Conditional full-duplex operation

Abstract

A wireless communication device (20) receives a first wireless signal (51) from a further wireless communication device (10). The first wireless signal (51) indicates information on one or more conditions for reception of a second wireless signal (52) by the further wireless communication device (10) during ongoing transmission of the first wireless signal (51). Based on the one or more conditions, the wireless communication device (20) controls transmission of the second wireless signal (52) to the further wireless communication device (10).

Description

[0001] Conditional full-duplex operation

[0002] Technical Field

[0003] The present invention relates to methods for controlling wireless transmissions and to corresponding devices, systems, and computer programs.

[0004] Background

[0005] Wireless communication technologies may use licensed frequency bands and / or licenseexempt frequency bands. A typical example of a wireless communication technology operating in license-exempt frequency bands is the WL N (Wireless Local Area Network) technology, according to "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," in IEEE Std 802.11-2020 (Revision of IEEE Std 802.11-2016), pp.1- 4379, 26 Feb. 2021 , in the following denoted as “IEEE 802.11 standard”. The WLAN technology based on the IEEE 802.11 Standard is also referred to as “Wi-Fi”. In the WLAN technology, a wireless communication device is typically denoted a STA (station). Such a STA may be an AP (access point) or a non-AP STA.

[0006] In view of increasing interest in wireless communication offering low or bounded latency and / or high reliability, the IEEE 802.11 working group has created an Ultra High Reliability (UHR) study group in July 2022 whose objective is to develop a Project Authorization Request (PAR) and a Criteria for Standards Development (CSD) for a new 802.11 MAC / PHY amendment. The emphasis in the UHR study group is on improvements to the IEEE 802.11 standard to increase the reliability of wireless connectivity and to better support applications requiring lower or deterministic latencies. Drivers for such requirements concerning latency or reliability for example include extended reality (XR) applications, wireless control of industrial processes, and online gaming services. In such applications a maximum allowed end-to-end latency is often 5 ms or lower, e.g., 1 ms.

[0007] While operating in license-exempt frequency spectrum, wideband wireless communication systems, such as WLAN systems, typically operate using a listen before talk (LBT) mechanism, also referred to as carrier sense multiple access with collision avoidance (CSMA / CA). In such LBT mechanism, before initiating a transmission, a STA listens on the wireless medium to determine whether the medium is busy or available and performs the transmission only if the medium is available. Correspondingly, in a typical basic service set (BSS) comprising an AP device and multiple non-AP STAs, the wireless communications are based on contentionbased channel access operations: Multiple STAs contend for winning a transmission opportunity (TXOP), and the STA winning the contention can then get exclusive access to the channel for a certain period of time, i.e., for the duration of the TXOP.

[0008] WLAN systems may use unscheduled uplink (UL) transmissions, which means that non-AP devices independently contend for channel access and undertake their own transmissions whenever they have data to transmit. However, a recent amendment to the IEEE 802.11 standard, “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 Amendment 1 : Enhancements for High-Efficiency WLAN”, in the following denoted as “802.11 ax amendment”, introduced support of two further modes of operation: an orthogonal frequency-division multiple access (OFDMA) based mode of operation and a trigger-based UL mode of operation. In these modes of operation, an AP device can schedule UL transmissions from one or more specific non-AP devices in its BSS and also select timing and transmission parameters of the UL transmissions. Thus, these mechanisms can help an AP device to better orchestrate UL communications in its BSS and thereby improve the overall performance of the BSS. This works particularly well when the data traffic is deterministic, so that the AP knows which non-AP STAs may have data to transmit and when such transmissions are needed. However, when the data traffic is event based and non-deterministic, it can be very challenging for an AP device to provision for appropriate and timely UL transmissions or to orchestrate scheduled UL transmissions.

[0009] One way to improve the handling of non-deterministic data traffic is to use full-duplex (FD) operation, e.g., as for example described in WO 2023 / 046287 A1. In FD operation, a wireless communication device can simultaneously transmit a first wireless signal, in the following denoted as “TX signal” and receive a second wireless signal, in the following denoted as “RX signal”. In the case of a WLAN system, this could for example enable scenarios where an AP contends for the medium to send downlink (DL) data, and a non-AP STA associated with the AP sends UL data during the ongoing transmission of the DL data, without requiring that the non-AP STA contends for access to the medium or that the transmission of the UL data is scheduled by the AP.

[0010] For a device that is capable of FD operation, it may however be challenging to ensure a high probability of successfully receiving an unscheduled RX signal while transmitting a TX signal. Specifically, due to the RX signal being unscheduled, it may be impossible to beforehand set transmission parameters in such a way that the RX signal can be successfully received while sending the TX signal. The situation may be further complicated by dynamic variation of receiver conditions, e.g., due to presence or absence of interference from other devices using the same frequency resources of license-exempt frequency spectrum.

[0011] Accordingly, there is a need for techniques which allow for efficiently utilizing FD operation for wireless communication, in particular in the case of wireless communication involving wireless transmissions which are, at least in part, unscheduled or otherwise non-deterministic.

[0012] Summary

[0013] According to an embodiment, a method of controlling wireless transmissions in a wireless communication system is provided. According to the method, a wireless communication device receives a first wireless signal from a further wireless communication device. The first wireless signal indicates information on one or more conditions for reception of a second wireless signal by the further wireless communication device during ongoing transmission of the first wireless signal. Based on the one or more conditions, the wireless communication device controls transmission of the second wireless signal to the further wireless communication device.

[0014] According to a further embodiment, a method of controlling wireless transmissions in a wireless communication system is provided. According to the method, a wireless communication device sends a first wireless signal. The first wireless signal indicates information on one or more conditions for reception of a second wireless signal by the wireless communication device during ongoing transmission of the first wireless signal.

[0015] According to a further embodiment, a wireless communication device for a wireless communication system is provided. The wireless communication device is configured to receive a first wireless signal from a further wireless communication device. The first wireless signal indicates information on one or more conditions for reception of a second wireless signal by the further wireless communication device during ongoing transmission of the first wireless signal. Further, the wireless communication device is configured to, based on the one or more conditions, control transmission of the second wireless signal to the further wireless communication device.

[0016] According to a further embodiment, a wireless communication device for a wireless communication system is provided. The wireless communication device comprises at least one processor and a memory. The memory contains instructions executable by said at least one processor, whereby the wireless communication device is operative to receive a first wireless signal from a further wireless communication device. The first wireless signal indicates information on one or more conditions for reception of a second wireless signal by the further wireless communication device during ongoing transmission of the first wireless signal. Further, the memory contains instructions executable by said at least one processor, whereby the wireless communication device is operative to, based on the one or more conditions, control transmission of the second wireless signal to the further wireless communication device.

[0017] According to a further embodiment, a wireless communication device for a wireless communication system is provided. The wireless communication device is configured to send a first wireless signal. The first wireless signal indicates information on or more conditions for reception of a second wireless signal by the wireless communication device during ongoing transmission of the first wireless signal.

[0018] According to a further embodiment, a wireless communication device for a wireless communication system is provided. The wireless communication device comprises at least one processor and a memory. The memory contains instructions executable by said at least one processor, whereby the wireless communication device is operative to send a first wireless signal. The first wireless signal indicates information on or more conditions for reception of a second wireless signal by the wireless communication device during ongoing transmission of the first wireless signal.

[0019] According to a further embodiment, a computer program or computer program product is provided, e.g., in the form of a non-transitory storage medium, which comprises program code to be executed by at least one processor of a wireless communication device for a wireless communication system. Execution of the program code causes the wireless communication device to receive a first wireless signal from a further wireless communication device. The first wireless signal indicates information on one or more conditions for reception of a second wireless signal by the further wireless communication device during ongoing transmission of the first wireless signal. Further, execution of the program code causes the wireless communication device to, based on the one or more conditions, control transmission of the second wireless signal to the further wireless communication device.

[0020] According to a further embodiment, a computer program or computer program product is provided, e.g., in the form of a non-transitory storage medium, which comprises program code to be executed by at least one processor of a wireless communication device for a wireless communication system. Execution of the program code causes the wireless communication device to send a first wireless signal. The first wireless signal indicates information on or more conditions for reception of a second wireless signal by the wireless communication device during ongoing transmission of the first wireless signal.

[0021] Details of such embodiments and further embodiments will be apparent from the following detailed description.

[0022] Brief Description of the Drawings

[0023] Fig. 1 schematically illustrates a wireless communication system according to an embodiment.

[0024] Fig. 2 schematically illustrates an example of conditional FD operation in accordance with an embodiment of the present disclosure.

[0025] Fig. 3 schematically illustrates a further example of conditional FD operation in accordance with an embodiment of the present disclosure.

[0026] Figs. 4A and 4B schematically illustrate examples FD modes of operation which may be used in embodiments of the present disclosure.

[0027] Fig. 5 illustrates an exemplary scenario involving conditional FD operation in accordance with an embodiment of the present disclosure.

[0028] Fig. 6 shows a flowchart for schematically illustrating a method according to an embodiment of the present disclosure.

[0029] Fig. 7 shows a flowchart for schematically illustrating a further method according to an embodiment of the present disclosure.

[0030] Fig. 8 schematically illustrates structures of a wireless communication device according to an embodiment of the present disclosure.

[0031] Detailed Description In the following, concepts in accordance with exemplary embodiments of the invention will be explained in more detail and with reference to the accompanying drawings. The illustrated embodiments relate to control of wireless communication in a wireless communication system, in particular also in view of the possibility of unscheduled wireless transmissions or otherwise non-deterministic wireless transmissions, e.g., carrying event-based or other kinds of non- deterministic traffic. In this context, a scheduled wireless transmission, i.e., a wireless transmission which is planned beforehand and for which the involved wireless communication devices, such as transmitter(s) and receiver(s), are specifically chosen may be considered as a wireless transmission which is completely deterministic. Such scheduling may involve requesting resources for the wireless transmission and performing the wireless transmission in response to such request being granted. Such scheduling may also involve specifically assigning timing and / or transmit parameters for the wireless transmission(s) and performing the wireless transmission(s) based on the assigned parameters. Also, wireless transmissions which are performed on periodically assigned resources, e.g., based on semi-persistent scheduling or based on system configuration may be considered as deterministic. On the other hand, wireless transmissions which are not predictable or only predictable to some degree, such as random access transmissions or wireless transmissions triggered by an event at the transmitter, may be considered as non-deterministic. The wireless communication system may be a WLAN system based on IEEE 802.11 technology. However, it is noted that the illustrated concepts could also be applied to other wireless communication technologies, e.g., to contention-based modes of the LTE (Long Term Evolution) or NR (New Radio) technology specified by 3GPP (3rd Generation Partnership Project) or to the Bluetooth technology.

[0032] In the illustrated concepts, a FD capability of a wireless communication device may be used in a conditional manner. Such wireless communication device is herein also denoted as “conditionally FD capable device”. The FD capability of the wireless communication device depends on one or more conditions. That is to say, depending on the condition(s), the wireless communication device is capable, or not, of successfully receiving an RX signal while sending a TX signal. In the TX signal, the wireless communication device includes an indication of the condition(s), so that another wireless communication device may take the condition(s) into account when sending the RX signal. This indication is herein also denoted as CFD (Conditional FD) indication. In some cases, the other wireless communication device may adapt transmit parameters of the RX signal, e.g., transmit power and / or MCS (modulation and coding scheme) and / or transmission bandwidth. In some cases, the other wireless communication device could also decide to refrain from sending the RX signal or postpone sending the RX signal. Based on the CFD indication, the chances of successful reception of the RX signal may thus be improved without requiring scheduling of the RX signal. The other wireless communication device may thus still trigger the sending of the RX signal immediately when it has data to be sent, provided that the indicated one or more conditions are considered, e.g., by appropriately selecting transmit power and / or MCS and / or transmission bandwidth. This may for example be beneficial in scenarios where the data to be sent is subject to rather strict requirements concerning latency and / or reliability and / or where the data to be sent is event-based and non-deterministic. The FD capability of wireless communication devices may thus be utilized in a more efficient manner.

[0033] Fig. 1 illustrates an exemplary wireless communication system according to an embodiment. In the illustrated example, the wireless communication system includes multiple APs 10, in the illustrated example referred to as AP1 , AP2, AP3, AP4, and multiple stations 20, in the illustrated example referred to as STA11 , STA21 , STA22, STA31 , and STA41. STA11 is served by AP1 , in a first BSS denoted as BSS1. STA21 and STA22 are served by AP2, in a second BSS denoted as BSS2. STA31 is served by AP3, in a third BSS denoted as BSS3. STA41 is served by AP4, in a fourth BSS denoted as BSS4. The stations 20 may be non-AP STAs and correspond to various kinds of wireless communication devices, for example user terminals, such as mobile or stationary computing devices like smartphones, laptop computers, desktop computers, tablet computers, gaming devices, or the like. Further, the stations 20 could for example correspond to other kinds of equipment like smart home devices, printers, multimedia devices, data storage devices, or the like.

[0034] In the example of Fig. 1 , each of the stations 20 may connect through a radio link to one of the APs 10. For example, depending on location or channel conditions experienced by a given station 20, the station 20 may select an appropriate AP 10 and BSS for establishing the radio link. The radio link may be based on OFDM (Orthogonal Frequency Division Multiplexing) using one or more carriers from a frequency spectrum which is shared on the basis of a contentionbased mechanism, e.g., an unlicensed or license-exempt band like the 2.4 GHz ISM (Industrial, Scientific and Medical) band, the 5 GHz band, the 6 GHz band, or the 60 GHz band.

[0035] Each AP 10 may provide data connectivity of the stations 20 connected to the AP 10. As further illustrated, the APs 10 may be connected to a data network (DN) 110. In this way, the APs 10 may also provide data connectivity between stations 20 connected to different APs 10. Further, the APs 10 may also provide data connectivity of the stations 20 to other entities, e.g., to one or more servers, service providers, data sources, data sinks, user terminals, or the like. Accordingly, the radio link established between a given station 20 and its serving AP 10 may be used for providing various kinds of services to the station 20, e.g., a voice service, a multimedia service, or other data service. Such services may be based on applications which are executed on the station 20 and / or on a device linked to the station 20. By way of example, Fig. 1 illustrates an application service platform 150 provided in the DN 110. The application(s) executed on the station 20 and / or on one or more other devices linked to the station 20 may use the radio link for data communication with one or more other stations 20 and / or the application service platform 150, thereby enabling utilization of the corresponding service(s) at the station 20.

[0036] For at least some of the radio links between the APs 10 and STAs 20, a conditional FD mode of operation may be utilized. In some examples, the device utilizing the conditional FD mode of operation may be an AP. Fig. 2 illustrates a corresponding example. In other examples, the device utilizing the conditional FD mode of operation may be a non-AP STA. Fig. 3 illustrates a corresponding example. In the following an AP or non-AP STA that uses FD operation will also be denoted as FD device.

[0037] In the example of Fig. 2, the FD device corresponds to an AP 10. The AP 10 sends a TX signal 51 which includes a CFD indication and typically also data, e.g., user data and / or control data. The TX signal 51 is received by a non-AP STA 20. Based on the CFD indication in the TX signal 51 , the non-AP STA 20 sends an RX signal 52 to the AP 10. This is accomplished during ongoing transmission of the TX signal 51 by the AP 10. The RX signal 52 may convey data, e.g., user data and / or control data.

[0038] In the example of Fig. 3, the FD device corresponds to a non-AP STA 10. The non-AP STA 20 sends a TX signal 51 which includes a CFD indication and typically also data, e.g., user data and / or control data. The TX signal 51 is received by an AP 10. Based on the CFD indication in the TX signal 51 , the AP 10 sends an RX signal 52 to the non-AP STA 10. This is accomplished during ongoing transmission of the TX signal 51 by the non-AP STA 20. The RX signal 52 may convey data, e.g., user data and / or control data.

[0039] It is noted that the device which transmits the RX signal 52 may or may not be the intended receiver of the TX signal 51. That is to say, in some cases the device that transmits or intends to transmit the RX signal 52 could “overhear” the transmission of the TX signal 51 intended for some other device and extract the CFD indication from the TX signal 51 , typically disregarding other data conveyed by the TX signal 51 . For example, in the scenario of Fig. 2, the TX signal 51 could convey data intended for some other non-AP STA than the one that sends the RX signal 52. Further, it is noted that the one that transmits the RX signal 52 could itself be an FD device, which would allow for performing bi-directional FD communication, but could also be a device without FD capability. The conditional FD mode of operation may be based on various flavors of FD operation. Figs. 4A and 4B schematically illustrate some examples of such flavors, namely a flavor typically denoted as single frequency FD (SFFD) or in-band FD (IBFD) and a flavor denoted as subband FD (SBFD). Specifically, Figs. 4A and 4B show usage of resources of a channel (CH) in the time (t) dimension and frequency (f) dimension. These flavors differ with respect to the way of using frequency resources used for the simultaneous transmission and reception: In the case of SFFD or IBFD, illustrated by Fig. 4A, the simultaneous transmission and reception are performed on the same frequency resources, e.g., using fully overlapping portions of the same frequency channel. The transmission of the TX signal starts at t1 and ends at t4. The reception of the RX signal starts at t2 and ends at t3. As can be seen, transmission of the TX signal and reception of the RX signal is performed simultaneously between time t2 and t3, using fully overlapping frequency resources. In the case of SBFD, illustrated by Fig. 4B, the simultaneous transmission and reception are performed using non-overlapping frequency resources of a single channel. The non-overlapping portions are typically denoted as “sub-bands” (SBs). One or more sub-bands may be allocated for transmission and similarly, one or more sub-bands may be allocated for reception. In the example of Fig. 4B, a first sub-band (SB1) is allocated for transmission of the TX signal, and a second sub-band (SB2) is allocated for reception of the RX signal. The transmission of the TX signal starts at t1 and ends at t4. The reception of the RX signal starts at t2 and ends at t3. As can be seen, transmission of the TX signal and reception of the RX signal is performed simultaneously between time t2 and t3, using nonoverlapping frequency resources, namely different sub-bands of the channel CH.

[0040] The self-interference caused by the TX signal to the RX signal presents a huge challenge to achieve successful FD operation, and it may require rather sophisticated solutions in spatial domain, analog domain as well as digital domain to sufficiently suppress or cancel the selfinterference. As an example, if the transmit power of the TX signal is 20 dBm, the received signal power of the RX signal is -80 dBm, and the minimum required signal to interference ratio (SIR) for successful reception of the RX signal is 10 dB, then the resultant self-interference caused by the transmission of the TX signal must be suppressed by at least 110 dB. Since SBFD features use of non-overlapping frequency resources for the TX and RX signals, it may be easier to implement in practice than SFFD operation.

[0041] For the FD device, if the self-interference is not suppressed or canceled sufficiently, it may happen that the RX signal is not decoded successfully or not even detected. Typically, the selfinterference will need to be suppressed or cancelled such that the residual self-interference is well below the noise floor of the receiver of the FD device, thereby avoiding receiver desensitization. However, sufficient suppression or cancellation of the self-interference may be difficult or impossible to achieve under certain conditions, in particular if the FD-based communication is at least in part based on unscheduled or otherwise non-deterministic wireless transmissions. In the case of unscheduled or otherwise non-deterministic wireless transmissions, there are only limited possibilities of choosing timing and transmit parameters for the TX signal and the RX signal in such a way that successful reception of the RX signal at the FD device is achieved. Accordingly, for the FD device, the ability to successfully receive the RX signal may depend on various criteria, such as:

[0042] Transmit parameters of the TX signal, such as transmit power. For example, FD operation may be possible if the TX signal power is sufficiently low so that also the level of the self-interference is low.

[0043] Spatial characteristics of the TX signal, such as direction and strength of the main lobe and / or side lobes when beamforming is used. For example, FD operation may be possible if the beamforming applied to the TX signal is such that the significant part of the self-interference energy is directed away from the receiver of the FD device.

[0044] Transmit parameters of the RX signal, such as transmit power and / or MCS. For example, FD operation may be possible if the received RX signal power is sufficiently high and / or if the MCS of the RX signal corresponds to a rather robust MCS.

[0045] Characteristics of the wireless medium, such as its reflective nature, in the vicinity of the FD device: For example, FD operation may be possible if the wireless medium is not highly reflective, which may result in significantly lower level of self-interference due to reflections in the medium thereby facilitating good self-interference cancellation performance since the self-interference cancellation algorithms would have to deal with lesser reflected self-interference signal components.

[0046] Characteristics of the propagation path, such as path loss, from the device to another device that transmits the RX signal: For example, FD operation may be possible if the path loss experienced by the RX signal is low, so that the received signal power of the RX signal at the receiver of the FD device is relatively high.

[0047] OFDM symbol level time alignment of the RX signal and the TX signal: For example, FD operation may be possible if the TX signal and the RX signal are time aligned on OFDM symbol level such that the self-interference is orthogonal to the RX signal at the receiver of the FD device. By the time alignment on OFDM symbol level, it can be achieved that there is none or negligible interference caused by the FFT (Fast Fourier Transform) operation from the OFDM subcarriers of the TX signal to the OFDM subcarriers of the RX signal. The resultant interference-to-noise ratio (I NR) at the receiver of the FD device during transmission of the TX signal. For example, FD operation may be possible if the resultant INR is sufficiently low, such that the RX signal can be successfully decoded.

[0048] In the illustrated concepts, the FD device may share information about its receiver conditions during transmission of the TX signal 51 , i.e., based on the above-mentioned CFD indication in the TX signal 51. Based on the CFD indication, another device, which sends the RX signal 52 or intends to send the RX signal 52, can assess whether the FD device will be able to successfully receive the RX signal 52 and may also appropriately select transmit parameters of the RX signal 52, e.g., transmit power and / or MCS and / or transmission bandwidth, such that successful reception of the RX signal 52 by the FD device becomes possible, e.g., based on the probability of successful reception being above a threshold. The CFD indication may be included in various ways into the TX signal 51 . For example, if the TX signal 51 has a preamble portion and a data portion, the indication may be included in the preamble portion, in the data portion, or in both the preamble portion and the data portion.

[0049] The CFD indication provided in the TX signal 51 may include information on one or more of the following:

[0050] The resultant minimum receiver input sensitivity level. This resultant minimum receiver input sensitivity level may correspond to the most robust MCS available for the RX signal 52.

[0051] The resultant degradation of the receiver sensitivity level. This resultant degradation may correspond to the most robust MCS available for the RX signal 52.

[0052] The resultant INR at the receiver of the FD device.

[0053] The minimum required absolute signal power of the RX signal 52, e.g., in terms of dBm. This minimum required absolute signal power may correspond to a specific bandwidth of the RX signal 52 and / or the most robust MCS available for the RX signal 52.

[0054] The minimum required power spectral density of the RX signal 52, e.g., in terms of dBm / Hz or dBm / MHz. This minimum required power spectral density may correspond to the most robust MCS available for the RX signal 52.

[0055] The amount of suppression of the self-interference caused by the TX signal 51 or the resultant residual self-interference level at the receiver of the FD device.

[0056] Such information may be provided in terms of measured values and / or estimated or expected values. In some scenarios, the CFD indication may further include information on the transmit power of the TX signal 51 . This information can be used by a device, which would potentially transmit the RX signal 52, to compute the path loss conditions between that device and the FD device. If the communication is based on the IEEE 802.11 standard, such information can be included in the TX signal 51 by including a Transmit Power Used field, as for example defined in section 9.4.1.20 of the IEEE 802.11 standard. The Transmit Power Used field may contains a value that indicates the actual power used as measured at the antenna connector, in units of dBm, by a device when transmitting the frame containing the Transmit Power Used field. The Transmit Power Used value may be determined at any time prior to sending the frame in which it is contained.

[0057] In some scenarios, the frequency resources being used for transmitting the TX signal 51 and the frequency resources that may be used for receiving the RX signal 52 are at least in part overlapping, e.g., as in SFFD or IBFD (see Fig. 4A). Alternatively, the frequency resources being used for transmitting the TX signal and the frequency resources that may be used for receiving the RX signal 52 are non-overlapping. In the latter case, the non-overlapping frequency resources may belong to the same channel, e.g., as in SBFD (see Fig. 4B). In case of SBFD, the level of the self-interference typically decreases with larger frequency distance between the sub-band used for the TX signal 51 and the sub-band used for the RX signal 52. To address such cases, the information provided by the indication may be provided per subband used for the RX signal 52, e.g., may contain different parameters for the different subbands which may be used of the RX signal 52. As an example, if the channel is 80 MHz wide and the TX signal is transmitted in the lowest 20 MHz sub-band, the resultant residual selfinterference level in the other three different 20 MHz sub-bands may be -70 dBm, -80 dBm, and -90 dBm, and such values may be indicated individually in the CFD indication.

[0058] In some scenarios, the CFD indication may further include information on rules or conditions that must be met at the device that transmits the RX signal 52. This information may help to achieve multiple goals, e.g., improving the probability of successful reception of an unscheduled RX signal 52, reducing the probability of failure of the ongoing reception of the TX signal 51 , or the like. The rules or conditions include one or more of the following:

[0059] Frequency resources that may be used for transmitting the RX signal 52: For example, the FD device may indicate whether it can receive an RX signal 52 based on SBFD or based on SFFD, thereby also indicating which frequency resources can be used for reception of the RX signal 52. Such indication of frequency resources may be based on a consideration of minimum required guard band between the frequency resources being used for the TX signal 51 and the frequency resources that may be used for receiving a RX signal 52.

[0060] Duration of the RX signal 52. For example, the FD device may indicate whether the RX signal 52 may extend beyond the duration of the TX signal 51 , or whether it should end before or in sync with the TX signal 51. For example, if an indication of minimum required received signal power is strictly only applicable for that specific TX signal 51 , the FD device may indicate that the RX signal 52 should not continue after the TX signal 51 , because the reception situation may be completely different when the TX signal 51 has ended or another TX signal 51 is being transmitted.

[0061] OFDM symbol level time-alignment of the RX signal 52 and the TX signal 51. For example, the FD device may indicate whether it requires the transmitter of the RX signal 52 to ensure that the OFDM symbols of the TX signal 51 and RX signal 52 are time- aligned at the receiver of the FD device. This may help to achieve orthogonality and thus reduce or avoid inter-OFDM symbol interference. Such rules relating to OFDM symbol level time alignment may be applicable when the TX signal 51 and the RX signal 52 are based on OFDM modulation.

[0062] MCS(s) that may be used for encoding the RX signal 52. For example, the FD device may indicate a specific MOS or a set of MCSs that it may be able to decode while transmitting that specific TX signal 51. For example, the FD device may be able to receive signals corresponding to only some robust MCSs during its FD operation, and these may be indicated as candidate MCS(s) in the CFD indication provided in the TX signal 51.

[0063] Type of data, e.g., in terms of AC (Access Category) or TID (Traffic Identifier), that is allowed to be included in the RX signal 52: For example, the FD device may indicate that transmission of the RX signal 52 may only be allowed if the data type corresponds to a high priority data type, e.g., voice data. That may be useful if the FD operation is aimed at better supporting latency-critical communication. Alternatively, the FD device may also indicate that the transmission of the RX signal 52 may only be allowed if the data type corresponds to a low priority data type, e.g., background data. That may be useful if the FD operation is aimed at better supporting best-effort communication in the direction of the RX signal 52.

[0064] Interference that may be caused by the RX signal 52 to the intended receiver of the TX signal 51 . For example, the FD device may indicate that the transmitter of the RX signal 52 should ensure that its transmission would cause no or limited interference to the reception of the TX signal 51 . As a result, any device which might intend to transmit the RX signal 52 may have to first perform a self-assessment before attempting to transmit the RX signal 52. For example, such a self-assessment may be based on computation of potential resultant interference power for the reception of the TX signal 51. Such computation may be based on a certain transmit power chosen for the RX signal 51. Alternatively, or in addition, such a self-assessment may be based on whether that device has detected and read any clear-to-send (CTS) signal from the intended receiver of the TX signal 51 prior to the start of the TX signal 51 , or whether the signal strength of such a CTS signal was below a certain pre-determined threshold. Such a CTS detection may indirectly help a device to assess whether its own transmission of the RX signal 52 may cause excessive interference to reception of the TX signal 51. For example, if a CTS has not been detected or if it was detected at a very low power level, then the self-assessment may be that it is okay to attempt to transmit a RX signal 52.

[0065] In some scenarios, the CFD indication may include information on one or more devices that are allowed to transmit the RX signal 52. For example, the FD device may indicate that only a specific device or any device among a specific set of devices is allowed to transmit an RX signal 52 while the FD devices is transmitting the TX signal 51. For example, the FD device may enforce such a restriction based on an assessment of which specific device(s) may cause negligible or least interference to the reception of the TX signal 51. Based on such indication of allowed devices, it may be possible that a device allowed to transmit the RX signal 52 only needs to know that it is allowed to transmit the RX signal while the FD device is transmitting the TX signal 51 , so that complexity of processes at the device potentially transmitting the RX signal 52 can be reduced in a significant manner.

[0066] In the following the illustrated concepts are further explained by referring to an exemplary scenario involving a BSS according to the IEEE 802.11 standard, e.g., corresponding to one of the BSSs of Fig. 1. As illustrated by Fig. 5, the scenario assumes that the BSS includes a conditionally FD capable AP and three associated non-AP devices, denoted as Non-AP 1 , Non-AP 2, and Non-AP 3. The path loss from the AP to Non-AP 1 , Non-AP 2, and Non-AP 3 is assumed to be 60 dB, 80 dB, and 100 dB, respectively.

[0067] In the scenario of Fig. 5, it is assumed that at a first time instance, the AP transmits a first downlink (DL) signal to Non-AP 3, using a transmit power of 23 dBm. From the perspective of the AP, the first DL signal is a TX signal. Based on empirical analysis, knowledge of its selfinterference suppression capability as well as operating environment conditions, the AP estimates that its resultant interference in the receiver during transmission of the first DL signal to Non-AP 3 is -67 dBm. Accordingly, the AP can suppress the resultant self-interference by 90 dB. In accordance with the illustrated concepts, the AP includes this information into a CFD indication in the first DL signal, such that it can be read and processed by all three Non-AP devices. When now assuming that, at the same time as the AP is transmitting the first DL signal to Non-AP 3, Non-AP 2 intends to transmit a first UL signal to the AP. From the perspective of the AP the first UL signal is an RX signal. The first UL signal could for example carry some event-based data, so that scheduling or otherwise planning the first UL signal beforehand is not possible. Based on the CFD indication received from the AP, and the path loss conditions, Non-AP 2 can suitably select the transmit parameters for the first UL signal, so that the first UL signal can be successfully received by the AP during ongoing transmission of the first DL signal. The path loss conditions can be learnt by Non-AP 2 using various known techniques, e.g., based of features of the IEEE 802.11 standard, or by simply subtracting the received signal power from the transmit power used by the AP for the first DL signal. As mentioned above, information about the used transmit power may also be also included in the first DL signal. Non-AP 2 could, for example, select 15 dBm transmit power and correspondingly an MCS that can be decoded at resultant (15-80) - (-67) = 2 dB signal to interference ratio (SIR). Alternatively, Non-AP 2 could select 20 dBm transmit power and correspondingly a MCS that can be decoded at resultant (20-80) - (-67) = 7 dB SIR. The actual transmit power and MCS selection by Non-AP 2 may, for example, additionally depend on the amount and type of data it intends to transmit and / or on a desired latency performance for the first UL signal.

[0068] When assuming that, at a second time instance, the AP transmits a second DL signal (which from the perspective of the AP is a TX signal) to Non-AP 1 , using a transmit power of 15 dBm. Correspondingly, the AP estimates that its resultant interference in the receiver during transmission of the second DL signal to Non-AP 1 is -75 dBm. Accordingly, it can again suppress the resultant self-interference by 90 dB. The AP includes corresponding information in a CFD indication provided in the second DL signal. Again, if Non-AP 2 aims to transmit a second UL signal carrying data to the AP and ensure that the AP can succeed in receiving the second UL signal during ongoing transmission of the second DL signal, Non-AP 2 can leverage the information shared by the AP in the CFD indication to make appropriate transmit parameter selection for the second UL signal. It could, for example, select 15 dBm transmit power and correspondingly an MCS that can be decoded at resultant (15-80) - (-75) = 10 dB SIR or select 20 dBm transmit power and correspondingly an MCS that can be decoded at resultant (20-80) - (-75) = 15 dB SIR.

[0069] Thus, in this considered example, the solutions proposed in this disclosure can help the conditionally FD capable AP to successfully perform FD operation by being able to share relevant information with its associated non-AP devices and thereby enabling them to successfully perform unscheduled or otherwise non-deterministic UL transmissions. Fig. 6 shows a flowchart for illustrating a method of controlling wireless transmissions in a wireless communication system, which may be utilized for implementing the illustrated concepts. The method of Fig. 6 may be used for implementing the illustrated concepts in a wireless communication device operating in a wireless communication system, e.g., in an AP of the wireless communication system, e.g., one of the above-mentioned APs 10, or in a non- AP STA, such as one of the above-mentioned stations 20. The wireless communication system may be based on a wireless local area network, WL N, technology, e.g., according to the IEEE 802.11 standards family.

[0070] If a processor-based implementation of the wireless communication device is used, at least some of the steps of the method of Fig. 6 may be performed and / or controlled by one or more processors of the wireless communication device. Such wireless communication device may also include a memory storing program code for implementing at least some of the below described functionalities or steps of the method of Fig. 6.

[0071] At step 610, the wireless communication device receives a first wireless signal from a further wireless communication device. The above-mentioned TX signal 51 and the first and second DL signals in the scenario of Fig. 5 are examples of such first wireless signal. The first wireless signal indicates information on one or more conditions for reception of a second wireless signal by the further wireless communication device during ongoing transmission of the first wireless signal. The above-mentioned CFD indication is an example of such information.

[0072] In some cases, frequency resources for transmission of the second wireless signal may be at least partially overlapping with frequency resources for transmission of the first wireless signal, such as in SFFD or IBFD. Alternatively, frequency resources for transmission of the second wireless signal could be non-overlapping with frequency resources for transmission of the first wireless signal, such as in SBFD.

[0073] The information indicated by the first wireless signal may indicate an expected sensitivity level of the further wireless communication device for reception of the second wireless signal. Such sensitivity level could be indicated in terms of a minimum limit or in terms of a level of degradation. The sensitivity level may correspond to a most robust MCS available for transmission of the second wireless signal.

[0074] Alternatively or in addition, the information indicated by the first wireless signal may indicate an expected INR for reception of the second wireless signal. Alternatively or in addition, the information indicated by the first wireless signal may indicate a minimum required received signal power for reception of the second wireless signal. The minimum required received signal power may correspond to a most robust MCS available for transmission of the second wireless signal. In some scenarios, the information indicated by the first wireless signal may further indicate a bandwidth to which the minimum required received signal power relates, e.g., a sub-band.

[0075] Alternatively or in addition, the information indicated by the first wireless signal may indicate a minimum required power spectral density for reception of the second wireless signal. The minimum required power spectral density corresponds to a most robust MCS available for transmission of the second wireless signal.

[0076] Alternatively or in addition, the information indicated by the first wireless signal may indicate a degree to which the further wireless communication device can suppress self-interference caused by the first wireless signal and / or an expected amount of residual self-interference caused by the first wireless signal.

[0077] In some scenarios, the information indicated by the first wireless signal may further indicate information on transmit power of the first wireless signal, e.g., in terms of a used power value.

[0078] In some scenarios, the information indicated by the first wireless signal may further indicate one or more frequency resources allowed to be used for transmission of the second wireless signal, e.g., in terms of sub-bands.

[0079] In some scenarios, the information indicated by the first wireless signal may further indicate indicated by the first wireless signal indicates a maximum allowed duration for transmission of the second wireless signal.

[0080] In some scenarios, the information indicated by the first wireless signal may further indicate a requirement of modulation symbol alignment of the first wireless signal and the second wireless signal, e.g., information concerning time-alignment of OFDM symbols.

[0081] In some scenarios, the information indicated by the first wireless signal may further indicate one or more MCSs to be used for transmission of the second wireless signal. Such one or more MCSs could each correspond to an allowed MCS, a suggested MCS, or a preferred MCS. The wireless communication device may select the MCS for the second wireless signal from these indicated one or more MCSs.

[0082] In some scenarios, the information indicated by the first wireless signal may further indicate one or more types of data allowed to be conveyed by the second wireless signal.

[0083] In some scenarios, the information indicated by the first wireless signal may further indicate a set of one or more devices allowed to transmit the second wireless signal.

[0084] In some scenarios, the information indicated by the first wireless signal may further indicate an allowed level of interference caused by the second wireless signal to one or more intended receivers of the first wireless signal.

[0085] At step 620, the wireless communication device controls transmission of the second wireless signal to the further wireless communication device. This is accomplished based on the one or more conditions as indicated by the first wireless signal. This may involve selecting a transmit power of the second wireless signal and / or selecting an MCS of the second wireless signal and / or selecting a transmission bandwidth of the second wireless signal. In some cases, step 620 may also involve that, depending on the one or more conditions, the wireless communication device decides to not perform transmission of the second wireless signal or to postpone transmission of the second wireless signal.

[0086] Fig. 7 shows a flowchart for illustrating a method of controlling wireless transmissions in a wireless communication system, which may be utilized for implementing the illustrated concepts. The method of Fig. 7 may be used for implementing the illustrated concepts in a wireless communication device operating in a wireless communication system, e.g., in an AP of the wireless communication system, e.g., one of the above-mentioned APs 10, or in a non- AP STA, such as one of the above-mentioned stations 20. The wireless communication system may be based on a wireless local area network, WL N, technology, e.g., according to the IEEE 802.11 standards family.

[0087] If a processor-based implementation of the wireless communication device is used, at least some of the steps of the method of Fig. 7 may be performed and / or controlled by one or more processors of the wireless communication device. Such wireless communication device may also include a memory storing program code for implementing at least some of the below described functionalities or steps of the method of Fig. 7. At step 710, the wireless communication device sends a first wireless signal. The above- mentioned TX signal 51 and the first and second DL signals in the scenario of Fig. 5 are examples of such first wireless signal. The first wireless signal indicates information on one or more conditions for reception of a second wireless signal by the wireless communication device during ongoing transmission of the first wireless signal. The above-mentioned CFD indication is an example of such information.

[0088] In some cases, frequency resources for transmission of the second wireless signal may be at least partially overlapping with frequency resources for transmission of the first wireless signal, such as in SFFD or IBFD. Alternatively, frequency resources for transmission of the second wireless signal could be non-overlapping with frequency resources for transmission of the first wireless signal, such as in SBFD.

[0089] The information indicated by the first wireless signal may indicate an expected sensitivity level of the further wireless communication device for reception of the second wireless signal. Such sensitivity level could be indicated in terms of a minimum limit or in terms of a level of degradation. The sensitivity level may correspond to a most robust MCS available for transmission of the second wireless signal.

[0090] Alternatively or in addition, the information indicated by the first wireless signal may indicate an expected INR for reception of the second wireless signal.

[0091] Alternatively or in addition, the information indicated by the first wireless signal may indicate a minimum required received signal power for reception of the second wireless signal. The minimum required received signal power may correspond to a most robust MCS available for transmission of the second wireless signal. In some scenarios, the information indicated by the first wireless signal may further indicate a bandwidth to which the minimum required received signal power relates, e.g., a sub-band.

[0092] Alternatively or in addition, the information indicated by the first wireless signal may indicate a minimum required power spectral density for reception of the second wireless signal. The minimum required power spectral density corresponds to a most robust MCS available for transmission of the second wireless signal.

[0093] Alternatively or in addition, the information indicated by the first wireless signal may indicate a degree to which the further wireless communication device can suppress self-interference caused by the first wireless signal and / or an expected amount of residual self-interference caused by the first wireless signal.

[0094] In some scenarios, the information indicated by the first wireless signal may further indicate information on transmit power of the first wireless signal, e.g., in terms of a used power value.

[0095] In some scenarios, the information indicated by the first wireless signal may further indicate one or more frequency resources allowed to be used for transmission of the second wireless signal, e.g., in terms of sub-bands.

[0096] In some scenarios, the information indicated by the first wireless signal may further indicate indicated by the first wireless signal indicates a maximum allowed duration for transmission of the second wireless signal.

[0097] In some scenarios, the information indicated by the first wireless signal may further indicate a requirement of modulation symbol alignment of the first wireless signal and the second wireless signal, e.g., information concerning time-alignment of OFDM symbols.

[0098] In some scenarios, the information indicated by the first wireless signal may further indicate one or more MCSs to be used for transmission of the second wireless signal. Such one or more MCSs could each correspond to an allowed MCS, a suggested MCS, or a preferred MCS. The wireless communication device may select the MCS for the second wireless signal from these indicated one or more MCSs.

[0099] In some scenarios, the information indicated by the first wireless signal may further indicate one or more types of data allowed to be conveyed by the second wireless signal.

[0100] In some scenarios, the information indicated by the first wireless signal may further indicate a set of one or more devices allowed to transmit the second wireless signal.

[0101] In some scenarios, the information indicated by the first wireless signal may further indicate an allowed level of interference caused by the second wireless signal to one or more intended receivers of the first wireless signal.

[0102] At step 720, the wireless communication device may receive the second wireless signal based on the one or more conditions as indicated by the first wireless signal. The wireless communication device may receive the second wireless signal from a further wireless communication device which received the first wireless signal. A transmit power of the second wireless signal and / or an MCS of the second wireless signal and / or a transmission bandwidth of the second wireless signal may be selected based on the information indicated by the first wireless signal.

[0103] Fig. 8 illustrates a processor-based implementation of a wireless communication device 800. The structures as illustrated in Fig. 8 may be used for implementing the above-described concepts. The wireless communication device 800 may for example correspond to one of above-mentioned STAs 20 or to one of the above-mentioned APs 10.

[0104] As illustrated, the wireless communication device 800 includes a radio interface 810. The radio interface 810 may for example be based on a WL N technology, e.g., according to an IEEE 802.11 family standard. However, other wireless technologies could be supported as well, e.g., the LTE technology or the NR technology. Further, the wireless communication device 800 may be provided with a network interface 820 for connecting to a data network, e.g., using a wire-based connection.

[0105] Further, the wireless communication device 800 may include one or more processors 850 coupled to the interfaces 810, 820, and a memory 860 coupled to the processor(s) 850. By way of example, the interfaces 810, 820, the processor(s) 850, and the memory 860 could be coupled by one or more internal bus systems of the wireless communication device 800. The memory 860 may include a Read-Only-Memory (ROM), e.g., a flash ROM, a Random Access Memory (RAM), e.g., a Dynamic RAM (DRAM) or Static RAM (SRAM), a mass storage, e.g., a hard disk or solid state disk, or the like. As illustrated, 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 so as to implement the above-described functionalities for controlling wireless transmissions, such as explained in connection with the method of Fig. 6 or the method of Fig. 7.

[0106] It is to be understood that the structures as illustrated in Fig. 8 are merely schematic and that the wireless communication device 800 may actually include further components which, for the sake of clarity, have not been illustrated, e.g., further interfaces or further processors. Also, it is to be understood that the memory 860 may include further program code for implementing known functionalities of an AP or non-AP STA in an IEEE 802.11 standard compliant technology. According to some embodiments, also a computer program may be provided for implementing functionalities of the wireless communication device 800, e.g., in the form of a physical medium storing the 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.

[0107] As can be seen, the concepts as described above may be used for efficiently using FD operation in a wireless communication system. More specifically, the FD operation may also be used in a reliable and efficient manner in the case of wireless communication that, at least in part, involves unscheduled or otherwise non-deterministic wireless transmissions.

[0108] It is to be understood that the examples and embodiments as explained above are merely illustrative and susceptible to various modifications. For example, the illustrated concepts may be applied in connection with various kinds of wireless technologies, without limitation to WL N technologies. Moreover, it is to 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. Further, it should be noted that the illustrated apparatuses or devices may each be implemented as a single device or as a system of multiple interacting devices or modules.

Claims

Claims1. A method of controlling wireless transmissions in a wireless communication system, the method comprising: a wireless communication device (10, 20; 800) receiving a first wireless signal (51) from a further wireless communication device (10, 20; 800), the first wireless signal (51) indicating information on one or more conditions for reception of a second wireless signal (51) by the further wireless communication device (10, 20; 800) during ongoing transmission of the first wireless signal (51); and based on the one or more conditions, the wireless communication device (10, 20; 800) controlling transmission of the second wireless signal (52) to the further wireless communication device (10, 20; 800).

2. The method according to claim 1 , wherein the information indicated by the first wireless signal (51) indicates an expected sensitivity level of the further wireless communication device (10, 20; 800) for reception of the second wireless signal (52).

3. The method according to claim 2, wherein the sensitivity level corresponds to a most robust modulation and coding scheme, MCS, available for transmission of the second wireless signal (52).

4. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) indicates an expected interference-to-noise ratio for reception of the second wireless signal (52).

5. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) indicates a minimum required received signal power for reception of the second wireless signal (52).

6. The method according to claim 5, wherein the minimum required received signal power corresponds to a most robust MCS available for transmission of the second wireless signal (52).

7. The method according to claim 5 or 6, wherein the information indicated by the first wireless signal (51) further indicates a bandwidth to which the minimum required received signal power relates.

8. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) indicates a minimum required power spectral density for reception of the second wireless signal (52).

9. The method according to claim 8, wherein the minimum required power spectral density corresponds to a most robust MCS available for transmission of the second wireless signal (52).

10. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) indicates a degree to which the further wireless communication device can suppress self-interference caused by the first wireless signal (51).

11. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) indicates an expected amount of residual self-interference caused by the first wireless signal (51).

12. The method according to any one of the preceding claims, wherein the information indicated by the first wireless signal (51) further indicates information on transmit power of the first wireless signal (51).

13. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) further indicates one or more frequency resources allowed to be used for transmission of the second wireless signal (52).

14. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) further indicates a maximum allowed duration for transmission of the second wireless signal (52).

15. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) further indicates a requirement of modulation symbol alignment of the first wireless signal (51) and the second wireless signal (52).

16. The method according to any of the preceding claims,wherein the information indicated by the first wireless signal (51) further indicates one or more MCSs to be used for transmission of the second wireless signal (52).

17. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) further indicates one or more types of data allowed to be conveyed by the second wireless signal (52).

18. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) further indicates a set of one or more devices allowed to transmit the second wireless signal (52).

19. The method according to any of the preceding claims, wherein the information indicated by the first wireless signal (51) further indicates an allowed level of interference caused by the second wireless signal (52) to one or more intended receivers of the first wireless signal (51).

20. The method according to any of the preceding claims, wherein controlling transmission of the second wireless signal (52) comprises selecting a transmit power of the second wireless signal (52) and / or selecting an MCS of the second wireless signal (52) and / or selecting a transmission bandwidth of the second wireless signal (52).

21. The method according to any of the preceding claims, wherein frequency resources for transmission of the second wireless signal (52) are at least partially overlapping with frequency resources for transmission of the first wireless signal (51).

22. The method according to claims 1 to 20, wherein frequency resources for transmission of the second wireless signal (52) are nonoverlapping with frequency resources for transmission of the first wireless signal (51).

23. The method according to any one of the preceding claims, wherein the wireless communication system is based on a Wireless Local Area Network technology according to the IEEE 802.11 standards family.

24. The method according to claim 23, wherein the wireless communication device (10, 20; 800) is a non-access point device (20).

25. The method according to claim 23, wherein the wireless communication device (10, 20; 800) is an access point device (10).

26. A method of controlling wireless transmissions in a wireless communication system, the method comprising: a wireless communication device (10, 20; 800) sending a first wireless signal (51), the first wireless signal (51) indicating information on one or more conditions for reception of a second wireless signal (52) by the wireless communication device during ongoing transmission of the first wireless signal (51).

27. The method according to claim 26, comprising: based on the one or more conditions, the wireless communication device (10, 20; 800) receiving the second wireless signal (52) from a further wireless communication device which received the first wireless signal (51).

28. The method according to claim 26 or 27, wherein the information indicated by the first wireless signal (51) indicates an expected sensitivity level of the first wireless communication device for reception of the second wireless signal (52).

29. The method according to claim 28, wherein the sensitivity level corresponds to a most robust modulation and coding scheme, MCS, available for transmission of the second wireless signal (52).

30. The method according to any of claims 26 to 29, wherein the information indicated by the first wireless signal (51) indicates an expected interference-to-noise ratio for reception of the second wireless signal (52).

31. The method according to any of claims 26 to 30, wherein the information indicated by the first wireless signal (51) indicates a minimum required received signal power for reception of the second wireless signal (52).

32. The method according to claim 31 , wherein the minimum required received signal power corresponds to a most robust MCS available for transmission of the second wireless signal (52).

33. The method according to claim 31 or 32,wherein the information indicated by the first wireless signal (51) further indicates a bandwidth to which the minimum required received signal power relates.

34. The method according to any of claims 26 to 33, wherein the information indicated by the first wireless signal (51) indicates a minimum required power spectral density for reception of the second wireless signal (52).

35. The method according to claim 34, wherein the minimum required power spectral density corresponds to a most robust MCS available for transmission of the second wireless signal (52).

36. The method according to any of claims 26 to 35, wherein the information indicated by the first wireless signal (51) indicates a degree to which the wireless communication device can suppress self-interference caused by the first wireless signal (51).

37. The method according to any of claims 26 to 36, wherein the information indicated by the first wireless signal (51) indicates an expected amount of residual self-interference caused by the first wireless signal (51).

38. The method according to any one of claims 26 to 37, wherein the information indicated by the first wireless signal (51) further indicates information on transmit power of the first wireless signal (51).

39. The method according to any of claims 26 to 38, wherein the information indicated by the first wireless signal (51) further indicates one or more frequency resources allowed to be used for transmission of the second wireless signal (52).

40. The method according to any of claims 26 to 39, wherein the information indicated by the first wireless signal (51) further indicates a maximum allowed duration for transmission of the second wireless signal (52).

41. The method according to any of claims 26 to 40, wherein the information indicated by the first wireless signal (51) further indicates a requirement of modulation symbol alignment of the first wireless signal (51) and the second wireless signal (52).

42. The method according to any of claims 26 to 41 , wherein the information indicated by the first wireless signal (51) further indicates one or more MCSs to be used for transmission of the second wireless signal (52).

43. The method according to any of claims 26 to 42, wherein the information indicated by the first wireless signal (51) further indicates one or more types of data allowed to be conveyed by the second wireless signal (52).

44. The method according to any of claims 26 to 43, wherein the information indicated by the first wireless signal (51) further indicates a set of one or more devices allowed to transmit the second wireless signal (52).

45. The method according to any of claims 26 to 44, wherein the information indicated by the first wireless signal (51) further indicates an allowed level of interference caused by the second wireless signal (52) to one or more intended receivers of the first wireless signal (51).

46. The method according to any of claims 26 to 45, wherein frequency resources for transmission of the second wireless signal (52) are at least partially overlapping with frequency resources for transmission of the first wireless signal (51).

47. The method according to claims 26 to 46, wherein frequency resources for transmission of the second wireless signal (52) are nonoverlapping with frequency resources for transmission of the first wireless signal (51).

48. The method according to any one of claims 26 to 47, wherein the wireless communication system is based on a Wireless Local Area Network technology according to the IEEE 802.11 standards family.

49. The method according to claim 48, wherein the wireless communication device (10, 20; 800) is an access point device (10).

50. The method according to claim 49, wherein the wireless communication device (10, 20; 800) is a non-access point device (20).

51. A wireless communication device for a wireless communication system, the wireless communication device being configured to:receive a first wireless signal (51) from a further wireless communication device (10, 20; 800), the first wireless signal (51) indicating information on one or more conditions for reception of a second wireless signal (52) by the further wireless communication device (10, 20; 800) during ongoing transmission of the first wireless signal (51); and based on the one or more conditions, control transmission of the second wireless signal (52) to the further wireless communication device (10, 20; 800).

52. The wireless communication device (10, 20; 800) according to claim 51 , wherein the wireless communication device (10, 20; 800) is configured to perform a method according to any one of claims 2 to 25.

53. The wireless communication device (10, 20; 800) according to claim 51 or 52, comprising: at least one processor (850), and a memory (860) containing program code executable by the at least one processor (850), whereby execution of the program code by the at least one processor (850) causes the wireless communication device (10, 20; 800) to perform a method according to any one of claims 1 to 25.

54. A wireless communication device (10, 20; 800) for a wireless communication system, the wireless communication device (10, 20; 800) being configured to: send a first wireless signal (51), the first wireless signal (51) indicating information on or more conditions for reception of a second wireless signal (52) by the wireless communication device (10, 20; 800) during ongoing transmission of the first wireless signal (51).

55. The wireless communication device (10, 20; 800) according to claim 54, wherein the wireless communication device (10, 20; 800) is configured to perform a method according to any one of claims 27 to 50.

56. The wireless communication device (10, 20; 800) according to claim 54 or 55, comprising: at least one processor (850), and a memory (860) containing program code executable by the at least one processor (850), whereby execution of the program code by the at least one processor (850) causes the wireless communication device (10, 20; 800) to perform a method according to any one of claims 26 to 50.

57. A computer program or computer program product comprising program code to be executed by at least one processor (850) of a wireless communication device (10, 20; 800),whereby execution of the program code causes the wireless communication device (10, 20;800) to perform a method according to any one of claims 1 to 50.

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