Continuous mode multilink communication between devices in unlicensed spectrum

Abstract

A non-access point device may communicate with an access point device in a continuous or near-continuous mode. To initiate such a mode, a non-access point device may indicate to an access point device that continuous multi-link mode operation is enabled by setting a sub-field in a multi-link element within an association or re-association request to a predetermined value. This request may then be sent to the access point device, which may indicate this in response if the access point device supports this mode.

Description

Technical Field

[0001] Various example embodiments relate to communications within an unlicensed spectrum. Background Art

[0002] Unlicensed spectrum provides an opportunity to increase the bandwidth available for signals to be transmitted. However, because this bandwidth is shared with other devices, scanning may be required before transmission to reduce interference. In addition, there may be rules about how often devices can scan to allow the spectrum to be shared fairly, and these issues can lead to increased latency.

[0003] The unlicensed band is divided into sub-bands or channels, each of which covers a certain frequency band. A scanning process (such as listen before talk LBT) including sensing the channel to determine whether it is available can be used before sending a signal. If the channel is determined to be available, the node can acquire the channel within a predetermined occupation time (which can be referred to as the channel occupation time COT). During this period, signals can be sent and other nodes are blocked from using the channel.

[0004] Increasingly, devices are capable of transmitting and receiving on more than one channel, and this can be used to increase throughput and / or increase reliability. Communication discontinuities can create potential problems when an occupancy period in one channel expires and another channel has not yet been acquired. Summary of the invention

[0005] The scope of protection sought by various exemplary embodiments of the present disclosure is set out by the independent claims. Exemplary embodiments and features (if any) described in this specification that do not fall within the scope of the independent claims should be interpreted as examples that help understand the various embodiments of the present invention.

[0006] According to various but not necessarily all example embodiments of the present disclosure, there is provided a non-access point device configured for multi-link communication, the non-access point device comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, causes the device to at least perform: indicating to an access point device that continuous multi-link mode operation is to be enabled by: setting a subfield of a multi-link element within an association or re-association request to a predetermined value; causing the association or re-association request to be transmitted to the access point device.

[0007] Continuous (sometimes referred to as near-continuous) multilink operation is one in which two devices communicate and at least one channel is available at any time. That is, there is an acquired channel during the occupancy time that is ongoing and / or available for both devices. This mode allows for reduced latency in communications, but requires cooperation between the two devices. Therefore, in order to initiate such a process, one device may need to indicate to the other device that such a mode is enabled. Aspects achieve this by using fields or subfields in existing association or reassociation requests, thereby allowing information to be transferred without increasing or excessively changing existing signaling.

[0008] The signaling may be performed during a multi-link setup or reset procedure using an access point device.

[0009] Association and reassociation requests are signals sent between devices during the multilink setup process. Therefore, these signals are used to indicate the enablement of continuous mode operation, which allows the node to initiate when the nodes are set up or reset to communicate with each other. In this way, potential delays in the enabling of this mode are avoided or at least reduced, and there may be no or very little additional signaling overhead. These request signals have fields or subfields within a signal element or frame, and the values ​​in these fields or subfields are defined to provide certain information. Therefore, an embodiment defines a field or subfield to indicate whether continuous multilink operation is to be enabled, thereby allowing the information to be sent at the appropriate time during the multilink process by using the signaling used in the multilink setup or reset process.

[0010] In this embodiment, the non-access point device is a first initiating device, and the signal sent from it to the access point device is an uplink signal. The signal sent from the access point device to the non-access point device is a downlink signal.

[0011] In some example embodiments, the subfields include: a multilink device capability within a common information field of a multilink element, and a reserved subfield within an operation subfield.

[0012] In some example embodiments, in response to receiving an association or reassociation response, the apparatus is caused to: determine from a value within a multi-link device capabilities subfield of the response whether the access point apparatus agrees to operate in the continuous multi-link mode; and if agreeing to do so, perform scanning and acquisition of channels within a predetermined occupation time.

[0013] In some example embodiments, the device is caused to perform scanning and acquisition of channels within a predetermined occupied time by: scanning at least one channel; acquiring an available scanning channel within the predetermined occupied time; and indicating to the access point device that the non-access point device has acquired a channel within the predetermined occupied time.

[0014] In some example embodiments, the non-access point device is caused to indicate the acquisition of the channel within the predetermined occupation time to the access point device by: setting at least one subfield in a stream classification service (SCS) signal to a value indicating at least one of: the acquired start time of the predetermined occupation time; the acquired duration of the predetermined occupation time; and sending the SCS signal to the access point device.

[0015] In some example embodiments, the non-access point device is caused to indicate the acquired start time of the predetermined occupation time and the acquired duration of the predetermined occupation time by setting a subfield in the flow classification service SCS signal.

[0016] In some example embodiments, the SCS signal comprises an SCS request.

[0017] In some example embodiments, the at least one subfield within the SCS signal is within a Quality of Service (QOS) characteristic element.

[0018] In some example embodiments, the quality of service QOS characteristic element is included in an SCS descriptor element of an SCS service description support.

[0019] In some example embodiments, the obtained start time of the scheduled occupation time is indicated by setting a service start time subfield within a control information subfield of the QOS characteristic element to a value indicating the scheduled occupation time start time.

[0020] In some example embodiments, the duration of the predetermined occupation time is indicated by setting a maximum service interval subfield within the QOS characteristics element to a value indicating the duration.

[0021] In some example embodiments, the non-access point device is configured to indicate to the access point device that a plurality of communications using a plurality of the acquired predetermined occupation times are sent from the non-access point device to the access point device by sending at least one additional SCS signal indicating at least one additional acquired predetermined occupation time start time, and duration.

[0022] In some example embodiments, the apparatus is caused to commence scanning of at least one other channel at a time that is an estimated time for the non-access point apparatus to perform the scanning of the other channel before expiration of the indicated acquired predetermined occupancy time.

[0023] In some example embodiments, the non-access point device is caused to respond to receiving an SCS signal indicating at least the following items: a start time of the acquired scheduled occupation time, and a duration of the scheduled occupation time, by causing the non-access point device to initiate a scan of the channel at a time that is an estimated time LBT at which the non-access point device is able to scan the channel and determine that the channel is available before the indicated acquired scheduled occupation time expires.

[0024] In some example embodiments, the received SCS signal comprises an SCS response.

[0025] According to various but not necessarily all example embodiments of the present disclosure, an access point device is provided, comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the device to at least perform: receiving an association or reassociation request from a non-access point device; determining from a value of a subfield in a multilink element that the non-access point device requests continuous multilink mode operation to be enabled; setting a subfield of a multilink element within an association or reassociation response to a predetermined value, the predetermined value indicating that the request is received; and causing the association or reassociation response to be transmitted to the non-access point device.

[0026] In some example embodiments, the access point device is caused to respond to receipt of an SCS signal by initiating a scan of channels at a time that is an estimated time LBT at which the access point device is able to scan channels and determine that channels are available before expiration of the indicated acquired scheduled occupation time, the SCS signal indicating at least: a start time of the acquired scheduled occupation time of the non-access point device, and a duration of the scheduled occupation time.

[0027] In some example embodiments, the device is caused to perform scanning and acquisition of channels within a predetermined occupation time in response to receiving the SCS signal by: scanning the channels; acquiring an available scanning channel within the predetermined occupation time; and indicating to the non-access point device that the access point device has acquired the predetermined occupation time and providing an indication of the duration of the predetermined occupation time.

[0028] In some example embodiments, the access point device is configured to respond to receiving the SCS signal by setting a status subfield within the SCS response signal to a value indicating success, that is, the SCS signal is received.

[0029] In some example embodiments, the access point device is caused to indicate to the non-access point device by: setting at least one subfield in a flow classification service (SCS) signal to a value indicating at least one of: the acquired start time of the predetermined occupation time; the acquired duration of the predetermined occupation time; and sending the SCS signal to the non-access point device.

[0030] In some example embodiments, the subfield is within a Quality of Service (QOS) characteristic element.

[0031] In some example embodiments, the obtained start time of the scheduled occupation time is indicated by setting a service start time subfield to a value indicating the scheduled occupation time start time, the service start time subfield being within a control information field of the QOS characteristic element.

[0032] In some example embodiments, the duration of the predetermined occupation time is indicated by setting a maximum service interval subfield within the QOS characteristics element to a value indicating the duration.

[0033] In some example embodiments, the transmitted SCS signal comprises an SCS response signal, and the received SCS signal comprises an SCS request signal.

[0034] In some example embodiments, the SCS signal including the start time and duration of the COT is the same SCS response signal as the SCS response signal including the success indication. In other embodiments, they are two different SC responses.

[0035] In some example embodiments, the access point device is caused to perform indicating to the non-access point device that a plurality of communications using a plurality of predetermined occupation times are to be sent from the access point device to the non-access point device by sending at least one additional SCS signal indicating a start time and a duration of at least one additional predetermined occupation time.

[0036] According to various but not necessarily all example embodiments of the present disclosure, there is provided a method performed at a non-access point device, the method comprising: indicating to an access point device that continuous multi-link mode operation is to be enabled by: setting a subfield in a multi-link element within an association or re-association request to a predetermined value; and sending the association or re-association request to the access point device.

[0037] In some example embodiments, the method includes: in response to receiving an association or reassociation response, determining from a value within a multi-link device capability subfield of the response whether the access point device agrees to operate in the continuous multi-link mode operation; and if agreeing to do so, performing scanning and acquisition of channels within a predetermined occupation time.

[0038] In some example embodiments, the method includes: scanning and acquiring channels within a predetermined occupied time by: scanning at least one channel; acquiring an available scanning channel within the predetermined occupied time; and indicating to the access point device that the non-access point device has acquired the channel within the predetermined occupied time.

[0039] In some example embodiments, the method further includes: indicating the acquisition of the predetermined occupation time to the access point device by: setting at least one subfield in a flow classification service SCS signal to a value indicating at least one of: the acquired start time of the predetermined occupation time; the acquired duration of the predetermined occupation time; and sending the SCS signal to the access point device.

[0040] In some example embodiments, the method includes indicating both the acquired start time of the predetermined occupied time and the acquired duration of the predetermined occupied time by setting a subfield in the flow classification service (SCS) signal.

[0041] In some example embodiments, the method includes: the obtained start time of the scheduled occupation time is indicated by setting a service start time subfield to a value indicating the scheduled occupation time start time, the service start time subfield being within a control information subfield of the QOS characteristic element.

[0042] In some example embodiments, the method comprises the duration of the predetermined occupation time being indicated by setting a maximum service interval subfield within the QOS characteristics element to a value indicating the duration.

[0043] In some example embodiments, the method includes indicating to the access point device that a plurality of communications using a plurality of the acquired predetermined occupation times are sent from the non-access point device to the access point device by sending at least one additional SCS signal, the at least one additional SCS signal indicating at least one additional acquired predetermined occupation time start time, and duration.

[0044] In some example embodiments, the method includes commencing scanning of at least one other channel at a time that is an estimated time for the non-access point device to perform the scanning of the other channel before expiration of the indicated acquired predetermined occupancy time.

[0045] In some example embodiments, the method includes: responding to receiving an SCS signal by initiating a scan of a channel at a time that is an estimated time LBT at which the non-access point device is able to scan the channel and determine that the channel is available before the indicated acquired scheduled occupation time expires, the SCS signal indicating at least the following items: a start time of the acquired scheduled occupation time, and a duration of the scheduled occupation time.

[0046] According to various but not necessarily all example embodiments of the present disclosure, there is provided a method performed at an access point device, the method comprising: receiving an association or reassociation request from a non-access point device; determining from a value of a subfield in a multilink element that the non-access point device requests continuous multilink mode operation to be enabled; setting a subfield of the multilink element within an association or reassociation response to a predetermined value, the predetermined value indicating that the request is received; and sending the association or reassociation response to the non-access point device.

[0047] In some example embodiments, the method includes initiating a scan of a channel at a time that is an estimated time LBT at which the access point device is able to scan the channel and determine that the channel is available before the indicated acquired scheduled occupation time expires, in response to receiving an SCS signal, the SCS signal indicating at least: a start time of the acquired scheduled occupation time of the non-access point device, and a duration of the scheduled occupation time.

[0048] In some example embodiments, the method includes the steps of performing scanning and acquisition of channels within a predetermined occupation time in response to receiving the SCS signal by: scanning the channels; acquiring an available scanning channel within the predetermined occupation time; and indicating to the non-access point device that the access point device has acquired a channel within the predetermined occupation time and providing an indication of the duration of the predetermined occupation time.

[0049] In some example embodiments, the method includes responding to receiving the SCS signal by setting a status subfield within the SCS response signal to a value indicating success, that is, the SCS signal is received.

[0050] In some example implementations, the method includes: instructing the non-access point device by: setting at least one subfield in a flow classification service (SCS) signal to a value indicating at least one of: the acquired start time of the COT; the acquired duration of the predetermined occupancy time; and sending the SCS signal to the non-access point device.

[0051] In some example embodiments, the method performs indicating to the non-access point device that a plurality of communications using a plurality of the acquired predetermined occupation times are sent from the access point device to the non-access point device by sending at least one additional SCS signal indicating a start time and a duration of at least one additional acquired predetermined occupation time.

[0052] According to various but not necessarily all example embodiments of the present disclosure, there is provided a computer program comprising computer-readable instructions, which when executed by a processor on a non-access point device are operable to control the device to: indicate to an access point device that continuous multi-link mode operation is to be enabled by: setting a subfield of a multi-link element within an association or re-association request to a predetermined value; and sending the association or re-association request to the access point device.

[0053] According to various but not necessarily all example embodiments of the present disclosure, there is provided a computer program comprising computer-readable instructions, which when executed by a processor on an access point device are operable to control the device to: receive an association or reassociation request from a non-access point device; determine from a value of a subfield in a multilink element that the non-access point device requests continuous multilink mode operation to be enabled; set a subfield of a multilink element within an association or reassociation response to a predetermined value, the predetermined value indicating that the request is received; and send the association or reassociation response to the non-access point device.

[0054] According to various but not necessarily all example embodiments of the present disclosure, there is provided a non-transitory computer-readable medium including computer-readable instructions stored thereon, the instructions being operable when executed by a processor on a non-access point device to control the device to: indicate to an access point device that continuous multi-link mode operation is to be enabled by: setting a subfield of a multi-link element within an association or re-association request to a predetermined value; and sending the association or re-association request to the access point device.

[0055] According to various but not necessarily all example embodiments of the present disclosure, a non-transitory computer-readable medium is provided, including computer-readable instructions stored thereon, which, when executed by a processor on a non-access point device, are operable to control the device to: receive an association or reassociation request from a non-access point device; determine from a value of a subfield in a multilink element that the non-access point device requests continuous multilink mode operation to be enabled; set a subfield of a multilink element within an association or reassociation response to a predetermined value, the predetermined value indicating that the request is received; and send the association or reassociation response to the non-access point device.

[0056] The instructions may be used to cause the apparatus to perform the optional features described with respect to the above method.

[0057] According to various but not necessarily all example embodiments of the present disclosure, there is provided a non-access point device configured for multi-link communication, the non-access point device comprising: means for indicating to an access point device that continuous multi-link mode operation is enabled by setting a subfield in a multi-link element within an association or re-association request to a predetermined value; and means for causing the association or re-association request to be transmitted to the access point device.

[0058] The components may perform optional features discussed with respect to the above-described apparatus.

[0059] According to various but not necessarily all embodiments of the present disclosure, there is provided an access point device, comprising: a component for receiving an association or reassociation request from a non-access point device; a component for determining, from a value of a subfield in a multilink element, that the non-access point device requests continuous multilink mode operation to be enabled; a component for setting a subfield in a multilink element within an association or reassociation response to a predetermined value, the predetermined value indicating that the request is received; and a component for causing the association or reassociation response to be transmitted to the non-access point device.

[0060] The components may perform optional features discussed with respect to the above-described apparatus.

[0061] According to various but not necessarily all example embodiments of the present disclosure, there is provided a non-access point device configured for multi-link communication, the non-access point device comprising: a circuit system configured to indicate to an access point device that continuous multi-link mode operation is enabled by: generating an association or re-association request and setting a subfield in a multi-link element within the association or re-association request to a predetermined value; and a circuit system configured to send the association or re-association request to the access point device.

[0062] The circuit system may be configured to perform the optional features set forth in relation to the apparatus described above.

[0063] According to various but not necessarily all embodiments of the present disclosure, an access point device is provided, including: a circuit system configured to receive an association or reassociation request from a non-access point; a circuit system configured to determine from a value of a subfield in a multilink element that the non-access point device requests that continuous multilink mode operation be enabled; a circuit system configured to generate an association or reassociation response and set a subfield in the multilink element within the association or reassociation response to a predetermined value, the predetermined value indicating that the request is received; and a transmitter configured to transmit the association or reassociation response to the non-access point device.

[0064] The circuit system may be configured to perform the optional features set forth in relation to the apparatus described above.

[0065] Further particular and preferred aspects are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with features of the independent claims as appropriate, and in combinations other than those explicitly stated in the claims.

[0066] Where an apparatus feature is described as being operable to provide a function, it will be understood that this includes apparatus features that provide that function or that are adapted or configured to provide that function. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Some example embodiments are now described with reference to the accompanying drawings, in which:

[0068] Figure 1 illustrates configuration and setup signaling between non-access point and access point multi-link enabled devices;

[0069] Figure 2 illustrates additional signaling between multi-link enabled devices;

[0070] Figure 3 schematically illustrates steps in a method performed by a non-AP multi-link device according to an embodiment;

[0071] Figure 4 schematically illustrates steps in a method performed by an AP multi-link device according to an embodiment;

[0072] Figure 5 schematically illustrates steps performed by an AP and a non-AP device on two links when operating in a multi-link continuous mode operation according to an embodiment;

[0073] Figures 6 and 7 schematically illustrate fields and subfields of elements and frames sent in signaling during multilink setup and configuration; and

[0074] Figure 8A non-AP multi-link device and an AP multi-link device according to an embodiment are schematically illustrated. DETAILED DESCRIPTION

[0075] Before discussing example embodiments in greater detail, an overview will first be provided.

[0076] In the 25 years since its introduction, the peak data rates of WLAN / Wi-Fi have increased by about 4 orders of magnitude. However, any technology operating in a license-free band is subject to uncontrollable interference that can affect highly reliable operation. The lack of reliability became increasingly unacceptable, so the Ultra-Reliable Low-Latency Communication (URLLC) requirement was introduced to provide higher determinism in Wi-Fi communications. This is no easy task, as the medium access control (MAC) was originally designed based on carrier sense multiple access with collision avoidance (CSMA / CA) to cope with uncoordinated use in the license-free spectrum, rather than prioritizing determinism.

[0077] Development of a new revision, IEEE 802.11bn, has just begun to define new features for future Wi-Fi 8 products.

[0078] WO2021244747 (the entire contents of which are incorporated herein by reference) solves the problem of increased latency in unlicensed spectrum due to mandatory implementation of LBT (Listen Before Talk) by establishing near-continuous channel access opportunities consisting of partially overlapping channel occupancy periods in different parts / sub-bands of the available spectrum. The device involved can operate as a multi-link device configured to communicate on different channels.

[0079] It is recognized that in order to provide such continuous or near-continuous channel access opportunities for multi-link devices, certain indications of device capabilities and procedural requirements should be exchanged. It is also recognized that the latest 802.11be draft specifies new signaling to support multi-link operation and that this signaling needs to be exchanged with the multi-link signaling in order to proceed. Embodiments attempt to use or reuse certain fields or sub-fields within such signaling to provide information that allows continuous or near-continuous channel operation to proceed. In this way, continuous or near-continuous channel access is provided with minimal additional signaling overhead.

[0080] Figure 1 Example signaling exchanges between a non-access point multi-link device (non-AP MLD 10) and an access point multi-link device (AP MLD 20) before and during a multi-link setup or re-setup procedure are shown.

[0081] The multilink signaling elements can be carried in beacons, ML probe requests, ML probe responses, and (re)association request / response frames. Before performing multilink (re)settings with the AP Multilink Device (MLD) using the (re)association request / response frame exchange, the non-AP MLD and the AP MLD follow the authentication process (see Figure 1 ). Broadcast signals are marked (B), signals sent to individual or broadcast addresses are marked (IB), and signals that are conditionally broadcast are marked (CB).

[0082] Once authentication occurs, multilink setup signaling is performed. The multilink (re)setup process sets up (multiple) links between the non-AP MLD and the AP MLD and is done by exchanging (re)association request frames and (re)association response frames. Only when both the (re)association request frame and the (re)association response frame include the basic multilink elements ( Figure 6-1 ), the (re)association request / response frame exchange is used for multilink setup.

[0083] The non-AP MLD may initiate an ML (re)setup with the AP MLD to (re)setup one or more links with the AP MLD. When the non-AP MLD initiates an ML (re)setup with the AP MLD, the non-AP MLD should be transmitted by a non-AP STA that is associated with the non-AP MLD and operating on a link that is expected to be part of the ML (re)setup (re)association request frame.

[0084] The signal represented by 30 is a possible option for the non-AP MLD 10 to collect information about other APs associated with the AP MLD 20. The signal represented by 32 is a multi-link setup or reset signal that can be performed on any link or channel and signal, where the embodiment uses a field or subfield in the existing signaling to provide information indicating that continuous communication is to be initiated.

[0085] Figure 2 Additional signaling between the non-AP MLD 10 and the AP MLD 20 during multi-link communication is shown. The signaling may be modified to support the exchange of information required to allow continuous communication to operate. The signaling includes a flow classification signal SCS procedure, which is typically used by the non-AP MLD 10 to request the AP MLD 20 to classify incoming individually addressed MSDUs (MAC Service Data Units) based on parameters provided by the non-AP MLD 10 and / or describe its traffic characteristics to the AP MLD 20. In the event that continuous mode operation is to be used, the non-AP MLD may initiate SCS signaling by generating and sending an SCS request frame.

[0086] Upon receiving an SCS request frame from an associated non-AP STA 10, the AP 20 shall respond with a corresponding SCS response frame. When the AP receives an SCS request for the requested SCSID, it shall set the value of SUCCESS in the corresponding status field of the SCS status doublet in the SCS response frame. (From 802.11be D4.0).

[0087] A non-AP EHT STA that supports the transmission of SCS request frames containing SCS descriptor elements with QoS characteristics elements (where dot11SCSActivated is equal to "true") shall set the SCS Service Description Support subfield value in the EHT Capability element it sends to 1.

[0088] If the Request Type field in the frame is set to "Add" or "Change", the non-AP EHT STA may send an SCS Request frame with (multiple) SCS Descriptor elements containing QoS Characteristics elements. The QoS Characteristics elements describe the service characteristics of the requested SCS flow. It is this QoS Characteristics element that may be adapted to exchange information that allows continuous or near-continuous communication.

[0089] The QOS element is included in the SCS Descriptor element of the SCS Service Description Support. The QOS Characteristics element in the embodiment is used to exchange the required information to allow continuous mode operation. Therefore, it can be used to indicate the scheduled occupation time, such as the COT start time and duration of the acquired channel, so that the receiving device will know when the COT can be expected to end, so by then, a new COT should have been acquired. The QOS element can be present in both the SCS request and the SCS response.

[0090] In summary, the requirement to enable continuous or near-continuous communication is to pass information between devices in a multi-link framework, such as that introduced in 802.11be. The new 802.11bn (Wi-Fi 8) amendment attempts to extend the functionality that already exists in 802.11be (Wi-Fi 7). Embodiments attempt to pass information between devices within this multi-link framework in a manner that is compatible with the 802.11be message format.

[0091] Figure 3 1 shows steps in a method performed at a non-AP MLD device according to an embodiment, and Figure 4 The corresponding steps performed at the AP MLD are shown. It should be noted that although the steps are shown in a particular order, some steps may be performed simultaneously, or at overlapping times, or in a slightly different order.

[0092] exist Figure 3In step S10, the non-AP device 10 generates and sends an association request to the AP device 20, the association request indicating that continuous multi-link operation is to be enabled. In step D5, the device 10 monitors the response, and if it receives a response from the AP device 10 indicating that the AP device 10 receives the continuous operation, it proceeds to step S20. If it receives a response indicating that the AP does not receive the continuous operation, this indicates that the AP does not support such operation, and the attempt to generate such continuous multi-link operation ends.

[0093] In step S20, the non-AP MLD device scans and obtains the COT, and indicates the start time and duration of the COT to the AP device in the SCS request. Figure 5 As shown, scanning is LBT performed by the non-AP MLD in link 1, and the acquisition and use of COT is a subsequent process on link 1.

[0094] The non-AP device will then send an uplink signal on the acquired COT in step S30, and will determine in step D10 whether to send multiple uplink signals in sequence. The determination step is performed after step S20, but can be performed before or during step S30. If multiple subsequent uplink signals are not sent, the method proceeds to step S40, and if multiple uplink signals are present, the method performs step S20 again, scans and acquires COTs of different channels, and sends an indication of the start time and duration of the newly acquired COT. These steps are performed before the step S30 of sending the previous uplink signal is completed. The method then performs step S30 of sending an uplink signal to the AP on the newly acquired COT.

[0095] In step S40, the non-AP device 10 may receive an SCS response from the AP, the SCS response indicating the start time and duration of the COT acquired by the AP. This may again be received before step S30 is completed. The method may then receive a downlink signal sent on the COT in step S50. In step D15, the non-AP device 10 then determines whether a subsequent SCS response is received. If so, proceed to step S40 to determine the start time and duration of the COT. If not, in step S60, a scan of the channel is initiated at a predetermined LBT time before the end of the COT acquired by the AP. Then, return to step S20, where the COT is scanned and acquired, and the start time and duration of the COT are indicated to the AP device in the SCS request.

[0096] Figure 41 shows the steps performed in the method at the AP device 20 according to an embodiment. In step 100, the AP device receives an association request or a reassociation request indicating that continuous multi-link operation is to be enabled. The request is sent by a non-AP device, such as Figure 3 As shown in step S10 of . Assuming that the AP device does not support continuous multi-link operation, it responds in the multi-link operation in step S110. If it does not support multi-link operation, it will not be able to decode the received request and will not respond indicating that the request has not been received.

[0097] In step S120, the AP device may receive an SCS request indicating the start time and duration of the COT acquired by the non-AP device. Then, it will receive a signal sent on the COT in step S130.

[0098] It will then determine in step D105 whether a subsequent SCS request has been received. If a subsequent SCS request has been received, it will return to step 120 and determine the start time and duration of the COT from the request. It can then receive a signal sent on the COT. If it has not received a subsequent SCS request, it will initiate a scan of the channel at a predetermined LBT time before the end of the current COT where the signal is received in step S140. In step S150, it will then acquire the COT and indicate the start time and duration of the COT to the non-AP device in the SCS response. It will then send a downlink signal on the acquired COT in step S160. It will then determine in step D110 whether to send multiple downlink signals. If multiple downlink signals are to be sent, it will return to step S140, where it will initiate a scan of the channel at a predetermined LBT time before the end of the current COT. If multiple downlink signals are not to be sent, it will return to step S120, where it will receive an SCS request indicating the start time and duration of the COT acquired by the non-AP.

[0099] Figure 5 It schematically shows how non-AP devices and AP devices perform scanning of channels during an LBT period, how they obtain channel occupancy time for transmission of signals, and how to set the timing of starting the scanning of channels so that the scanning is completed just before the channels are needed.

[0100] Figure 5 It shows how the non-AP MLD and the AP MLD can take turns scanning channels and obtaining COTs so that there is always a COT available on one of the channels.

[0101] In step 1, the non-AP MLD instructs the AP-MLD:

[0102] a) it should enable continuous multi-link mode of operation, and

[0103] b) In the first transmission of the continuous multi-link operation mode, the non-AP itself will be the "initiating" device, and the "following" device should be the one receiving data in link P. This corresponds to Figure 3 Step S10.

[0104] In practice, this means that the role of the "below" device will alternate between non-AP and AP, and both devices should implement components of the proposed method.

[0105] In step 2, the AP replies to the non-AP, indicating that it agrees to operate in continuous multi-link mode of operation. This corresponds to Figure 4 Step S100.

[0106] In step 3, according to the protocol,

[0107] a) The non-AP will be the "initiating" device in the first COT, and

[0108] b) The AP will be the "below" device in the first COT.

[0109] In steps 4 and 5, after competing with LBT for channel access in both links, the non-AP obtains COT and initiates an uplink transmission to the AP in link 1 (now labeled "link P") (see Figure 5 ). As a "following" device, the AP initializes the COT timer to t=0.

[0110] Since the AP is already considered as a "following" device, it checks whether

[0111] t>(COTP-S start time - LBT cycle length), for all S≠P,

[0112] in

[0113] - The above operations are performed independently on link S=2,

[0114] - COTP-S start time is defined as the time starting from the moment when COT in link P starts, from which point on, a multi-link device is allowed to initiate transmission in a different link (link S).

[0115] The value of this parameter varies depending on the link pair being considered, i.e., link P and link S are different for each device and should be adjusted dynamically and independently by the relevant device(s), both AP and STA (non-AP) in this embodiment.

[0116] The LBT cycle length is defined as the time taken by a device between 1) the start of contention for channel access in link S, and 2) the start of transmission in link S. Thus, the "LBT cycle length" includes the time that such a device 1) senses that the channel is idle with a backoff counter equal to a non-zero value, and 2) the time that such a device senses that the channel is occupied.

[0117] The present disclosure provides a method for signaling between an access point (AP) multi-link device (MLD) and a non-AP MLD supporting multi-link communication to enable continuous multi-link operation. By introducing new fields / subfields within the messages specified in 802.11be, the present disclosure introduces a method for signaling and activating continuous operation between an access point (AP) multi-link device (MLD) and a non-AP MLD supporting multi-link communication.

[0118] The present disclosure can significantly improve the reliability and latency of communications performed by future Wi-Fi 8 products. Below, we propose a new method for implementing / sending steps related to the 802.11be framework.

[0119] Embodiment 1: We consider a scenario where an 802.11-compliant AP has multi-link capability and an 802.11-compliant non-AP has multi-link capability.

[0120] Link to discussion Figure 5 When following the steps outlined above, in step 1, in order to indicate to the AP-MLD that continuous mode operation is enabled, we recommend that the non-AP MLD utilize the MLD Capability and Operation fields of the basic multilink element.

[0121] The AP MLD and non-AP MLD should have completed the beacon frame or probe request and authentication frame exchange.

[0122] The non-AP MLD initiates a multilink setup with the AP MLD to (re)setup one or more links with the AP(s) operating in continuous mode with which the AP MLD is associated. When the non-AP MLD initiates a multilink (re)setup with the AP MLD, the non-AP MLD associated with the non-AP MLD shall send a (re)association request frame on link 1 which it wishes to use as part of the multilink (re)setup.

[0123] The multilink setup process between the non-AP MLD and the AP MLD is completed by exchanging (re)association request frames and (re)association response frames. (Re)association request / response frame exchange is used for multilink setup only when both the (re)association request frame and the (re)association response frame include basic multilink elements.

[0124] For the purposes of this embodiment, a non-AP sends an Association Request frame and an AP sends a (re)Association Response (see Figure 1 ).

[0125] Specifically, we consider using the basic multilink element carried in the (re)association request frame, which should include a common information field.

[0126] 6 and 7 illustrate the format of signaling exchanged during a multi-link setup and adapted to provide the information required to initiate continuous or near-continuous communications.

[0127] like Figure 6-1 As shown, the (re)association request may include a common information sub-element, which carries information about the current link and common information about all links associated with the AP MLD 20. The multi-link element may also include 0 or more Per-STA Profile sub-elements, which are carried in the link information field, such as Figure 6-1 Each Per-STA Profile sub-element can be used to carry information related to the STA in question.

[0128] To indicate that the multilink element is a basic multilink element, for 802.11be D3, the type subfield of the multilink control field (as shown in Figure 6.2) is set to 0.

[0129] In the (re)association response frame, the AP MLD shall indicate the requested link(s) that are accepted for (re)configuration and the requested link(s) that are rejected for (re)configuration, as well as the capabilities and operating parameters of the requested link(s). The AP MLD may perform one of the following operations:

[0130] accept all links that are requested to be (re)configured, or

[0131] accept the subset of links that were requested to be (re)configured, or

[0132] • Reject all links that are requested to be (re)configured.

[0133] Related to this idea, the EHT (Extremely High Throughput) Capability element is utilized by a STA (non-AP MLD) to declare that it is an EHT STA. The EHT Capability element contains a number of fields for publishing the EHT capabilities of an EHT STA ( Figure 6-3 ).

[0134] The format of the EHT MAC Capability Information field is Figure 6-4 is explained in .

[0135] The format is that of the common information fields shown in Figure 6.2. Figure 7-1 As shown in .

[0136] In the context of continuous multi-link mode operation, the MLD MAC Address subfield specifies the MAC address of the MLD described by the Basic Multi-Link Element. If the Basic Multi-Link Element is sent by a non-AP STA, the Link ID Information and AP MLD ID subfields in the Common Information field are not present, as occurs in this embodiment.

[0137] The MLD Capability and Operation subfields are present in the common information field of the basic multilink element carried in beacons, probe responses, (re)association requests, and (re)association responses. It is recommended to enable continuous transmission in the MLD Capability and Operation subfields sent in (re)association requests. The format of the MLD Capability and Operation subfields is as follows: Figure 7-2 We recommend setting the Reserved field to 1 to initiate continuous multilink mode activation.

[0138] In step 2, the AP replies to the non-AP, indicating that it agrees to operate in the continuous multi-link operation mode.

[0139] The format of the MLD Capabilities and Operations subfields is in Figure 7-2 The MLD Capability and Operation subfields are defined in the Association Response frame and are present in the Common Information Field of the Basic Multilink Element carried in Beacons, Probe Responses, (Re)Association Requests, and (Re)Association Responses. To send a reply from the AP to indicate agreement to activate the continuous multilink mode of operation, we recommend the use of the MLD Capability and Operation subfields. In the MLD Capability and Operation subfield of the Association Response frame, the AP device can confirm continuous mode operation by setting the Reserved field to 2.

[0140] In step 3, according to the protocol,

[0141] a) The non-AP will be the "initiating" device in the first COT, and

[0142] b) The AP will be the "below" device in the first COT.

[0143] The non-AP that sends the basic multilink element will take the role of initiating the transmission.

[0144] In the first transmission of the continuous multi-link operation mode, the non-AP MLD itself will be the "initiating" device, and the "following" device should be the one receiving data in link 1, which is the AP in this embodiment.

[0145] In steps 4 and 5, the device playing the role of the initiator includes control information in its transmission in order to inform the device playing the role of the STA. This control information at least indicates that the non-AP device has acquired the COT and its duration. Due to the alternation of UL and DL transmissions ( Figure 5 ), the initiating device (non-AP) needs to communicate the COTP-S start time and, in some cases, the duration. The following message exchange provides an example of Embodiment 1.

[0146] The following features are under consideration:

[0147] - The message used to convey the COTP-S start time shall contain a reserved or time element in the frame

[0148] - Both AP MLD and non-AP MLD have the possibility to send messages - Once the management frames of the association handshake in the multilink framework are completed, they will be sent

[0149] In this disclosure, we propose to include COTP-S start time and duration communication in the QoS Characteristics element (9.4.2.316) in SCS signaling. The SCS procedure is used by the non-AP MLD to request the AP MLD to classify the incoming individually addressed MSDUs and / or describe its service characteristics to the AP MLD based on the parameters provided by the non-AP MLD. The Service Description Support subfield indicates support for sending and receiving SCS Descriptor elements containing QoS subelements. These QoS subelements can be sent in SCS request or response frames.

[0150] Upon receiving an SCS request frame from an associated non-AP STA, the AP shall respond with a corresponding SCS response frame. When the AP receives an SCS request for the requested SCSID, it shall set the value of SUCCESS in the corresponding status field of the SCS status doublet in the SCS response frame.

[0151] Each SCS stream is identified by a SCSID. The SCSID is used by non-AP STAs to request the creation, modification, or deletion of an SCS stream. The SCSID is used by the AP to identify the SCS stream in the SCS response.

[0152] QOS characteristic elements (see Figure 7-3 ) contains a set of parameters that define the characteristics and QoS expectations of service flows in the context of a specific non-AP EHT STA for use by EHT APs and non-AP EHT STAs to support QOS service transmission using process SCS and restricted TWT.

[0153] The structure of the control information field is as follows Figure 7-4 is defined as shown.

[0154] The Direction subfield specifies the direction of the data described by this element (Uplink / Downlink / Directional Link / Reserved), as shown in Table 9-401r.

[0155] The Service Start Time field contains an unsigned integer specifying the expected time (in microseconds) when service for the associated TID will start. The Service Start Time indicates to the AP the time when the STA expects to exchange frames corresponding to the TID specified in this element. The Service Start Time field represents the four low-order octets of the TSF timer associated with the link specified in the LinkID field when the SP is expected to start.

[0156] The Maximum Service Interval field contains an unsigned integer specifying the maximum interval (in microseconds) between the start of two consecutive SPs allocated to a STA for UL frame exchange, and the value 0 is reserved. We consider here the case Uplink (direction subfield set to 0) related to embodiment 1.

[0157] NOTE: We believe that the identification and transmission of business requirements should be covered by the TID field of the MLD capabilities and operations of the basic multilink element.

[0158] The following table illustrates an example of how different information may be sent by setting fields or subfields in different requests and responses exchanged between an AP device and a non-AP device to predetermined values ​​during multi-link setup and configuration.

[0159]

[0160] Example II In the second embodiment (Embodiment II), we consider a non-AP MLD, which transmits data uninterruptedly in the uplink using continuous operation after enabling the continuous multi-link operation mode.

[0161] In this embodiment, steps 1, 2 and 3 are similar to the corresponding steps in embodiment 1. Unlike embodiment 1, in this embodiment, Figure 5 The UL transmission in will be followed by another UL transmission. For each transmission, the non-AP needs to communicate the COTP-S start time and, in some cases, the duration. In this case, the non-AP MLD initiates the SCS procedure to send the QoS element format associated with each data flow it intends to send.

[0162] Example III: We consider a scenario where an 802.11-compliant non-AP has multi-link capability and an 802.11-compliant AP does not have multi-link capability.

[0163] In this embodiment, the non-AP sends an association request frame to enable continuous multi-link mode operation. Similar to embodiment I, the reserved field in the MLD capability and operation subfield is set to 1 to initiate continuous multi-link mode activation.

[0164] In the case that AP MLD is not enabled to set up continuous mode operation, the reserved fields for checking MLD capability and operation will not be received by AP MLD in the association request. Therefore, AP MLD will not reply to the continuous mode operation request.

[0165]

[0166] Figure 8 A non-AP MLD device 10 is shown in accordance with an embodiment communicating with an AP MLD device 20 over multiple channels.

[0167] The non-AP MLD device 10 includes a transceiver 12 configured to send and receive signals on multiple channels, a signal generating circuit system 14 configured to generate signals to be sent by the transceiver 12 to the AP device 20, and a channel monitoring circuit system 16 configured to control the transceiver to monitor a specific channel.

[0168] The device 10 may initiate continuous mode operation by indicating to the AP device 20 that continuous multi-link mode operation will be enabled by: generating a (re)association request and setting a subfield in the multi-link element of the request to 1, and sending an association or re-association request to the AP device 20. The transceiver 12 may receive a response, and wherein the AP device 20 agrees to operate in continuous multi-link mode operation, the non-AP device 10 may initiate scanning of multiple channels using the channel monitoring circuit system 16, and acquire available channels within a predetermined occupation time COT. The channel monitoring circuit system 16 may estimate how long it is expected to take to scan and acquire channels, and may start the scanning process no later than this time before the end of the current COT. It may then indicate the acquired COT start time and duration to the AP device 20 using the signal generation circuit system 14 to generate an SCS request, and set the subfield in the request to a value indicating the acquired COT start time and duration. It may then be sent to the AP device.

[0169] In the event that there are multiple uplink signals to send, device 10 may repeat the process by scanning on another channel and acquiring a subsequent COT.

[0170] In the event that the device is to receive a downlink signal next, the transceiver 12 will then receive an SCS response from the AP device 20, and this will include the start time and duration of the COT. It can then set the transceiver 12 to receive the downlink signal.

[0171] The AP MLD device 20 includes a transceiver 22 configured to transmit and receive signals on a plurality of channels, a signal generation circuit system 24 configured to generate signals to be transmitted by the transceiver 22 to the non-AP device 10 , and a channel monitoring circuit system 26 .

[0172] Device 20 may use transceiver 22 to receive a (re)association request requesting to enable continuous mode operation. It may respond by generating a (re)association response and setting a subfield in the multilink element of the response to 2 and sending an association or reassociation response to the non-access point device 10. In the case where multiple uplink signals are to be sent, it may receive a subsequent SCS request indicating a different COT start time and duration. Alternatively, it may scan a channel different from the channel in which the uplink signal is to be sent using channel monitoring circuit system 26. It may start scanning at a time that is an estimated time to scan and acquire the channel before the current COT expires. When channel monitoring circuit system 26 determines that the channel is available and acquires the COT, signal generation circuit system 24 will generate an SCS response signal in which a subfield in the QoS element is set to a value indicating the start time and duration of the acquired COT. The signal may then be sent to the non-AP MLD device 10.

[0173] The signal generation circuitry and scanning circuitry may include one or more processors and a memory storing computer program instructions that, when executed by the one or more processors, generate signals and control the transceiver to monitor a desired channel.

[0174] The non-access point MLD device or apparatus 10 may include a user equipment, STA, such as an augmented / virtual reality station or UE.

[0175] The access point MLD device or apparatus 10 may include a WiFi access point, a gNB or a UE.

[0176] Although examples of AP and non-AP multi-link devices are given above, the communications may be between any two nodes configured to communicate using multiple channels in an unlicensed spectrum. For example, the communications may be cellular sidelink communications, where a cellular device communicates directly with another device without relaying its traffic through a base station. In this case, one of the devices will play the role of an AP (and therefore become the dominant device) while the other device plays the role of a non-AP. These roles may of course be interchanged as the communications progress, particularly when both devices are unable to transmit and receive simultaneously in multiple links due to self-interference / hardware constraints. Explicit signaling may be used for these devices to establish the described operations in the context of a sidelink.

[0177] In summary, the idea is part of a concept used to enable continuous transmission over Wi-Fi, which is a paradigm shift from Wi-Fi’s current discontinuous channel access acquisition and has the opportunity to significantly improve the reliability and latency of communications in Wi-Fi 8 products.

[0178] Those skilled in the art will readily recognize that the steps of various above-mentioned methods can be performed by programming computers.Herein, some embodiments are also intended to cover program storage devices, such as digital data storage media, which are machine or computer readable, and machine executable or computer executable programs of encoded instructions, wherein the instructions perform some or all of the steps of the above-mentioned methods.For example, the program storage device can be a digital memory, a magnetic storage medium (such as a disk and a tape), a hard drive, or an optically readable digital data storage medium.Embodiments are also intended to cover computers programmed to perform the steps of the above-mentioned methods.The term "non-transitory" used herein is a limitation of the medium itself (i.e., tangible, not a signal), in contrast to limitations on data storage permanence (e.g., RAM and ROM).

[0179] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0180] (a) pure hardware circuit implementation (such as implementation using only analog and / or digital circuits) and (b) a combination of hardware circuit and software, such as (as applicable):

[0181] (i) a combination of analog and / or digital hardware circuits and software / firmware and

[0182] (ii) any portion of hardware processor(s) with software (including digital signal processor(s)), software and memory(s) that work together to enable a device (such as a mobile phone or server) to perform various functions and (c) hardware circuit(s) and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), which requires software (e.g. firmware) to operate, but which may not be present when software is not required for operation.

[0183] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" also covers only a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware implementation. For example, if applicable to a particular claim element, the term "circuitry" also covers a baseband integrated circuit or processor integrated circuit of a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0184] Although example embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed.

[0185] Features described in the above description may be used in combinations other than the combinations explicitly described.

[0186] Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

[0187] Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

[0188] While an attempt has been made in the foregoing description to call attention to those features of the present invention which are regarded as particularly important, it will be understood that the applicant claims protection for any patentable feature or combination of features mentioned above and / or shown in the accompanying drawings whether or not particular emphasis has been placed thereon.

[0189] List of abbreviations

[0190] AP access point

[0191] COT channel occupation time

[0192] EHT extremely high throughput

[0193] LBT listens first and then speaks

[0194] MLD multi-link device

[0195] ·Quality of Service

[0196] SCS flow classification service

[0197] TXOP transmission opportunity

[0198] STA Augmented / Virtual Reality Station (STA).

Claims

1. A non-access point device configured for multi-link communication, the non-access point device comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least perform: Indicating to the access point device that continuous multi-link mode operation is to be enabled by: setting a subfield in a multilink element within an association or reassociation request to a predetermined value; The association or re-association request is caused to be transmitted to the access point device.

2. The non-access point device of claim 1, wherein the subfield comprises: The multi-link device capability in the common information field of the multi-link element and the reserved subfield in the operation subfield.

3. The non-access point device according to claim 1 or 2, wherein in response to receiving an association or re-association response, the device is caused to: determining from a value within the multi-link device capability subfield of the response whether the access point device agrees to operate in the continuous multi-link mode operation; and With consent to do so, scanning and acquisition of channels is performed during a predetermined occupancy time.

4. A non-access point device according to any one of the preceding claims, the device being caused to perform scanning and acquisition of channels within a predetermined occupancy time by: Scanning at least one channel; Acquire an available scanning channel within a predetermined occupation time; and An indication is given to the access point device that the non-access point device has acquired the channel within the predetermined occupancy time.

5. The non-access point device according to claim 4, wherein the non-access point device is configured to indicate acquisition of the channel within the predetermined occupation time by: Setting at least one subfield in the flow classification service SCS signal to a value indicating at least one of: the acquired start time of the predetermined occupation time, and the acquired duration of the predetermined occupation time; and The SCS signal is sent to the access point device. The non-access point device of claim 5 , wherein the SCS signal comprises an SCS request.

7. The non-access point device of claim 6, wherein the subfield is within a Quality of Service (QOS) characteristic element.

8. The non-access point device of claim 7, wherein the acquired start time of the scheduled occupation time is indicated by setting a service start time subfield to a value indicating the scheduled occupation time start time, the service start time subfield being within a control information field of the QOS characteristic element.

9. The non-access point device according to any one of claims 5 to 8, wherein the acquired duration of the predetermined occupation time is indicated by setting a maximum service interval subfield within the QOS characteristic element to a value indicating the duration.

10. The non-access point device according to any one of claims 5 to 9, wherein the non-access point device is configured to indicate to the access point device that multiple communications using multiple acquired predetermined occupation times are sent from the non-access point device to the access point device by sending at least one additional SCS signal, the at least one additional SCS signal indicating at least one additional acquired predetermined occupation time start time, and duration.

11. The non-access point device of claim 10, wherein the non-access point device is caused to begin scanning of at least one other channel at a time that is an estimated time for the non-access point device to perform the scanning of the at least one other channel before expiration of the indicated acquired predetermined occupancy time.

12. A non-access point device according to any one of the preceding claims, wherein the non-access point device is caused to respond to receiving an SCS signal from the access point device, the SCS signal indicating: a start time of the acquired scheduled occupation time, and a duration of the scheduled occupation time, by causing the non-access point device to initiate a scan of the channel at a time that is an estimated time LBT at which the non-access point device is able to scan the channel before the indicated acquired scheduled occupation time expires and determine that the channel is available.

13. An access point device configured for multi-link communication, the access point device comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least perform: receiving an association or reassociation request from a non-access point device; determining from a value of a subfield in a multilink element that the non-access point device requests continuous multilink mode operation to be enabled; setting a subfield in a multilink element within an association or reassociation response to a predetermined value, the predetermined value indicating that the request was received; and The association or re-association response is caused to be transmitted to the non-access point device.

14. The access point device according to claim 13, The access point device is caused to respond to receiving an SCS signal by initiating a scan of the channel at a time, which is an estimated time LBT that the access point device can scan the channel and determine that the channel is available before the indicated acquired scheduled occupation time expires, and the SCS signal indicates at least: the start time of the acquired scheduled occupation time of the non-access point device, and the duration of the scheduled occupation time.

15. The access point device of claim 14, wherein the device is caused to perform scanning and acquisition of channels within a predetermined occupation time in response to receiving the SCS signal by: Scanning the channel; Acquire an available scanning channel within a predetermined occupation time; and An indication is given to the non-access point device that the access point device has acquired a channel within a predetermined occupancy time, and an indication of a duration of the predetermined occupancy time is provided.

16. The access point device according to claim 15, wherein the access point device is configured to perform the indicating to the non-access point device by: Setting at least one subfield in the flow classification service SCS signal to a value indicating at least one of: the acquired start time of the predetermined occupation time, and the acquired duration of the predetermined occupation time; and The SCS signal is sent to the non-access point device.

17. The access point device of claim 16, wherein the transmitted SCS signal comprises an SCS response signal, and the received SCS signal comprises an SCS request signal.

18. An access point device according to any one of claims 15 to 17, wherein the access point device is caused to indicate to the non-access point device that multiple communications using multiple acquired predetermined occupation times are sent from the access point device to the non-access point device by sending at least one additional SCS signal, and the at least one additional SCS signal indicates a start time and a duration of at least one additional acquired predetermined occupation time.

19. A method performed at a non-access point device, the method comprising: Indicating to the access point device that continuous multi-link mode operation is to be enabled by: setting a subfield in a multilink element within an association or reassociation request to a predetermined value; The association or re-association request is sent to the access point device.

20. A method performed at an access point device, the method comprising: receiving an association or reassociation request from a non-access point device; determining from a value of a subfield in a multilink element that the non-access point device requests continuous multilink mode operation to be enabled; setting a subfield in a multilink element within an association or reassociation response to a predetermined value, the predetermined value indicating that the request was received; and The association or re-association response is sent to the non-access point device.

21. A computer program product comprising computer readable instructions operable when executed by a processor on a non-access point device to control the device to: Indicating to the access point device that continuous multi-link mode operation is to be enabled by: setting a subfield in a multilink element within an association or reassociation request to a predetermined value; and The association or re-association request is sent to the access point device.

22. A computer program product comprising computer readable instructions operable when executed by a processor on an access point device to control the device to: receiving an association or reassociation request from a non-access point device; determining from a value of a subfield in a multilink element that the non-access point device requests continuous multilink mode operation to be enabled; setting a subfield in a multilink element within an association or reassociation response to a predetermined value, the predetermined value indicating that the request was received; and The association or re-association response is sent to the non-access point device.

23. A non-access point device configured for multi-link communication, the non-access point device comprising: means for indicating to the access point device that continuous multilink mode operation is enabled by setting a subfield in a multilink element within an association or reassociation request to a predetermined value; as well as Means for causing the association or re-association request to be transmitted to the access point device.

24. An access point device, comprising: means for receiving an association or reassociation request from a non-access point device; means for determining from a value of a subfield in a multilink element that the non-access point device requests continuous multilink mode operation to be enabled; means for setting a subfield in a multilink element within an association or reassociation response to a predetermined value, the predetermined value indicating that the request was received; as well as Means for causing the association or re-association response to be transmitted to the non-access point device.

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