Method, apparatus, and computer storage medium for communication

Abstract

Embodiments of the present disclosure relate to methods, devices, and computer-readable media for communication. The method includes: determining, at a first terminal device, a time window during which a second terminal device is to filter a sidelink reference signal received power (SL-RSRP) of a sidelink transmission received from the first terminal device; receiving, during the time window, the filtered SL-RSRP from the second terminal device; estimating a sidelink path loss based on the filtered SL-RSRP; and applying the sidelink path loss to power control of at least one subsequent sidelink transmission from the first terminal device to the second terminal device. In this way, the SL path loss can be estimated more accurately and reasonably, so that the power control based on the SL path loss can be performed more effectively.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of telecommunications, and in particular, to methods, devices, and computer storage media for communication. Background Art

[0002] Device-to-device (D2D) communication is supported in 5G New Radio (NR). In D2D communication, two terminal devices can communicate with each other via a D2D communication link (also referred to as a sidelink (SL)). To perform SL open-loop power control, one terminal device acting as a transmitting (TX) device can send a reference signal (RS) for sidelink reference signal received power (SL-RSRP) measurement to another terminal device acting as a receiving (RX) device. The RX device can measure the SL-RSRP of the RS received from the TX device. For example, the RX device can filter the measured SL-RSRP and report the filtered SL-RSRP to the TX device. Then, the TX device can derive the path loss of the SL based on the filtered SL-RSRP.

[0003] In 3GPP discussions, it has been proposed not to indicate the transmission power of the RS to the RX device. However, due to various reasons (e.g., downlink-based power control, power sharing between the sidelink and the simultaneous uplink or between different sidelinks, etc.), the actual transmission power of the TX device may vary depending on the SL-RSRP measurement occasion. Without information about the transmission power of the TX device, the filtered SL-RSRP obtained at the RX device will be inaccurate, and thus the SL path loss estimated based on the filtered SL-RSRP will also be inaccurate. Summary of the Invention

[0004] Generally, example embodiments of the present disclosure provide methods, devices, and computer storage media for communication.

[0005] In a first aspect, a method for communication is provided. The method includes: determining, at a first terminal device, a time window during which a second terminal device is to filter a sidelink reference signal received power (SL-RSRP) of a sidelink transmission received from the first terminal device; receiving, during the time window, the filtered SL-RSRP from the second terminal device; estimating a sidelink path loss based on the filtered SL-RSRP; and applying the sidelink path loss to power control of at least one subsequent sidelink transmission from the first terminal device to the second terminal device.

[0006] In a second aspect, a method for communication is provided. The method includes: determining, at a second terminal device, a time window during which the second terminal device is to filter a side-link reference signal received power (SL-RSRP) of a side-link transmission received from a first terminal device; measuring the SL-RSRP of the side-link transmission received from the first terminal device during the time window; filtering the SL-RSRP during the time window; and sending the filtered SL-RSRP to the first terminal device such that the first terminal device performs power control of at least one subsequent side-link transmission from the first terminal device to the second terminal device based on the filtered SL-RSRP.

[0007] In a third aspect, a first terminal device is provided. The first terminal device includes a processor and a memory coupled to the processor. The memory stores instructions that, when run by the processor, cause the first terminal device to perform the method according to the first aspect of the present disclosure.

[0008] In a fourth aspect, a second terminal device is provided. The second terminal device includes a processor and a memory coupled to the processor. The memory stores instructions that, when run by the processor, cause the second terminal device to perform the method according to the second aspect of the present disclosure.

[0009] In a fifth aspect, a computer-readable medium storing instructions is provided. The instructions, when run on at least one processor, cause the at least one processor to perform the method according to the first aspect of the present disclosure.

[0010] In a sixth aspect, a computer-readable medium storing instructions is provided. The instructions, when run on at least one processor, cause the at least one processor to perform the method according to the second aspect of the present disclosure.

[0011] Other features of the present disclosure will become readily apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] By a more detailed description of some embodiments of the present disclosure in the drawings, the above and other objects, features, and beneficial effects of the present disclosure will become more apparent, wherein:

[0013] Figure 1 An example communication network in which embodiments of the present disclosure can be implemented is shown;

[0014] Figure 2 An example signaling diagram showing an example process of SL power control according to some embodiments of the present disclosure is shown;

[0015] Figure 3Illustrates examples of some embodiments of the present disclosure;

[0016] Figure 4 Illustrates examples of some embodiments of the present disclosure;

[0017] Figure 5 Shows a flowchart of an example method according to some embodiments of the present disclosure;

[0018] Figure 6 Shows a flowchart of an example method according to some embodiments of the present disclosure; and

[0019] Figure 7 Is a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

[0020] Throughout the drawings, the same or similar reference numerals denote the same or similar elements. Detailed Description

[0021] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that the description of these embodiments is only for illustration and to assist those skilled in the art in understanding and implementing the present invention, and does not imply any limitation on the scope of the present invention. The disclosure described herein can be implemented in various ways other than those described below.

[0022] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure pertains.

[0023] As used herein, the term "terminal device" refers to any device having wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to: user equipment (UE), personal computer, desktop computer, mobile phone, cellular phone, smart phone, personal digital assistant (PDA), portable computer, tablet computer, wearable device, Internet of Things (IoT) device, Internet of Everything (IoE) device, machine type communication (MTC) device, in-vehicle device for V2X communication (where X represents pedestrian, vehicle, or infrastructure / network), or image capture device such as a digital camera, gaming device, music storage and playback device, or Internet tool allowing wireless or wired Internet access and browsing, etc.

[0024] As used herein, the term "network device" or "base station" (BS) refers to a device that can provide or host a cell or coverage area over which a terminal device can communicate. Examples of network devices include, but are not limited to: Node B (NodeB or NB), evolved Node B (eNodeB or eNB), next generation Node B (gNB), transmit receive point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), low power nodes such as femto nodes, pico nodes, etc.

[0025] As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. The term "comprising" and its variants will be construed as open-ended terms, meaning "including but not limited to". The term "based on" will be construed as "at least partially based on". The terms "some embodiments" and "embodiments" will be construed as "at least one embodiment". The term "another embodiment" will be construed as "at least one other embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may be included below.

[0026] In some examples, a value, process or device is referred to as "optimal", "lowest", "highest", "minimum", "maximum", etc. It should be understood that such descriptions are intended to indicate that a selection can be made among many alternative functions in use, and such a selection is not necessarily better, smaller, higher or more preferred than other selections.

[0027] As described above, in D2D communication, two terminal devices can communicate with each other via SL. To perform SL open-loop power control, the TX terminal device can send an RS for SL-RSRP measurement to the RX terminal device. The RX terminal device can measure the SL-RSRP of the RS received from the TX terminal device. For example, the RX terminal device can filter the measured SL-RSRP and report the filtered SL-RSRP to the TX terminal device. Then, the TX terminal device can derive the SL path loss based on the filtered SL-RSRP.

[0028] In 3GPP discussions, it has been proposed not to indicate the transmission power of the RS to the RX terminal device. However, due to various reasons (e.g., downlink-based power control, power sharing between the sidelink and the simultaneous uplink or between different sidelinks, etc.), the actual transmission power of the TX terminal device may vary depending on the SL-RSRP measurement occasion. Without information about the transmission power of the TX terminal device, the filtered SL-RSRP obtained at the RX terminal device will be inaccurate, and thus the sidelink path loss estimated based on the filtered SL-RSRP will also be inaccurate.

[0029] Embodiments of the present disclosure provide a sidelink power control solution to solve the above problems and one or more other potential problems. According to this solution, time windows for filtering SL-RSRP are aligned between the TX terminal device and the RX terminal device. In addition, the transmit power to be used for estimating the SL path loss can be obtained at the TX terminal device. In this way, the SL path loss can be estimated more accurately and reasonably, so that power control based on the SL path loss can be performed more effectively.

[0030] Figure 1 A schematic diagram of an exemplary communication system 100 in which embodiments of the present disclosure can be implemented is shown. As Figure 1 shown, the communication system 100 may include a network device 110 and terminal devices 120 and 130. It should be understood that Figure 1 the number of devices in is given for illustrative purposes and does not imply any limitation to the present disclosure. The communication network 100 may include any suitable number of network devices and / or terminal devices suitable for implementing the embodiments of the present disclosure.

[0031] In some embodiments, a terminal device (e.g., terminal device 120 or 130) may be connected to a first network device and a second network device ( Figure 1 not shown in). One of the first network device and the second network device may be a master node, and the other may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In some embodiments, the first network device may be a first RAT device, and the second network device may be a second RAT device. In some embodiments, the first RAT device is an eNB and the second RAT device is a gNB. Information related to different RATs may be sent from at least one of the first network device and the second network device to the terminal device. In some embodiments, the first information may be sent from the first network device to the terminal device, and the second information may be sent from the second network device directly or via the first network device to the terminal device. In some embodiments, information related to the configuration for the terminal device configured by the second network device may be transmitted from the second network device via the first network device. Information related to the reconfiguration for the terminal device configured by the second network device may be sent directly from the second network device to the terminal device or may be sent to the terminal device via the first network device.

[0032] As Figure 1 shown, the network device 110 may communicate with the terminal devices 120 and 130 via channels (e.g., wireless communication channels) 132 and 133, respectively. Figure 1The terminal devices 120 and 130 are shown as vehicles that support D2D communication (such as V2X communication). It should be understood that the embodiments of the present disclosure are also applicable to other terminal devices other than vehicles, such as mobile phones, sensors, etc. In some embodiments, the terminal device 120 may communicate with the terminal device 130 via the sidelink 131. In some embodiments, the sidelink may be half-duplex or full-duplex. For example, the terminal device 120 may send information to the terminal device 130 via the sidelink 131. The terminal device 130 may also send information to the terminal device 120 via the sidelink 131.

[0033] In the transmission from the terminal device 120 to the terminal device 130 via the sidelink 131, the terminal device 120 may act as a TX device, and the terminal device 130 as an RX device. In the transmission from the terminal device 130 to the terminal device 120 via the sidelink 131, the terminal device 130 may act as a TX device, and the terminal device 120 may act as an RX device. Hereinafter, some embodiments will be described with reference to an example where the terminal device 120 is a TX device and an example where the terminal device 130 is an RX device. Hereinafter, the terminal device 120 may also be referred to as "TX device 120", "TX terminal device 120", or "first terminal device", and the terminal device 130 may also be referred to as "RX device 130", "RX terminal device 130", or "second terminal device". It should be understood that this is for the purpose of discussion only and does not imply any limitation on the scope of the present disclosure.

[0034] The communication in the communication system 100 may conform to any suitable standard, including but not limited to Global System for Mobile Communications (GSM), Long Term Evolution (LTE), LTE-Advanced, Advanced LTE (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE, General Packet Radio Service (GERAN), Machine Type Communication (MTC), etc. In addition, the communication may be performed according to any generation of communication protocols known currently or developed in the future. Examples of communication protocols include but are not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols.

[0035] Figure 2 A signaling diagram is shown that illustrates an example process 200 of SL power control according to some embodiments of the present disclosure. As Figure 2 shown, the process 200 may involve Figure 1 the TX device 120 and the RX device 130 shown. It should be understood that the process 200 may include additional actions not shown and / or some of the actions shown may be omitted, and the scope of the present disclosure is not limited in this regard.

[0036] As Figure 2 shown, the TX device 120 determines 210 a time window during which the RX device 130 filters the SL-RSRP of the SL transmission received from the TX device 120. Similarly, the RX device 130 may also determine 220 a time window during which the RX device 130 filters the SL-RSRP of the SL transmission received from the TX device 120. Hereinafter, the time window may also be referred to as a "filtering window" or an "SL-RSRP filtering window".

[0037] In some embodiments, the TX device 120 may determine the start of the time window based on the change in the transmission power of two adjacent SL transmissions, where the time window may end at the start of the next time window.

[0038] In some embodiments, the TX device 120 may determine the transmission power (also referred to as the "first transmission power") for the current SL transmission (also referred to as the "first SL transmission"). The TX device 120 may also determine the transmission power (also referred to as the "second transmission power") for the previous SL transmission (also referred to as the "second SL transmission"). In response to the difference between the first transmission power and the second transmission power exceeding a threshold, the TX device 120 may determine the start of the time window based on the time at which the first SL transmission occurred.

[0039] Alternatively, in some embodiments, the TX device 120 may apply a first SL path loss to control the transmission power of the first SL transmission, where the first SL path loss may be different from the second SL path loss applied to the power control of the previous SL transmission (i.e., the second SL transmission). In this case, the TX device 120 may determine the start of the time window based on the time at which the first SL transmission occurred.

[0040] Figure 3 An example of such an embodiment is shown. For example, as Figure 3As shown, the difference between the transmit power of SL transmission 301 and the transmit power of SL transmission 302 may exceed a threshold, or different SL path losses may be applied to control the transmit power for SL transmission 301 and 302 respectively. In this case, the new filtering window 325 may start at time A, while the previous filtering window 315 may end at time A. Similarly, the difference between the transmit power of SL transmission 303 and the transmit power of SL transmission 304 may exceed a threshold, or different SL path losses may be applied to control the transmit power for SL transmission 303 and 304 respectively. In this case, the new filtering window 335 may start at time C, while the previous filtering window 325 may end at time C. The difference between the transmit power of SL transmission 305 and the transmit power of SL transmission 306 may exceed a threshold, or different SL path losses may be applied to control the transmit power for SL transmission 305 and 306 respectively. In this case, the new filtering window 345 may start at time E, while the previous filtering window 335 may end at time E.

[0041] In some embodiments, the TX device 120 may send an indication of the start of a time window to the RX device 130, so that the RX device 130 can determine the start of the time window based on this indication.

[0042] In some embodiments, preferably, a flag may be transmitted in the PSCCH. The TX device 120 may switch the flag in response to different SL path losses (or different filtered SL-RSRP) being used for the power control of the current SL transmission compared to the previous SL transmission, or in response to the difference between the transmit power of the current SL transmission and the transmit power of the previous SL transmission exceeding a threshold. For example, in Figure 3 the flag in the SL transmission before time A (e.g., SL transmission 301) may be '0'. The flag in the SL transmission 302 at time A, or the flag in each SL transmission after time A and before time C (e.g., SL transmission 303) may be '1'. The flag in the SL transmission 304 at time C, or the flag in each SL transmission after time C and before time E (e.g., SL transmission 305) may be '0'. In this way, the RX device 130 can determine the start of a new time window based on the time when the flag in the PSCCH is switched.

[0043] Alternatively, in some embodiments, a flag may be transmitted in the PSCCH. For example, if different SL path losses (or different filtered SL-RSRPs) are used for power control of the current SL transmission compared to a previous SL transmission, or if the difference between the transmit power of the current SL transmission and the transmit power of the last SL transmission exceeds a threshold, the TX device 120 may set the flag to '1'. Otherwise, the TX device 120 may set the flag to '0'. For example, in Figure 3 , the flags in the SL transmission 302 at time A, the flags in the SL transmission 304 at time C, and the flags in the SL transmission 306 at time E may be '1'; while the flags in other SL transmissions may be '0'. In this way, the RX device 130 may determine the start of a new time window based on the times when the flag in the PSCCH is '1'.

[0044] In some embodiments, the TX device 120 may be configured with information about the time window. For example, the network device 110 may configure information about the time window for the TX device 120 via higher layer signaling, or the information about the time window may be pre-configured at the TX device 120. In some embodiments, the information about the time window may indicate the start and / or end of the time window. In this way, the TX device 120 may determine the start and / or end of the time window based on this information. In some embodiments, in response to determining that the difference between the transmit power of the current SL transmission and the transmit power of the last SL transmission exceeds a threshold, the TX device 120 may adjust the start of the time window. In addition, the TX device 120 may further send an indication (e.g., via the PSCCH) to the RX device 130 to indicate that the start of the time window should be adjusted. Alternatively, in some embodiments, the information about the time window may indicate the time for receiving the filtered SL-RSRP from the RX device 130 during the time window and the time offset between this time and the start of the time window. In this way, the TX device 120 may determine the start of the time window based on the time for receiving the filtered SL-RSRP during the time window and the time offset. The time offset may be related to the capabilities of the TX device 120. For example, different time windows may be associated with the same time offset or different time offsets.

[0045] In some embodiments, the RX device 130 may also be configured with information regarding a time window. For example, the network device 110 or the TX device 120 may configure information regarding the time window for the RX device 130 via higher layer signaling, or the information regarding the time window may be pre-configured at the RX device 130. In some embodiments, the information regarding the time window may indicate the start and / or end of the time window. The RX device 130 may determine the start and / or end of the time window based on this information. In some embodiments, the TX device 120 may send an indication (e.g., via the PSCCH) to the RX device 130 to indicate that the start of the time window should be adjusted, e.g., when the transmit power change between two adjacent SL transmissions exceeds a threshold. In response to receiving the indication from the TX device 120, the RX device 130 may adjust the start of the time window accordingly. Alternatively, in some embodiments, the information regarding the time window may indicate the time for sending the filtered SL-RSRP to the TX device 120 during the time window and the time offset between this time and the start of the time window. The RX device 130 may determine the start of the time window based on the time for sending the filtered SL-RSRP during the time window and the time offset. The time offset may be related to the capabilities of the TX device 120. For example, different time windows may be associated with the same time offset or different time offsets.

[0046] Figure 4 An example of such an embodiment is shown. As Figure 4 shown, the corresponding time for reporting each filtered SL-RSRP and the time offset relative to this corresponding time are configured. For example, regarding the time window 420, the start of the time window 420 may be determined based on the time of the filtered SL-RSRP report 310 and the time offset 401. Regarding the time window 430, the start of the time window 430 may be determined based on the time of the filtered SL-RSRP report 320 and the time offset 402. Regarding the time window 440, the start of the time window 440 may be determined based on the time of the filtered SL-RSRP report 330 and the time offset 403. The time offsets 401, 402, and 403 associated with different time windows may be the same as or different from each other. In the example as Figure 4 shown, each time window ends when the next time window starts.

[0047] Returning to Figure 2 , the TX device 120 sends 230 the RS for SL-RSRP measurement to the RX device 130 via the Physical SideLink Control Channel (PSCCH) and / or the Physical SideLink Shared Channel (PSSCH). In some embodiments, the TX device 120 may send the RS to the RX device 130 via one of unicast, multicast, and broadcast.

[0048] In response to receiving an SL transmission (e.g., PSCCH and / or PSSCH), the RX device 130 measures the SL-RSRP of 240 SL transmissions and filters the SL-RSRP during a time window 240.

[0049] In some embodiments, the RX device 130 may use a layer 1 filter or a layer 3 filter to filter the measured SL-RSRP during the time window. The RX device 130 may reset / restart the filter at the start of the time window to initiate filtering of the SL-RSRP during the time window. For example, in 3GPP specification TS38.331, the layer 3 filter is defined by the following formula:

[0050] F n = (1 – a)*F n-1 + a*M n (1)

[0051] where M n is the latest measurement result received from the physical layer. F n is the updated filtered measurement result for evaluating the reporting criteria or for measurement reporting. F n-1 is the old filtered measurement result, where F0 is set to M1 when the first measurement result is received from the physical layer. a = 1 / 2 (ki / 4) , where k i is the configured filter coefficient. In some embodiments, the RX device 130 may filter the SL-RSRP during the time window using the filter defined by equation (1) above. Alternatively, in other embodiments, the RX device 130 may use a different filter. The scope of the present disclosure will not be limited to this aspect.

[0052] In some embodiments, preferably, the RX device 130 is forced to measure the SL-RSRP of all received SL transmissions during the time window. For example, the RX device 130 is forced to measure the SL-RSRP of all received SL transmissions during the time window before reporting the filtered SL-RSRP to the TX device 120. For example, with respect to Figure 3 the time window 325 shown in, the RX device 130 is forced to measure the SL-RSRP of all received SL transmissions (including SL transmission 302) from time A to time B.

[0053] Returning to reference Figure 2 , the RX device 130 sends 250 the filtered SL-RSRP to the TX device 120. Thus, the TX device 120 receives 250 the filtered SL-RSRP from the RX device 130.

[0054] In some embodiments, the RX device 130 may be configured with a reporting period for reporting the filtered SL-RSRP. For example, the network device 110 or the TX device 120 may configure the reporting period for the RX device 130 via higher layer signaling. Alternatively, in some embodiments, the RX device 130 may determine the reporting period for reporting the filtered SL-RSRP. For example, the reporting period may be determined based on at least one of the following: the absolute speed of the RX device 130; the relative speed between the TX device 120 and the RX device 130; the difference between the power given by open-loop power control (OLPC) based on the downlink path loss and the power given by OLPC based on the SL path loss; and the capabilities of the RX device 130. In some embodiments, the RX device 130 may determine the time for sending the filtered SL-RSRP to the TX device 120 based on the reporting period such that the interval between the determined time and the time for reporting the previous filtered SL-RSRP exceeds the reporting period, and the RX device 130 has an SL grant at the determined time. In some embodiments, the TX device 120 or the network device 110 may determine the time for receiving the filtered SL-RSRP from the RX device 130 based on the reporting period in the same manner as the RX device 130. For example, the TX device 120 or the network device 110 may determine the time for receiving the filtered SL-RSRP from the RX device 130 based on the reporting period such that the interval between the determined time and the time for receiving the previous filtered SL-RSRP exceeds the reporting period, and the RX device 130 has an SL grant at the determined time.

[0055] Alternatively, in some embodiments, the RX device 130 may determine the time for sending the filtered SL-RSRP to the TX device 120 in response to the occurrence of an event. For example, the RX device 130 may determine the time for sending the filtered SL-RSRP to the TX device 120 based on the difference between the filtered SL-RSRP and the previous filtered SL-RSRP that has been sent to a first terminal device exceeding an RSRP threshold. For example, the RSRP threshold may be configured by the TX device 120 or the network device 110. As another example, the RSRP threshold may be determined by the RX device 130.

[0056] In some embodiments, the RX device 130 may send an indication to the TX device 120 for reporting the time of the filtered SL-RSRP. For example, the indication of the time may be sent to the TX device 120 via a MAC CE together with the filtered SL-RSRP. For example, if the reporting period is determined by the RX device 130 or if the reporting of the filtered SL-RSRP is triggered by an event, the indication may be sent to the TX device 120. In this way, the TX device 120 may determine the time for receiving the filtered SL-RSRP from the RX device 130 based on this indication.

[0057] In some embodiments, the reporting period and time offset for reporting the filtered SL-RSRP may be configured by the network device 110 at the TX device 120 and the RX device 130. In some embodiments, the reporting period and time offset for reporting the filtered SL-RSRP may be configured by the network device 110 at the TX device 120 or pre-configured at the TX device 120. The TX device 120 may configure the reporting period and time offset for the RX device 130 via higher layer signaling. In some embodiments, the RX device 130 may determine the time for sending the filtered SL-RSRP to the TX device 120 based on the reporting period and time offset. Similarly, the TX device 120 may determine the time for receiving the filtered SL-RSRP from the RX device 130 based on the reporting period and time offset. In some embodiments, for the case of multicast (i.e., the TX device 120 may send PSCCH and / or PSSCH to a group of RX devices), the same reporting period but different offsets may be configured for the RX devices in the group. For example, the offsets for different RX devices within the group may be determined by nested values, such as 0, 1, 2, 4, 8, 16... ms / slot, to reduce resource usage and duplexing issues.

[0058] In some embodiments, in response to the OLPC based on the SL path loss being disabled, the reporting of the filtered SL-RSRP may be disabled. In some embodiments, in response to the power given by the OLPC based on the downlink path loss being lower than the power given by the OLPC based on the SL path loss, the TX device 120 may disable the reporting of the filtered SL-RSRP via higher layer signaling. Alternatively, in some embodiments, in response to the power given by the OLPC based on the downlink path loss being lower than the power given by the OLPC based on the SL path loss and the difference between the two exceeding a threshold, the TX device 120 may disable the reporting of the filtered SL-RSRP via higher layer signaling. For example, the threshold may be configured by the network device 110 or the TX device 120.

[0059] Return reference Figure 2, in response to receiving the filtered SL-RSRP from the RX device 130, the TX device 120 estimates the path loss of SL131 based on the filtered SL-RSRP.

[0060] In some embodiments, the TX device 120 may estimate the SL path loss as follows:

[0061] Pathloss = Power_tx – Filtered_SL_RSRP (2)

[0062] where Pathloss represents the estimated SL path loss, Power_tx represents the transmit power to be used for estimating the SL path loss, and Filtered_SL_RSRP represents the filtered SL-RSRP received from the RX device 130.

[0063] In some embodiments, the transmit power Power_tx to be used for estimating the SL path loss may be determined based on one of the following: the average of the actual transmit powers of the sidelink transmissions between the start of the time window and the receipt of the filtered SL-RSRP; the actual transmit power of the initial sidelink transmission after the start of the time window; or the actual transmit power of the last sidelink transmission before the receipt of the filtered SL-RSRP.

[0064] In some embodiments, the TX device 120 may determine the transmit power Power_tx by filtering the actual transmit power of the SL transmissions between the start of the time window and the receipt of the filtered SL-RSRP, except for identifying SL transmissions with discontinuous transmission (DTX). For example, the layer 3 filter defined by the above equation (1) may be used by the TX device 120 to filter the actual transmit power of the SL transmissions, where the actual transmit power of each SL transmission may serve as M n , to replace the latest measurement result obtained from the physical layer. In the example shown in Figure 3 , for example, according to the above equation (1), the transmit power Power_tx used for estimating the SL path loss during the time window 325 may be determined as the filtered result of (P1, P2, P3…Pn), where P i (1≤i≤n) represents the actual transmit power of each SL transmission from time A to time B, except for identifying SL transmissions with DTX.

[0065] Alternatively, in some embodiments, to determine the transmit power Power_tx to be used for estimating the SL path loss during the time window, the TX device 120 may determine, for each SL transmission (except for the SL transmissions identified as DTX), the difference between the actual transmit power of the SL transmission and the reference transmit power P0 between the start of the time window and the reception of the filtered SL-RSRP. The TX device 120 may filter the respective differences determined for the SL transmissions and determine the transmit power Power_tx to be used for estimating the SL path loss based on the reference transmit power P0 and the filtering result. For example, the reference transmit power P0 may be defined as a constant value at least during the time window. For example, the reference transmit power P0 may be configured via higher layer signaling or determined based on the implementation of the TX device 120. In some cases, the reference transmit power P0 may be 0.

[0066] In some embodiments, the transmit power Power_tx for estimating the SL path loss during the time window may be determined as follows:

[0067] Power_tx = Power_filtered – P0 (3)

[0068] where Power_filtered represents the filtering result of (P1 – P0, P2 – P0, P3 – P0 … P n – P0) according to the above formula (1), where P i (1 ≤ i ≤ n) represents the actual transmit power of each SL transmission during the time window (e.g., from the start of the time window to the reception of the filtered SL-RSRP), except for the SL transmissions identified as DTX. In this case, the TX device 120 may estimate the SL path loss based on the above formula (2).

[0069] Alternatively, in some embodiments, the transmit power Power_tx to be used for estimating the SL path loss during the time window may be determined as follows:

[0070] Power_tx = P0 – Power_filtered (4)

[0071] where Power_filtered represents the filtering result of (P0 – P1, P0 – P2, P0 – P3 … P0 – P n ) according to the above formula (1), where P i (1 ≤ i ≤ n) represents the actual transmit power of each SL transmission during the time window (e.g., from the start of the time window to the reception of the filtered SL-RSRP), except for the SL transmissions identified as DTX. In this case, the TX device 120 may estimate the SL path loss as follows:

[0072] Pathloss = Filtered_SL_RSRP – Power_tx (5)

[0073] As Figure 2 shown, the TX device 120 applies the estimated SL path loss to the power control of at least one subsequent SL transmission from the TX device 120 to the RX device 130 via SL130 at 270.

[0074] In some embodiments, the TX device 120 may be configured with timing information for applying the estimated SL path loss to the OLPC of at least one subsequent SL transmission. The TX device 120 may apply the estimated SL path loss to the OLPC of at least one subsequent SL transmission based on the timing information.

[0075] In some embodiments, the timing information may indicate a time offset between the reception of the filtered SL-RSRP and the application of the estimated SL path loss. For example, the time offset may be related to the capabilities and / or processing time of the TX device 120. In such a case, the TX device 120 may apply the estimated SL path loss to the OLPC of at least one subsequent SL transmission after the time offset after receiving the filtered SL-RSRP.

[0076] Alternatively, in some embodiments, the timing information may indicate a time offset between the end of a time window and the application of the estimated SL path loss. For example, the time offset may be related to the capabilities and / or processing time of the TX device 120. In such a case, the TX device 120 may apply the estimated SL path loss to the OLPC of at least one subsequent SL transmission after the time offset after the end of the time window.

[0077] Figure 5 A flowchart of an example method 500 in accordance with some embodiments of the present disclosure is shown. For example, method 500 may be performed at a first terminal device 120 as Figure 1 and Figure 2 shown. It should be understood that method 500 may include additional blocks not shown and / or some of the shown blocks may be omitted, and the scope of the present disclosure is not limited in this regard.

[0078] At block 510, the first terminal device 120 determines a time window during which the second terminal device 130 is to filter the SL-RSRP of a sidelink transmission received from the first terminal device 120.

[0079] In some embodiments, determining the time window includes: determining a first transmit power of a first sidelink transmission from a first terminal device to a second terminal device; determining a second transmit power of a second sidelink transmission from the first terminal device to the second terminal device, where the second sidelink transmission occurs before the first sidelink transmission; and in response to a difference between the first transmit power and the second transmit power exceeding a threshold, determining a start of the time window based on a time at which the first sidelink transmission occurs, where the time window ends at a start of a next time window.

[0080] In some embodiments, determining the time window includes: determining a first sidelink path loss that is applied to power control of a first sidelink transmission from a first terminal device to a second terminal device; determining a second sidelink path loss that is applied to power control of a second sidelink transmission from the first terminal device to the second terminal device, where the second link transmission occurs before the first sidelink transmission; and in response to the first sidelink path loss being different from the second sidelink path loss, determining a start of the time window based on a time at which the first sidelink transmission occurs, where the time window ends at a start of a next time window.

[0081] In some embodiments, method 500 further includes: sending an indication of a start of a time window from the first terminal device to the second terminal device via a first sidelink transmission.

[0082] In some embodiments, determining the time window includes: in response to the first terminal device being configured with information about the time window, determining the time window based on the information.

[0083] In some embodiments, the information about the time window indicates a start and / or an end of the time window, and determining the time window based on the information includes: determining a start and / or an end of the time window based on the information.

[0084] In some embodiments, the information about the time window indicates a time to receive filtered SL-RSRP during the time window and a time offset between the time and a start of the time window, and determining the time window based on the information includes: determining a start of the time window based on the time and the time offset, where the time window ends at a start of a next time window.

[0085] In some embodiments, method 500 further includes: sending information about the time window from the first terminal device to the second terminal device.

[0086] In block 520, the first terminal device 120 receives filtered SL-RSRP from the second terminal device 130 during the time window.

[0087] In some embodiments, receiving the filtered SL-RSRP includes: determining a time for receiving the filtered SL-RSRP during a time window; and receiving the filtered SL-RSRP at the time.

[0088] In some embodiments, determining the time includes: in response to a first terminal device being configured with a period for receiving the filtered SL-RSRP from a second terminal device, determining the time based on the period such that an interval between the determined time and a time for receiving a previously filtered SL-RSRP exceeds the period, and the second terminal device has a sidelink grant at the determined time.

[0089] In some embodiments, determining the time includes: in response to a first terminal device being configured with a period and a time offset for receiving the filtered SL-RSRP from a second terminal device, determining the time based on the period and the time offset.

[0090] In some embodiments, determining the time includes: receiving an indication of the time from the second terminal device; and determining the time based on the indication.

[0091] At block 530, the first terminal device 120 estimates a sidelink path loss based on the filtered SL-RSRP.

[0092] In some embodiments, estimating the sidelink path loss includes: determining a transmit power for estimating the sidelink path loss; and estimating the sidelink path loss based on the transmit power and the filtered SL-RSRP.

[0093] In some embodiments, the transmit power to be used for estimating the sidelink path loss is determined based on one of the following: an average of actual transmit powers of sidelink transmissions between a start of a time window and a reception of the filtered SL-RSRP; an actual transmit power of an initial sidelink transmission after a start of the time window; or an actual transmit power of a last sidelink transmission before the reception of the filtered SL-RSRP.

[0094] In some embodiments, determining the transmit power to be used for estimating the sidelink path loss includes: filtering actual transmit powers of sidelink transmissions between a start of a time window and a reception of the filtered SL-RSRP; and determining, based on a result of the filtering, the transmit power for estimating the sidelink path loss.

[0095] In some embodiments, determining the transmit power to be used for estimating the sidelink path loss includes: for each sidelink transmission between the start of the time window and the reception of the filtered SL-RSRP, determining the difference between the actual transmit power of the sidelink transmission and the reference transmit power; filtering each of the determined differences for the sidelink transmissions that are between the start of the time window and the reception of the filtered SL-RSRP; and determining the transmit power for estimating the sidelink path loss based on the reference transmit power and the filtering result.

[0096] At block 540, the first terminal device 120 applies the sidelink path loss to power control of at least one subsequent sidelink transmission from the first terminal device 120 to the second terminal device 130.

[0097] In some embodiments, applying the sidelink path loss to power control of at least one subsequent sidelink transmission includes: in response to the first terminal device being configured with timing information for applying the sidelink path loss to power control of at least one subsequent sidelink transmission, applying the sidelink path loss to power control of at least one subsequent sidelink transmission based on the timing information.

[0098] Figure 6 A flowchart of an example method 600 according to some embodiments of the present disclosure is shown. For example, method 600 may be performed at the second terminal device 130 as shown in Figure 1 and Figure 2 It should be understood that method 600 may include additional blocks not shown and / or some of the shown blocks may be omitted, and the scope of the present disclosure is not limited in this regard.

[0099] At block 610, the second terminal device 130 determines a time window during which the second terminal device 130 is to filter the SL-RSRP of the sidelink transmissions received from the first terminal device 120.

[0100] In some embodiments, determining the time window includes: receiving an indication of the start of the time window from the first terminal device; and determining the start of the time window based on the indication, wherein the time window ends at the start of the next time window.

[0101] In some embodiments, determining the time window includes: in response to the second terminal device being configured with information about the time window, determining the time window based on the information.

[0102] In some embodiments, the information about the time window indicates the start and / or end of the time window, and determining the time window based on the information includes: determining the start and / or end of the time window based on the information.

[0103] In some embodiments, the information regarding the time window indicates the time for transmitting the filtered SL-RSRP during the time window and the time offset between the time and the start of the time window, and determining the time window based on the information includes: determining the start of the time window based on the time and the time offset, where the time window ends at the start of the next time window.

[0104] At block 620, the second terminal device 130 measures the SL-RSRP of the sidelink transmission received from the first terminal device 120 during the time window.

[0105] At block 630, the second terminal device 130 filters the SL-RSRP during the time window.

[0106] In some embodiments, filtering the SL-RSRP during the time window includes: resetting the filter for filtering the SL-RSRP at the start of the time window to initiate filtering of the SL-RSRP for the time window.

[0107] At block 640, the second terminal device 130 sends the filtered SL-RSRP to the first terminal device 120 such that the first terminal device 120 performs power control of at least one subsequent sidelink transmission from the first terminal device 120 to the second terminal device 130 based on the filtered SL-RSRP.

[0108] In some embodiments, sending the filtered SL-RSRP includes: determining the time for sending the filtered SL-RSRP to the first terminal device during the time window; and sending the filtered SL-RSRP to the first terminal device at the time.

[0109] In some embodiments, determining the time includes: in response to the second terminal device being configured with a time period for sending the filtered SL-RSRP to the first terminal device, determining the time based on the time period such that the interval between the determined time and the time for sending the previously filtered SL-RSRP exceeds the time period, and the second terminal device has a sidelink grant at the determined time.

[0110] In some embodiments, determining the time includes: in response to the second terminal device being configured with a time period and a time offset for sending the filtered SL-RSRP to the first terminal device, determining the time based on the time period and the time offset.

[0111] In some embodiments, determining the time includes: determining the time based on the difference between the filtered SL-RSRP and the previously filtered SL-RSRP sent to the first terminal device exceeding a threshold.

[0112] In some embodiments, method 600 further includes: before sending the filtered SL-RSRP to the first terminal device, sending an indication of time to the first terminal device.

[0113] Figure 7 is a simplified block diagram of a device 700 suitable for implementing embodiments of the present disclosure. The device 700 may be considered as a further exemplary implementation of the terminal device 120 or 130 as shown in Figure 1 FIG. Thus, the device 700 may be implemented at or as at least a part of the terminal device 120 or 130.

[0114] As shown, the device 700 includes a processor 710, a memory 720 coupled to the processor 710, a suitable transmitter (TX) and receiver (RX) 740 coupled to the processor 710, and a communication interface coupled to the TX / RX 740. The memory 710 stores at least a part of a program 730. The TX / RX 740 is used for two-way communication. The TX / RX 740 has at least one antenna to facilitate communication, but in fact, the access nodes mentioned in this application may have several antennas. The communication interface may represent any interface required for communicating with other network elements, such as an X2 interface for two-way communication between eNBs, an S1 interface for communication between a mobility management entity (MME) / serving gateway (S-GW) and an eNB, a Un interface for communication between an eNB and a relay node (RN), or a Uu interface for communication between an eNB and a terminal device.

[0115] Assume that the program 730 includes program instructions that, when executed by the associated processor 710, cause the device 700 to be operable in accordance with embodiments of the present disclosure, as referred to herein Figures 1 to 6 discussed. The embodiments herein may be implemented by computer software executable by the processor 710 of the device 700, or by hardware, or by a combination of software and hardware. The processor 710 may be configured to implement various embodiments of the present invention. In addition, the combination of the processor 710 and the memory 720 may form a processing component 750 suitable for implementing various embodiments of the present disclosure.

[0116] The memory 720 can be of any type suitable for the local technical network and can be implemented using any suitable data storage technology. By way of non-limiting example, such as a non-transitory computer-readable storage medium, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. Although only one memory 720 is shown in the device 700, there can be several physically distinct memory modules in the device 700. By way of non-limiting example, the processor 710 can be of any type suitable for the local technical network and can include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 700 can have multiple processors, such as an application-specific integrated circuit chip that is subordinate in time to a clock that synchronizes with a main processor.

[0117] In general, the various embodiments of the present disclosure can be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects can be implemented in hardware, while other aspects can be implemented in firmware or software that can be executed by a controller, a microprocessor, or other computing devices. Although aspects of the embodiments of the present disclosure are shown and described as block diagrams, flowcharts, or using some other graphical representation, it will be understood that the blocks, devices, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controllers, or other computing devices, or some combination thereof, by way of non-limiting example.

[0118] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, that are executed in a device on a target real or virtual processor to perform the processes or methods described above with reference to Figure 5 and Figure 6 the processes or methods described. In general, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The functions of the program modules can be combined or separated as needed in the various embodiments. The machine-executable instructions of the program modules can be executed within a local or distributed device. In a distributed device, the program modules can be located in both local storage media and remote storage media.

[0119] The program code for implementing the methods of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing devices, such that when the program codes are executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program codes can be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0120] The above program code can be contained on a machine-readable medium, which can be any tangible medium that can contain or store a program used by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium can include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination of the foregoing. More specific examples of the machine-readable storage medium will include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0121] In addition, although the operations are described in a specific order, this should not be construed as requiring that the operations be performed in the specific order shown or in sequential order, or that all of the illustrated operations be performed, to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these details should not be construed as limiting the scope of the present disclosure, but rather as descriptions of features specific to particular embodiments. Certain features described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment can also be implemented separately or in any suitable sub-combination in multiple embodiments.

[0122] Although the present disclosure has been described in language specific to structural features and / or method acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the above specific features and acts are disclosed as example forms of implementing the claims.

Claims

1. A method for communication, comprising: Determining, at a first terminal device, a time window during which a second terminal device is to filter a side - link reference signal received power (SL - RSRP) of a side - link transmission received from the first terminal device; Receiving, during the time window, the filtered SL - RSRP from the second terminal device; Estimating a side - link path loss based on the filtered SL - RSRP; and Applying the side - link path loss to power control of at least one subsequent side - link transmission from the first terminal device to the second terminal device.

2. The method according to claim 1, wherein determining the time window comprises: Determining a first transmission power of a first side - link transmission from the first terminal device to the second terminal device; Determining a second transmission power of a second side - link transmission from the first terminal device to the second terminal device, the second side - link transmission occurring before the first side - link transmission; And In response to a difference between the first transmission power and the second transmission power exceeding a threshold, determining a start of the time window based on a time at which the first side - link transmission occurs, wherein the time window ends at a start of a next time window.

3. The method according to claim 1, wherein determining the time window comprises: Determining a first side - link path loss applied to power control of a first side - link transmission from the first terminal device to the second terminal device; Determining a second side - link path loss applied to power control of a second side - link transmission from the first terminal device to the second terminal device, the second side - link transmission occurring before the first side - link transmission; And In response to the first side - link path loss being different from the second side - link path loss, determining a start of the time window based on a time at which the first side - link transmission occurs, wherein the time window ends at a start of a next time window.

4. The method according to claim 2 or 3, further comprising: Sending, via the first side - link transmission, an indication of the start of the time window from the first terminal device to the second terminal device.

5. The method according to claim 1, wherein determining the time window comprises: In response to the first terminal device being configured with information about the time window, determining the time window based on the information.

6. The method according to claim 5, wherein the information about the time window indicates a start and / or an end of the time window, and determining the time window based on the information comprises: Determining the start and / or the end of the time window based on the information.

7. The method according to claim 5, wherein the information about the time window indicates a time for receiving the filtered SL - RSRP during the time window and a time offset between the time and a start of the time window, and determining the time window based on the information comprises: Determine the start of the time window based on the time and the time offset, where the time window ends at the start of the next time window.

8. The method according to claim 5, further comprising: Transmit information about the time window from the first terminal device to the second terminal device.

9. The method according to claim 1, wherein receiving the filtered SL-RSRP comprises: Determine a time for receiving the filtered SL-RSRP during the time window; And Receive the filtered SL-RSRP at the time.

10. The method according to claim 9, wherein determining the time comprises: In response to the first terminal device being configured with a period for receiving the filtered SL-RSRP from the second terminal device, determine the time based on the period such that the interval between the determined time and the time for receiving a previously filtered SL-RSRP exceeds the period, and the second terminal device has a sidelink grant at the determined time.

11. The method according to claim 9, wherein determining the time comprises: In response to the first terminal device being configured with a period and a time offset for receiving the filtered SL-RSRP from the second terminal device, determine the time based on the period and the time offset.

12. The method according to claim 9, wherein determining the time comprises: Receive an indication of the time from the second terminal device; And Determine the time based on the indication.

13. The method according to claim 1, wherein estimating the sidelink path loss comprises: Determine a transmit power to be used for estimating the sidelink path loss; And Estimate the sidelink path loss based on the transmit power and the filtered SL-RSRP.

14. The method according to claim 13, wherein the transmit power to be used for estimating the sidelink path loss is determined based on one of the following: An average of the actual transmit powers of sidelink transmissions between the start of the time window and the reception of the filtered SL-RSRP; The actual transmit power of an initial sidelink transmission after the start of the time window; or The actual transmit power of the last sidelink transmission before the reception of the filtered SL-RSRP.

15. The method according to claim 13, wherein determining the transmit power to be used for estimating the sidelink path loss comprises: Filter the actual transmit powers of the sidelink transmissions between the start of the time window and the reception of the filtered SL-RSRP; And Based on the result of the filtering, determine the transmit power to be used for estimating the sidelink path loss.

16. The method according to claim 13, wherein determining the transmit power to be used for estimating the sidelink path loss comprises: For each sidelink transmission between the start of the time window and the reception of the filtered SL-RSRP, determine the difference between the actual transmit power and the reference transmit power of the sidelink transmission; Filter each of the determined differences for the sidelink transmissions between the start of the time window and the reception of the filtered SL-RSRP; And Based on the reference transmit power and the result of the filtering, determine the transmit power to be used for estimating the sidelink path loss.

17. The method according to claim 1, wherein applying the sidelink path loss to the power control of the at least one subsequent sidelink transmission includes: In response to the first terminal device being configured with timing information for applying the sidelink path loss to the power control of the at least one subsequent sidelink transmission, apply the sidelink path loss to the power control of the at least one subsequent sidelink transmission based on the timing information.

18. A method for communication, comprising: Determine, at a second terminal device, a time window during which the second terminal device is to filter the sidelink reference signal received power (SL-RSRP) of sidelink transmissions received from a first terminal device; Measure the SL-RSRP of the sidelink transmissions received from the first terminal device during the time window; Filter the SL-RSRP during the time window; and Send the filtered SL-RSRP to the first terminal device such that the first terminal device performs power control of at least one subsequent sidelink transmission from the first terminal device to the second terminal device based on the filtered SL-RSRP.

19. The method according to claim 18, wherein determining the time window includes: Receive an indication of the start of the time window from the first terminal device; And Determine the start of the time window based on the indication, wherein the time window ends at the start of the next time window.

20. The method according to claim 18, wherein determining the time window includes: In response to the second terminal device being configured with information about the time window, determine the time window based on the information.

21. The method according to claim 20, wherein the information about the time window indicates the start and / or end of the time window, and determining the time window based on the information includes: Determine the start and / or end of the time window based on the information.

22. The method according to claim 20, wherein the information about the time window indicates the time for sending the filtered SL-RSRP during the time window and the time offset between the time and the start of the time window, and determining the time window based on the information includes: Determine the start of the time window based on the time and the time offset, wherein the time window ends at the start of the next time window.

23. The method according to claim 18, wherein filtering the SL-RSRP during the time window includes: Resetting a filter for filtering the SL-RSRP at the start of the time window to initiate the filtering of the SL-RSRP for the time window.

24. The method according to claim 18, wherein transmitting the filtered SL-RSRP includes: Determining a time during the time window for transmitting the filtered SL-RSRP to the first terminal device; And Transmitting the filtered SL-RSRP to the first terminal device at the time.

25. The method according to claim 24, wherein determining the time includes: In response to the second terminal device being configured with a time period for transmitting the filtered SL-RSRP to the first terminal device, determining the time based on the time period such that the interval between the determined time and the time for transmitting a previously filtered SL-RSRP exceeds the time period, and the second terminal device has a sidelink grant at the determined time.

26. The method according to claim 24, wherein determining the time includes: In response to the second terminal device being configured with a time period and a time offset for transmitting the filtered SL-RSRP to the first terminal device, determining the time based on the time period and the time offset.

27. The method according to claim 24, wherein determining the time includes: Determining the time based on determining that the difference between the filtered SL-RSRP and a previously filtered SL-RSRP that has been transmitted to the first terminal device exceeds a threshold.

28. The method according to claim 24, further comprising: Before transmitting the filtered SL-RSRP to the first terminal device, transmitting an indication of the time to the first terminal device.

29. A first terminal device, comprising: A processor; And A memory coupled to the processor and storing instructions thereon, the instructions when run by the processor cause the first terminal device to perform the method according to any one of claims 1 to 17.

30. A second terminal device, comprising: A processor; And A memory coupled to the processor and storing instructions thereon, the instructions when run by the processor cause the second terminal device to perform the method according to any one of claims 18 to 28.

31. A computer-readable medium having instructions stored thereon, the instructions when run on at least one processor cause the at least one processor to perform the method according to any one of claims 1 to 17.

32. A computer-readable medium having instructions stored thereon, the instructions when run on at least one processor cause the at least one processor to perform the method according to any one of claims 18 to 28.

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