Sounding reference signal resource release

Abstract

Embodiments of the present disclosure relate to sounding reference signal (SRS) resource release. In one aspect, a terminal device is provided, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device to at least: send a request for an extension of a time alignment timer (TAT) to a first network device; and receiving, from the first network device, information indicating a time period during which the TAT is extended.

Description

Technical Field

[0001] Various example embodiments relate to the field of communications, and in particular, to devices, methods, apparatuses, and computer-readable storage media for sounding reference signal (SRS) resource release. Background Art

[0002] With the development of communication technology, low power high precision positioning (LPHAP) has been introduced to further enhance 3GPPRAN1 New Radio (NR) positioning. Enhancements to enable LPHAP have been defined, for example, extending the extended discontinuous reception (eDRX) cycle to more than 10.24s in the RRC_INACTIVE state to meet the battery life requirements of LPHAP. The enhancement also includes: for uplink (UL) positioning or downlink (DL) and UL positioning of UEs in the RRC_INACTIVE state, SRS configuration enhancements are specified based on the SRS positioning validity area to avoid frequent radio resource control (RRC) connections for SRS configuration or reconfiguration. However, the SRS resource configuration in the communication network can still be optimized and improved, especially for LPHAP. Summary of the invention

[0003] Generally speaking, example embodiments of the present disclosure provide a solution for SRS resource release.

[0004] In a first aspect, a first network device is provided. The first network device includes: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the first network device to at least: send information to a location management function (LMF), wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region.

[0005] In a second aspect, a location management function (LMF) is provided. The LMF includes: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, causes the LMF to at least: receive information from a first network device, wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; and send the information to one or more network devices.

[0006] In a third aspect, a second network device is provided. The second network device includes: at least one processor; and at least one memory, the at least one memory storing instructions, which, when executed by the at least one processor, causes the second network device to at least: receive information from a location management function (LMF), wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region, wherein the second network device is one of the one or more network devices; and based on the information, release at least one SRS resource.

[0007] In a fourth aspect, a terminal device is provided. The terminal device includes: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause a first network device to at least: send a request for an extension of a time alignment timer (TAT) to the first network device; and receive information from the first network device indicating a time period for which the TAT is extended.

[0008] In a fifth aspect, a method at a first network device is provided. The method comprises: sending information to a location management function (LMF), wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region.

[0009] In a sixth aspect, a method at a location management function (LMF) is provided. The method comprises: receiving information from a first network device, wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; and sending the information to the one or more network devices.

[0010] In a seventh aspect, a method at a second network device is provided. The method comprises: receiving information from a location management function (LMF), wherein the information is used for one or more network devices other than a first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region, wherein the second network device is one of the one or more network devices; and based on the information, releasing at least one SRS resource.

[0011] In an eighth aspect, a method at a terminal device is provided. The method comprises: sending a request for extension of a time alignment timer (TAT) to a first network device; and receiving information from the first network device indicating a time period for which the TAT is extended.

[0012] In a ninth aspect, a device of a first network device is provided. The device includes: a component for sending information to a location management function (LMF) at the first network device, wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region.

[0013] In a tenth aspect, a location management function (LMF) apparatus is provided. The apparatus comprises: a component for receiving information from a first network device at a location management function (LMF), wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; and a component for sending the information to the one or more network devices.

[0014] In an eleventh aspect, a device of a second network device is provided. The device includes: a component for receiving information from a location management function (LMF) at the second network device, wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region, wherein the second network device is one of the one or more network devices; and a component for releasing at least one SRS resource based on the information.

[0015] In a twelfth aspect, a terminal device apparatus is provided, comprising: a component for sending a request for extension of a time alignment timer (TAT) to a first network device at the terminal device; and a component for receiving information indicating a time period for which the TAT is extended from the first network device.

[0016] In a thirteenth aspect, a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium comprising program instructions for causing an apparatus to execute a method according to at least any one of the fifth to eighth aspects described above.

[0017] In a fourteenth aspect, a computer program comprising instructions is provided, which, when executed by an apparatus, causes the apparatus to at least: send information to a location management function (LMF), wherein the information is used by one or more network devices other than a first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity area.

[0018] In a fifteenth aspect, a computer program comprising instructions is provided, which, when executed by an apparatus, causes the apparatus to at least: receive information from a first network device, wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; and send the information to one or more network devices.

[0019] In a sixteenth aspect, a computer program comprising instructions is provided, which, when executed by an apparatus, causes the apparatus to at least: receive information from a location management function (LMF), wherein the information is used by one or more network devices other than a first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity area, wherein the second network device is one of the one or more network devices; and based on the information, release at least one SRS resource.

[0020] In a seventeenth aspect, there is provided a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to at least: send a request for an extension of a time alignment timer (TAT) to a first network device; and receive information from the first network device indicating a time period for which the TAT is extended.

[0021] In an eighteenth aspect, a first network device is provided. The first network device includes: a transmitting circuit system configured to send information to a location management function (LMF), wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region.

[0022] In a nineteenth aspect, a location management function is provided. The location management function includes: a receiving circuit system configured to receive information from a first network device, wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; and a sending circuit system configured to send the information to one or more network devices.

[0023] In a twentieth aspect, a second network device is provided. The second network device comprises: a receiving circuit system configured to receive information from a location management function (LMF), wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region, wherein the second network device is one of the one or more network devices; and a releasing circuit system configured to release at least one SRS resource based on the information.

[0024] In a twenty-first aspect, a terminal device is provided. The terminal device includes: a transmitting circuit system configured to send a request for extension of a time alignment timer (TAT) to a first network device; and a receiving circuit system configured to receive information indicating a time period for which the TAT is extended from the first network device.

[0025] It should be understood that the invention summary is not intended to determine the key or essential features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0027] Figure 1 illustrates an example network environment in which example embodiments of the present disclosure may be implemented;

[0028] Figure 2 illustrates an example signaling diagram illustrating an example process according to some embodiments of the present disclosure;

[0029] Figure 3 illustrates an example process of the proposed solution according to some embodiments of the present disclosure;

[0030] Figure 4 illustrates another example process of the proposed solution according to some embodiments of the present disclosure;

[0031] Figure 5 A flowchart of a method implemented at a first network device according to some other embodiments of the present disclosure is illustrated;

[0032] Figure 6 illustrates a flow chart of a method implemented at a LMF according to some other embodiments of the present disclosure;

[0033] Figure 7 A flowchart of a method implemented at a second network device according to some embodiments of the present disclosure is illustrated;

[0034] Figure 8 A flowchart of a method implemented at a terminal device according to some other embodiments of the present disclosure is illustrated;

[0035] Fig. 9 illustrates a simplified block diagram of an apparatus suitable for implementing embodiments of the present disclosure; and

[0036] Fig.10 A block diagram of an example computer-readable medium is illustrated in accordance with some embodiments of the present disclosure.

[0037] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0038] The principle of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described only for the purpose of illustration and to help those skilled in the art understand and implement the present disclosure, and do not represent any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in various other ways except for the way described below.

[0039] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0040] In this disclosure, references to "one embodiment," "an embodiment," and "an example embodiment" indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include the particular feature, structure, or characteristic. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, those skilled in the art believe that it is within the knowledge of those skilled in the art to affect such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0041] It should be understood that although the terms "first" and "second" etc. can be used to describe various elements in this article, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the exemplary embodiment, the first element can be referred to as the second element, and similarly, the second element can be referred to as the first element. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0042] The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments. As used herein, unless the context clearly states otherwise, the singular forms "a", "an" and "the" also include plural forms. It is further understood that the terms "comprises", "comprising", "has", "having", "includes" and / or "including" when used herein specify the presence of the features, elements and / or components, but do not exclude the presence or addition of one or more other features, elements, components and / or their combinations. As used herein, "at least one of the following: <list of two or more elements>" and "at least one of the list of <two or more elements>" and similar wording (wherein the list of two or more elements is connected by "and" or "or") refer to at least any one of these elements, or at least any two or more of these elements, or at least all of these elements.

[0043] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0044] (a) a pure hardware circuit implementation (such as an implementation using only analog and / or digital circuitry), and

[0045] (b) a combination of hardware circuitry and software such as (where applicable):

[0046] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0047] (ii) any portion of hardware processor(s) (including digital signal processor(s)), software and memory(s) with software that work together to enable a device (such as a mobile phone or server) to perform various functions, and

[0048] (c) Hardware circuits and / or processor(s), such as microprocessor(s), or portions of microprocessor(s), that require software (e.g., firmware) to operate, but in which the software may not be present when not required for operation.

[0049] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors), or a portion of a hardware circuit or processor and its accompanying software and / or firmware. For example, if applicable to a particular claim element, the term circuitry also covers a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0050] As used herein, the term "communication network" refers to a network that complies with any suitable communication standard, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. In addition, the communication between the terminal equipment and the network equipment in the communication network can be performed according to any suitable generation of communication protocol, including but not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocol, and / or any other protocol currently known or to be developed in the future. The embodiments of the present disclosure can be applied to various communication systems. In view of the rapid development of communication, there will certainly be future types of communication technologies and systems that can embody the present disclosure. The scope of the present disclosure should not be limited to the above-mentioned systems.

[0051] As used herein, the term "network device" refers to a node in a communication network, via which a terminal device accesses the network and receives services from the network. Depending on the terminology and technology applied, a network device may refer to a base station (BS) or an access point (AP), such as a NodeB (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR NB (also known as a gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a repeater, a low-power node (such as a femto node, a pico node), etc.

[0052] The term "terminal device" refers to any terminal device capable of wireless communication. As an example and not limitation, the terminal device may also be referred to as a communication device, a user equipment (UE), a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT). The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet computer, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a game terminal device, a music storage and playback device, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop embedded device (LEE), a laptop mounted device (LME), a USB dongle, a smart device, a wireless customer premises equipment (CPE), an Internet of Things (IoT) device, a watch or other wearable device, a head mounted display (HMD), a vehicle, a drone, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots and / or other wireless devices operating in the context of an industrial and / or automated processing chain), consumer electronic devices, commercially operated equipment, and / or industrial wireless networks, etc. In the following description, the terms “terminal device”, “communication device”, “terminal”, “end device”, “station”, “STA”, “user equipment” and “UE” may be used interchangeably.

[0053] With the development of communication technology, LPHAP is introduced to further enhance 3GPP RAN1NR positioning. Enhancements for enabling LPHAP have been defined, for example, in the RRC_INACTIVE state, the eDRX cycle exceeds 10.24s to meet the battery life requirements of LPHAP. The enhancement also includes: for uplink (UL) positioning or downlink (DL) and UL positioning of UEs in the RRC_INACTIVE state, SRS configuration enhancement is specified based on the SRS positioning validity area to avoid frequent radio resource control (RRC) connections for SRS configuration or reconfiguration. SRS for positioning configuration in multiple cells, pre-configuration of one or more SRS for positioning configuration, and SRS for (multiple) positioning activation / request processes can be specified. In addition, solutions for DL ​​positioning reference signal (PRS) measurements for UEs in the RRC_IDLE state and measurement reports in the RRC_CONNECTED state, solutions for alignment between eDRX and PRS configurations, corresponding new core requirements, and identification and specification of impacts on RAN4 specifications (including RRM measurements and processes) are also specified.

[0054] At the RAN2#121-bis meeting, it was agreed that further discussion was needed on how to release SRS.

[0055]

[0056] In the RAN2#122 meeting, inactivePosSRS-ValidityArea-TAT was introduced.

[0057]

[0058] It is still unclear how to release the SRS configuration at the cells in the validity area when the area-specific time alignment timer (TA timer TAT) expires. When the area-specific TAT expires, both the UE and the serving cell will release the SRS configuration because they both know the information of the TAT. However, other cells in the validity area will not know when the area-specific TAT expires, so these cells will retain the SRS configuration, which will result in a waste of resources.

[0059] According to some embodiments of the present invention, a solution for SRS resource release is provided. In one aspect of the solution, a first network device sends information to a location management function (LMF), and the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires. The cells of the first network device and one or more network devices are in the SRS validity area. In this way, the first network device can indicate this information to other network devices whose cells are in the SRS validity area to assist in the release of SRS resources. Therefore, resource efficiency is improved by avoiding unnecessary resource reservations at all cells in the SRS validity area. Reference will be made below to Figures 1 to 10 The principles and implementations of the embodiments of the present disclosure are described in detail.

[0060] Figure 1 An example network environment 100 is illustrated in which an example embodiment of the present disclosure may be implemented. The environment 100 (which may be part of a communication network) includes a terminal device, a network device. Figure 1As shown in FIG. 1 , a network environment 100 may include a terminal device 110 (hereinafter may also be referred to as UE 110), a first network device 120, an LMF 130, and a second network device 140. The first network device 120 may manage a cell 102, and the second network device 140 may manage a cell 104. The first network device 120 and the terminal device 110 may communicate with each other within the coverage of the cell 102. The first network device 120 may communicate with the second network device 140 via the LMF 130. The first network device 120 and the second network device may be in a validity region of a configuration of an SRS resource. A link from the terminal device 110 to the first network device 120 is referred to as an uplink (UL), and a link from the first network device 120 to the terminal device 110 is referred to as a downlink (DL).

[0061] It should be understood that the number of terminal devices or network devices is for illustrative purposes only and does not represent any limitation. System 100 may include any suitable number of devices suitable for implementing the embodiments of the present disclosure. Although not shown, it should be understood that one or more terminal devices or second network devices may be located in environment 100.

[0062] The communication in the communication system 100 can be implemented according to any appropriate communication protocol, including but not limited to cellular communication protocols of the first generation (1G), second generation (2G), third generation (3G), fourth generation (4G) and fifth generation (5G), wireless local area network communication protocols such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocol currently known or to be developed in the future. In addition, the communication can utilize any appropriate wireless communication technology, including but not limited to: code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplex (FDD), time division duplex (TDD), multiple input multiple output (MIMO), orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread spectrum OFDM (DFT-s-OFDM) and / or any other technology currently known or to be developed in the future.

[0063] Figure 2 A signaling diagram of an example process 200 according to some embodiments of the present disclosure is illustrated. For the purpose of discussion, reference will be made to Figure 1 The process 200 is described. The process 200 may involve the terminal device 110, the first network device 120, the LMF 130, and the second network device 140. It should be understood that although Figure 1 The process 200 is described in the communication environment 100 of FIG. 1 , but the process can also be applied to other communication scenarios with similar problems.

[0064] In process 200, the first network device 120 sends 205 information 210 to the LMF 130. The information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of the terminal device 110 when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires. It should be understood that the TAT is a region-specific TAT of the SRS validity area. The first network device 120 and the cells of the one or more network devices are in the SRS validity area. The terminal device 110 may be in an inactive state, and before the terminal device 110 enters the inactive state, the first network device 120 configures the SRS resources for the terminal device 110. For example, when the region-specific TAT expires, the last serving cell (i.e., the serving cell managed by the first network device 120) will trigger all cells in the validity area (i.e., the cells managed by one or more network devices) to release the SRS resources.

[0065] In some embodiments, the information 210 may include: a first indication to release at least one SRS resource, and the first indication is sent when the TAT expires. In other words, the first network device 120 may explicitly send the indication. For example, when the area-specific TAT expires, the last serving gNB (corresponding to the first network device 120) will instruct all cells in the validity area to release the SRS resources.

[0066] Additionally or alternatively, if the expired TAT is restarted, the first network device 120 may send a third indication to the LMF 130 to reserve at least one SRS resource. For example, when the expired TAT is restarted, the last serving gNB will indicate that the cells in the validity area reserve the previously released SRS resources again. In addition, after the expired TAT is restarted, the first network device 120 may reuse at least one released SRS resource that is valid for multiple cells of the terminal device. In addition, after the expired TAT is restarted, the terminal device 110 may reuse at least one released SRS resource that is valid for multiple cells of the terminal device 110.

[0067] In addition, in the case where the expired TAT is restarted, LMF 130 can receive a third indication from the first network device, and then LMF 130 can send the third indication to one or more network devices. In addition, in the case where the expired TAT is restarted, the second network device 140 can receive a third indication of reserving at least one SRS resource from the LMF, and then the second network device 140 can reserve at least one SRS resource based on the third indication.

[0068] In one example, when the expired TAT is restarted, the previously released SRS resource configuration will be restored to "on". When the expired TAT is reset or restarted, the terminal device 110 can use the previously released SRS resources again. Therefore, the last serving cell will trigger all cells in the validity area to retain the previously released SRS resources again.

[0069] In some embodiments, the information 210 may include: information of the TAT, a second indication that the terminal device 110 moves out of the SRS validity area, or any combination of two of the above items. Additionally or alternatively, the information of the TAT may include: a time point when the TAT is started, a time point when the TAT is restarted, an extension of the TAT, a time point when the TAT expires, or any combination of two or more of the above items.

[0070] On the other side of the communication, LMF 130 receives 215 information 210 from first network device 120. LMF 130 sends 220 information 210 to second network device 140.

[0071] Continue to refer Figure 2 , the second network device 140 receives 230 information 210 from the LMF 130. Based on the information, the second network device 140 releases 265 at least one SRS resource.

[0072] In one example, the TAT may be synchronized at each cell in the validity area, and the cells in the validity area may autonomously release SRS resources. When the TAT is started or restarted, the serving cell (corresponding to the first network device 120) may instruct the cells in the validity area to start or restart the TAT. When the SRS resources are configured, the validity period value of the TAT may also be indicated to the cells in the validity area. Therefore, the cells in the validity area may know when the TAT expires. When the TAT expires, the cells in the validity area may autonomously release the SRS resources.

[0073] In some embodiments, the second network device 140 may release at least one SRS resource upon receiving the first indication. In some other embodiments, the second network device 140 may release at least one SRS resource upon expiration of the TAT. In some other embodiments, the second network device 140 may release at least one SRS resource based on determining that the terminal device moves out of the SRS validity area.

[0074] Additionally or alternatively, if the TAT information includes a time point of TAT restart, the second network device 140 may reserve at least one SRS resource. Furthermore, if the TAT information includes an extension of TAT, the second network device 140 may extend a time period of at least one SRS resource.

[0075] Continue to refer Figure 2 , the terminal device 110 sends 235 a request for an extension of the TAT 240 to the first network device 120. After receiving 245 the request for an extension of the TAT 240, the first network device 120 sends 250 information indicating the time period for which the TAT is extended to the terminal device 110. Accordingly, the terminal device 110 receives 260 information indicating the time period 255 from the first network device 120.

[0076] In some embodiments, before the TAT expires, the first network device 120 may receive at least one request for extension of the TAT from at least one terminal device or the LMF 130. For example, the terminal device is allowed to issue a TAT extension request before the region-specific TAT expires.

[0077] Additionally or alternatively, if the number of at least one terminal device is above a threshold, the first network device 120 may determine to extend the TAT by a time period. The first network device 120 may then extend the validity period of the TAT based on the time period.

[0078] In one example, a single report is sufficient for the extension. The report may include a request for an extension of the TAT. After issuing the request, the terminal device shall reset the region-specific TAT for the extension. In addition, the first network device 120 will automatically grant the reporting terminal device an extension configured for the validity region. The decision of the serving cell will be indicated to the neighboring cells (i.e., all cells in the validity region except the serving cell).

[0079] In another example, the extension requires multiple reports.If a certain number of terminal devices issue TAT extension requests before the area-specific timer expires (eg, the number of requests is greater than a threshold), the triggering of the SRS configuration release will be delayed for a certain period of time.

[0080] In addition, when the TAT expires, the first network device 120 may receive a request for an extension of the TAT from at least one of the LMF 130 or at least one terminal device. In some embodiments, when the TAT expires, the LMF 130 may send a request for an extension of the TAT to the first network device.

[0081] For example, when TAT expires, time synchronization may still be valid. For example, according to a TA verification standard based on reference signal received power (RSRP), it may still be valid. In order to avoid unnecessary resource reconfiguration, the terminal device may issue a "TAT extension" request. Alternatively, LMF 130 may issue a "TAT extension" request to the first network device 120.

[0082] In some embodiments, the terminal device 110 may determine the time period for which the TAT is extended. In addition, the terminal device 110 may send information indicating the time period for which the TAT is extended to the first network device 120. In addition, the terminal device 110 may extend the validity period of the TAT based on the time period.

[0083] Additionally or alternatively, the first network device 120 may receive information indicating a time period for which the TAT is extended from at least one terminal device. The first network device 120 may then extend the validity period of the TAT based on the time period.

[0084] Additionally or alternatively, the first network device 120 may send information indicating the time period to at least one terminal device. In some embodiments, the first network device 120 may send a fourth indication that the TAT is extended to the LMF 130. In other words, the time period may be determined by at least one terminal device or the first network device 120. The first network device 120 may indicate the time period to at least one terminal device and one or more network devices for autonomous extension of the region-specific TAT.

[0085] In addition, LMF 130 may receive a fourth indication that the TAT is extended from first network device 120. Then, LMF 130 may send the fourth indication to one or more network devices. In addition, the fourth indication may include information indicating the time period.

[0086] In some embodiments, second network device 140 may receive information indicating a time period for which TAT is extended from LMF 130. Second network device 140 may then extend the validity period of TAT based on the time period, and run TAT based on the validity period. In one example, the time period may be proportional to the number of at least one request. In another example, the time period may be an integer multiple of the duration of TAT. For example, second network device 140 may run TAT upon receiving the time period from LMF 130.

[0087] For example, the trigger delay period may be proportional to the number of requests. Alternatively, the delay period may be given by an integer multiple of the region-specific TAT period. The first network device 120 may indicate the integer value to the terminal device and one or more network devices for autonomous extension of the region-specific TAT.

[0088] In some embodiments, if the TAT expires, the first network device 120 may release the at least one SRS resource. Additionally or alternatively, if the terminal device 110 moves out of the SRS validity area, the first network device 120 may release the at least one SRS resource.

[0089] In some embodiments, if the TAT expires, the first network device 120 may release the configuration of at least one SRS resource configured for the SRS validity region. Additionally or alternatively, if the terminal device 110 moves out of the SRS validity region, the first network device 120 may release the configuration of at least one SRS resource configured for the SRS validity region. It should be understood that the configuration of at least one SRS resource may be a region-specific SRS configuration.

[0090] In some embodiments, if the TAT expires, the second network device 140 may release the configuration of at least one SRS resource configured for the SRS validity region. Additionally or alternatively, if the terminal device 110 moves out of the SRS validity region, the second network device 140 may release the configuration of at least one SRS resource configured for the SRS validity region.

[0091] In some embodiments, the terminal device 110 may release the at least one SRS resource if the TAT expires. Additionally or alternatively, the terminal device 110 may release the at least one SRS resource if the terminal device 110 moves out of the SRS validity region.

[0092] In some embodiments, if the TAT expires, the terminal device 110 may release the configuration of at least one SRS resource configured for the SRS validity region. Additionally or alternatively, if the terminal device 110 moves out of the SRS validity region, the terminal device 110 may release the configuration of at least one SRS resource configured for the SRS validity region.

[0093] Typically, when the area-specific TAT expires, all cells in the validity area are triggered to release SRS resources. The (final) serving cell can indicate TAT information (i.e., TAT expiration, TAT start / restart, and TAT validity period) to other cells in the validity area to assist in SRS resource release. In this way, SRS resource release and indication are associated with TAT, and when TAT expires, SRS resource release is efficiently triggered at the cells in the validity area. This helps to improve resource efficiency by avoiding unnecessary resource reservations at all cells in the validity area. Thereby, waste of resources is reduced.

[0094] Figure 3 300 may involve a UE 301, a last serving cell 302, a LMF 303, and cells in a validity area 304. It should be understood that the process 300 may be viewed as Figure 2 A more specific example of process 200 in FIG. Figure 3 The UE 301 in may be Figure 1 or Figure 2 An example of a terminal device 110 in FIG. Figure 3 The last serving cell 302 in may correspond to Figure 1 or Figure 2 The first network device 120 in Figure 3 The LMF 303 can be Figure 1 or Figure 2 An example of LMF 130 in Figure 3 The cells in the validity area 304 in may correspond to Figure 1 or Figure 2 The second network device 140 in.

[0095] like Figure 3 As shown in , at 310, UE 301 receives a TA command from the last serving cell 302, and then TAT starts. Before receiving the TA command, UE 301 may send a request to start TAT. The last serving cell refers to the cell managed by the base station that sets the SRS resource configuration for UE 301 before UE 301 enters the inactive state.

[0096] At 315, before the TAT expires, the UE 301 requests a TAT extension from the last serving cell 302. At 320, the last serving cell 302 provides the extension time to the UE 301, and the TAT is extended.

[0097] At 325, the expiration of the TAT triggers the release of SRS resources. At 330, the last serving cell 302 is triggered to release the SRS resources. At 335, the last serving cell 302 sends an SRS resource release indication to the LMF 303. At 340, the LMF 303 sends an SRS resource release indication to the cells in the validity area 304. The validity area refers to the validity area of ​​the SRS, and the last serving cell 302 and the cells in the validity area 304 in the same validity area of ​​the SRS. At 345, the cells in the validity area 304 release the SRS resources.

[0098] At 350, UE 301 receives a TA command from the last serving cell 302, and the expired TAT is restarted. UE 301 reuses the previously released SRS resources. Before receiving the TA command, UE 301 may send a request to restart the TAT via a random access channel (RACH). At 355, the last serving cell 302 sends an SRS resource retention indication to LMF 303. At 360, LMF 303 sends an SRS resource retention indication to the cells in the validity region 304. At 365, the cells in the validity region 304 retain the previous SRS resources.

[0099] Figure 3 An example of SRS resource release and reservation by explicit network indication is shown. In process 300, cells in the validity area do not have information about TAT. SRS resource release and reservation at cells in the validity area may be indicated by the last serving cell via LMF.

[0100] Figure 4 400 may involve a UE 401, a last serving cell 402, a LMF 403, and cells in a validity area 404. It should be understood that the process 400 may be viewed as Figure 2 A more specific example of process 200 in FIG. Figure 4 The UE 401 in may be Figure 1 or Figure 2 An example of a terminal device 110 in FIG. Figure 4 The last serving cell 402 in may correspond to Figure 1 or Figure 2 The first network device 120 in Figure 4 The LMF 403 can be Figure 2 or Figure 1 An example of LMF 130 in Figure 4 The cells in the validity area 404 in may correspond to Figure 1 or Figure 2 The second network device 140 in.

[0101] like Figure 4 As shown in , at 410, UE 401 receives a TA command from the last serving cell 402, and then TAT starts. Before receiving the TA command, UE 401 may send a request to start TAT. The last serving cell refers to a cell managed by a base station that sets SRS resource configuration for UE 401 before UE 401 enters an inactive state.

[0102] At 415, the last serving cell 402 indicates TAT ​​start to the LMF 403. At 420, the LMF 403 indicates TAT ​​start to the cells in the validity area 404. At 425, before the TAT expires, the UE 401 requests TAT ​​extension from the last serving cell 402. At 430, the last serving cell 402 provides the extension time to the UE 401, and the TAT is extended. At 435, the last serving cell 402 indicates the extension of TAT to the LMF 403. At 440, the LMF 403 indicates the extension of TAT to the cells in the validity area 404. At 445, the expiration of TAT triggers SRS resource release. At 450, the last serving cell 402 is triggered to release SRS resources. At 455, the cells in the validity area 404 are triggered to release SRS resources.

[0103] At 460, UE 401 receives a TA command from the last serving cell 402, and then the expired TAT is restarted. UE 401 reuses the previously released SRS resources. Before receiving the TA command, UE 401 may send a request to restart TAT via a random access channel (RACH). At 465, the last serving cell 402 indicates the expired TAT restart to LMF 403. At 470, LMF 403 indicates the expired TAT restart to the cells in the validity region 404. At 475, the cells in the validity region 404 retain the previous SRS resources.

[0104] Figure 4 An example of SRS resource release and reservation by TAT synchronization between cells in the validity area is shown. In process 400, the cells in the validity area have known information about TAT, such as when TAT is started, restarted, TAT extended, and TAT expires. Therefore, the cells in the validity area can autonomously release or reserve SRS resources based on TAT.

[0105] It should be understood that in processes 300 and 400, TAT extension is performed before TAT expires. Additionally or alternatively, TAT extension may also be performed after TAT expires. For example, it may still be valid according to the RSRP-based TA verification criteria. In order to avoid SRS resource reconfiguration, the UE or LMF may issue a "TAT extension" request. It is assumed that the validity period of TAT is pre-configured before the last serving cell issues a TA command.

[0106] Figure 5 FIG. 5 is a flow chart showing an example method 500 implemented at a first network device according to some embodiments of the present disclosure. For discussion purposes, reference will be made to Figure 1 , method 500 is described from the perspective of the first network device 120.

[0107] At box 510, the first network device 120 sends information to a location management function (LMF), wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of the terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity area.

[0108] In some embodiments, the information may include: a first indication of releasing at least one SRS resource, and wherein the first indication is sent based on determining that the TAT expires. In some embodiments, the information may include: information of the TAT, a second indication that the terminal device moves out of the SRS validity area, or any combination of two of the above items.

[0109] In some embodiments, the information of the TAT may include a time point when the TAT is started, a time point when the TAT is restarted, an extension of the TAT, a time point when the TAT expires, or any combination of two or more of the above items.

[0110] In some embodiments, the first network device 120 may also send a third indication to the LMF to reserve at least one SRS resource based on determining that the expired TAT is restarted. In some embodiments, the first network device 120 may also reuse at least one released SRS resource valid for multiple cells of the terminal device after the expired TAT is restarted.

[0111] In some embodiments, the first network device 120 may also receive at least one request for extension of the TAT from at least one terminal device or the LMF before the TAT expires.

[0112] In some embodiments, the first network device 120 may also determine to extend the TAT for a time period based on determining that the number of at least one terminal device is higher than a threshold, and extend the validity period of the TAT based on the time period.

[0113] In some embodiments, the first network device 120 may also receive a request for extension of the TAT from at least one terminal device or the LMF when the TAT expires.

[0114] In some embodiments, the first network device may also receive information indicating a time period for which the TAT is extended from at least one terminal device, and extend the validity period of the TAT based on the time period.

[0115] In some embodiments, the time period may be proportional to the number of at least one request, or the time period may be an integer multiple of the duration of the TAT.

[0116] In some embodiments, the first network device 120 may also send information indicating the time period to at least one terminal device.

[0117] In some embodiments, the first network device 120 may also send a fourth indication to the LMF that the TAT is extended. In some embodiments, the fourth indication may include: information indicating the time period. In some embodiments, the first network device may also release at least one SRS resource based on determining at least one of the following items: TAT expiration; or the terminal device moves out of the SRS validity area.

[0118] In some embodiments, the first network device 120 may also release the configuration of at least one SRS resource configured for the SRS validity region based on determining at least one of the following items: TAT expiration; or the terminal device moves out of the SRS validity region.

[0119] Figure 6 FIG. 6 is a flow chart showing an example method 600 implemented at a LMF according to some embodiments of the present disclosure. For discussion purposes, reference will be made to Figure 1 , method 600 is described from the perspective of LMF 130.

[0120] At block 610, LMF 130 receives information from a first network device, wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region. At block 620, LMF 130 sends the information to the one or more network devices.

[0121] In some embodiments, the information may include: a first indication of releasing at least one SRS resource, and wherein the first indication is sent based on determining that the TAT expires. In some embodiments, the information may include information of the TAT, a second indication that the terminal device moves out of the SRS validity area, or any combination of two of the above items.

[0122] In some embodiments, the information of the TAT may include: a time point when the TAT is started, a time point when the TAT is restarted, an extension of the TAT, a time point when the TAT expires, or any combination of two or more of the above items.

[0123] In some embodiments, the LMF may also receive a third indication to reserve at least one SRS resource from the first network device when the expired TAT is restarted, and send the third indication to one or more network devices.

[0124] In some embodiments, the LMF may also send a request for extending the TAT to the first network device when the TAT expires. In some embodiments, the LMF may also receive a fourth indication that the TAT is extended from the first network device, and send the fourth indication to one or more network devices.

[0125] In some embodiments, the fourth indication may include information indicating that the time period of the TAT is extended. In some embodiments, the time period may be proportional to the number of at least one request for extension of the TAT sent by at least one terminal device, or the time period may be an integer multiple of the duration of the TAT.

[0126] Figure 7 FIG. 7 is a flow chart showing an example method 700 implemented at a second network device according to some embodiments of the present disclosure. For discussion purposes, reference will be made to Figure 1 , method 700 is described from the perspective of the second network device 140.

[0127] At block 710, the second network device 140 receives information from a location management function (LMF), wherein the information is used for one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region, wherein the second network device is one of the one or more network devices. At block 720, the second network device 140 releases at least one SRS resource based on the information.

[0128] In some embodiments, the information may include: a first indication of releasing at least one SRS resource, and wherein the first indication is sent based on determining that the TAT expires. In some embodiments, the information may include: information of the TAT, a second indication that the terminal device moves out of the SRS validity area, or any combination of two of the above items.

[0129] In some embodiments, the information of the TAT may include: a time point when the TAT is started, a time point when the TAT is restarted, an extension of the TAT, a time point when the TAT expires, or any combination of two or more of the above items.

[0130] In some embodiments, in order to release at least one SRS resource based on the information, the second network device may release at least one SRS resource upon receiving a first indication; release at least one SRS resource based on determining that the terminal device has moved out of the SRS validity area; or release at least one SRS resource when the TAT expires.

[0131] In some embodiments, the second network device may also receive a third indication from the LMF to reserve at least one SRS resource when the expired TAT is restarted; and reserve at least one SRS resource based on the third indication.

[0132] In some embodiments, the second network device may also reserve at least one SRS resource based on determining that the information about TAT includes a time point for restarting TAT; or extend a time period of at least one SRS resource based on determining that the information about TAT includes an extension of TAT.

[0133] In some embodiments, the second network device may also receive information indicating a time period for which the TAT is extended from the LMF, and extend the validity period of the TAT based on the time period.

[0134] In some embodiments, the time period may be proportional to the number of at least one request for an extension of the TAT sent by at least one terminal device, or the time period may be an integer multiple of the duration of the TAT.

[0135] In some embodiments, the second network device may also release the configuration of at least one SRS resource configured for the SRS validity region based on determining at least one of the following items: TAT expiration; or the terminal device moves out of the SRS validity region.

[0136] Figure 8 FIG. 8 is a flowchart of an example method 800 implemented at a terminal device according to some embodiments of the present disclosure. For the purpose of discussion, reference will be made to Figure 1 , method 800 is described from the perspective of terminal device 110.

[0137] At block 810, the terminal device 110 sends a request for an extension of a time alignment timer (TAT) to the first network device. At block 820, the terminal device 110 receives information from the first network device indicating a time period for which the TAT is extended.

[0138] In some embodiments, the terminal device 110 may also determine a time period for which the TAT is extended. In some embodiments, the terminal device may also extend the validity period of the TAT based on the time period. In some embodiments, the terminal device may also reuse at least one released SRS resource valid for multiple cells of the terminal device after the expired TAT is restarted. In some embodiments, the terminal device may also release at least one SRS resource based on determining at least one of the following items: TAT expiration; or the terminal device moves out of the SRS validity area.

[0139] In some embodiments, the terminal device 110 may also release the configuration of at least one SRS resource configured for the SRS validity region based on determining at least one of the following items: TAT expiration; or the terminal device moves out of the SRS validity region.

[0140] In some embodiments, a device (e.g., first network device 120) capable of performing any of the methods 500 is provided. The device may include components for performing the corresponding steps of the method 500. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0141] In some embodiments, the apparatus includes a component for sending information to a location management function (LMF), wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity area.

[0142] In some embodiments, the information may include: a first indication of releasing at least one SRS resource, and wherein the first indication is sent based on determining that the TAT expires. In some embodiments, the information may include: information of the TAT, a second indication that the terminal device moves out of the SRS validity area, or any combination of two of the above items.

[0143] In some embodiments, the information of the TAT may include: a time point when the TAT is started, a time point when the TAT is restarted, an extension of the TAT, a time point when the TAT expires, or any combination of two or more of the above items.

[0144] In some embodiments, the apparatus may further include: a component for sending a third indication to the LMF to reserve at least one SRS resource based on determining that the due TAT is restarted.

[0145] In some embodiments, the apparatus may further include: a component for reusing at least one released SRS resource valid for multiple cells of the terminal device after the expired TAT is restarted. In some embodiments, the apparatus may further include: a component for receiving at least one request for an extension of the TAT from at least one terminal device or LMF before the TAT expires.

[0146] In some embodiments, the apparatus may further include: a component for determining to extend the TAT for a time period based on determining that the number of at least one terminal device is above a threshold; and a component for extending the validity period of the TAT based on the time period.

[0147] In some embodiments, the apparatus may further include: a component for receiving a request for extension of the TAT from at least one terminal device or LMF when the TAT expires. In some embodiments, the apparatus may further include: a component for receiving information indicating a time period for which the TAT is extended from at least one terminal device; and a component for extending the validity period of the TAT based on the time period.

[0148] In some embodiments, the time period may be proportional to the number of at least one request, or the time period may be an integer multiple of the duration of the TAT.

[0149] In some embodiments, the apparatus may further include: a component for sending information indicating the time period to at least one terminal device. In some embodiments, the apparatus may further include: a component for sending a fourth indication that the TAT is extended to the LMF.

[0150] In some embodiments, the fourth indication may include: information indicating the time period. In some embodiments, the apparatus may further include: a component for releasing at least one SRS resource based on determining at least one of the following: TAT expiration; or the terminal device moving out of the SRS validity area.

[0151] In some embodiments, the apparatus may further include: a component for releasing the configuration of at least one SRS resource configured for the SRS validity region based on determining at least one of the following: expiration of the TAT; or movement of the terminal device out of the SRS validity region.

[0152] In some embodiments, the apparatus further comprises: means for performing other steps in some embodiments of method 500. In some embodiments, the means comprises at least one processor and at least one memory comprising computer program code, the at least one memory and the computer program code being configured to cause execution of the apparatus together with the at least one processor.

[0153] In some embodiments, a device (e.g., LMF 130) capable of performing any of the methods 600 is provided. The device may include components for performing the corresponding steps of the method 600. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0154] In some embodiments, the apparatus includes: a component for receiving information from a first network device, wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; and a component for sending the information to one or more network devices.

[0155] In some embodiments, the information may include: a first indication of releasing at least one SRS resource, and wherein the first indication is sent based on determining that the TAT expires. In some embodiments, the information may include: information of the TAT, a second indication that the terminal device moves out of the SRS validity area, or any combination of two of the above items.

[0156] In some embodiments, the information of the TAT may include: a time point when the TAT is started, a time point when the TAT is restarted, an extension of the TAT, a time point when the TAT expires, or any combination of two or more of the above items.

[0157] In some embodiments, the apparatus may further include: means for receiving a third indication from the first network device to reserve at least one SRS resource when the expired TAT is restarted; and means for sending the third indication to one or more network devices.

[0158] In some embodiments, the apparatus may further include: a component for sending a request for an extension of the TAT to the first network device when the TAT expires. In some embodiments, the apparatus may further include: a component for receiving a fourth indication that the TAT is extended from the first network device; and a component for sending the fourth indication to one or more network devices.

[0159] In some embodiments, the fourth indication may include information indicating that the time period of the TAT is extended. In some embodiments, the time period may be proportional to the number of at least one request for extension of the TAT sent by at least one terminal device, or the time period may be an integer multiple of the duration of the TAT.

[0160] In some embodiments, the apparatus further comprises: means for performing other steps in some embodiments of method 600. In some embodiments, the means comprises at least one processor and at least one memory comprising computer program code, the at least one memory and the computer program code being configured to cause execution of the apparatus together with the at least one processor.

[0161] In some embodiments, a device (e.g., second network device 140) capable of performing any of method 700 is provided. The device may include components for performing the corresponding steps of method 700. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0162] In some embodiments, the apparatus includes: a component for receiving information from a location management function (LMF), wherein the information is used by one or more network devices other than a first network device to release at least one SRS resource valid for multiple cells of a sounding reference signal (SRS) of a terminal device when a time alignment timer (TAT) configured for a validity area of ​​the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity area, wherein the second network device is one of the one or more network devices; and a component for releasing at least one SRS resource based on the information.

[0163] In some embodiments, the information may include: a first indication of releasing at least one SRS resource, and wherein the first indication is sent based on determining that the TAT expires. In some embodiments, the information may include: information of the TAT, a second indication that the terminal device moves out of the SRS validity area, or any combination of two of the above items.

[0164] In some embodiments, the information of the TAT may include: a time point when the TAT is started, a time point when the TAT is restarted, an extension of the TAT, a time point when the TAT expires, or any combination of two or more of the above items.

[0165] In some embodiments, the component for releasing at least one SRS resource based on the information may include: a component for releasing at least one SRS resource when a first indication is received; a component for releasing at least one SRS resource based on determining that the terminal device has moved out of the SRS validity area; or a component for releasing at least one SRS resource when the TAT expires.

[0166] In some embodiments, the apparatus may further include: a component for receiving a third indication from the LMF to reserve at least one SRS resource when the expired TAT is restarted; and a component for reserving at least one SRS resource based on the third indication.

[0167] In some embodiments, the apparatus may further include: a component for reserving at least one SRS resource based on determining that the information of TAT includes a time point at which TAT is restarted; or a component for extending a time period of at least one SRS resource based on determining that the information of TAT includes an extension of TAT.

[0168] In some embodiments, the apparatus may further include: means for receiving information indicating a time period for which the TAT is extended from the LMF; and means for extending the validity period of the TAT based on the time period.

[0169] In some embodiments, the time period may be proportional to the number of at least one request for an extension of the TAT sent by at least one terminal device, or the time period may be an integer multiple of the duration of the TAT.

[0170] In some embodiments, the apparatus may further include: a component for releasing the configuration of at least one SRS resource configured for the SRS validity region based on determining at least one of the following: expiration of the TAT; or movement of the terminal device out of the SRS validity region.

[0171] In some embodiments, the apparatus further comprises: means for performing other steps in some embodiments of method 700. In some embodiments, the means comprises at least one processor and at least one memory comprising computer program code, the at least one memory and the computer program code being configured to cause execution of the apparatus together with the at least one processor.

[0172] In some embodiments, a device (e.g., terminal device 110) capable of performing any of the methods 800 is provided. The device may include components for performing the corresponding steps of the method 800. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0173] In some embodiments, the apparatus includes means for sending a request for an extension of a time alignment timer (TAT) to the first network device; and means for receiving information from the first network device indicating a time period for which the TAT is extended.

[0174] In some embodiments, the apparatus may further include: a component for determining a time period for which the TAT is extended. In some embodiments, the apparatus may further include: a component for extending the validity period of the TAT based on the time period.

[0175] In some embodiments, the apparatus may further include: a component for reusing at least one released SRS resource valid for multiple cells of the terminal device after the expired TAT is restarted. In some embodiments, the apparatus may further include: a component for releasing at least one SRS resource based on determining at least one of the following items: TAT expiration; or the terminal device moves out of the SRS validity area.

[0176] In some embodiments, the apparatus may further include: a component for releasing the configuration of at least one SRS resource configured for the SRS validity region based on determining at least one of the following: expiration of the TAT; or movement of the terminal device out of the SRS validity region.

[0177] In some embodiments, the apparatus further comprises: means for performing other steps in some embodiments of method 800. In some embodiments, the means comprises at least one processor and at least one memory comprising computer program code, the at least one memory and the computer program code being configured to cause execution of the apparatus together with the at least one processor.

[0178] Fig. 9 900 is a simplified block diagram of a device suitable for implementing an embodiment of the present disclosure. The device 900 may be provided to implement a communication device, such as Figure 1 The terminal device 110, the first network device 120, the LMF 130, or the second network device 140 shown in the figure. As shown in the figure, the device 900 includes one or more processors 910, one or more memories 920 coupled to the processor 910, and one or more communication modules 940 coupled to the processor 910.

[0179] The communication module 940 is used for two-way communication. The communication module 940 has at least one antenna to facilitate communication. The communication interface may represent any interface necessary for communication with other network elements.

[0180] Processor 910 may be of any type suitable for the local technology network, and may include, as non-limiting examples, one or more of the following: 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. Device 900 may have multiple processors, such as application specific integrated circuit chips that are time slaved to a clock synchronized with a main processor.

[0181] The memory 920 may include one or more non-volatile memories, and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 924, electrically programmable read-only memory (EPROM), flash memory, hard disk, compact disk (CD), digital video disk (DVD), and other magnetic storage devices and / or optical storage devices. Examples of volatile memories include, but are not limited to, random access memory (RAM) 922, and other volatile memories that do not persist during power outages.

[0182] The computer program 930 includes computer executable instructions executed by the associated processor 910. The program 930 may be stored in the ROM 924. The processor 910 may perform any suitable actions and processes by loading the program 930 into the RAM 922.

[0183] The embodiments of the present disclosure can be implemented by means of program 930, so that the device 900 can execute the reference Figures 2 to 8 Any process of the present disclosure discussed. The embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0184] In some embodiments, the program 930 may be tangibly contained in a computer-readable medium, which may be included in the device 900 (such as in the memory 920), or in other storage devices accessible to the device 900. The device 900 may load the program 930 from the computer-readable medium to the RAM 922 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Fig.10 An example of a computer readable medium 1000 in the form of a CD or DVD is shown. The computer readable medium has a program 930 stored thereon.

[0185] Generally, various embodiments of the present disclosure may be implemented using hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented using hardware, while other aspects may be implemented using firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that, as non-limiting examples, the boxes, devices, systems, techniques, or methods described herein may be implemented using hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof.

[0186] 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 instructions included in a program module, which are executed in a device on a target real or virtual processor to perform the above reference Figures 5 to 8 The methods 500, 600, 700 and 800 are described. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functions of the program modules can be combined or split between program modules as needed. The machine executable instructions of the program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in both local and remote storage media.

[0187] The program code for executing the method 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 device so that the program code, when executed by the processor or controller, enables the function / operation specified in the flow chart and / or block diagram to be realized. The program code can be executed completely on the machine, partially on the machine, as an independent software package, partially on the machine and partially on a remote machine, or completely on a remote machine or server.

[0188] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform various processes and operations as described above. Examples of carriers include signals, computer-readable media, etc.

[0189] Computer readable medium can be a computer readable signal medium or a computer readable storage medium. Computer readable medium can include but is not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. A more specific example of a computer readable storage medium will include an electrical connection with one or more wires, a portable computer floppy 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. The term "non-transient" used herein is a restriction on the medium itself (i.e., tangible, rather than a signal), rather than a restriction on data storage persistence (e.g., RAM and ROM).

[0190] In addition, although the operations are described in a specific order, this should not be understood as requiring such operations to be performed in the specific order shown or in order or performing all the operations shown to obtain 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 should not be interpreted as limitations on the scope of the present disclosure, but rather descriptions of features that may be specific to a particular embodiment. Certain features described in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0191] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Instead, the specific features or acts described above are disclosed as example forms of implementing the claims.

[0192] The embodiments of the present disclosure provide the following examples:

[0193] Example 1. A first network device, comprising:

[0194] at least one processor; and

[0195] at least one memory storing instructions that, when executed by at least one processor, cause the first network device to at least:

[0196] Information is sent to a location management function (LMF), wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of the terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity area.

[0197] Example 2. The first network device of Example 1, wherein the information includes: a first indication to release the at least one SRS resource, and wherein the first indication is sent based on determining that the TAT is expired.

[0198] Example 3. The first network device of Example 1, wherein the information includes at least one of the following:

[0199] TAT information; or

[0200] A second indication that the terminal device moves out of the SRS validity area.

[0201] Example 4. The first network device of Example 3, wherein the information of the TAT includes at least one of the following:

[0202] The time when TAT starts;

[0203] The time point when TAT restarts;

[0204] Extension of TAT; or

[0205] The time when TAT expires.

[0206] Example 5. The first network device of example 1 or 2, wherein the first network device is further configured to:

[0207] Based on determining that the expired TAT is restarted, a third indication is sent to the LMF to reserve the at least one SRS resource.

[0208] Example 6. The first network device of Example 5, wherein the first network device is further configured to:

[0209] After the expired TAT is restarted, at least one released SRS resource valid for multiple cells of the terminal device is reused.

[0210] Example 7. The first network device of any one of Examples 1 to 6, wherein the first network device is further configured to:

[0211] Before the TAT expires, at least one request for an extension of the TAT is received from at least one terminal device or the LMF.

[0212] Example 8. The first network device of Example 7, wherein the first network device is further configured to:

[0213] Determining to extend the TAT for a period of time based on determining that the number of the at least one terminal device is above a threshold; and

[0214] Based on this time period, the validity period of the TAT is extended.

[0215] Example 9. The first network device of any one of Examples 1 to 6, wherein the first network device is further configured to:

[0216] When the TAT expires, a request for extension of the TAT is received from the at least one terminal device or the LMF.

[0217] Example 10. The first network device of Example 7, wherein the first network device is further caused to:

[0218] receiving, from the at least one terminal device, information indicating a time period for which the TAT is extended; and

[0219] Based on this time period, the validity period of the TAT is extended.

[0220] Example 11. The first network device of any one of Examples 8 to 10, wherein one of the following:

[0221] The time period is proportional to the number of the at least one request; or

[0222] This time period is an integer multiple of the duration of the TAT.

[0223] Example 12. The first network device of Example 8 or 11, wherein the first network device is further caused to:

[0224] Information indicating the time period is sent to the at least one terminal device.

[0225] Example 13. The first network device of any one of Examples 7 to 12, wherein the first network device is further configured to:

[0226] A fourth indication that the TAT is extended is sent to the LMF.

[0227] Example 14. The first network device of Example 13, wherein the fourth indication includes: information indicating the time period.

[0228] Example 15. The first network device of any one of Examples 1 to 14, wherein the first network device is further configured to:

[0229] The at least one SRS resource is released based on determining at least one of the following:

[0230] TAT expires; or

[0231] The terminal device moves out of the SRS validity area.

[0232] Example 16. The first network device of any one of Examples 1 to 15, wherein the first network device is further configured to:

[0233] Releasing the configuration of the at least one SRS resource configured for the SRS validity area based on determining at least one of the following:

[0234] TAT expires; or

[0235] The terminal device moves out of the SRS validity area.

[0236] Example 17. A location management function (LMF), comprising:

[0237] at least one processor; and

[0238] at least one memory storing instructions that, when executed by at least one processor, cause the LMF to at least:

[0239] receiving information from a first network device, wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of the terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; and

[0240] The information is sent to the one or more network devices.

[0241] Example 18. The LMF of Example 17, wherein the information comprises: a first indication to release the at least one SRS resource, and wherein the first indication is sent based on determining that the TAT is expired.

[0242] Example 19. The LMF of Example 17, wherein the information includes at least one of:

[0243] TAT information; or

[0244] A second indication that the terminal device moves out of the SRS validity area.

[0245] Example 20. The LMF of Example 19, wherein the information of the TAT includes at least one of the following:

[0246] The time when TAT starts;

[0247] The time point when TAT restarts;

[0248] Extension of TAT; or

[0249] The time when TAT expires.

[0250] Example 21. The LMF of example 17 or 18, wherein the LMF is further made:

[0251] In case of an expired TAT restart, receiving a third indication from the first network device to reserve the at least one SRS resource; and

[0252] A third indication is sent to the one or more network devices.

[0253] Example 22. The LMF of any one of Examples 17 to 21, wherein the LMF is further made:

[0254] When the TAT expires, a request for extension of the TAT is sent to the first network device.

[0255] Example 23. The LMF of any one of Examples 17 to 22, wherein the LMF is further made:

[0256] receiving a fourth indication from the first network device that the TAT is extended; and

[0257] A fourth indication is sent to the one or more network devices.

[0258] Example 24. The LMF of Example 23, wherein the fourth indication comprises: information indicating that the time period of the TAT is extended.

[0259] Example 25. The LMF of Example 24, wherein one of the following:

[0260] The time period is proportional to the number of at least one request for an extension of the TAT sent by at least one terminal device; or

[0261] This time period is an integer multiple of the duration of the TAT.

[0262] Example 26. A second network device comprising:

[0263] at least one processor; and

[0264] at least one memory storing instructions that, when executed by at least one processor, cause the second network device to at least:

[0265] Receiving information from a location management function (LMF), wherein the information is used by one or more network devices other than a first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires, wherein the first network device and cells of the one or more network devices are in the SRS validity area, wherein the second network device is one of the one or more network devices; and based on the information, releasing the at least one SRS resource.

[0266] Example 27. The second network device of Example 26, wherein the information includes: a first indication to release the at least one SRS resource, and wherein the first indication is sent based on determining that the TAT is expired.

[0267] Example 28. The second network device of Example 26, wherein the information includes at least one of the following:

[0268] TAT information; or

[0269] A second indication that the terminal device moves out of the SRS validity area.

[0270] Example 29. The second network device of Example 28, wherein the information of the TAT includes at least one of the following:

[0271] The time when TAT starts;

[0272] The time point when TAT restarts;

[0273] Extension of TAT; or

[0274] The time when TAT expires.

[0275] Example 30. The second network device of any of Examples 26 to 29, wherein the second network device is caused to release the at least one SRS resource based on the information by at least one of:

[0276] upon receiving the first indication, releasing the at least one SRS resource;

[0277] Based on determining that the terminal device has moved out of the SRS validity area, releasing the at least one SRS resource; or

[0278] When the TAT expires, the at least one SRS resource is released.

[0279] Example 31. The second network device of Example 26 or 27, wherein the second network device is further caused to:

[0280] receiving, from the LMF, a third indication to retain the at least one SRS resource in case the expired TAT is restarted; and

[0281] Based on the third indication, the at least one SRS resource is reserved.

[0282] Example 32. The second network device of Example 29, wherein the second network device is further caused to:

[0283] Based on determining that the information of the TAT includes a time point at which the TAT is restarted, retaining the at least one SRS resource; or

[0284] Based on determining that the information of the TAT includes an extension of the TAT, a time period of the at least one SRS resource is extended.

[0285] Example 33. The second network device of any of Examples 26 to 32, wherein the second network device is further caused to:

[0286] receiving, from the LMF, information indicating a time period for which the TAT is extended;

[0287] Based on the time period, extend the validity period of the TAT; and

[0288] Based on this validity period, TAT is run.

[0289] Example 34. The second network device of any of Examples 26 to 33, wherein one of the following:

[0290] The time period is proportional to the number of at least one request for an extension of the TAT sent by the at least one terminal device; or

[0291] This time period is an integer multiple of the duration of the TAT.

[0292] Example 35. The second network device of any of Examples 26 to 34, wherein the second network device is further caused to:

[0293] Releasing the configuration of the at least one SRS resource configured for the SRS validity area based on determining at least one of the following:

[0294] TAT expires; or

[0295] The terminal device moves out of the SRS validity area.

[0296] Example 36. A terminal device comprising:

[0297] at least one processor; and

[0298] At least one memory storing instructions, which, when executed by at least one processor, cause the terminal device to at least:

[0299] sending a request for an extension of a time alignment timer (TAT) to the first network device; and

[0300] Information indicating a time period for which the TAT is extended is received from the first network device.

[0301] Example 37. The terminal device of Example 36, wherein the terminal device is further caused to:

[0302] Determine the period of time for which the TAT is extended.

[0303] Example 38. The terminal device of Example 36 or 37, wherein the terminal device is further caused to:

[0304] Based on this time period, the validity period of the TAT is extended.

[0305] Example 39. A terminal device according to any one of Examples 36 to 38, wherein the terminal device is further caused to:

[0306] After the expired TAT is restarted, at least one released SRS resource valid for multiple cells of the terminal device is reused.

[0307] Example 40. A terminal device according to any one of Examples 36 to 39, wherein the terminal device is further caused to:

[0308] The at least one SRS resource is released based on determining at least one of the following:

[0309] TAT expires; or

[0310] The terminal device moves out of the SRS validity area.

[0311] Example 41. A terminal device according to any one of Examples 36 to 40, wherein the terminal device is further caused to:

[0312] Releasing the configuration of the at least one SRS resource configured for the SRS validity area based on determining at least one of the following:

[0313] TAT expires; or

[0314] The terminal device moves out of the SRS validity area.

[0315] Example 42. A method comprising:

[0316] At a first network device, information is sent to a location management function (LMF), wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity area.

[0317] Example 43. A method comprising:

[0318] receiving, at a location management function (LMF), information from a first network device, wherein the information is used by one or more network devices other than the first network device to release at least one sounding reference signal (SRS) resource valid for a plurality of cells of the terminal device upon expiration of a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; and

[0319] The information is sent to the one or more network devices.

[0320] Example 44. A method comprising:

[0321] At the second network device, receiving information from a location management function (LMF), wherein the information is used by one or more network devices other than the first network device to release at least one sounding reference signal (SRS) resource valid for multiple cells of the terminal device when a time alignment timer (TAT) configured for the terminal device expires, wherein the first network device and cells of the one or more network devices are in the SRS validity area, wherein the second network device is one of the one or more network devices; and

[0322] Based on the information, the at least one SRS resource is released.

[0323] Example 45. A method comprising:

[0324] At the terminal device, sending a request for an extension of a time alignment timer (TAT) to the first network device; and

[0325] Information indicating a time period for which the TAT is extended is received from the first network device.

[0326] Example 46. An apparatus comprising:

[0327] A component for sending information to a location management function (LMF) at a first network device, wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity area.

[0328] Example 47. An apparatus comprising:

[0329] means for receiving information from a first network device at a location management function (LMF), wherein the information is used by one or more network devices other than the first network device to release at least one sounding reference signal (SRS) resource valid for a plurality of cells of the terminal device upon expiration of a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity region of the terminal device, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; and

[0330] Means for sending the information to the one or more network devices.

[0331] Example 48. An apparatus comprising:

[0332] means for receiving information from a location management function (LMF) at the second network device, wherein the information is used by one or more network devices other than the first network device to release at least one sounding reference signal (SRS) resource valid for multiple cells of the terminal device when a time alignment timer (TAT) configured for the terminal device expires, wherein the first network device and cells of the one or more network devices are in the SRS validity area, wherein the second network device is one of the one or more network devices; and

[0333] Means for releasing the at least one SRS resource based on the information.

[0334] Example 49. An apparatus comprising:

[0335] means for sending, at the terminal device, to the first network device, a request for an extension of a time alignment timer (TAT); and

[0336] Means for receiving, from the first network device, information indicating a time period for which the TAT is extended.

[0337] Example 50. A non-transitory computer-readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to at least perform a method according to any one of Examples 42 to 45.

Claims

1. A terminal device, comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the terminal device to at least: sending a request for an extension of a time alignment timer (TAT) to the first network device; and Information indicating a time period for which the TAT is extended is received from the first network device.

2. The terminal device according to claim 1, wherein the terminal device is further configured to: A time period for which the TAT is extended is determined.

3. The terminal device according to claim 1 or 2, wherein the terminal device is further configured to: Based on the time period, the validity period of the TAT is extended.

4. The terminal device according to any one of claims 1 to 3, wherein the terminal device is further configured to: After the expired TAT is restarted, at least one released SRS resource valid for a plurality of cells of the terminal device is reused.

5. The terminal device according to any one of claims 1 to 4, wherein the terminal device is further configured to: The at least one SRS resource is released based on determining at least one of the following: The TAT expires; or The terminal device moves out of the SRS validity area.

6. The terminal device according to any one of claims 1 to 5, wherein the terminal device is further configured to: Releasing the configuration of the at least one SRS resource configured for the SRS validity area based on determining at least one of the following: The TAT expires; or The terminal device moves out of the SRS validity area.

7. A method for communication, comprising: At the terminal device, sending a request for an extension of a time alignment timer (TAT) to the first network device; as well as Information indicating a time period for which the TAT is extended is received from the first network device.

8. A first network device, comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the first network device to at least: Information is sent to a location management function (LMF), wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of the terminal device when a time alignment timer (TAT) configured for a sounding reference signal (SRS) validity area of ​​the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity area.

9. A location management function (LMF), comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the LMF to at least: receiving information from a first network device, wherein the information is used by one or more network devices other than the first network device to release at least one SRS resource valid for multiple cells of a sounding reference signal (SRS) validity region of the terminal device when a time alignment timer (TAT) configured for the terminal device expires, wherein the cells of the first network device and the one or more network devices are in the SRS validity region; as well as The information is sent to the one or more network devices.

10. A second network device, comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the second network device to at least: receiving information from a location management function (LMF), wherein the information is used by one or more network devices other than the first network device to release at least one sounding reference signal (SRS) resource valid for multiple cells of the terminal device when a time alignment timer (TAT) configured for the terminal device expires, wherein the first network device and the cells of the one or more network devices are in the SRS validity area, wherein the second network device is one of the one or more network devices; and Based on the information, the at least one SRS resource is released.

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