packet error rate may correspond to an aggregated statistic of transmissions, collected over a time period. The packet loss ratio of the one or more high priority AC frames lastly transmitted (i.e. the packet loss ratio of the one or more high priority AC frames of a DL traffic) may be referred to as “ transmitted packet loss ratio”. The transmitted packet loss ratio may correspond to an aggregated statistic of transmissions, collected over a time period.

Moreover, in particular, the one or more QoS indicators of one or more high priority AC frames lastly received by the device or a neighboring AP (i.e. one or more QoS indicators of one or more high priority AC frames of a uplink (UL) traffic) may comprise a packet error rate, and/or a packet loss ratio of the one or more high priority AC frames lastly received by the device respectively the neighboring AP.

The packet error rate of the one or more high priority AC frames lastly received (i.e. the packet error rate of the one or more high priority AC frames of a UL traffic) may be referred to as “ eceived packet error rate”. The received packet error rate may correspond to an aggregated statistic of transmissions, collected over a time period.

The packet loss ratio of the one or more high priority AC frames lastly received (i.e. the packet loss ratio of the one or more high priority AC frames of a UL traffic) may be referred to as “ received packet loss ratio”. The received packet loss ratio may correspond to an aggregated statistic of transmissions, collected over a time period.

Therefore, depending on the one or more QoS indicators, the first threshold may comprise or correspond to a threshold value for the delay time, and/or a threshold value for the queuing time, and/or a threshold value for the number of packets in the transmit queue, and/or a threshold value for the total size of the transmit queue, and/or a threshold value for the packet error rate (in particular, a threshold value for the received packet error rate and/or a threshold value for the transmitted packet error rate), and/or a threshold value for the packet loss ratio (in particular, a threshold value for the received packet loss ratio and/or a threshold value for the transmitted packet loss ratio).

For example, the queuing time of the top Video AC frame (VI AC frame)/ Voice AC frame (VO AC frame) in a Video AC transmit queue (VI AC transmit queue)/Voice AC transmit queue (VO AC transmit queue) may be an integer value in an interval between 0 to 500 ms and can be decoded in 2 bytes. As described above, besides the queuing time other QoS indicators may be shared. A threshold value for the queuing time as an QoS indicator may e.g. be larger than 100 ms, in particular may be 200 ms.

The “ top frame ” in a transmit queue may also be referred to as the frame in the front of the queue or as the frame that is next for transmission. In particular, the top frame in a transmit queue is the frame with the highest time of staying in the transmit queue among the frames of the transmit queue.

In an implementation form of the first aspect, the device is configured to change the one or more own EDCA parameters on the further basis of the amount of messages, in particular beacon frames, received within a time interval from the one or more neighboring APs.

In an implementation form of the first aspect, the device is configured to change the one or more own EDCA parameters on the further basis of the amount of messages, in particular beacon frames, received within a time interval from the one or more neighboring APs, in addition to the one or more QoS indicators.

As outlined already above, in an implementation form of the first aspect, the one or more QoS indicators correspond to the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs. In another implementation form of the first aspect, the one or more QoS indicators correspond to the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs and the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the device.

In an implementation form of the first aspect, the device is configured to decrease the CWMin and/or the CWMax as the one or more own EDCA parameters of one or more low priority AC frames and at the same time to increase the CWMin and/or CWMax as the one or more own EDCA parameters of one or more high priority AC frames, in case the device received within a first time interval messages, in particular beacon frames, from all neighboring APs. Additionally, the device is configured to rollback the change of the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames, in case the device did not receive within a second time interval messages, in particular beacon frames, from one or more neighboring APs.

In case the device does not receive messages, in particular beacon frames, from one or more neighboring APs within the second time interval, the device has not considered/taken into account said one or more neighboring APs until a message is received again from said one or more APs. Therefore, in case the device has not received messages, in particular beacon frames, from one or more neighboring APs for a too long time (longer than the second time interval), the device has not taken into account said one or more neighboring APs, in particular the first traffic managed by said one or more neighboring APs, for a too long time (longer than the second time interval). Therefore, in such a case the device is configured to perform the above described rollback.

By decreasing the CWMin and/or the CWMax of the one or more low priority AC frames, such as the Best Effort AC frame and or the Background AC frame, and at the same time increasing the CWMin and/or the CWMax of the one or more high priority AC frames, such as the Voice AC frame and/or the Video AC frame, the priority of the low priority AC frames is increased. As a result, the throughput for less prioritized ACs, such as the Best Effort AC and the Background AC, and total throughput in a wireless Multi AP network is increased. The QoS with regard to more prioritized ACs, such as the Video AC and Voice AC, is not effected negatively (i.e. the effect on the QoS is negligible), because the device is configured to rollback the change of the CWMin and/or CWMax of the one or more low priority AC frames and one or more high priority AC frames, in case the device did not receive within the second time interval messages, in particular beacon frames, from one or more neighboring APs.

In an implementation form of the first aspect, the device may be configured to decrease, starting from the respective initial value, the CWMin and/or the CWMax as the one or more own EDCA parameters of one or more low priority AC frames, and at the same time to increase, starting from the respective initial value, the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames, in case the device received within the first time interval messages, in particular beacon frames, from all neighboring APs. Additionally, the device may be configured to rollback the change of the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames such that the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames correspond to the respective initial values, in case the device did not receive within the second time interval messages, in particular beacon frames, from one or more neighboring APs.

In another implementation form of the first aspect, the device may be configured to decrease, starting from the respective initial value, the CWMin and/or the CWMax as the one or more own EDCA parameters of one or more low priority AC frames, and at the same time to increase, starting from the respective initial value, the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames, in case the device received within the first time interval messages, in particular beacon frames, from all neighboring APs. Additionally, the device may be configured to increase the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more low priority AC frames back in the direction towards the respective initial value, and at the same time to decrease the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames back in the direction towards the respective initial value, in case the device did not receive within the second time interval messages, in particular beacon frames, from one or more neighboring APs.

In an implementation form of the first aspect, the passage “ increasing/decreasing a parameter back in the direction towards the respective initial value'^’’ is to be understood as “ increasing/decreasing the parameter in the direction towards the respective initial value, but not setting the parameter immediately to the respective initial value". The parameter may be increased/decreased stepwise or continuously over a time period greater than a minimum time period.

Therefore, according to said implementation form, in case the device did not receive within the second time interval messages, in particular beacon frames, from one or more neighboring APs, the device may be configured to increase the CWMin and/or the CWMax as the one or more own EDCA parameters of the one or more low priority AC frames in the direction towards the respective initial value, wherein the CWMin and/or the CWMax of the one or more low priority AC frames are not set immediately to the respective initial value, and at the same time to decrease the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames in the direction towards the respective initial value, wherein the CWMin and/or the CWMax of the one or more high priority AC frames are not set immediately to the respective initial value.

In an implementation form of the first aspect, the term “ rollback ” is to be understood as not a full rollback but a reverse type action. That is, the device may be configured to gradually increase the CWMin and/or the CWMax as the one or more own EDCA parameters of the one or more low priority AC frames back in the direction towards the respective initial value, and at the same time to gradually decrease the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames back in the direction towards the respective initial value, in case the device did not receive within the second time interval messages, in particular beacon frames, from one or more neighboring APs.

In the above described implementation forms of the first aspect regarding a rollback, the device may be configured to rollback the change of the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames, in case the device did not receive within the second time interval messages, in particular beacon frames, from all neighboring APs.

In particular, the first time interval and the second time interval are different. More particular, the second time interval is longer/greater than the first time interval. The first time interval may beneficially be less than a half of maximum delay before packet is discarded in AC queue. For example, according to WLAN, in particular Wi-Fi, MAC (Media Access Control) queue management, packets which stay in transmission queue more than the maximum delay are discarded. Therefore, two time thresholds (the first and second time interval) are used for the adaptive EDCA management.

The terms “ transmission queue ” and “ transmit queue" may be used as synonyms. For example, the first time interval may be 200 ms and the second time interval may be 400 ms.

In an implementation form of the first aspect, the one or more high priority AC frames comprise a Voice AC frame (VO AC frame) and/or a Video AC frame (VI AC frame), wherein the VO AC frame is of higher priority than the priority of the VI AC frame; and the one or more low priority AC frames comprise a Background AC frame (BK AC frame) and/or a Best Effort AC frame (BE AC frame), wherein the VI AC frame is of higher priority than the priority of the BK AC frame and the BK AC frame is of higher priority than the priority of the BE AC frame.

That is, the device may be configured to change one or more own EDCA parameters, such as CWMin and/or CWMax, for one or more of the access categories Voice AC (VO AC), Video AC (VI AC), Best Effort AC (BE AC) and Background AC (BK AC).

In another implementation form of the first aspect, the one or more high priority AC frames comprise the VO AC frame and/or the VI AC frame, wherein the VO AC frame is of higher priority than the priority of the VI AC frame; and the one or more low priority AC frames comprise the BK AC frame and/or the BE AC frame, wherein the VI AC frame is of higher priority than the priority of the BE AC frame and the BE AC frame is of higher priority than the priority of the BK AC frame.

In order to achieve the device according to the first aspect of the present disclosure, some or all of the implementation forms and optional features of the first aspect, as described above, may be combined with each other.

A second aspect of the present disclosure provides a device for operating as an access point (AP) in a wireless Multi AP network, wherein the device is configured to send a message over a wireless medium to one or more neighboring access points, APs, the message comprising information indicative of traffic over the wireless medium, the traffic being managed by the device itself.

This has the advantage of the one or more neighboring APs being able to use the information of the traffic managed by the device for an adaptive EDCA management, in case the one or more neighboring APs are configured for an adaptive EDCA management by changing one or more respective own EDCA parameters for one or more ACs on the basis of the received information (from the device).

The device may be referred to by the terms “transceiver device ” and “ etwork device Since the device is a device for operating as an AP in a wireless Multi AP network, the device is configured to operate as an AP in the wireless Multi AP network and, thus, the device may function as an AP in the wireless Multi AP network. Therefore, when the device is being used as an AP in a wireless Multi AP network, it may be referred to as an access point (AP) of the one or more APs of the wireless Multi AP network.

A message may comprise or correspond to one or more frames.

The traffic managed by the device may refer to messages respectively frames that are communicated, in particular send/transmitted, over the wireless medium, wherein the communication of said messages respectively frames is managed by the device. The terms “ communication traffic ” or “frame traffic” may be used as synonyms for the term “traffic". The transmission of the messages respectively frames may be prioritized according to the ACs. That is a high priority AC frame, such as a Voice AC frame (VO AC frame) or Video AC frame (VI AC frame), is transmitted with a higher priority than a low priority AC frame, such as a Best Effort AC frame (BE AC frame) or Background AC frame (BK AC frame).

The information indicative of the traffic may comprise or correspond to information indicative of downlink (DL) traffic over the wireless medium managed by the device and/or information indicative of uplink (UL) traffic over the wireless medium managed by the device.

In particular, the downlink (DL) traffic managed by the device corresponds to the traffic starting from the device to one or more stations, i.e. in the direction of the one or more stations. The uplink (UL) traffic managed by the device corresponds to the traffic starting from one or more stations to the device, i.e. in the direction of the device.

In an implementation form of the second aspect, the wireless Multi AP network is a wireless LAN (WLAN) network, e.g. a Wi-Fi network. In particular, the wireless Multi AP network may be a WLAN network according to the industry standard IEEE 802.1 lac, also known as Wi-Fi 5. Alternatively or additionally, the wireless Multi AP network may be a WLAN network according to the industry standard IEEE 802.1 lax, also known as Wi-Fi 6.

The device according to the second aspect may comprise a transmission (Tx) circuitry, a reception (Rx) circuitry and a processing circuitry which are configured to cooperate to perform the various operations and methods described herein.

The processing circuitry is configured to perform, conduct or initiate the various operations of the device described herein. The processing circuitry may comprise hardware and/or software. Alternatively or additionally, the processing circuitry may be controlled by software. The hardware may comprise analog circuitry or digital circuitry, or both analog and digital circuitry. The digital circuitry may comprise components such as application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), digital signal processors (DSPs), or multipurpose processors.

The device may further comprise memory circuitry, which stores one or more instruction(s) that can be executed by the processing circuitry, in particular under control of the software. For instance, the memory circuitry may comprise a non-transitory storage medium storing executable software code which, when executed by the processing circuitry, causes the various operations of the device to be performed.

In an implementation form of the second aspect, the message of the device is a beacon frame and the device is configured to periodically broadcast the beacon frame.

This has the advantage, that the information indicative of the traffic is periodically shared with the neighboring APs. Thus, the one or more neighboring APs may base an adaptive EDCA management on the basis of up-to-date information. In an implementation form of the second aspect, the information indicative of the traffic, in particular the information indicative of the traffic and its QoS indicators, is stored within one or more fields of the public section of the beacon frame.

That is, in an implementation form of the second aspect, the information indicative of the traffic may be stored within one or more fields of the public section of the beacon frame. In a further implementation form of the second aspect, the information indicative of the traffic and its QoS indicators may be stored within one or more fields of the public section of the beacon frame.

According to an embodiment, in a WLAN network, such as a wireless Multi AP network, each AP, in particular the device according to the second aspect and its implementation form and/or the one or more neighboring APs, broadcasts beacon frames (e.g. each 100ms by default) with different information described in the respective WLAN (e.g. Wi-Fi) industry standard, such as IEEE 802.1 lac, also known as Wi-Fi 5, or IEEE 802.1 lax, also known as Wi-Fi 6. This different information may include Service Set Identifier (SSID), Rates, Very High Throughput (VHT), Quality of Service (QoS) parameters (e.g. Wi-Fi Multimedia (WWM), Wireless Multimedia Extensions (WME) with EDCA) and vendor specific information. The public section of a beacon frame may correspond to the fields for the vendor specific information, i.e. the fields given to vendors for their purposes. That is, said vendor fields respectively one or more fields of the public section may be used for storing the information indicative of the traffic, in particular the information indicative of the traffic and its QoS indicators, in case of a beacon frame from the device. Thus, said fields may be used for AP cooperation between the APs of the Multi AP network, in particular between the device and the one or more neighboring APs, to improve QoS.

In an implementation form of the second aspect, the information of the message comprises one or more QoS indicators of one or more high priority AC frames lastly transmitted and/or received by the device.

That is, the information of the message may comprise one or more QoS indicators of one or more high priority AC frames lastly transmitted by the device. Additionally or alternatively, the information of the message may comprise one or more QoS indicators of one or more high priority AC frames lastly received by the device. In an implementation form of the second aspect, the one or more QoS indicators comprise a delay time and/or a queuing time of the one or more high priority AC frames.

The one or more QoS indicators may comprise a delay time of the one or more high priority AC frames, and/or a queuing time of the one or more high priority AC frames, and/or a number of packets in the transmit queue, or the total size of the transmit queue, in the device, and/or a packet error rate of the one or more high priority AC frames, and/or a packet loss ratio of the one or more high priority AC frames.

In particular, the one or more QoS indicators of one or more high priority AC frames lastly transmitted by the device (i.e. one or more QoS indicators of one or more high priority AC frames of a downlink (DL) traffic) may comprise at least one of a delay time, a queuing time, a number of packets or total size of transmit queue, a packet error rate, and a packet loss ratio of the one or more high priority AC frames lastly transmitted by the device.

Moreover, in particular, the one or more QoS indicators of one or more high priority AC frames lastly received by the device (i.e. one or more QoS indicators of one or more high priority AC frames of a uplink (UL) traffic) may comprise a packet error rate, and/or a packet loss ratio of the one or more high priority AC frames lastly received by the device.

The implementation forms and optional features of the device according to the first aspect are correspondingly valid for the device according to the second aspect.

In order to achieve the device according to the second aspect of the present disclosure, some or all of the implementation forms and optional features of the second aspect, as described above, may be combined with each other. A third aspect of the present disclosure provides a system comprising one or more devices according to the first aspect or any implementation form thereof for operating as an access point (AP) and/or one or more devices according to the second aspect or any implementation form thereof for operating as an AP.

The one or more devices according to the first aspect or any implementation form thereof and/or the one or more devices according to the second aspect or any implementation form thereof may form respectively may be part of a wireless Multi AP network, wherein each device is configured to function as an AP in the wireless Multi AP network. That is, the system may comprise or correspond to a wireless Multi AP network.

The wireless Multi AP network may be a wireless LAN (WLAN) network, e.g. a Wi-Fi network. In particular, the wireless Multi AP network may be a WLAN network according to the industry standard IEEE 802.1 lac, also known as Wi-Fi 5. Alternatively or additionally, the wireless Multi AP network may be a WLAN network according to the industry standard IEEE 802.1 lax, also known as Wi-Fi 6.

The system of the third aspect and its implementation forms and optional features achieve the same advantages as the device of the first aspect and its respective implementation forms and respective optional features and/or the same advantages as the device of the second aspect and its respective implementation forms and respective optional features.

In order to achieve the system according to the third aspect of the present disclosure, some or all of the implementation forms and optional features of the third aspect, as described above, may be combined with each other.

A fourth aspect of the present disclosure provides a method for managing a wireless communication over a wireless medium by a device according to the first aspect or any implementation form thereof, comprising the steps of receiving, by the device, a message over the wireless medium from one or more neighboring APs, the message comprising information indicative of first traffic over the wireless medium, the first traffic being managed by the one or more neighboring APs, and changing, by the device, one or more own Enhanced Distributed Channel Access, EDCA, parameters for one or more access categories, ACs, on the basis of the received information.

In an implementation form of the fourth aspect, the method comprises the step of sending, by the device, a message over the wireless medium to one or more neighboring APs, the message comprising information indicative of second traffic over the wireless medium, the second traffic being managed by the device itself.

In an implementation form of the fourth aspect, the message of the device is a beacon frame and the device periodically broadcasts the beacon frame. Alternatively or additionally the message of the one or more neighboring APs is a beacon frame that is periodically broadcasted by the one or more neighboring APs.

In an implementation form of the fourth aspect, the information indicative of the second traffic is stored within one or more fields of the public section of the beacon frame of the device. Alternatively or additionally, the information indicative of the first traffic is stored within one or more fields of the public section of the beacon frame that is periodically broadcasted by the one or more neighboring APs.

In an implementation form of the fourth aspect, the information of the message of the device comprises one or more Quality of Service (QoS) indicators of one or more high priority AC frames lastly transmitted and/or received by the device. Additionally or alternatively, the information of the message receivable by the device comprises one or more QoS indicators of one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs.

In an implementation form of the fourth aspect, the device changes the one or more own EDCA parameters on the basis of the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs.

In an implementation form of the fourth aspect, the device changes the one or more own EDCA parameters on the basis of the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs and the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the device itself.

In an implementation form of the fourth aspect, the device decreases the Minimum Contention Window (CWMin) and/or the Maximum Contention Window (CWMax) as the one or more own EDCA parameters of one or more low priority AC frames and at the same time increases the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames, in case the one or more QoS indicators are less or equal to a first threshold for the one or more QoS indicators. The device rollbacks the change of the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames, in case the one or more QoS indicators are greater than the first threshold.

In an implementation form of the fourth aspect, the one or more QoS indicators comprise at least one of a delay time, a queuing time, a number of packets or total size of transmit queue, a packet error rate, and a packet loss ratio of the one or more high priority AC frames.

In particular, the one or more QoS indicators of one or more high priority AC frames lastly transmitted by the device or a neighboring AP (i.e. one or more QoS indicators of one or more high priority AC frames of a downlink (DL) traffic) may comprise at least one of a delay time, a queuing time, a number of packets or total size of transmit queue, a packet error rate, and a packet loss ratio of the one or more high priority AC frames lastly transmitted by the device respectively the neighboring AP. Moreover, in particular, the one or more QoS indicators of one or more high priority AC frames lastly received by the device or a neighboring AP (i.e. one or more QoS indicators of one or more high priority AC frames of a uplink (UL) traffic) may comprise a packet error rate, and/or a packet loss ratio of the one or more high priority AC frames lastly received by the device respectively the neighboring AP.

In an implementation form of the fourth aspect, the device changes the one or more own EDCA parameters on the further basis of the amount of messages, in particular beacon frames, received within a time interval from the one or more neighboring APs; in particular in addition to the one or more QoS indicators.

In an implementation form of the fourth aspect, the device decreases the CWMin and/or the CWMax as the one or more own EDCA parameters of one or more low priority AC frames and at the same time increases the CWMin and/or CWMax as the one or more own EDCA parameters of one or more high priority AC frames, in case the device received within a first time interval messages, in particular beacon frames, from all neighboring APs. The device rollbacks the change of the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames, in case the device did not receive within a second time interval messages, in particular beacon frames, from one or more neighboring APs.

In an implementation form of the fourth aspect, the one or more high priority AC frames comprise a Voice AC frame (VO AC frame) and/or a Video AC frame(VI AC frame), wherein the VO AC frame is of higher priority than the priority of the VI AC frame; and the one or more low priority AC frames comprise a Background AC frame (BK AC frame) and/or a Best Effort AC frame (BE AC frame), wherein the VI AC frame is of higher priority than the priority of the BK AC frame and the BK AC frame is of higher priority than the priority of the BE AC frame.

In another implementation form of the fourth aspect, the one or more high priority AC frames comprise the VO AC frame and/or the VI AC frame, wherein the VO AC frame is of higher priority than the priority of the VI AC frame; and the one or more low priority AC frames comprise the BK AC frame and/or the BE AC frame, wherein the VI AC frame is of higher priority than the priority of the BE AC frame and the BE AC frame is of higher priority than the priority of the BK AC frame.

The method of the fourth aspect and its implementation forms and optional features achieve the same advantages as the device of the first aspect and its respective implementation forms and respective optional features.

The implementation forms and optional features of the device according to the first aspect are correspondingly valid for the method according to the fourth aspect.

In order to achieve the method according to the fourth aspect of the present disclosure, some or all of the implementation forms and optional features of the fourth aspect, as described above, may be combined with each other.

It has to be noted that all devices, elements, units and means described in the present application could be implemented in software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be performed by external entities is not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof.

BRIEF DESCRIPTION OF DRAWINGS

The above described aspects and implementation forms will be explained in the following description of specific embodiments in relation to the enclosed drawings, in which

Figure 1 shows an example for sending a frame according to Enhanced Distributed

Channel Access (EDCA).

Figure 2 shows devices according to an embodiment of the invention. Figures 3A and 3B show a method according to an embodiment of the invention.

Figure 4 shows an example of a beacon frame.

Figure 5 shows an overview of a method according to an embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Figure 2 shows devices according to an embodiment of the invention.

The first device 1 is a device for operating as an access point (AP) in a wireless Multi AP network. The second device 2 is a neighboring AP of the first device 1. The first device 1 may correspond to the device according to the first aspect or any implementation form thereof. Therefore, the above description with respect to the device according to the first aspect and its implementation forms is correspondingly valid for the first device 1 and second device 2 of Figure 2.

The first device 1 is configured to receive a message 3 over a wireless medium, such as an air channel, from the second device 2 (neighboring AP). The message 3 comprises information indicative of first traffic (not shown in Figure 2) over the wireless medium, wherein the first traffic is managed by the second device 2 (neighboring AP). The device 1 is configured to change one or more own Enhanced Distributed Channel Access (EDCA) parameters for one or more access categories (ACs) on the basis of the received information of the message 3.

As outlined already above, the information indicative of the first traffic may comprise or correspond to information indicative of first downlink (DL) traffic over the wireless medium, wherein the first DL traffic is managed by the second device 2 (neighboring AP). Alternatively or additionally, the information of the first traffic may comprise or correspond to information indicative of first uplink (UL) traffic over the wireless medium, wherein the first UL traffic is managed by the second device 2 (neighboring device).

Since the first device 1 considers the information indicative of the first traffic over the wireless medium, which is managed by the second device (neighboring AP), when changing one or more own EDCA parameters for performing an adaptive EDCA management, the first device 1 may increase throughput for less prioritized ACs, such as the Best Effort AC and the Background AC, and total throughput in the wireless Multi AP network, without changes or with only negligible changes of the QoS with regard to more prioritized ACs, such as the Video AC and Voice AC.

As indicated in Figure 2, the first device 1 may optionally be configured to send a message 4 over the wireless medium to the second device 2 (neighboring AP). The message 4 comprises information indicative of second traffic over the wireless medium, wherein the second traffic is managed by the first device 1 itself.

As outlined already above, the information indicative of the second traffic may comprise or correspond to information indicative of second downlink (DL) traffic over the wireless medium, wherein the second DL traffic is managed by the first device 1. Alternatively or additionally, the information indicative of the second traffic may comprise or correspond to information indicative of second uplink (UL) traffic over the wireless medium, wherein the second UL traffic is managed by the first device 1.

This has the advantage of the second device 2 (neighboring AP) being able to use the information of the second traffic managed by the first device 1 for an adaptive EDCA management, in ¾ase the second device 2 is configured for an adaptive EDCA management by changing one or more respective own EDCA parameters for one or more ACs on the basis of the received information (from the device).

The second device 2 may correspond to the device according to the second aspect or any implementation form thereof. Therefore, the above description with respect to the device according to the second aspect and its implementation forms is correspondingly valid for the second device 2 of Figure 2.

The second device 2 is configured to send the message 3 over the wireless medium to the first device 1 (neighboring AP). The message 3 comprises information indicative of traffic (first traffic) over the wireless medium, wherein the traffic (first traffic) is managed by the second device 2 itself. This has the advantage of the first device (neighboring AP) being able to use the information of the traffic (first traffic) managed by the second device 2 for an adaptive EDCA management.

The first device 1 and the second device 2 are each a device for operating as an AP and may form or be part of a system 5. In particular, the first device 1 and the second device 2 may form a wireless Multi AP network and may function as APs of the wireless Multi AP network. In other words, the first device 1 and the second device 2 may be two APs of a Multi AP network.

The wireless Multi AP network may be a wireless LAN (WLAN) network, e.g. a Wi-Fi network, such as a WLAN network according to the industry standard IEEE 802.1 lac, also known as Wi-Fi 5, and/or a WLAN network according to the industry standard IEEE 802.1 lax, also known as Wi-Fi 6.

The above description with respect to the system according to the third aspect and its implementation forms is correspondingly valid for the system 5 of Figure 2.

According to Figure 2, besides the first device 1 there is only one neighboring AP (second device 2). As mentioned already above, there may be more than one neighboring AP. Thus, the first device 1 and one or more neighboring APs may form the system 5.

One or more of such one or more neighboring APs may correspond to the device according to the first aspect or any implementation form thereof. In an embodiment, each neighboring AP may correspond to the device according to the first aspect or any implementation form thereof.

Therefore, the first device 1, being a device for operating as an access point (AP) in a wireless Multi AP network, is configured to receive a message over the wireless medium from one or more neighboring APs (not shown in Figure 2). The message from each neighboring AP comprises information indicative of first traffic over the wireless medium, wherein the first traffic is managed by the respective neighboring AP. Further, the first device 1 is configured to change one or more own Enhanced Distributed Channel Access (EDCA) parameters for one or more access categories, ACs, on the basis of the received information.

An embodiment of a method, which may be performed by the first device 1 , for changing one or more own EDCA parameters for one or more ACs on the basis of the received information is described with regard to Figures 3 A and 3B below. That is, an embodiment of an adaptive EDCA management that may be performed by the first device 1 is described with regard to Figures 3 A and 3B below.

The first device 1 and the second device 2 each may comprise a transmission (Tx) circuitry, a reception (Rx) circuitry and a processing circuitry which are configured to cooperate to perform the various operations and methods described herein (not shown in Figure 2).

The processing circuitry (of the first device 1/second device 2) is configured to perform, conduct or initiate the various operations of the respective device (first device 1/second device 2) described herein. The processing circuitry may comprise hardware and/or software. Alternatively or additionally, the processing circuitry may be controlled by software. The hardware may comprise analog circuitry or digital circuitry, or both analog and digital circuitry. The digital circuitry may comprise components such as application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), digital signal processors (DSPs), or multipurpose processors.

The first device 1 and second device 2 each may further comprise memory circuitry, which stores one or more instruction(s) that can be executed by the processing circuitry, in particular under control of the software. For instance, the memory circuitry may comprise a non-transitory storage medium storing executable software code which, when executed by the processing circuitry, causes the various operations of the device to be performed.

In one embodiment, the processing circuitry (of the first device 1 /second device 2) comprises one or more processors and a non-transitory memory connected to the one or more processors. The non-transitory memory may carry executable program code which, when executed by the one or more processors, causes the respective device (first device 1/second device 2) to perform, conduct or initiate the operations or methods described herein.

Figures 3 A and 3B show a method according to an embodiment of the invention.

The above description with respect to the method according to the fourth aspect and its implementation forms is correspondingly valid for the method shown in Figures 3 A and 3B. The device for operating as an access point (AP) in a wireless Multi AP network indicated in Figures 3 A and 3B corresponds to the device according to the first aspect and its implementation forms. In particular, the device for operating as an AP of Figures 3A and 3B may correspond to the first device 1 (and optionally to the second device 2) of Figure 2. In the following description of the method of Figures 3A and 3B, the device for operation as an AP, such as the first device 1 of Figure 2, is only referred to by the term “device”. The device and one or more neighboring APs form a wireless Multi AP network.

At step S41, the device manages a traffic (second traffic) over a wireless medium. At the same time, at step S42, one or more neighboring APs manage a traffic (first traffic) over the same wireless medium. That is, each of the device and the one or more neighboring APs manage a traffic over the wireless medium. Namely, each of the one or more neighboring APs manage a respective first traffic over the wireless medium (step S42) and the device manages a second traffic over the wireless medium (step S41).

At step S43, each neighboring AP sends a message comprising information indicative of the respective first traffic. The message of each neighboring AP may be a beacon frame that is periodically broadcasted by the respective neighboring AP. The message of each neighboring AP comprises one or more QoS indicators of one or more high priority AC frames lastly transmitted and/or received by the respective neighboring AP. The one or more high priority AC frames may comprise a Voice AC frame (VO AC frame) and/or a Video AC frame (VI AC frame). The VO AC frame may be of higher priority than the priority of the VI AC frame.

The one or more QoS indicators comprise at least one of a delay time, a queuing time, a number of packets or total size of transmit queue, a packet error rate, and a packet loss ratio of the one or more high priority AC frames. In particular, the one or more QoS indicators of one or more high priority AC frames lastly transmitted by a neighboring AP may comprise at least one of a delay time, a queuing time, a number of packets or total size of transmit queue, a packet error rate, and a packet loss ratio of the one or more high priority AC frames lastly transmitted by the neighboring AP. In particular, the one or more QoS indicators of one or more high priority AC frames lastly received by a neighboring AP may be a packet error rate and/or a packet loss ratio of the one or more high priority AC frames lastly received by the neighboring AP. For the following description and, thus, only by way of example not limiting the present disclosure, the VO AC frame is considered as a high priority AC frame and only one QoS indicator of a VO AC frame lastly transmitted is used. Therefore, information of the message of each neighboring AP may comprise a QoS indicator of the VO AC frame lastly transmitted by the respective neighboring AP.

At step S44 the device receives the message from each neighboring AP, wherein the message comprises the respective one or more QoS indicators of one or more high priority AC frames lastly transmitted by the respective neighboring AP and/or the respective one or more QoS indicators of one or more high priority AC frames lastly received by the respective neighboring AP. For example, the device receives the message from each neighboring AP, wherein the message comprises a respective QoS indicator of the VO AC frame lastly transmitted by the respective neighboring AP.

At step S45 the device determines for each message received from the one or more neighboring APs whether the one or more QoS indicators of the respective message are less or equal to a first threshold for the one or more QoS indicators. For example, in case each message comprises only one QoS indicator, the device determines for each message received from the one or more neighboring APs whether the one QoS indicator of the respective message is less or equal to a first threshold for the one QoS indicator. In an embodiment, at step S45, the device determines additionally whether the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the device itself are less or equal to the first threshold value.

In case this is true for each message received by the device (Yes at step S45), the method proceeds to step S46. In case this is not true for one message received from the one or more neighboring APs, that is one QoS indicator of one message received from the one or more neighboring APs is greater than the respective first threshold (No at step S45), the method proceeds to step S53.

According to the above embodiment, in case the one or more QoS indicators of each message received by the device and the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the device itself are less or equal to the first threshold value for the one or more QoS indicators (Yes at step S45), the method proceeds to step S46. In case, one QoS indicator of one message received from the one or more neighboring APs or one QoS indicator of the one or more high priority AC frames lastly transmitted and/or received by the device itself is greater than the respective first threshold (No at step S45), the method proceeds to step S53.

At step S46, the device determines, whether it received within a first time interval messages from all neighboring APs. In case this is true, that is the device received within the first time interval a message from each neighboring AP of the one or more neighboring APs (Yes at step S46), the method proceeds to step S52. In case the device did not receive within the first time interval a message from each neighboring AP of the one or more neighboring APs (No at step S46), the method proceeds to step S51.

At step S51, the device determines, whether it did not receive within a second time interval messages from one or more neighboring APs. In case this is true (Yes at step S51), that is the device received within the second time interval no messages from one or more neighboring APs, the method proceeds to step S53. In case the device received within the second time interval messages from all neighboring APs (No at step S51), the method proceeds to step S41 again. That is, the method is performed again on the basis of new messages received by the device from the one or more neighboring APs.

At step S52, the device decreases the CWMin and/or the CWMax of one or more low priority AC frames, such as a BE AC frame and/or a BK AC frame, and at the same time increases CWMin and/or CWMax of one or more high priority AC frames, such as a VO AC frame and/or a VI AC frame. After step S52, the method proceeds to step S41 again. That is, the method is performed again on the basis of new messages received by the device from the one or more neighboring APs.

At step S53, the device rollbacks (performs a rollback of) a change of the CWMin and/or CWMax of the one or more low priority AC frames (e.g. the BE AC frame and/or the BK AC frame) and the one or more high priority AC frames (e.g. the VO AC frame and/or the VI AC fame).

At step S53, in particular, the device may increase the CWMin and/or the CWMax of the one or more low priority AC frames in the direction towards the respective initial value, wherein the CWMin and/or the CWMax of the one or more low priority AC frames are not set immediately to the respective initial value, and at the same time decrease the CWMin and/or CWMax of the one or more high priority AC frames in the direction towards the respective initial value, wherein the CWMin and/or the CWMax of the one or more high priority AC frames are not set immediately to the respective initial value.

That is, the term “rollback may be understood as not a full rollback but a reverse type action. Therefore, at step S53, the device may gradually increase the CWMin and/or the CWMax of the one or more low priority AC frames back in the direction towards the respective initial value, and at the same time gradually decrease the CWMin and/or CWMax of the one or more high priority AC frames back in the direction towards the respective initial value. After step S53, the method proceeds to step S41 again. That is, the method is performed again on the basis of new messages received by the device from the one or more neighboring APs.

In an embodiment, the device and the one or more neighboring APs each comprise a timer and are configured to periodically check the statistics. That is, the device is configured to periodically check the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the device. Each neighboring AP may be configured to periodically check the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by itself. The device is also configured to periodically check the information received from the one or more neighboring APs, that is the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs. The device is configured to perform an adaptive EDCA management, in particular as described with regard to the method of Figures 3 A and 3B, on the basis of the one or more QoS indicators received from the one or more neighboring APs and the own one or more QoS indicators. Thus, the device allows to achieve stability between different types of traffic (traffic of different ACs) managed by the device itself and between the traffic managed by neighboring APs (managed by the device and the one or more neighboring APs).

Figure 4 shows an example of a beacon frame.

The beacon frame (beacon packet) comprises a MAC header and a variable Frame Body, as shown in Figure 4. The Frame Body may comprise a mandatory part and an optional part, as shown in Figure 4. The optional part comprises or corresponds to the one or more fields of the public section of the beacon frame. In said fields of the public section of the beacon frame, the information indicative of the second traffic may be stored, in case a device for operating as an AP in a wireless Multi AP network, such as the device according to the first aspect and its implementation forms, sends (periodically broadcasts) the beacon frame shown in Figure 4 to one or more neighboring APs, wherein the second traffic is managed by the device itself. In said fields of the public section of the beacon frame, the information indicative of the first traffic managed by a neighboring AP of the device may be stored, in case the neighboring AP sends (periodically broadcasts) the beacon frame shown in Figure 4 to the device.

In a wireless Multi-AP network comprising two or more access points (AP), wherein one AP corresponds to a device according to the first aspect and its implementation forms, the method shown in Figure 5 may be performed for an adaptive EDCA management in the wireless Multi- AP network. In particular, each AP of the wireless Multi-AP network may correspond to a device according to the first aspect and its implementation forms.

Periodically an AP collects the statistics of the traffic managed by itself. The AP may periodically collect the statistics of the downlink (DL) traffic managed by itself and/or the statistics of the uplink (UL) traffic managed by itself. In particular, the AP determines one or more QoS indicators of one or more high priority AC frames, such as a VO AC frame and/or a VI AC frame, lastly transmitted and/or received by the AP itself. That is, the AP may determine one or more QoS indicators of one or more high priority AC frames lastly transmitted by the AP. Additionally or alternatively the AP may determine one or more QoS indicators of one or more high priority AC frames lastly received by the AP.

Next the AP obtains the statistics of each neighboring AP. That is, the AP receives/obtains a message, in particular a beacon frame, from each neighboring AP, wherein the message comprises information indicative of the traffic managed by the respective neighboring AP and statistics of said traffic. The message may comprise information indicative of the downlink (DL) traffic managed by the respective neighboring AP and statistics of said DL traffic. Additionally or alternatively, the message may comprise information indicative of the uplink (UL) traffic managed by the respective neighboring AP and statistic of said UL traffic. In particular, the message comprises one or more QoS indicators of one or more high priority AC frames, such as a VO AC frame and/or a VI AC frame, lastly transmitted and/or received by the respective neighboring AP. That is, the message may comprise one or more QoS indicators of one or more high priority AC frames lastly transmitted by the respective neighboring AP. Additionally or alternatively, the message may comprise one or more QoS indicators of one or more high priority AC frames lastly received by the respective neighboring AP.

Next the AP determines/calculates on the basis of the own statistics and the statistics received from the neighboring APs new own EDCA parameters. In particular, the AP changes one or more own EDCA parameters for one or more ACs on the basis of the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the AP itself and the one or more QoS indicators received from the neighboring APs.

Next the AP shares the new own EDCA and own statistics, in particular the own QoS indicators. In particular, the AP broadcasts this information in a beacon frame.

The present invention has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed invention, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word “comprising” does not exclude other elements or steps and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

1. A device (1) for operating as an access point, AP, in a wireless Multi AP network, wherein the device (1) is configured to receive (S44) a message (3) over a wireless medium from one or more neighboring APs (2), the message (3) comprising information indicative of first traffic over the wireless medium, the first traffic being managed by the one or more neighboring APs (2), and change (S45, S46, S51 , S52, S53) one or more own Enhanced Distributed Channel Access, EDCA, parameters for one or more access categories, ACs, (ACO, AC1, AC2, AC3) on the basis of the received information.

2. The device (1) according to claim 1, wherein the device (1) is configured to send a message (4) over the wireless medium to one or more neighboring APs (2), the message comprising information indicative of second traffic over the wireless medium, the second traffic being managed by the device (1) itself.

3. The device (1) according to claim 1 or 2, wherein the message (4) of the device (1) is a beacon frame and the device (1) is configured to periodically broadcast the beacon frame; and/or the message (3) of the one or more neighboring APs (2) is a beacon frame that is periodically broadcasted by the one or more neighboring APs (2).

4. The device (1) according to claim 3, wherein the information indicative of the second traffic is stored within one or more fields of the public section of the beacon frame of the device (1); and/or the information indicative of the first traffic is stored within one or more fields of the public section of the beacon frame that is periodically broadcasted by the one or more neighboring APs (2).

5. The device (1) according to any one of the previous claims, wherein the information of the message of the device (1) comprises one or more Quality of Service, QoS, indicators of one or more high priority AC frames lastly transmitted and/or received by the device (1), and/or the information of the message receivable by the device (1) comprises one or more QoS indicators of one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs (2).

6. The device (1) according to claim 5, wherein the device (1) is configured to change the one or more own EDCA parameters on the basis of the one or more QoS indicators of the one or more high priority AC frames lastly transmitted and/or received by the one or more neighboring APs (2).

7. The device (1) according to claim 5 or 6, wherein the device (1) is configured to decrease (S52) the Minimum Contention Window, CWMin, and/or the Maximum Contention Window, CWMax, as the one or more own EDCA parameters of one or more low priority AC frames and at the same time to increase (S52) the CWMin and/or CWMax as the one or more own EDCA parameters of the one or more high priority AC frames, in case the one or more QoS indicators are less or equal to a first threshold for the one or more QoS indicators; and rollback (S53) the change of the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames, in case the one or more QoS indicators are greater than the first threshold.

8. The device (1) according to any one of claims 5 to 7, wherein the one or more QoS indicators comprise at least one of a delay time, a queuing time, a number of packets or total size of transmit queue, a packet error rate, and a packet loss ratio of the one or more high priority AC frames.

9. The device (1) according to any one of the previous claims, wherein the device is configured to change the one or more own EDCA parameters on the further basis of the amount of messages, in particular beacon frames, received within a time interval from the one or more neighboring APs; in particular in addition to the one or more QoS indicators.

10. The device (1) according to any one of the previous claims, wherein the device is configured to decrease (S52) the CWMin and/or the CWMax as the one or more own EDCA parameters of one or more low priority AC frames and at the same time to increase (S52) the CWMin and/or CWMax as the one or more own EDCA parameters of one or more high priority AC frames, in case the device (1) received within a first time interval messages, in particular beacon frames, from all neighboring APs (2); and rollback (S53) the change of the one or more own EDCA parameters of the one or more low priority AC frames and one or more high priority AC frames, in case the device did not receive within a second time interval messages, in particular beacon frames, from one or more neighboring APs (2).

11. The device (1) according to any one of claim 5 to 10, wherein the one or more high priority AC frames comprise a Voice AC frame, VO AC frame, and/or a Video AC frame, VI AC frame, wherein the VO AC frame is of higher priority than the priority of the VI AC frame; and the one or more low priority AC frames comprise a Background AC frame, BK AC frame, and/or a Best Effort AC frame, BE AC frame, wherein the VI AC frame is of higher priority than the priority of the BK AC frame and the BK AC frame is of higher priority than the priority of the BE AC frame.

12. A device (2) for operating as an access point, AP, in a wireless Multi AP network, wherein the device (2) is configured to send a message (3) over a wireless medium to one or more neighboring access points, APs, (1) the message (3) comprising information indicative of traffic over the wireless medium, the traffic being managed by the device (2) itself.

13. The device (2) according to claim 12, wherein the message (3) of the device (2) is a beacon frame and the device (2) is configured to periodically broadcast the beacon frame, and in particular the information indicative of the traffic, in particular the information indicative of the traffic and its QoS indicators, is stored within one or more fields of the public section of the beacon frame.

14. The device (2) according to claim 12 or 13, wherein the information of the message (3) comprises one or more QoS indicators of one or more high priority AC frames lastly transmitted and/or received by the device (2), and in particular, the one or more QoS indicators comprise a delay time and/or a queuing time of the one or more high priority AC frames.

15. A system (5) comprising one or more devices (1) according to any one of claims 1 to 11 for operating as an access point, AP, and/or one or more devices (2) according to any one of claims 12 to 14 for operating as an AP.

16. A method for managing a wireless communication over a wireless medium by a device (1) according to any one of the claims 1 to 11, comprising the steps of receiving (S44), by the device (1), a message (3) over the wireless medium from one or more neighboring APs (2), the message (3) comprising information indicative of first traffic over the wireless medium, the first traffic being managed by the one or more neighboring APs (2), and changing (S45, S46, S51, S52, S53), by the device, one or more own Enhanced Distributed Channel Access, EDCA, parameters for one or more access categories, ACs, (ACO, AC1, AC2, AC3) on the basis of the received information.