Multilink Operation-Based Measurement Reporting

Abstract

A wireless communication device (11) maintains a wireless link to a further wireless communication device (10) on a first channel. The wireless communication device (11) sends an indication to the further wireless communication device (11) that the wireless communication device supports multi-link operation. Furthermore, the wireless communication device (11) receives a request from the further wireless communication device (10). In response to the request, the wireless communication device (11) utilizes multi-link operation to perform at least one measurement on a second channel while maintaining a wireless link to the further wireless communication device (10). Furthermore, the wireless communication device (11) sends one or more measurement reports representative of the at least one measurement to the further wireless communication device.

Description

[Technical Field]

[0001] The present invention relates to a method for controlling radio transmissions, and to corresponding devices, systems and computer programs. [Background technology]

[0002] In wireless communication technologies, there is growing interest in using unlicensed bands such as the 2.4 GHz ISM band, the 5 GHz band, the 6 GHz band, and the 60 GHz band using more advanced channel access techniques. Historically, WLAN (Wireless Local Area Network) technology based on the IEEE 802.11 family of standards, also referred to as Wi-Fi, has been the dominant standard in unlicensed bands, especially for applications requiring support for high data rates.

[0003] WLAN technology also supports reporting of radio measurements. For example, a corresponding radio measurement framework is specified in “IEEE Standard for Information technology—Telecommunications and information exchange between systems Local and metropolitan area networks—Specific requirements—Part 11:Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications,” IEEE Standard 802.11-2016 (a revision of IEEE Standard 802.11-2012), vol., no., pp. 1-3534, December 14, 2016, hereinafter referred to as the “IEEE 802.11 PHY specification.” See, in particular, Section 11.11 of the IEEE 802.11 specification. The radio measurement framework can provide support for operation and management of WLAN networks.

[0004] More specifically, a station (STA) can ask another STA to perform radio measurements based on requests and reports. In some circumstances, the STA may refuse to perform the requested measurements. Measurement quantities that may be requested include a beacon or frame report indicating the signal strength of the beacon or frame, a channel load report indicating the load on the channel for the portion of time the channel is busy, a noise histogram report indicating the measured noise power and interference for a histogram, and a STA statistics report indicating STA statistics such as the number of MSDUs (medium access control service data units) received during a requested time interval.

[0005] A STA may be requested to perform measurements on either an operating channel or a non-working channel. When a STA is requested to measure on a non-working channel, the STA generally needs to temporarily suspend transmission and reception of data traffic while performing measurements on the non-working channel. In some circumstances, the STA may also refuse to perform measurements. In that case, the STA is required to report back that it is refusing to perform measurements. Reasons for refusing measurements may include fear of reduced quality of service (QoS), an unacceptable increase in power consumption, measurement scheduling conflicts, etc. As an example, a STA performing a requested measurement on a non-working channel may need to retune its radio circuitry to a center frequency different from that of the STA's operating channel, which may result in loss of synchronization with the medium and adversely affect the STA's ability to rapidly transmit or receive on the operating channel. If an urgent packet arrives in the STA's transmit (TX) buffer, the STA may first need to synchronize to the medium, which may take some time, and then contend for access to the operating channel or request scheduling of an uplink (UL) transmission. Such a situation may very well result in the STA refusing to perform the requested measurements.

[0006] WLAN technology also supports enhancements that involve access to the medium being controlled by an access point (AP). For example, corresponding mechanisms are specified in the IEEE 802.11ax technology, see "IEEE P802.11ax / D6.0 Draft Standard for Information technology - Telecommunications and information exchange between systems Local and metropolitan area networks - Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 1: Enhancements for High Efficiency WLAN (November 2019)," hereinafter referred to as the "IEEE 802.11ax draft." For example, the "IEEE 802.11ax draft" specifies trigger frames that allow an AP to schedule UL transmissions from STAs. Furthermore, an enhancement to WLAN technology called EHT (extremely high throughput), which will be introduced with the amendment referred to as IEEE 802.11be, includes plans to support multi-AP systems in which APs collaborate in allocating radio resources. Radio measurements reported by STAs are useful in such scenarios, but the availability of such measurements may be limited, for example, because the STAs may refuse to perform the requested measurements.

[0007] Therefore, there is a need for techniques that allow measurements to be efficiently performed and reported in wireless communication systems. Summary of the Invention

[0008] According to one embodiment, a method for controlling wireless transmissions in a wireless communication system is provided. According to the method, a wireless communication device maintains a wireless link to an additional wireless communication device on a first channel. The wireless communication device sends an indication to the additional wireless communication device that the wireless communication device supports multilink operation. Furthermore, the wireless communication device receives a request from the additional wireless communication device. In response to the request, the wireless communication device utilizes multilink operation to perform at least one measurement on a second channel while maintaining the wireless link to the additional wireless communication device. Furthermore, the wireless communication device sends one or more measurement reports representing the at least one measurement to the additional wireless communication device.

[0009] According to a further embodiment, a method for controlling wireless transmissions in a wireless communication system is provided. According to the method, a wireless communication device maintains a wireless link to at least one additional wireless communication device on a first channel. The wireless communication device receives an indication from the at least one additional wireless communication device that the additional wireless communication device supports multilink operation. Furthermore, the wireless communication device sends a request to the at least one additional wireless communication device to utilize multilink operation to perform at least one measurement on a second channel while maintaining the wireless link to the wireless communication device. Furthermore, the wireless communication device receives one or more measurement reports from the at least one additional wireless communication device that represent the at least one measurement.

[0010] According to a further embodiment, a wireless communication device is provided. The wireless communication device is configured to maintain a wireless link to an additional wireless communication device over a first channel. The wireless communication device is further configured to send an indication to the additional wireless communication device that the wireless communication device supports multilink operation. The wireless communication device is further configured to receive a request from the additional wireless communication device. In response to the request, the wireless communication device is further configured to utilize multilink operation to perform at least one measurement over a second channel while maintaining the wireless link to the additional wireless communication device. The wireless communication device is further configured to send one or more measurement reports representing the at least one measurement to the additional wireless communication device.

[0011] According to a further embodiment, a wireless communication device is provided. The wireless communication device includes at least one processor and a memory. The memory includes instructions executable by the at least one processor, whereby the wireless communication device is operable to maintain a wireless link to an additional wireless communication device on a first channel. Furthermore, the memory includes instructions executable by the at least one processor, whereby the wireless communication device is operable to send an indication to the additional wireless communication device that the wireless communication device supports multilink operation. Furthermore, the memory includes instructions executable by the at least one processor, whereby the wireless communication device is operable to receive a request from the additional wireless communication device. Furthermore, the memory includes instructions executable by the at least one processor, whereby the wireless communication device is operable to utilize multilink operation to perform at least one measurement on a second channel while maintaining the wireless link to the additional wireless communication device in response to the request. Furthermore, the memory includes instructions executable by the at least one processor, whereby the wireless communication device is operable to send one or more measurement reports representing the at least one measurement to the additional wireless communication device.

[0012] According to a further embodiment, a wireless communication device is provided. The wireless communication device is configured to maintain a wireless link to at least one additional wireless communication device on a first channel. The wireless communication device is further configured to receive an indication from the at least one additional wireless communication device that the additional wireless communication device supports multilink operation. The wireless communication device is further configured to send a request to the at least one additional wireless communication device to utilize multilink operation to perform at least one measurement on a second channel while maintaining the wireless link to the wireless communication device. The wireless communication device is further configured to receive one or more measurement reports from the at least one additional wireless communication device, the measurement reports representing the at least one measurement.

[0013] According to a further embodiment, a wireless communication device is provided. The wireless communication device includes at least one processor and a memory. The memory includes instructions executable by the at least one processor, whereby the wireless communication device is operable to maintain a wireless link to at least one additional wireless communication device on a first channel. Furthermore, the memory includes instructions executable by the at least one processor, whereby the wireless communication device is operable to receive an indication from the at least one additional wireless communication device that the additional wireless communication device supports multilink operation. Furthermore, the memory includes instructions executable by the at least one processor, whereby the wireless communication device is operable to send a request to the at least one additional wireless communication device to utilize multilink operation to perform at least one measurement on a second channel while maintaining the wireless link to the wireless communication device. Furthermore, the memory includes instructions executable by the at least one processor, whereby the wireless communication device is operable to receive one or more measurement reports representing the at least one measurement from the at least one additional wireless communication device.

[0014] According to a further embodiment of the present invention, a computer program or computer program product is provided, e.g., in the form of a non-transitory storage medium, comprising program code to be executed by at least one processor of a wireless communication device. Execution of the program code causes the wireless communication device to maintain a wireless link to an additional wireless communication device on a first channel. Furthermore, execution of the program code causes the wireless communication device to send an indication to the additional wireless communication device that the wireless communication device supports multilink operation. Furthermore, execution of the program code causes the wireless communication device to receive a request from the additional wireless communication device. Furthermore, execution of the program code causes the wireless communication device, in response to the request, to utilize multilink operation to perform at least one measurement on a second channel while maintaining the wireless link to the additional wireless communication device. Furthermore, execution of the program code causes the wireless communication device to send one or more measurement reports representative of the at least one measurement to the additional wireless communication device.

[0015] According to a further embodiment of the present invention, a computer program or computer program product is provided, e.g., in the form of a non-transitory storage medium, comprising program code to be executed by at least one processor of a wireless communication device. Execution of the program code causes the wireless communication device to maintain a wireless link to an additional wireless communication device on a first channel. Furthermore, execution of the program code causes the wireless communication device to send an indication to the additional wireless communication device that the wireless communication device supports multilink operation. Furthermore, execution of the program code causes the wireless communication device to receive a request from the additional wireless communication device. Furthermore, execution of the program code causes the wireless communication device, in response to the request, to utilize multilink operation to perform at least one measurement on a second channel while maintaining the wireless link to the additional wireless communication device. Furthermore, execution of the program code causes the wireless communication device to send one or more measurement reports representative of the at least one measurement to the additional wireless communication device.

[0016] Details of such and further embodiments will be apparent from the detailed description that follows. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram illustrating a wireless communication system according to one embodiment; [Figure 2] FIG. 1 illustrates a process for sharing a TXOP according to one embodiment. [Figure 3] FIG. 2 is a diagram illustrating a schematic of multi-link operation according to one embodiment. [Figure 4] 1 is a flowchart to outline a method according to one embodiment. [Figure 5] 1 is a block diagram for illustrating in outline the functionality of a wireless communication device according to one embodiment; [Figure 6] 10 is a flow chart for schematically illustrating a method according to a further embodiment; [Figure 7] FIG. 10 is a block diagram for illustrating schematically the functionality of a wireless communication device according to a further embodiment; [Figure 8] 2 is a diagram illustrating the structure of a STA according to one embodiment; [Figure 9] FIG. 2 is a diagram illustrating a schematic structure of an AP according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] In the following, concepts according to exemplary embodiments of the present invention will be described in more detail and with reference to the accompanying drawings. The illustrated embodiment relates to controlling radio transmissions in a wireless communication system. The wireless communication system may be a WLAN (Wireless Local Area Network) system based on IEEE 802.11 technology. However, it should be noted that the illustrated concepts may also be applied to other wireless communication technologies, for example, to contention-based modes of LTE (Long Term Evolution) or NR (New Radio) technologies specified by 3GPP (Third Generation Partnership Project).

[0019] The illustrated concept involves a wireless communication device utilizing multi-link operation (MLO) to efficiently perform and report the requested measurements. In particular, utilizing MLO involves a wireless communication device maintaining a wireless link to another wireless communication device on a first channel while simultaneously performing measurements on one or more second channels, which are then reported to the additional wireless communication device. Reporting can be achieved via the maintained wireless link. Assuming that the wireless communication system is based on an IEEE 802.11 technology WLAN, the wireless communication device can be a non-AP STA, and the other wireless communication device can be an AP to which the non-AP STA is connected. However, other scenarios are also possible, such as a scenario in which both APs are non-AP STAs connected by ad-hoc wireless links.

[0020] The illustrated concepts may be applied, for example, in a situation where an AP either does not support MLO or determines to operate in single-link mode, and one or more STAs connected to the AP support MLO. In such a situation, the AP may request that one or more of the STAs utilize MLO to perform measurements and report the measurements to the AP. By utilizing MLO, the STAs can maintain their existing wireless links while performing measurements, without losing synchronization with the medium and without risking QoS degradation or delays, resulting in a low risk of refusal to perform the requested measurements. The AP may utilize the reported measurements in combination with measurements performed by the AP itself, thereby gaining a more comprehensive knowledge of conditions in the AP's vicinity.

[0021] The illustrated concept may involve an AP signaling support for an operating mode for cooperating with STAs that support the use of MLO to maintain a radio link on one channel while simultaneously performing measurements on one or more other channels. This operating mode is also referred to below as limited MLO. For example, an AP may signal support for limited MLO via one or more management frames, e.g., in the capabilities element of a beacon frame. STAs that support MLO may advertise their MLO capabilities. Furthermore, an AP may also utilize support signaling that is also used for MLO, even when the AP operates on a single channel. Upon association, non-AP STAs inform the AP of their MLO capabilities. To request measurement reports, the AP may select one or more STAs that advertised support for MLO.

[0022] MLO may be based on the ML (Multi-Link) features of EHT technology according to the IEEE 802.11be amendment. In these ML features, a Multi-Link Device (MLD) has multiple associated STAs, each of which can communicate using an independent wireless channel or link. For example, an MLD may have two associated STAs, one of which operates using one or more channels in the 5 GHz frequency band and the other of which operates using one or more channels in the 6 GHz frequency band. According to another example, an MLD may have two associated STAs, each of which operates using a channel in the 6 GHz frequency band. As used herein, a STA capable of implementing MLO is considered to be an MLD.

[0023] An MLD can use its associated STAs and corresponding supported channels to perform simultaneous transmit (TX) MLO, simultaneous receive (RX) MLO, or simultaneous transmit and receive (STR) MLO. If TX operation on one channel results in the inability to perform RX operation on another channel, the pair of channels is classified as non-STR (NSTR).

[0024] 1 illustrates an exemplary wireless communication system in which the illustrated concepts may be implemented. In the illustrated example, the wireless communication system includes multiple access points (APs) 10, referred to in the illustrated example as AP1, AP2, AP3, and AP4, and multiple stations (STAs) 11, referred to in the illustrated example as STA11, STA12, STA13, STA21, STA31, STA32, and STA41. Stations STA11, STA12, and STA13 are served by AP1 (in a first BSS denoted as BSS1), and station STA21 is served by AP2 (in a second BSS denoted as BSS2). Stations STA31 and STA32 are served by AP3 (in a third BSS denoted as BSS3). Station STA41 is served by AP4 (in a fourth BSS denoted as BSS4). Station 11 may correspond to various types of wireless devices, e.g., user terminals, such as mobile or stationary computing devices, such as smartphones, laptop computers, desktop computers, tablet computers, gaming devices, etc. Additionally, station 11 can correspond to other types of equipment, such as, e.g., smart home devices, printers, multimedia devices, data storage devices, etc.

[0025] In the example of Figure 1, each of the stations 11 may connect to one of the APs 10 through a wireless link. For example, depending on the location or channel conditions experienced by a given station 11, the station 11 may select an appropriate AP 10 and BSS for establishing a wireless link. The wireless link may be based on a frequency spectrum shared based on a contention-based mechanism, e.g., one or more OFDM carriers from an unlicensed band such as the 2.4 GHz ISM band, the 5 GHz band, the 6 GHz band, or the 60 GHz band. Some of the stations 11 may support MLO, i.e., MLD.

[0026] Each AP 10 may provide data connectivity for stations 11 connected to the AP 10. As further shown, the AP 10 may be connected to a data network (DN) 110. In this manner, an AP 10 may also provide data connectivity for stations 11 connected to different APs 10. Additionally, an AP 10 may also provide data connectivity for the station 11 to other entities, e.g., one or more servers, service providers, data sources, data sinks, user terminals, etc. Thus, the wireless link established between a given station 11 and its serving AP 10 may be used to provide various types of services to the station 11, e.g., voice services, multimedia services, or other data services. Such services may be based on applications running on the station 11 and / or on devices linked to the station 11. By way of example, FIG. 1 illustrates an application service platform 150 provided in the DN 110. An application(s) running on station 11 and / or on one or more other devices linked to station 11 may use the wireless link for data communication with one or more other stations 11 and / or application service platform 150, thereby enabling use of corresponding service(s) at station 11.

[0027] As mentioned above, the illustrated concept may be based on an MLO-only mode of operation. In the MLO-only mode, an AP and each of its associated STAs communicate using a single wireless link, i.e., on a single channel. All exchanges of wireless frames, including management frames, control frames, action frames, and data frames, occur on this single channel. However, the AP may request that the associated STAs perform additional measurements on one or more other channels, utilizing MLO supported by the STAs to simultaneously maintain a wireless link to the AP. The illustrated concept may be based on signaling using various types of frames, particularly beacon frames, probe request frames, probe response frames, association request frames, association response frames, reassociation request frames, and / or reassociation response frames.

[0028] A beacon frame may be periodically broadcast by an AP in a BSS. The beacon frame may include a capabilities element and an operations element. In some scenarios, the AP may include an indication in the beacon frame, capabilities element, or operations element to indicate the AP's MLO restrictions.

[0029] A probe response frame may be sent by an AP to one or more STAs in response to a probe request frame received from each STA. The probe response frame may include a capabilities element and an actions element. In some scenarios, the AP may include an indication in the probe response frame, for example, in the capabilities element or the actions element, to indicate the MLO restriction of the AP.

[0030] Association request frames and reassociation request frames may be sent by a STA to an AP managing a basic service set (BSS) to request to join the BSS, and the AP responds to these frames by sending an association response frame or a reassociation response frame, respectively. A reassociation request frame may be considered a specific case of an association request frame, which is used in scenarios when the STA has already previously associated with the AP. Similarly, a reassociation response frame may be considered a specific case of an association response frame. An association request frame or a reassociation request frame may include a capabilities element and an actions element. In some scenarios, the STA includes an element in the association / reassociation frame, for example, in the capabilities element or in the actions element, to indicate support for MLO to the AP. The instructions may also provide further information related to the supported MLOs, such as the number of simultaneous links supported, whether STR or NSTR MLOs are supported, the supported frequency bands, e.g., 2.4 GHz, 5 GHz, or 6 GHz, and / or the supported bandwidths, e.g., 40 MHz, 80 MHz, 160 MHz, 80+80 MHz, etc., the supported capabilities of each link, etc.

[0031] A probe request frame may be sent by a STA to solicit a probe response frame from an AP operating on a particular channel or from several APs. The probe request frame may include a capability element and an action element. In some scenarios, the STA may include an indication in the probe request frame, for example, in the capability element or in the action element, to indicate support for MLO to the AP. The indication may also provide further information related to the supported MLO, such as the number of supported simultaneous links, whether STR or NSTR MLO is supported, the supported frequency band (e.g., 2.4 GHz, 5 GHz, or 6 GHz), and / or the supported bandwidth (e.g., 40 MHz, 80 MHz, 160 MHz, 80+80 MHz, etc.), the supported capabilities of each link, etc.

[0032] Based on the indicated information, the AP may select one or more STAs and send measurement requests to these one or more STAs, and these selected STAs may then provide measurement reports to the AP. As a first example, consider the situation shown in FIG. 1 for BSS1, where three STAs, namely, STA11, STA12, and STA13, are associated with AP1. In this example, it may be assumed that STA11 does not support MLO, STA12 supports NSTR MLO, and STA13 supports STR MLO. It may also be assumed that AP1 requires measurement information on its operating channel and on a non-operating channel, and that AP1 has downlink (DL) data to be transmitted to STA13. In this case, AP1 may decide to request measurements from STA12. This decision may be beneficial because STA12 can potentially perform the requested measurements faster and with less overhead than STA11, and because, compared to STA13, the measurements may not impair the QoS of upcoming DL data transmissions. As a second example, in the same situation, it may be assumed that AP1 needs measurement information on a non-working channel and has received buffer status reports from STA11, STA12, and STA13 indicating that each of these STAs has UL data to transmit. In this case, AP1 may request STA13 to perform measurements on the non-working channel because, compared to STA11 and STA12, STA13 can perform measurements without excessively delaying the upcoming transmission of UL data.

[0033] In some scenarios, an AP may also be MLD but still decide to use MLO restriction. The AP may then be provided with an MLD MAC (medium access control) address, which may be used to establish security keys to be used in MLO restriction. MLD STAs may then use the security keys to communicate with the AP based on the MLD security mechanism.

[0034] An example of a scenario in which measurement requests and reports based on the illustrated concept may be utilized is when an AP is preparing to change to another channel. For example, if the AP detects that the performance of its BSS is deteriorating, the AP may consider changing to another channel. A possible reason for such performance degradation may be increased traffic in overlapping BSSs using the same channel. As a result, the likelihood that the channel used by the AP will be found busy may increase, and therefore the risk that an attempt to access the channel will fail. Furthermore, even if the channel is found to be idle, there may be more interference on the channel, which may require the use of a lower data rate. Before changing to another channel, the AP may utilize the reported measurements to determine whether there is a new channel available that would improve performance. By utilizing measurements performed by STAs utilizing MLO, the search for a new channel may be performed without interrupting or otherwise impairing data traffic on the AP's operating channel.

[0035] The AP may request the STA(s) to perform measurements on a particular channel, or the AP may request the STA(s) to search for candidate channels to be used as the AP's new operating channel and report the found candidate channels to the AP. Because of this possibility of utilizing its associated STAs in the search, the search can be performed without impacting transmissions on the AP's operating channel even if the AP itself does not support MLO.

[0036] Furthermore, even if the AP itself supports MLO and can itself use MLO operation to perform measurements without interrupting transmissions on its operating channel, it may still be beneficial for the AP to request MLO-enabled non-AP devices to perform measurements to scan other channels. For example, the AP and the reporting STA may experience very different interference situations, and therefore measurements reported by the STA may provide valuable additional information for the selection of a new channel that has low interference also from the perspective of the STA associated with the AP.

[0037] Figure 2 shows an example of a process for requesting and reporting measurements in accordance with the illustrated concepts. The process of Figure 2 involves an AP 10, e.g., corresponding to one of the APs 10 shown in Figure 1, and one or more STAs, e.g., corresponding to one or more of the STAs 11 shown in Figure 1.

[0038] 1, AP 10 may send a beacon frame 201 that is received by the STA(s). Beacon frame 201 may include an indication, for example, in a capabilities element or in an operations element, that indicates the MLO limitations of AP 10.

[0039] Additionally or alternatively, one or more of the STAs 11 may send a probe request frame 202 to the AP. The probe request frame 202 may include an indication, e.g., in a capabilities element or in an operations element, that instructs the AP that the STA 11 sending the probe request frame 202 supports MLO. The indication may also provide further information related to the supported MLO, such as the number of supported simultaneous links, whether STR or NSTR MLO is supported, the supported frequency bands (e.g., 2.4 GHz, 5 GHz, or 6 GHz), and / or the supported bandwidths (e.g., 40 MHz, 80 MHz, 160 MHz, 80+80 MHz, etc.), the supported capabilities of each link, etc. In some scenarios, the STA may include the indication in response to receiving a beacon frame 201 from the AP 10 and the beacon frame 201 indicating the MLO limitations of the AP 10.

[0040] In response to the probe request frame 202, the AP 10 may send a probe response frame 203 to the STA 11. The probe response frame 203 may include an indication, for example in a capabilities element or in an operations element, that indicates the MLO limitations of the AP 10.

[0041] Additionally or alternatively, one or more of the STAs 11 may send an association request frame or reassociation request frame 204 to the AP. The association request frame or reassociation request frame 204 may include an indication, e.g., in a capabilities element or in an operations element, that instructs the AP that the STA 11 sending the association request frame or reassociation request frame 204 supports MLO. The indication may also provide further information related to the supported MLO, e.g., the number of supported simultaneous links, whether STR or NSTR MLO is supported, the supported frequency band (e.g., 2.4 GHz, 5 GHz, or 6 GHz), and / or the supported bandwidth (e.g., 40 MHz, 80 MHz, 160 MHz, 80+80 MHz, etc.), the supported capabilities of each link, etc. In some scenarios, the STA may include the indication in response to receiving a beacon frame 201 from the AP 10 and the beacon frame 201 indicating the MLO restrictions of the AP 10. In some scenarios, the STA may include an indication in response to receiving the probe response frame 203 from the AP 10 and the probe response frame 203 indicating the MLO restriction of the AP 10.

[0042] In response to the association request or reassociation request frame 204, the AP 10 may send an association response or reassociation response frame 205 to the STA 11. The association response or reassociation response frame 205 may include an indication, for example, in a capabilities element or in an operations element, that indicates the MLO limitation of the AP 10.

[0043] It should be noted that the above messages may be transmitted in different orders, for example, the exchange of probe request frames 202 and probe response frames 203 could occur after the exchange of association request or re-association request frames 204 and association response or re-association response frames 205, the transmission of beacon frames could be omitted, there could be multiple exchanges of association request or re-association request frames and association response or re-association response frames, or there could be multiple exchanges of probe request and probe response frames.

[0044] 2, after associating at least one of the STAs 11 with the AP 10, the process may also involve the AP 10 sending DL data to the STAs 11 on its operating channel, or the STAs 11 sending UL data to the AP 10 on its operating channel. Thus, the associated STA(s) can utilize the operating channel of the AP 10 to maintain a wireless link to the AP 10.

[0045] At some point, the AP 10 may decide to request measurements from at least one of its associated STAs 11. This decision may be based on the STAs' MLO capabilities, as indicated by a probe request frame 202 or an association or reassociation request frame 204. To request measurements, the AP 10 sends a measurement request 208 to the STA(s) 11. The measurement request 208 may also indicate the type of measurement to be performed, for example, by indicating which quantities to measure or report and / or on which channel(s) the measurement should be performed. The quantities to be reported may include, for example, a beacon or frame report indicating the signal strength of the beacon or frame, respectively; a channel load report indicating the load on the channel for the portion of time the channel is busy; a noise histogram report indicating the measured noise power and interference for a histogram; a STA statistics report indicating STA statistics, such as the number of MSDUs received during a requested time interval; or a set of candidate channels for selection of a new operating channel for the AP 10.

[0046] As further shown, in response to the measurement request 208, STA 11 may return a measurement request acknowledgement 209 indicating that STA 11 is willing to perform the requested measurements. Alternatively, STA 11 may also indicate a refusal to perform the requested measurements.

[0047] However, in the example of FIG. 2, it is assumed that STA 11 accepts the measurement request 208 and at some point sends to AP 10 at least one measurement report 210 representing at least one measurement quantity specified by the measurement request 208.

[0048] 2, it is further assumed that the AP 10 utilizes information provided by the received measurement report(s) to control channel switching to a new operating channel of the AP 10, as indicated by block 211. This may also involve the AP 10 performing signaling 212 to move its associated STAs to the new operating channel.

[0049] FIG. 3 illustrates a schematic diagram of measurements based on MLO restrictions according to the illustrated concept. Specifically, FIG. 3 illustrates an AP 10, e.g., corresponding to one of the APs 10 in FIG. 1 or the AP 10 in FIG. 2, and a STA, e.g., corresponding to one of the STAs 11 in FIG. 1 or FIG. 2. In the example of FIG. 3, the AP 10 is assumed to be equipped with a single radio 21. Alternatively, the AP 10 may be equipped with multiple radios, which are not utilized in the functionality illustrated in FIG. 3. The STA 11 is equipped with multiple radios, specifically, a first radio 31 and a second radio 32. The radio 21 of the AP 10 and the first radio 31 of the STA 11 are used to maintain a wireless link 40 between the AP 10 and the STA 11. For this purpose, the first radio is tuned to the operating channel of the AP 19. At the same time, the second radio 32 of the STA 11 is available to perform measurements on another channel as requested by the AP 10.

[0050] 4 shows a flowchart illustrating a method that may be utilized to implement the illustrated concepts. The method of FIG. 4 may be used to implement the illustrated concepts in a wireless communication device operated in a wireless communication system. The wireless communication system may be based on WLAN technology, for example, according to the IEEE 802.11 family of standards. The wireless communication device may correspond, for example, to a STA associated with an AP of the wireless communication system, for example, any of the STAs 11 described above.

[0051] If a processor-based implementation of a wireless communication device is used, at least some of the steps of the method of Figure 4 may be performed and / or controlled by one or more processors of the wireless communication device. Such a wireless communication device may also include a memory storing program code for implementing at least some of the below-described functions or steps of the method of Figure 4.

[0052] In step 410, the wireless communication device maintains a wireless link to a further wireless communication device on the first channel. The wireless communication device may correspond, for example, to a STA, and the further wireless communication device may correspond to an AP with which the STA is associated, for example, any of the APs 10 described above. To establish the wireless link, the STA may discover the AP, for example, based on an exchange of beacon frames, probe request frames, or probe response frames, and may join the AP's BSS, for example, based on an exchange of association request or reassociation request frames and association response or reassociation response frames.

[0053] In some scenarios, the additional wireless communication device does not support MLO, while in other scenarios the additional wireless communication device may support MLO in a mode based on cooperation with a wireless communication device that utilizes MLO for communication on one channel and performs measurements on another channel.

[0054] In step 420, the wireless communication device sends an indication to the further wireless communication device that the wireless communication device supports MLO. In some scenarios, the wireless communication device sends the indication in a probe request frame. Alternatively or additionally, the wireless communication device may send the indication in an association request frame. In some cases, the association request frame may be a reassociation request frame. The probe request frame, association request frame, or reassociation request frame may be sent during establishment of the first wireless link, for example, as described with respect to step 410.

[0055] In step 430, the wireless communication device may receive a further indication from the further wireless communication device that the further wireless communication device utilizes MLO for communication on one channel and supports cooperation with wireless communication devices that perform measurements on another channel. The above-mentioned indication of MLO restriction from the AP is an example of such an indication. The wireless communication device may receive the further indication in a probe response frame. Alternatively or additionally, the wireless communication device may receive the further indication in an association response frame. In some cases, the association response frame may be a reassociation response frame. Alternatively or additionally, the wireless communication device may receive the further indication in a beacon frame. The beacon frame, probe response frame, association response frame, or reassociation response frame may be received, for example, during establishment of the first wireless link, as described with respect to step 410.

[0056] It should be noted that steps 410, 420, and 430 may be performed in various orders, and that in some scenarios, the wireless device may send the instruction for step 430 in response to receiving a further instruction for step 430. Similarly, the wireless communication device may receive the further instruction for step 430 in response to sending the instruction for step 420.

[0057] In step 440, the wireless communication device receives a request from a further wireless communication device. The measurement request 208 described above is an example of such a request.

[0058] In step 450, in response to the request received in step 440, the wireless communication device utilizes MLO to perform at least one measurement on a second channel while maintaining a wireless link to the further wireless communication device, for example, utilizing the configuration shown in FIG.

[0059] In step 460, the wireless communication device sends to the further wireless communication device one or more measurement reports representative of the at least one measurement performed in step 450. The wireless communication device may send the measurement report via the maintained wireless link.

[0060] The one or more measurement reports may include, for example, at least one measurement report indicating a measured signal strength associated with one or more received frames, e.g., with respect to a received signal strength indicator (RSSI). Alternatively or additionally, the one or more measurement reports may include at least one measurement report indicating a load on the second channel, e.g., with respect to a portion of time when the channel is busy. Alternatively or additionally, the one or more measurement reports may include at least one measurement report indicating noise power on the second channel, e.g., with respect to a histogram and / or based on an idle power indicator (IPI). Alternatively or additionally, the one or more measurement reports may include at least one measurement report indicating a number of frames received per time interval, e.g., the number of received MSDUs. Alternatively or additionally, the one or more measurement reports may include at least one measurement report indicating a candidate set of channels for selection of a new operating channel of the wireless communication device.

[0061] 5 shows a block diagram illustrating functionality of a wireless communication device 500 operating according to the method of FIG. 4. The wireless communication device 500 may correspond, for example, to one of the STAs 11 described above. As shown, the wireless communication device 500 may comprise a module 510 configured to maintain a wireless link to an additional wireless communication device on a first channel, as described with respect to step 410. Further, the wireless communication device 500 may comprise a module 520 configured to send an indication of MLO support to the additional wireless communication device, as described with respect to step 420. Further, the wireless communication device 500 may comprise a module 530 configured to receive an indication from the additional wireless communication device, as described with respect to step 440. Further, the wireless communication device 500 may comprise a module 540 configured to receive a request from the additional wireless communication device, as described with respect to step 440. Further, the wireless communication device 500 may comprise a module 550 configured to utilize MLO to perform at least one measurement while maintaining the wireless link, as described with respect to step 450. Additionally, the wireless communication device 500 may comprise a module 560 configured to send one or more measurement reports as described with respect to step 560 .

[0062] It should be noted that the wireless communication device 500 may include additional modules for implementing other functions, such as known functions of a WLAN STA. Furthermore, it should be noted that the modules of the wireless communication device 500 do not necessarily represent the hardware structure of the wireless communication device 500, but may also correspond to functional elements that are implemented, for example, by hardware, software, or a combination thereof.

[0063] 6 shows a flowchart illustrating a method that can be utilized to implement the illustrated concepts. The method of FIG. 6 can be used to implement the illustrated concepts in a wireless communication device operated in a wireless communication system. The wireless communication system can be based on WLAN technology, for example, according to the IEEE 802.11 family of standards. The wireless communication device can correspond, for example, to an AP, for example, any of the APs 10 described above.

[0064] If a processor-based implementation of a wireless communication device is used, at least some of the steps of the method of Figure 6 may be performed and / or controlled by one or more processors of the wireless communication device. Such a wireless communication device may also include a memory storing program code for implementing at least some of the below-described functions or steps of the method of Figure 6.

[0065] In step 610, the wireless communication device maintains a wireless link to at least one additional wireless communication device on the first channel. The wireless communication device may, for example, correspond to an AP, and the at least one additional wireless communication device may correspond to a STA associated with the AP, for example, any of the above-mentioned STAs 11. To establish the wireless link, the STA may discover the AP, for example, based on an exchange of beacon frames, probe request frames, or probe response frames, and may have joined the AP's BSS, for example, based on an exchange of association request or reassociation request frames and association response or reassociation response frames.

[0066] In some scenarios, the wireless communication device does not support MLO, while in other scenarios the wireless communication device may support MLO in a mode based on cooperation with an additional wireless communication device that utilizes MLO for communication on one channel and performs measurements on another channel.

[0067] In step 620, the wireless communication device receives an indication from at least one additional wireless communication device that the at least one additional wireless communication device supports MLO. In some scenarios, the wireless communication device receives the indication in a probe request frame. Alternatively or additionally, the wireless communication device may receive the indication in an association request frame. In some cases, the association request frame may be a reassociation request frame. The probe request frame, association request frame, or reassociation request frame may be received during establishment of the first wireless link, for example, as described with respect to step 610.

[0068] In step 630, the wireless communication device may send a further indication to at least one further wireless communication device that the wireless communication device utilizes MLO for communication on one channel and supports cooperation with further wireless communication devices that perform measurements on another channel. The above-mentioned indication of MLO restriction of the AP is an example of such an indication. The wireless communication device may send the further indication in a probe response frame. Alternatively or additionally, the wireless communication device may send the further indication in an association response frame. In some cases, the association response frame may be a reassociation response frame. Alternatively or additionally, the wireless communication device may send the further indication in a beacon frame. The beacon frame, probe response frame, association response frame, or reassociation response frame may be sent during establishment of the first wireless link, for example, as described with respect to step 610.

[0069] It should be noted that steps 610, 620, and 630 may be performed in various orders, and that in some scenarios, the wireless device may receive the instruction of step 620 in response to sending the further instruction of step 630. Similarly, the wireless communication device may send the further instruction of step 630 in response to receiving the instruction of step 620.

[0070] In step 640, the wireless communication device sends a request to at least one further wireless communication device to utilize MLO to perform at least one measurement on a second channel while maintaining a wireless link to the further wireless communication device, e.g., utilizing the configuration shown in Figure 3. Measurement request 208 described above is an example of such a request.

[0071] In step 650, in response to the request sent in step 640, the wireless communication device receives from the at least one further wireless communication device one or more measurement reports representative of the at least one measurement requested in step 640. The wireless communication device may receive the at least one measurement report via the maintained wireless link.

[0072] The one or more measurement reports may include, for example, at least one measurement report indicating a measured signal strength associated with one or more received frames, e.g., with respect to RSSI. Alternatively or additionally, the one or more measurement reports may include at least one measurement report indicating a load on the second channel, e.g., with respect to a portion of time when the channel is busy. Alternatively or additionally, the one or more measurement reports may include at least one measurement report indicating noise power on the second channel, e.g., with respect to a histogram and / or based on an idle power indicator (IPI). Alternatively or additionally, the one or more measurement reports may include at least one measurement report indicating a number of frames received per time interval, e.g., a number of MSDUs received per second. Alternatively or additionally, the one or more measurement reports may include at least one measurement report indicating a candidate set of channels for selection of a new operating channel of the wireless communication device.

[0073] In step 660, the wireless communication device may control the configuration of the wireless link in response to the one or more measurement reports received in step 650. For example, based on the received one or more measurement reports, the wireless communication device may control switching of communication operation to the second channel. Thus, based on the received one or more measurement reports, the wireless communication device may select the second channel as the new operating channel of the wireless communication device.

[0074] 7 shows a block diagram illustrating functionality of a wireless communication device 700 operating according to the method of FIG. 6. The wireless communication device 700 may correspond, for example, to one of the APs 10 described above. As shown, the wireless communication device 700 may comprise a module 710 configured to maintain a wireless link to at least one additional wireless communication device on a first channel, as described with respect to step 610. Further, the wireless communication device 700 may comprise a module 720 configured to receive an indication of MLO support from the at least one additional wireless communication device, as described with respect to step 620. Further, the wireless communication device 700 may comprise a module 730 configured to send an indication to the at least one additional wireless communication device, as described with respect to step 630. Further, the wireless communication device 700 may comprise a module 740 configured to send a request to the at least one additional wireless communication device to perform at least one measurement, as described with respect to step 640. Further, the wireless communication device 700 may comprise a module 750 configured to receive one or more measurements, as described with respect to step 650. Additionally, the wireless communication device 700 may comprise a module 760 configured to control the configuration of the wireless link as described with respect to step 660 .

[0075] It should be noted that the wireless communication device 700 may include additional modules for implementing other functions, such as known functions of a WLAN AP. Furthermore, it should be noted that the modules of the wireless communication device 700 do not necessarily represent the hardware structure of the wireless communication device 700, but may also correspond to functional elements that are implemented, for example, by hardware, software, or a combination thereof.

[0076] It should be noted that the functionality described with respect to Figures 4 to 7 may also be implemented in a system, for example a system including a first wireless communication device that operates according to the method of Figure 4 and a second wireless communication device that corresponds to the further wireless communication device in the method of Figure 4 and operates according to the method of Figure 6.

[0077] As examples of structures for implementing the above-mentioned wireless communication devices, FIG. 8 shows a structure for implementing a STA, for example, corresponding to any of the above-mentioned STA11, and FIG. 9 shows a structure for implementing an AP, for example, corresponding to any of the above-mentioned AP10.

[0078] 8 shows a processor-based implementation of a STA 800 that can be used to implement the concepts described above. For example, the structure shown in FIG. 8 can be used to implement the concepts in any of the STAs 11 described above.

[0079] As shown, the STA 800 includes one or more wireless interfaces 810. The wireless interface(s) 810 may be based on, for example, WLAN technology, e.g., according to the IEEE 802.11 family of standards. However, other wireless technologies, e.g., LTE technology or NR technology, may also be supported. In some scenarios, the wireless interface(s) 810 may be based on multiple radios to support MLO operation of the STA 800.

[0080] Additionally, the STA 800 may include one or more processors 850 coupled to the wireless interface(s) 810 and memory 860 coupled to the processor(s) 850. By way of example, the wireless interface(s) 810, the processor(s) 850, and the memory 860 may be coupled by one or more internal bus systems of the STA 800. The memory 860 may include read-only memory (ROM), e.g., flash ROM, random access memory (RAM), e.g., dynamic RAM (DRAM) or static RAM (SRAM), mass storage, e.g., a hard disk or solid-state disk, etc. As shown, the memory 860 may include software 870 and / or firmware 880. The memory 860 may include suitably configured program code to be executed by the processor(s) 850 to implement the above-described functions for controlling wireless transmissions, as described with respect to FIGS. 4-7.

[0081] 8 is only schematic, and that the STA 800 may actually include additional components, e.g., additional interfaces or additional processors, that are not shown for clarity. It should also be understood that the memory 860 may include additional program code for implementing known functions of a WLAN STA. According to some embodiments, a computer program may also be provided to implement the functions of the STA 800, for example, in the form of a physical medium that stores program code and / or other data to be stored in the memory 860, or by making the program code available for download or by streaming.

[0082] 9 shows a processor-based implementation of an AP 900 that can be used to implement the concepts described above. For example, the structure shown in FIG. 9 can be used to implement the concepts in any of the APs 10 described above.

[0083] As shown, the AP 900 includes one or more wireless interfaces 910. The wireless interface(s) 910 may be based on, for example, WLAN technology, e.g., according to the IEEE 802.11 family of standards. However, other wireless technologies, e.g., LTE technology or NR technology, may also be supported. In some scenarios, the wireless interface(s) 910 may be based on multiple radios to support MLO operation of the AP 900. As further shown, the AP 900 may also include one or more network interfaces 920 that may be used for communication with other nodes of a wireless communication network, e.g., with other APs or with the application services platform shown in FIG. 1.

[0084] Additionally, the AP 900 may include one or more processors 950 coupled to the interface(s) 910, 920 and memory 960 coupled to the processor(s) 950. By way of example, the interface(s) 910, 920, the processor(s) 950, and the memory 960 may be coupled by one or more internal bus systems of the AP 900. The memory 960 may include ROM, e.g., flash ROM, RAM, e.g., DRAM or SRAM, mass storage, e.g., a hard disk or solid-state disk, etc. As shown, the memory 960 may include software 970 and / or firmware 980. The memory 960 may include appropriately configured program code to be executed by the processor(s) 950 to implement the above-described functions for controlling wireless transmissions, as described with respect to FIGS. 4-7.

[0085] 9 is only schematic, and that the AP 900 may actually include additional components, e.g., additional interfaces or additional processors, that are not shown for clarity. It should also be understood that the memory 960 may include additional program code for implementing known functions of a WLAN AP. According to some embodiments, computer programs may also be provided to implement the functions of the AP 900, for example, in the form of a physical medium that stores program code and / or other data to be stored in the memory 960, or by making the program code available for download or by streaming.

[0086] As can be seen, the concepts described above can be used to efficiently perform and report measurements in a wireless communication system. In particular, a wireless communication device can benefit from the MLO capabilities of another wireless communication device by requesting measurements from the other wireless communication device, which is performed by utilizing MLO to maintain a wireless link on one channel while performing measurements on another channel. In this way, an AP can, for example, utilize the MLO capabilities of its associated MLD to collect measurements performed by the MLD. Since the adverse effects of the MLD on existing wireless links can be avoided, there is less risk of a measurement request to the MLD being rejected. Furthermore, an MLD can scan the medium more quickly than a non-MLD. For example, an MLD can perform simultaneous measurements on an operating channel and a non-operating channel, or can perform simultaneous measurements on two non-operating channels. Therefore, an AP can receive desired measurement reports quickly and with low overhead. Medium occupation by measurement requests and responses can be reduced. Furthermore, the illustrated concepts can be implemented in various wireless communication technologies, including IEEE 801.11be technology and technologies based on earlier members of the IEEE 802.11 family of standards, e.g., IEEE 802.11ac / ax technology. On the AP side, such implementation can be achieved, e.g., by a software upgrade, without requiring hardware modifications. Furthermore, an AP can operate over a single link even if the AP supports MLO, and the illustrated concepts can enable such an AP to leverage the MLO capabilities of its associated STAs.

[0087] It should be understood that the examples and embodiments described above are merely illustrative and subject to various modifications. For example, the concepts shown may be applied to various types of wireless technologies, not limited to WLAN technology. Furthermore, the concepts may be applied to various types of APs and STAs. Furthermore, the concepts shown may be applied to various combinations of channels and channels from various frequency bands.

[0088] Moreover, it should be understood that the above concepts may be implemented by using correspondingly designed software to be executed by one or more processors of an existing device or apparatus, or by using dedicated device hardware. Furthermore, it should be noted that the illustrated apparatus or devices may each be implemented as a single device or as a system of multiple interacting devices or modules.

Claims

1. 1. A method for controlling radio transmission in a wireless communication system, the method comprising: maintaining, on a first channel, a wireless communication device (11; 500; 800) a wireless link (40) to a further wireless communication device (10; 700; 900) that does not support multi-link operation; - said wireless communication device (11; 500; 800) sending to said further wireless communication device (10; 700; 900) an indication that said wireless communication device supports multi-link operation; receiving a request (208) from the further wireless communication device (10; 700; 900) to utilize the multilink operation to perform at least one measurement on a second channel while maintaining the wireless link (40) to the further wireless communication device (10; 700; 900); in response to said request (208), said wireless communication device (11; 500; 800) utilizing said multilink operation to perform at least one measurement on said second channel while maintaining said wireless link (40) to said further wireless communication device; said wireless communication device (11; 500; 800) sending to said further wireless communication device (10; 700; 900) one or more measurement reports (210) representative of said at least one measurement; A method comprising:

2. the wireless communication device (11; 500; 800) sends the indication in a probe request frame (202); The method of claim 1.

3. the wireless communication device (11; 500; 800) sends the indication in an association request frame (204); 3. The method according to claim 1 or 2.

4. the wireless communication device (11; 500; 800) receiving from the further wireless communication device (10; 700; 900) a further indication that the further wireless communication device (10; 700; 900) supports cooperation with a wireless communication device that utilizes multilink operation for communication on one channel and performs measurements on another channel.

4. The method of claim 1, comprising:

5. The wireless communication device (11; 500; 800) receives the further indication in a probe response frame (203). The method of claim 4, comprising:

6. The wireless communication device (11; 500; 800) receives the further indication in an association response frame (205). The method of claim 4 or 5, comprising:

7. The wireless communication device (11; 500; 800) receives the further indication in a beacon frame (201).

7. The method of claim 4, comprising:

8. the one or more measurement reports (210) comprising at least one measurement report indicative of a measured signal strength associated with one or more received frames; 8. The method according to any one of claims 1 to 7.

9. the one or more measurement reports (210) comprising at least one measurement report indicative of a load on the second channel.

9. The method according to any one of claims 1 to 8.

10. the one or more measurement reports (210) comprising at least one measurement report representative of noise power on the second channel.

10. The method according to any one of claims 1 to 9.

11. the one or more measurement reports (210) comprising at least one measurement report indicative of interference power on the second channel.

11. The method according to any one of claims 1 to 10.

12. the one or more measurement reports (210) comprising at least one measurement report indicating a number of frames received per time interval; 12. The method according to any one of claims 1 to 11.

13. said one or more measurement reports (210) comprising at least one measurement report indicating a candidate set of channels for selection of a new operating channel of said further wireless communication device (10; 700; 900); 13. The method according to any one of claims 1 to 12.

14. The wireless communication system is based on wireless local area network technology according to the IEEE 802.11 family of standards; 14. The method of any one of claims 1 to 13.

15. the further wireless communication device (10; 700; 900) is an access point of the wireless communication system and the wireless communication device (11; 500; 800) is a station served by the access point, 15. The method of claim 14.

16. 1. A method for controlling radio transmission in a wireless communication system, the method comprising: a wireless communication device (10; 700; 900) that does not support multi-link operation maintaining a wireless link (40) to at least one further wireless communication device (11; 500; 800) on a first channel; receiving, by the wireless communication device (10; 700; 900), from the at least one further wireless communication device (11; 500; 800), an indication that the further wireless communication device (11; 500; 800) supports multi-link operation; sending a request from the wireless communication device (10; 700; 900) to the at least one further wireless communication device (11; 500; 800) to utilize the multilink operation to perform at least one measurement on a second channel while maintaining the wireless link (40) to the wireless communication device (10; 700; 900); said wireless communication device (10; 700; 900) receiving from said at least one further wireless communication device (11; 500; 800) one or more measurement reports (210) representing said at least one measurement; A method comprising:

17. and controlling the wireless communication device (10; 700; 900) to switch communication operations to the second channel based on the one or more received measurement reports.

17. The method of claim 16, comprising:

18. the wireless communication device (10; 700; 900) is an access point of the wireless communication system and the at least one further wireless communication device (11; 500; 800) is a station served by the access point, 18. The method of claim 16 or 17.

19. at least one processor (850); a memory (860) containing program code executable by said at least one processor (850); Equipped with A wireless communication device (11; 500; 800) whereby execution of the program code by the at least one processor (850) causes the wireless communication device (11; 500; 800) to perform a method according to any one of claims 1 to 15.

20. at least one processor (950); a memory (960) containing program code executable by said at least one processor (950); Equipped with A wireless communication device (10; 700; 900) whereby execution of the program code by the at least one processor (950) causes the wireless communication device (10; 700; 900) to perform a method according to any one of claims 16 to 18.

21. 16. A computer program comprising program code to be executed by at least one processor (850) of a wireless communication device (11; 500; 800), whereby execution of the program code causes the wireless communication device (11; 500; 800) to perform a method according to any one of claims 1 to 15.

22. 19. A computer program comprising program code to be executed by at least one processor (950) of a wireless communication device (10; 700; 900), whereby execution of said program code causes said wireless communication device (10; 700; 900) to perform a method according to any one of claims 16 to 18.

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