First node, second node, user equipment and methods performed thereby

Abstract

The method comprises: sending a first notification message to a second node; receiving a second notification message from the second node, the second notification message comprising information related to an identity of a first cell and at least one of the following information corresponding to the first cell: first information related to a first resource for uplink synchronization; second information related to releasing a second resource for uplink synchronization; third information related to updating a third resource for uplink synchronization; sending a first reconfiguration message to a UE, the first reconfiguration message comprising information related to an identity of a second cell and at least one of the following information corresponding to the second cell: fourth information related to a fourth resource for uplink synchronization; fifth information related to releasing a fifth resource for uplink synchronization; sixth information related to updating a sixth resource for uplink synchronization; and sending a sixth request message to the second node.

Description

Technical Field

[0001] This disclosure relates to the field of communications, and more specifically to a first node, a second node, a user equipment, and methods performed thereon. Background Technology

[0002] To meet the increased demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or near-5G communication systems. Therefore, 5G or near-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems".

[0003] Wireless communication is one of the most successful innovations in modern history. Recently, the number of subscribers to wireless communication services surpassed 5 billion and continues to grow rapidly. The demand for wireless data services is growing rapidly due to the increasing prevalence of smartphones and other mobile data devices (such as tablets, laptops, netbooks, e-book readers, and machine-type devices) among consumers and businesses. To meet the rapid growth of mobile data services and support new applications and deployments, improving the efficiency and coverage of wireless interfaces is crucial. Summary of the Invention

[0004] According to one aspect of this disclosure, a method performed by a first node in a communication system is provided, the method comprising: sending a first notification message to a second node relating to a request for resources for uplink synchronization; receiving a second notification message from the second node, wherein the second notification message includes information relating to an identifier of a first cell of the second node and at least one of the following information corresponding to the first cell: first information relating to a first resource for uplink synchronization; second information relating to the release of a second resource for uplink synchronization; and third information relating to updating a third resource for uplink synchronization; sending a first reconfiguration message to a user equipment (UE), wherein the first reconfiguration message includes information relating to an identifier of a second cell determined by the first node for the UE and at least one of the following information corresponding to the second cell: fourth information relating to a fourth resource for uplink synchronization; fifth information relating to the release of a fifth resource for uplink synchronization; and sixth information relating to updating a sixth resource for uplink synchronization; and sending a sixth request message to the second node relating to a request to configure a target cell and / or candidate cell for the UE.

[0005] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, the first notification message includes at least one of the following: seventh information related to the type of the requested uplink synchronization resource; eighth information related to the quantity of the requested uplink synchronization resource set; and ninth information related to assisting the second node in allocating resources for uplink synchronization.

[0006] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided in this disclosure, the ninth information includes at least one of the following: information related to the number of UEs that may move; information related to the potential trajectory of the UEs that may move; and information related to the usage status of the radio resources of the cell of the first node.

[0007] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, the sixth request message includes tenth information related to the Random Access Channel (RACH) resources used for uplink synchronization of the UE.

[0008] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, the method further includes: sending a third request message to a third node, wherein the third request message includes eleventh information related to a seventh resource for uplink synchronization determined by the first node for the third node; and receiving a third request response message from the third node, wherein the third request response includes information related to the usage status of an eighth resource for uplink synchronization determined by the first node for the third node.

[0009] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, the method further includes: receiving a fourth request message from a third node, wherein the fourth request message includes at least one of the following: information related to a UE that needs to use resources for uplink synchronization; twelfth information related to the type of the requested resources for uplink synchronization; thirteenth information related to the number of the requested resource set; and sending a fourth request response message to the third node, wherein the fourth request response message includes fourteenth information related to a ninth resource for uplink synchronization determined by the first node for the third node.

[0010] In conjunction with any of the above embodiments, according to the method executed by a first node in a communication system provided by this disclosure, at least one of the first information, fourth information, eleventh information, and fourteenth information includes at least one of the following: information related to the number of the resource used for uplink synchronization; information related to the type of the time-frequency resource used for uplink synchronization; information related to the purpose of use of the resource used for uplink synchronization; information related to the effective time of the resource used for uplink synchronization; the subcarrier spacing of the resource used for uplink synchronization; the starting frequency or starting frequency band of the resource used for uplink synchronization; the number of random access opportunities of the Random Access Channel (RACH); the entries of the random access configuration of the RACH; the number of synchronization signal blocks (SSBs) for each random access opportunity; the frequency domain length of the random access opportunity; the zero-correlation interval configuration of the random access; and the random access response window.

[0011] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, the purpose of use includes at least one of the following: for handover; for conditional handover; for triggering mobility LTM in Layer 1 / Layer 2; for conditional LTM; for secondary cell activation.

[0012] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, any one of the first resources for uplink synchronization to the ninth resources for uplink synchronization includes uplink carrier resources and / or supplementary uplink carrier resources.

[0013] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, the method further includes: sending a fifth request message to a third node, wherein the fifth request message includes: information related to triggering uplink synchronization of the UE; and receiving a fifth request response message from the third node, wherein the fifth request response message includes fifteenth information related to the random access channel (RACH) resources used by the UE for uplink synchronization.

[0014] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, the tenth or fifteenth information includes at least one of the following: information related to the preamble entry used for uplink synchronization of the UE; and information related to the source entity of the handover.

[0015] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided in this disclosure, the method further includes: receiving a sixth request response message from a second node, wherein the sixth request message includes a timing advance TA value for uplink synchronization by the UE; and sending a second reconfiguration message to the UE, wherein the second reconfiguration message includes the TA value.

[0016] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, the first node is a first base station or a centralized unit of a first base station; and / or the second node is a second base station or a centralized unit of a second base station; and / or the third node is a distributed unit of the first base station.

[0017] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, wherein a second request message is sent by a second node to a fourth node, wherein the second request message includes at least one of the following: sixteenth information related to the type of the requested uplink synchronization resource; seventeenth information related to the number of the requested uplink synchronization resource set; eighteenth information related to assisting the fourth node in allocating resources for uplink synchronization; and wherein a second request response message is received by the second node from the fourth node, wherein the second request response message includes information related to the identifier of the second cell and at least one of the following information corresponding to the second cell: nineteenth information related to a tenth resource for uplink synchronization; twentieth information related to releasing an eleventh resource for uplink synchronization; and twenty-first information related to updating a twelfth resource for uplink synchronization.

[0018] In conjunction with any of the above embodiments, according to the method performed by a first node in a communication system provided by this disclosure, the seventh request message is sent by a second node to a fourth node, wherein the seventh request message includes twenty-second information related to the random access channel (RACH) resources used by the UE for uplink synchronization; and wherein the seventh request response message is received by the second node from the fourth node, wherein the seventh request response message includes the timing advance (TA) value used by the UE for uplink synchronization.

[0019] According to another aspect of this disclosure, a method performed by a second node in a communication system is provided, the method comprising: receiving from a first node a first notification message related to a request for resources for uplink synchronization; sending to the first node a second notification message, wherein the second notification message includes information related to an identifier of a first cell of the second node and at least one of the following information corresponding to the first cell: first information related to a first resource for uplink synchronization; second information related to releasing a second resource for uplink synchronization; and third information related to updating a third resource for uplink synchronization; receiving from the first node a sixth request message related to a request to configure a target cell and / or candidate cell of the UE; wherein a first reconfiguration message sent by the first node to the user equipment UE includes information related to an identifier of a second cell determined by the first node for the UE and at least one of the following information corresponding to the second cell: fourth information related to a fourth resource for uplink synchronization; fifth information related to releasing a fifth resource for uplink synchronization; and sixth information related to updating a sixth resource for uplink synchronization.

[0020] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, the method further includes: sending a second request message to a fourth node, wherein the second request message includes at least one of the following: sixteenth information related to the type of the requested uplink synchronization resource; seventeenth information related to the number of the requested uplink synchronization resource set; eighteenth information related to assisting the fourth node in allocating resources for uplink synchronization; receiving a second request response message from the fourth node, wherein the second request response message includes information related to the identifier of the second cell and at least one of the following information corresponding to the second cell: nineteenth information related to a tenth resource for uplink synchronization; twentieth information related to releasing an eleventh resource for uplink synchronization; and twenty-first information related to updating a twelfth resource for uplink synchronization.

[0021] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, a seventh request message is sent to a fourth node, wherein the seventh request message includes twenty-second information related to the random access channel (RACH) resources used by the UE for uplink synchronization; and a seventh request response message is received from the fourth node, wherein the seventh request response message includes the timing advance (TA) value used by the UE for uplink synchronization.

[0022] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, the first notification message includes at least one of the following: seventh information related to the type of the requested uplink synchronization resource; eighth information related to the quantity of the requested uplink synchronization resource set; and ninth information related to assisting the second node in allocating resources for uplink synchronization.

[0023] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided in this disclosure, the ninth information includes at least one of the following: information related to the number of UEs that may move; information related to the potential trajectories of UEs that may move; and information related to the usage status of radio resources of the cell of the first node.

[0024] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, the sixth request message includes tenth information related to the Random Access Channel (RACH) resources used for uplink synchronization of the UE.

[0025] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, a third request message is sent by a first node to a third node, wherein the third request message includes eleventh information related to a seventh resource for uplink synchronization determined by the first node for the third node; and wherein a third request response message is received by the first node from the third node, wherein the third request response includes information related to the usage status of an eighth resource for uplink synchronization determined by the first node for the third node.

[0026] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, wherein a fourth request message is received by a first node from a third node, wherein the fourth request message includes at least one of the following: information related to a UE that needs to use resources for uplink synchronization; twelfth information related to the type of the requested resources for uplink synchronization; thirteenth information related to the number of the requested resource set; and wherein a fourth request response message is sent by the first node to the third node, wherein the fourth request response message includes fourteenth information related to a ninth resource for uplink synchronization determined by the first node for the third node.

[0027] In conjunction with any of the above embodiments, according to the method executed by a second node in a communication system provided by this disclosure, at least one of the first information, fourth information, eleventh information, and fourteenth information includes at least one of the following: information related to the number of the resource used for uplink synchronization; information related to the type of the time-frequency resource used for uplink synchronization; information related to the purpose of use of the resource used for uplink synchronization; information related to the effective time of the resource used for uplink synchronization; the subcarrier spacing of the resource used for uplink synchronization; the starting frequency or starting frequency band of the resource used for uplink synchronization; the number of random access opportunities of the Random Access Channel (RACH); the entries of the random access configuration of the RACH; the number of synchronization signal blocks (SSBs) for each random access opportunity; the frequency domain length of the random access opportunity; the zero-correlation interval configuration of the random access; and the random access response window.

[0028] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, the purpose of use includes at least one of the following: for handover; for conditional handover; for triggering mobility LTM in Layer 1 / Layer 2; for conditional LTM; for secondary cell activation.

[0029] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, any one of the first resources for uplink synchronization to the ninth resources for uplink synchronization includes uplink carrier resources and / or supplementary uplink carrier resources.

[0030] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, a fifth request message is sent by a first node to a third node, wherein the fifth request message includes: information related to triggering the UE to perform uplink synchronization; and wherein a fifth request response message is received by the first node from the third node, wherein the fifth request response message includes fifteenth information related to the random access channel (RACH) resources used by the UE to perform uplink synchronization.

[0031] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, the tenth or fifteenth information includes at least one of the following: information related to the preamble entry used for uplink synchronization of the UE; and information related to the source entity of the handover.

[0032] In conjunction with any of the above embodiments, according to the method executed by a second node in a communication system provided by this disclosure, the sixth request response message is received by the first node from the second node, wherein the sixth request message includes a timing advance TA value for uplink synchronization by the UE; and wherein the second reconfiguration message is sent by the first node to the UE, wherein the second reconfiguration message includes the TA value.

[0033] In conjunction with any of the above embodiments, according to the method performed by a second node in a communication system provided by this disclosure, the first node is a first base station or a centralized unit of the first base station; and / or the second node is a second base station or a centralized unit of the second base station; and / or the third node is a distributed unit of the first base station.

[0034] According to another aspect of this disclosure, a method performed by a user equipment (UE) in a communication system is provided, the method comprising: receiving a first reconfiguration message from a first node, wherein the first reconfiguration message includes information related to an identifier of a second cell determined by the first node for the UE and at least one of the following information corresponding to the second cell: fourth information related to a fourth resource for uplink synchronization; fifth information related to releasing a fifth resource for uplink synchronization; and sixth information related to updating a sixth resource for uplink synchronization; and sending a preamble to a second node; wherein the first reconfiguration message is based on a second notification message received by the first node from the second node, wherein the second notification message includes information related to an identifier of a first cell of the second node and at least one of the following information corresponding to the first cell: first information related to a first resource for uplink synchronization; second information related to releasing a second resource for uplink synchronization; and third information related to updating a third resource for uplink synchronization; wherein the second notification message is based on a first notification message sent by the first node to the second node related to a request for resources for uplink synchronization; wherein a sixth request message related to a request to configure a target cell and / or candidate cell of the UE is sent by the first node to the second node.

[0035] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, wherein a second request message is sent by a second node to a fourth node, wherein the second request message includes at least one of the following: sixteenth information related to the type of the requested uplink synchronization resource; seventeenth information related to the number of the requested uplink synchronization resource set; eighteenth information related to assisting the fourth node in allocating resources for uplink synchronization; and wherein a second request response message is received by the second node from the fourth node, wherein the second request response message includes information related to the identifier of the second cell and at least one of the following information corresponding to the second cell: nineteenth information related to a tenth resource for uplink synchronization; twentieth information related to releasing an eleventh resource for uplink synchronization; and twenty-first information related to updating a twelfth resource for uplink synchronization.

[0036] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, the seventh request message is sent by the second node to the fourth node, wherein the seventh request message includes twenty-second information related to the random access channel (RACH) resources used by the UE for uplink synchronization; and wherein the seventh request response message is received by the second node from the fourth node, wherein the seventh request response message includes the timing advance (TA) value used by the UE for uplink synchronization.

[0037] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided in this disclosure, the first notification message includes at least one of the following: seventh information related to the type of the requested uplink synchronization resource; eighth information related to the quantity of the requested uplink synchronization resource set; and ninth information related to assisting the second node in allocating resources for uplink synchronization.

[0038] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided in this disclosure, the ninth information includes at least one of the following: information related to the number of UEs that may move; information related to the potential trajectory of the UEs that may move; and information related to the usage status of the radio resources of the cell of the first node.

[0039] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, the sixth request message includes tenth information related to the random access channel (RACH) resources used by the UE for uplink synchronization.

[0040] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, a third request message is sent by a first node to a third node, wherein the third request message includes eleventh information related to a seventh resource for uplink synchronization determined by the first node for the third node; and wherein a third request response message is received by the first node from the third node, wherein the third request response includes information related to the usage status of an eighth resource for uplink synchronization determined by the first node for the third node.

[0041] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, a fourth request message is received by a first node from a third node, wherein the fourth request message includes at least one of the following: information related to a UE that needs to use resources for uplink synchronization; twelfth information related to the type of the requested uplink synchronization resources; thirteenth information related to the number of the requested resource set; and wherein a fourth request response message is sent by the first node to the third node, wherein the fourth request response message includes fourteenth information related to a ninth resource for uplink synchronization determined by the first node for the third node.

[0042] In conjunction with any of the above embodiments, according to the method executed by a user equipment (UE) in a communication system provided by this disclosure, at least one of the first information, fourth information, eleventh information, and fourteenth information includes at least one of the following: information related to the number of the resource used for uplink synchronization; information related to the type of the time-frequency resource used for uplink synchronization; information related to the purpose of use of the resource used for uplink synchronization; information related to the effective time of the resource used for uplink synchronization; the subcarrier spacing of the resource used for uplink synchronization; the starting frequency or starting frequency band of the resource used for uplink synchronization; the number of random access opportunities of the Random Access Channel (RACH); the entries of the random access configuration of the RACH; the number of synchronization signal blocks (SSBs) for each random access opportunity; the frequency domain length of the random access opportunity; the zero-correlation interval configuration of the random access; and the random access response window.

[0043] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided in this disclosure, the purpose of use includes at least one of the following: for handover; for conditional handover; for triggering mobility LTM in Layer 1 / Layer 2; for conditional LTM; for secondary cell activation.

[0044] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, any one of the first resources for uplink synchronization to the ninth resources for uplink synchronization includes uplink carrier resources and / or supplementary uplink carrier resources.

[0045] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, a fifth request message is sent by a first node to a third node, wherein the fifth request message includes information related to triggering the UE to perform uplink synchronization; and wherein a fifth request response message is received by the first node from the third node, wherein the fifth request response message includes fifteenth information related to the random access channel (RACH) resources used by the UE to perform uplink synchronization.

[0046] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, the tenth or fifteenth information includes at least one of the following: information related to the preamble entry used for uplink synchronization of the UE; and information related to the source entity of the handover.

[0047] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, the sixth request response message is received by the first node from the second node, wherein the sixth request message includes a timing advance (TA) value for uplink synchronization by the UE; and wherein the second reconfiguration message is sent by the first node to the UE, wherein the second reconfiguration message includes the TA value.

[0048] In conjunction with any of the above embodiments, according to the method performed by a user equipment (UE) in a communication system provided by this disclosure, the first node is a first base station or a centralized unit of the first base station; and / or the second node is a second base station or a centralized unit of the second base station; and / or the third node is a distributed unit of the first base station.

[0049] According to another aspect of this disclosure, a first node is provided, the first node comprising: a transceiver configured to transmit and / or receive signals; and a controller configured to control the transceiver to perform the methods described above performed by the first node.

[0050] According to another aspect of this disclosure, a second node is provided, the second node comprising: a transceiver configured to transmit and / or receive signals; and a controller configured to control the transceiver to perform the methods described above performed by the second node.

[0051] According to another aspect of this disclosure, a user equipment (UE) is provided, the UE comprising: a transceiver configured to transmit and / or receive signals; and a controller configured to control the transceiver to perform the methods described above performed by the UE.

[0052] According to another aspect of this disclosure, a non-transitory computer-readable recording medium is provided, on which a program is stored for execution by a computer as described above. Attached Figure Description

[0053] Figure 1 This is an exemplary system architecture for System Architecture Evolution (SAE);

[0054] Figure 2 This is a schematic diagram of the architecture of 5G according to various embodiments of the present disclosure;

[0055] Figure 3 This is a schematic diagram illustrating the interaction between the first node, the second node, and the fourth node according to various embodiments of this disclosure;

[0056] Figure 3a This is a schematic diagram illustrating the interaction between a first node and a second node according to various embodiments of the present disclosure;

[0057] Figure 4 This is a schematic diagram illustrating the interaction between the first node, the third node, and the fifth node according to various embodiments of this disclosure;

[0058] Figure 4a This is a schematic diagram illustrating the interaction between the first node and the fifth node according to various embodiments of this disclosure;

[0059] Figure 5 This is a schematic diagram illustrating the interaction between the first to fifth nodes according to various embodiments of this disclosure;

[0060] Figure 5a This is a schematic diagram illustrating the interaction between the first node, the second node, and the fifth node according to various embodiments of this disclosure;

[0061] Figure 6 This is a schematic diagram illustrating the interaction between a UE and a network node according to various embodiments of the present disclosure;

[0062] Figure 7 This is a schematic diagram illustrating another interaction between a UE and a network node according to various embodiments of the present disclosure;

[0063] Figure 8 This is a block diagram of a first node according to various embodiments of the present disclosure;

[0064] Figure 9This is a block diagram of a second node according to various embodiments of the present disclosure;

[0065] Figure 10 This is a block diagram of a user equipment (UE) according to various embodiments of the present disclosure. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0067] Before proceeding with the detailed description below, it may be advantageous to define certain words and phrases used throughout this patent document. The term “coupled” and its derivatives refer to any direct or indirect communication between two or more elements, regardless of whether these elements are physically in contact with each other. The terms “transmit,” “receive,” and “communicate,” and their derivatives cover both direct and indirect communication. The terms “comprising” and “including,” and their derivatives mean including but not limited to. The term “or” is inclusive, meaning and / or. The phrase “associated with,” and its derivatives mean including, comprising, connected to, interconnected with, containing, contained within, connected to or connected to, coupled to or coupled with, communicable with, cooperating with, intertwined, juxtaposed, proximate, bound to or bound to, having, possessing attributes of, having a relationship with, or having a relationship with. The term “controller” means any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware or in a combination of hardware and software and / or firmware. The functionality associated with any particular controller may be centralized or distributed, local or remote. The phrase "at least one of..." when used with a list of items means that different combinations of one or more of the listed items may be used, and it may be necessary to use only one item from the list. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C. Similarly, "at least one of A, B, or C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0068] Furthermore, the various functions described below can be implemented or supported by one or more computer programs, each computer program being formed by computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, instances, associated data, or portions thereof suitable for implementation in appropriate computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, optical disc (CD), digital video disc (DVD), or any other type of storage. "Non-transitory" computer-readable media excludes wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media includes media that can permanently store data and media that can store and later rewrite data, such as rewritable optical discs or erasable memory devices.

[0069] The terminology used herein to describe embodiments of this application is not intended to limit and / or restrict the scope of this application. For example, unless otherwise defined, the technical or scientific terms used in this disclosure should be understood in their ordinary sense by one of ordinary skill in the art to which this application pertains.

[0070] It should be understood that the terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Unless the context clearly indicates otherwise, the singular forms “a,” “one,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one.

[0071] As used herein, any reference to “an example” or “example,” “an embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. The phrases “in one embodiment” or “in one example” appearing in different places in the specification do not necessarily refer to the same embodiment.

[0072] As used in this article, “a part” of something means “at least some” of that thing, and therefore may mean less than or all of that thing. Thus, “a part” of something includes the whole thing as a special case, that is, an example where the whole thing is a part of something.

[0073] To further understand, the terms "including" or "contains," and similar words, mean that the element or object preceding the word covers the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Above," "below," "left," and "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly.

[0074] The various embodiments discussed below for describing the principles of this disclosure in this patent document are illustrative only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged wireless communication system. For example, although the following detailed description of embodiments of this disclosure is directed to LTE and 5G communication systems, those skilled in the art will understand that the main points of this disclosure, with slight modifications, can also be applied to other communication systems with similar technical backgrounds and channel formats without substantially departing from the scope of this disclosure. The technical solutions of this application embodiment can be applied to various communication systems. For example, communication systems may include Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), General Packet Radio Service (GPRS), Long Term Evolution (LTE), LTE Frequency Division Duplex (FDD), LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX), 5th Generation (5G), or New Radio (NR), etc. Furthermore, the technical solutions of this application embodiment can be applied to future-oriented communication technologies.

[0075] The following description, with reference to the accompanying drawings, is provided to aid in a thorough understanding of the various embodiments of this disclosure as defined by the claims and their equivalents. This description includes various specific details to aid understanding but should be considered exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of this disclosure. Furthermore, for clarity and brevity, descriptions of well-known functions and structures may be omitted.

[0076] The terms and wording used in the following description and claims are not limited to their dictionary meanings, but are merely used by the inventors to enable a clear and consistent understanding of this disclosure. Therefore, it will be apparent to those skilled in the art that the following description of various embodiments of this disclosure is for illustrative purposes only and not for limiting the purpose of this disclosure as defined in the appended claims and their equivalents.

[0077] It should be understood that the singular forms of “one,” “an,” and “the” include plural references unless the context clearly indicates otherwise. Thus, for example, the reference to “component surface” includes one or more such surfaces.

[0078] The terms “comprising” or “may include” refer to the presence of a corresponding disclosed function, operation, or component that may be used in the various embodiments of this disclosure, rather than limiting the presence of one or more additional functions, operations, or features. Furthermore, the terms “comprising” or “having” may be interpreted as indicating certain characteristics, numbers, steps, operations, constituent elements, components, or combinations thereof, but should not be construed as excluding the possibility of the presence of one or more other characteristics, numbers, steps, operations, constituent elements, components, or combinations thereof.

[0079] The term "or" as used in the various embodiments of this disclosure includes any of the listed terms and all combinations thereof. For example, "A or B" may include A, may include B, or may include both A and B.

[0080] Unless otherwise defined, all terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of those skilled in the art as described herein. Common terms as defined in dictionaries are to be interpreted as having a meaning consistent with the context in the relevant technical field and should not be interpreted ideally or overly formally unless expressly defined in this disclosure.

[0081] The accompanying drawings and various embodiments used to illustrate the principles of this disclosure in this patent document are for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged system or apparatus.

[0082] Figure 1 This is an exemplary system architecture 100 of System Architecture Evolution (SAE). User Equipment (UE) 101 is a terminal device used to receive data. Evolved Universal Terrestrial Radio Access Network (E-UTRAN) 102 is a radio access network, including macro base stations (eNodeB / NodeB) that provide the UE with an interface to access the wireless network. Mobility Management Entity (MME) 103 is responsible for managing the UE's mobility context, session context, and security information. Serving Gateway (SGW) 104 primarily provides user plane functions; MME 103 and SGW 104 may reside in the same physical entity. Packet Data Network Gateway (PGW) 105 is responsible for functions such as charging and lawful interception, and may also reside in the same physical entity as SGW 104. Policy and Charging Rules Function Entity (PCRF) 106 provides Quality of Service (QoS) policies and charging criteria. Universal Packet Radio Service Support Node (SGSN) 108 is a node device in the Universal Mobile Telecommunications System (UMTS) that provides routing for data transmission. The Home Subscriber Server (HSS) 109 is the UE's home subsystem, responsible for protecting user information including the UE's current location, the address of the serving node, user security information, and the UE's packet data context.

[0083] Figure 2 This is an exemplary system architecture 200 according to various embodiments of the present disclosure. Other embodiments of the system architecture 200 can be used without departing from the scope of the present disclosure.

[0084] User Equipment (UE) 201 is the terminal equipment used to receive data. Next-Generation Radio Access Network (NG-RAN) 202 is the radio access network, which includes base stations (gNBs or eNBs connected to the 5G core network 5GC; eNBs connected to the 5GC are also called ng-gNBs) that provide the UE with an access radio network interface. Access Control and Mobility Management Function Entity (AMF) 203 is responsible for managing the UE's mobility context and security information. User Plane Function Entity (UPF) 204 primarily provides user plane functions. Session Management Function Entity (SMF) 205 is responsible for session management. Data Network (DN) 206 includes services such as operator services, internet access, and third-party services.

[0085] Exemplary embodiments of this disclosure are further described below with reference to the accompanying drawings.

[0086] The text and accompanying drawings are provided by way of example only to aid in understanding this disclosure. They should not be construed as limiting the scope of this disclosure in any way. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art, based on the content disclosed herein, that changes may be made to the illustrated embodiments and examples without departing from the scope of this disclosure.

[0087] Before introducing the specific content, some assumptions and definitions of this invention are given below.

[0088] ■ The message name in this invention is just an example; other message names can also be used.

[0089] ■The terms "first," "second," etc., included in the message names of this invention are merely examples of messages and do not represent the execution order.

[0090] ■Detailed descriptions of steps unrelated to this invention have been omitted in this invention.

[0091] The nodes involved in this invention:

[0092] ■ First Node: This node is a network node device.

[0093] ■ Second node: This node is a network node device that is distinct from the first node.

[0094] ■Third Node: This node is a network node device.

[0095] ■ Fourth Node: This node is a network node device that is distinct from the third node.

[0096] ■ Fifth node: This node is a terminal or user equipment (UE).

[0097] In one example, the network node device described above can be a base station; in another example, the network node device described above can be an access point; in one example, if a base station comprises multiple parts, the network node device described above can be a part of the base station, such as the central unit of the base station, the control plane part of the central unit of the base station, or the user plane part of the central unit of the base station.

[0098] The base stations mentioned above can be one of the following types (other types that can be used for user terminal access are also excluded):

[0099] ■LTE base station

[0100] ■5G base station

[0101] ■6G base station

[0102] ■NTN base station

[0103] ■HAPS base station

[0104] ■Drone base station

[0105] ■WIFI access point

[0106] During cell handover, when a user equipment (UE) switches to the target cell, it needs to perform random access. The interruption caused by random access is a problem that has not yet been fully resolved during mobile operation.

[0107] Embodiments of this disclosure provide a method executed by a first node in a communication system, comprising: sending a first notification message to a second node related to requesting resources for uplink synchronization; receiving a second notification message from the second node, wherein the second notification message includes information related to an identifier of a first cell of the second node and at least one of the following information corresponding to the first cell: first information related to a first resource for uplink synchronization; second information related to releasing a second resource for uplink synchronization; and third information related to updating a third resource for uplink synchronization; sending a first reconfiguration message to a user equipment (UE), wherein the first reconfiguration message includes information related to an identifier of a second cell determined by the first node for the UE and at least one of the following information corresponding to the second cell: fourth information related to a fourth resource for uplink synchronization; fifth information related to releasing a fifth resource for uplink synchronization; and sixth information related to updating a sixth resource for uplink synchronization; and sending a sixth request message to the second node related to requesting configuration of a target cell and / or candidate cell for the UE.

[0108] Embodiments of this disclosure provide a method executed by a second node in a communication system, comprising: receiving from a first node a first notification message related to a request for resources for uplink synchronization; sending a second notification message to the first node, wherein the second notification message includes information related to an identifier of a first cell of the second node and at least one of the following information corresponding to the first cell: first information related to a first resource for uplink synchronization; second information related to releasing a second resource for uplink synchronization; and third information related to updating a third resource for uplink synchronization; receiving from the first node a sixth request message related to a request to configure a target cell and / or candidate cell of the UE; wherein a first reconfiguration message sent by the first node to the user equipment UE includes information related to an identifier of a second cell determined by the first node for the UE and at least one of the following information corresponding to the second cell: fourth information related to a fourth resource for uplink synchronization; fifth information related to releasing a fifth resource for uplink synchronization; and sixth information related to updating a sixth resource for uplink synchronization.

[0109] Embodiments of this disclosure provide a method performed by a user equipment (UE) in a communication system, comprising: receiving a first reconfiguration message from a first node, wherein the first reconfiguration message includes information related to an identifier of a second cell determined by the first node for the UE and at least one of the following information corresponding to the second cell: fourth information related to a fourth resource for uplink synchronization; fifth information related to releasing a fifth resource for uplink synchronization; and sixth information related to updating a sixth resource for uplink synchronization; and sending a preamble to a second node; wherein the first reconfiguration message is based on a second notification message received by the first node from the second node, wherein the second notification message includes information related to an identifier of a first cell of the second node and at least one of the following information corresponding to the first cell: first information related to a first resource for uplink synchronization; second information related to releasing a second resource for uplink synchronization; and third information related to updating a third resource for uplink synchronization; wherein the second notification message is based on a first notification message sent by the first node to the second node related to a request for resources for uplink synchronization; wherein a sixth request message related to requesting configuration of a target cell and / or candidate cell of the UE is sent by the first node to the second node.

[0110] The methods provided in various embodiments of this disclosure, by pre-allocating / reserving resources for uplink synchronization between base stations, enable the source base station to notify the UE of the pre-allocated / reserved resources for uplink synchronization in UE mobility scenarios, thereby achieving uplink synchronization without random access. This reduces UE interruptions caused by random access during movement. Furthermore, by pre-allocating / reserving uplink synchronization resources between base stations, the methods provided in various embodiments of this disclosure eliminate the need to request uplink synchronization resources from candidate cells based on the UE's request when a cell handover occurs. Compared to UE-request-based schemes, this reduces signaling overhead related to uplink synchronization, thereby reducing the load on the network interface. Furthermore, compared to existing LTM schemes where resources for uplink synchronization can only be requested during the handover preparation process related to the UE (e.g., including requests for resources for uplink synchronization in the handover request message), the methods provided by various embodiments of this disclosure request resources for uplink synchronization in advance before handover preparation (e.g., before sending a sixth request message related to requesting configuration of the target cell and / or candidate cell of the UE). This allows the methods of this disclosure to perform per-node interactions between networks without relying on the mobility preparation process with the UE. Moreover, the pre-allocated resources for uplink synchronization can be used not only for LTM but also for HO / CHO / C-LTM / secondary cell activation, etc., thus providing a general uplink synchronization resource allocation scheme that is not limited to LTM scenarios (Layer 1 / Layer 2 triggered mobility) and makes the methods provided by various embodiments of this disclosure applicable to a wider range of scenarios.

[0111] The various embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0112] Please refer to Figure 3 , Figure 3 This is a schematic diagram illustrating the interaction between the first node, the second node, and the fourth node according to various embodiments of this disclosure. Figure 3 In the example, as one implementation, the first node can be, for example, a CU of a first base station, the second node can be, for example, a CU of a second base station, and the fourth node can be, for example, a distribution unit (DU) of the second base station. Figure 3 In the example, the network does not need to wait until the UE moves before requesting resources for synchronization; it can allocate synchronization resources and exchange relevant information in advance. Figure 3 The method shown may include one or more of steps 301 to 304:

[0113] Step 301: The first node sends a first notification message to the second node related to the request for resources for uplink synchronization. For example, the first node can send the request for resources related to uplink synchronization to the neighboring base station via the first notification message, and provide mobility-related information about the UE served by this base station, thereby assisting the neighboring base station in making decisions regarding the advance allocation or reservation of resources for uplink synchronization. The resources requested by the first node can be used in subsequent mobility procedures, for example, for uplink synchronization between the UE and the target / candidate cell.

[0114] In one implementation, the first notification message may include, for example, at least one of the following information or a list of information:

[0115] ■ Information related to the identifier of the cell for which the requested allocation of resources for uplink synchronization is requested, such as the requested cell identifier information.

[0116] ■ Seventh information relating to the type of resource requested for uplink synchronization. The type of resource for uplink synchronization can be classified in various ways. For example, the type of resource for uplink synchronization can be classified based on the following methods; it is understood that regardless of the classification method, it falls within the scope of this disclosure.

[0117] ◆If classified according to the purpose of resource use, resources used for uplink synchronization can be one or more of the following types:

[0118] ● Synchronization resources used for Layer 3 (L3) switching;

[0119] ● Synchronization resources used for LTM;

[0120] ● Synchronization resources used for Conditional Hitch (CHO);

[0121] ● Synchronization resources for the type of Conditional LTM (C-LTM);

[0122] ● Synchronization resources used for secondary cell activation (Scell ​​activation).

[0123] ◆If classified according to the type of time-frequency resources, the resources used for uplink synchronization can be one or more of the following types:

[0124] ●Time-division multiplexed synchronization resources;

[0125] ●Frequency division multiplexing synchronization resources;

[0126] ● Synchronization resources for Code Division Multiple Access;

[0127] ●Synchronization resources for full-duplex sub-bands.

[0128] ◆If classified according to the type of uplink carrier, the resources used for uplink synchronization can be one or more of the following types:

[0129] ● Synchronization resources for the uplink carrier;

[0130] ●Supplement the synchronization resources of the uplink carrier.

[0131] ■ Eighth information related to the number of resource sets requested for uplink synchronization. This eighth information may, for example, be used to indicate the number of resource sets requested by the first node from a cell in the second node. In one implementation, the number of resource sets requested for uplink synchronization is related to the number of DUs or candidate DUs corresponding to the first node (if the first node is a CU). For example, if the first node is a CU of a first base station, and the CU has x corresponding DUs or candidate DUs, then the number of resource sets requested by the first node from a cell in the second node is x. In another implementation, the number of resource sets requested for uplink synchronization is related to the number of cells under the DU or candidate DU corresponding to the first node (if the first node is a CU). For example, if the first node is a CU of a first base station, and the CU has x corresponding DUs or candidate DUs, and each DU or candidate DU has y cells, then the number of resource sets requested by the first node from a cell in the second node is x*y. Furthermore, it is understood that the above embodiments refer to the number of resource sets requested for a single cell in the second node. In the embodiments of this disclosure, the first node may request resource sets for one or more or all cells in the second node; that is, the aforementioned number of resource sets can be requested for each cell in the second node. In one implementation, the first node may determine the resource set to request for uplink synchronization from one or more cells in the second node based on L3 or L1 measurements or other available information.

[0132] In one implementation, the resource set used for uplink synchronization may include one or more of the following:

[0133] ● Information related to the number of the resource used for uplink synchronization;

[0134] ● Information related to the type of time-frequency resources used for uplink synchronization;

[0135] ● Information related to the purpose of using resources for uplink synchronization;

[0136] ● Information related to the validity period of resources used for uplink synchronization;

[0137] ● Subcarrier spacing;

[0138] ●Starting frequency or starting frequency band. This information can be an integer value, such as INTEGER(0..maxNrofPhysicalResourceBlocks-1), where maxNrofPhysicalResourceBlocks is the maximum number of physical resource blocks.

[0139] ● The number of random access opportunities for the Random Access Channel (RACH). This information can be an enumeration type, such as ENUMERATED{1, 2, 4, 8}.

[0140] ● The RACH random access configuration entry (index) can be an integer value, such as INTEGER(0..255, ...) or INTEGER(263..299, ...). The maximum value defined in the encoding of this information can be any integer greater than 0.

[0141] ● The number of Synchronization Signal Blocks (SSBs) for each random access opportunity. This information can be an enumerated value, such as ENUMERATED{1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, 16, ...}.

[0142] ● The frequency domain length of the random access timing. This information can be a selectable value, with options including L839, L139, L571, L1151, etc. For example, if the value is L139, it means the prach-RootSequenceIndex L = 139.

[0143] ● The zero-correlation interval configuration for random access can be an integer value, such as INTEGER(0..15, ...). The maximum value defined in this information encoding can be any integer greater than 0.

[0144] ● Random Access Response Window: This information indicates the length of the random access response time window for sub-band full-duplex (SBFD).

[0145] ■ Ninth information related to assisting the second node in allocating resources for uplink synchronization, which may include, for example, at least one of the following information or a list of information:

[0146] ◆ Information related to the number of UEs that may move, such as the total number of UEs that may move or information indicating the number of UEs that may move. The second node can use this information to decide / determine the amount of resources allocated to the first node for uplink synchronization. In one implementation, if the number of UEs that may move is large, the second node will allocate more uplink synchronization resources to the first node for uplink synchronization during potential UE movement. In one implementation, the first node can select or determine whether a UE is a potential UE; for example, a UE at the cell edge or in an area with poor coverage can be identified as a potential UE by the first node.

[0147] ◆ Information related to the identifiers (IDs) of UEs that may be moved, such as UE IDs or a list of UE IDs that may be moved. The second node can use this information to obtain the identifier information of UEs that may be moved.

[0148] ◆ Information related to the potential / future / possible trajectory of a UE that may move. The second node can refer to this information to allocate resources for uplink synchronization. For example, when a UE may move to a cell within the second node's range, the second node can consider allocating appropriate resources to the first node. This information may include, for example, at least one of the following information or a list of information:

[0149] ●Identification information of the cell the UE may move to, such as the global NG-RAN cell identity.

[0150] ●The time at which the UE may move, which can be, for example, an absolute time or a difference relative to a certain absolute time, i.e., a relative time.

[0151] ●The time the UE stays in the cell it may move to. This information can be, for example, an integer value or a time period consisting of a start time and an end time.

[0152] ◆The number of radio link failures (RLFs) that occurred to the UE. The second node can refer to this information to understand the network status of the first node. For example, if the number of RLFs for the UE is large, the second node may consider that the network status of the first node is not suitable for serving the UE. Therefore, the first node may move the UE to a neighboring cell base station or other base stations that may provide services to the UE. Thus, the second node can refer to this information to determine the resources allocated to the first node for uplink synchronization, so as to facilitate uplink synchronization for the UE during subsequent possible moves.

[0153] ◆ Information related to the radio resource usage status of the cell of the first node. The second node can use this information to understand the radio resource usage status of the cell of the first node. For example, if the radio resource usage status of the cell of the first node is high, the second node can assume that the first node is more likely to move the UE it serves to a neighboring cell base station. As one embodiment, this information may include at least one of the following information or a list of information:

[0154] ● Information related to the radio resource status of SSB areas. This information may be, for example, a list of radio resource statuses for one or more SSB areas, wherein for each SSB area, it may include at least one of the following:

[0155] -SSB entry (SSB Index), which can be an integer between 0 and 63.

[0156] - Downlink PRB usage in the SSB area (SSB Area DL PRB usage). This information can be an integer between 0 and 100, indicating, for example, the percentage of downlink PRB resources used (measured) in the SSB area. This information can be, for example, downlink PRB usage in the SSB area for Guaranteed Bit Rate (GBR) services (SSB Area DL GBRPRB usage), downlink PRB resource usage in the SSB area for non-Guaranteed Bit Rate (non-GBR) services (SSB Area DL non-GBR PRB usage), or total downlink PRB usage in the SSB area (SSB Area DL Total PRB usage).

[0157] - SSB Area UL PRB usage: This information is an integer between 0 and 100, used to indicate the percentage of uplink PRB resources used (measured) within the SSB area. This information can be, for example, the uplink PRB usage in the SSB area for GBR services (SSB Area UL UL PRB usage), the uplink PRB resource usage in the SSB area for non-GBR services (SSB Area UL non-GBR PRB usage), or the total uplink PRB usage in the SSB area (SSB Area UL Total PRB usage).

[0158] ● Radio resource information related to the slice, such as a list of radio resources associated with the slice, which may be radio resource status information for the slice. For each PLMN (Public Land Mobile Network), this information includes an S-NSSAI (Single Network Slice Selection Assistance Information) radio resource status list, which may contain at least one of the following:

[0159] - Slice identifier, for example, S-NSSAI, where an S-NSSAI is used to identify a slice.

[0160] -S-NSSAI downlink PRB usage (S-NSSAIDL PRB usage) refers to the uplink PRB usage of the slice corresponding to S-NSSAI. This information can be an integer from 0 to 100, indicating the percentage of downlink resources used by the slice corresponding to S-NSSAI. This information can be, for example, S-NSSAI downlink PRB usage for GBR services (S-NSSAIDL GBRPRB usage), S-NSSAI downlink PRB usage for non-GBR services (S-NSSAIDL non-GBR PRB usage), or total S-NSSAI downlink PRB usage (S-NSSAIDL Total PRB usage).

[0161] -S-NSSAI Uplink PRB Usage (S-NSSAI UL PRB usage) refers to the uplink PRB usage of the slice corresponding to S-NSSAI. This information is an integer from 0 to 100, used to indicate the percentage of uplink resources used by the slice corresponding to S-NSSAI. This information can be, for example, S-NSSAI Uplink PRB Usage for GBR services (S-NSSAI UL GBR PRB usage), S-NSSAI Uplink PRB Usage for non-GBR services (S-NSSAI UL non-GBRPRB usage), or total S-NSSAI Uplink PRB Usage (S-NSSAI UL Total PRB usage).

[0162] ● Information relating to the usage of physical resource blocks (PRBs) used for multiple-input multiple-output (MIMO), which may include, for example, at least one of the following:

[0163] - Downlink PRB utilization rate for MIMO. This information is an integer from 0 to 100, indicating, for example, the percentage of downlink PRB resources used for MIMO. This information could be, for example, the PRB utilization rate for GBR services, the PRB resource utilization rate for non-GBR services, or the total PRB utilization rate.

[0164] - Uplink PRB utilization rate for MIMO. This information is an integer from 0 to 100, indicating, for example, the percentage of uplink PRB resources used for MIMO. This information could be, for example, the PRB utilization rate for GBR services, the PRB resource utilization rate for non-GBR services, or the total PRB utilization rate.

[0165] ◆Information related to the cell load of the first node, which the second node can use to understand the cell load information of the first node. In one implementation, if the cell load of the first node is high, the second node may assume that the first node may offload some UEs to neighboring base stations or other base stations that can serve UEs to alleviate the cell load of the first node. Therefore, the second node can refer to this information to determine the resources allocated to the first node for uplink synchronization, for uplink synchronization of UEs during subsequent possible mobility. This information may include, for example, at least one of the following information or a list of information:

[0166] ● The number of UEs that are active, which can be an integer value, for example.

[0167] ● The number of Radio Resource Control (RRC) connections, which may be, for example, an integer value;

[0168] ● The available RRC connection capacity, which can be an integer from 0 to 100, and can be used to indicate the percentage of available RRC connections relative to the total number of RRC connections that the cell can support.

[0169] ◆ Information related to the current coverage status of the first node. The second node can use this information to understand the current coverage status of the first node. For example, if the first node has poor coverage, the second node can assume that the first node will move UEs located in poorly covered areas to neighboring base stations. Therefore, the second node can refer to this information to determine the resources allocated to the first node for uplink synchronization, for uplink synchronization of the UE during subsequent possible movements. For each cell under the first node, this information may include, for example, at least one of the following information or a list of information:

[0170] ●Information related to cell identifiers, such as the cell identifiers of each cell in the first node.

[0171] ● Cell coverage status, which can be an integer between 0 and 63.

[0172] ●SSB Override Status List, for each SSB, may include information such as the following:

[0173] -SSB entry;

[0174] -SSB coverage status, which can be an integer between 0 and 15, for example.

[0175] ● Information related to the future / potential coverage of the first node. The second node can use this information to understand the future / potential coverage of the first node. For example, if the first node has poor future coverage, the second node can assume that the first node will move UEs in poorly covered locations to neighboring base stations. Therefore, the second node can refer to this information to determine the resources allocated to the first node for uplink synchronization, for uplink synchronization of UEs during subsequent possible moves. This information may include, for example, at least one of the following or a list of information: the future cell coverage status of the first node, which is an integer from 0 to 63.

[0176] ● The time corresponding to the information related to the future / potential coverage of the first node, which can be an absolute time or a difference relative to an absolute time, i.e., a relative time.

[0177] ● A list of future SSB coverage states for the first node, for each SSB, which may include information such as the following:

[0178] -SSB entry.

[0179] - Future SSB coverage status, this information is an integer between 0 and 15.

[0180] - The time corresponding to the future SSB coverage status. This information can be an absolute time or a difference relative to an absolute time, i.e., a relative time.

[0181] ■ Information related to the type of operation requested for the resources used for uplink synchronization, such as requesting allocation, requesting release, or requesting modification / update of the resources used for uplink synchronization. This information can be an enumeration type containing the operation method requested by the first node for the second node to use for the resources used for uplink synchronization, for example, ENUMERATED(Method 1, Method 2, Method 3, ...), where Method 1, Method 2, and Method 3 can be any one of allocation, release, modification, and update, respectively.

[0182] ■ Information related to the requested release of resources used for uplink synchronization. This information requests the second node or its corresponding DU to release the resources allocated to the first node for uplink synchronization. Upon receiving this information, the second node can release the resources indicated in the information for uplink synchronization and report the resource release status back to the first node. This information may include, for example, at least one of the following:

[0183] ◆ This is used to indicate information related to the release of resources used for uplink synchronization. This information can be a value of type ENUMERATED, such as ENUMERATED(true, ...).

[0184] ◆ Resource information requested for release used for uplink synchronization. This information may include, for example, at least one of the following or a list of information:

[0185] ● The number of the resource used for uplink synchronization that is requested to be released. This information can be an integer or a string.

[0186] ● The type of time-frequency resources requested for uplink synchronization, such as TDD, FDD, CDMA, SBFD, etc.

[0187] ● The purpose of requesting the release of resources used for uplink synchronization, such as for HO, CHO, LTM, C-LTM, secondary cell activation, etc.

[0188] ● The time for requesting the release of resources used for uplink synchronization. This information can be an absolute time or a difference relative to a certain absolute time; it can also be a time period, indicating that the first node requests the second node to release resources used for uplink synchronization within that time period.

[0189] ● Subcarrier spacing.

[0190] ●Starting frequency or starting frequency band. This information can be an integer value, such as INTEGER(0..maxNrofPhysicalResourceBlocks-1), where maxNrofPhysicalResourceBlocks is the maximum number of physical resource blocks.

[0191] ● The number of RACH random access opportunities, which can be an enumeration type, such as ENUMERATED{1, 2, 4, 8}.

[0192] ● The RACH random access configuration entry (index) can be an integer value, such as INTEGER(0..255, ...) or INTEGER(263..299, ...). The maximum value defined in the encoding of this information can be any integer greater than 0.

[0193] ● The number of SSBs for each random access opportunity. This information can be an enumeration type value, such as ENUMERATED(1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, 16, ...).

[0194] ● The frequency domain length of the random access timing. This information can be a selectable value, with options including L839, L139, L571, L1151, etc. For example, if the value is L139, it means the prach-RootSequenceIndex L = 139.

[0195] ● The zero-correlation interval configuration for random access can be an integer value, such as INTEGER(0..15, ...). The maximum value defined in this information encoding can be any integer greater than 0.

[0196] ● Random access response window: This information indicates the length of the SBFD random access response time window.

[0197] It should be noted that the information mentioned above related to the requested release of resources used for uplink synchronization can be applied to both uplink carriers and supplementary uplink carriers.

[0198] ■ Information related to the requested modification / update of resources used for uplink synchronization. This information requests the second node or the corresponding DU to modify / update the resources allocated to the first node for uplink synchronization. Upon receiving this information, the second node can modify / update the resources for uplink synchronization indicated in the information and feed back the modified / updated information to the first node. This information may include, for example, at least one of the following:

[0199] ◆ Used to indicate the modification / update of information related to resources used for uplink synchronization. This information can be a value of type ENUMERATED, such as ENUMERATED(true, ...).

[0200] ◆ Resource information requested for modification / update during uplink synchronization. This information may include, for example, at least one of the following or a list of information:

[0201] ● The number of the resource used for uplink synchronization that is requested to be modified / updated. This information can be an integer or a string.

[0202] ● The type of resource requested for modification / update for uplink synchronization, such as TDD, FDD, CDMA, SBFD, etc.

[0203] ●Request modification / update of the purpose of using resources for uplink synchronization, such as for HO, for CHO, for LTM, for C-LTM, for secondary cell activation, etc.

[0204] ● The time when the request is made to modify / update the resources used for uplink synchronization. This information can be an absolute time or a difference relative to a certain absolute time; this information can also be a time period, indicating that the first node requests the second node to modify / update the resources used for uplink synchronization within this time period.

[0205] ● Subcarrier spacing.

[0206] ●Starting frequency or starting frequency band. This information can be an integer value, such as INTEGER(0..maxNrofPhysicalResourceBlocks-1), where maxNrofPhysicalResourceBlocks is the maximum number of physical resource blocks.

[0207] ● The number of RACH random access opportunities, which can be an enumeration type, such as ENUMERATED{1, 2, 4, 8}.

[0208] ● The RACH random access configuration entry (index) can be an integer value, such as INTEGER(0..255, ...) or INTEGER(263..299, ...). The maximum value defined in the encoding of this information can be any integer greater than 0.

[0209] ● The number of SSBs for each random access opportunity. This information can be an enumeration type value, such as ENUMERATED(1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, 16, ...).

[0210] ● The frequency domain length of the random access timing. This information can be a selectable value, with options including L839, L139, L571, L1151, etc. For example, if the value is L139, it means the prach-RootSequenceIndex L = 139.

[0211] ● The zero-correlation interval configuration for random access can be an integer value, such as INTEGER(0..15, ...). The maximum value defined in this information encoding can be any integer greater than 0.

[0212] ● Random access response window: This information indicates the length of the SBFD random access response time window.

[0213] It should be noted that the information mentioned above related to the requested modification / update of resources used for uplink synchronization can be applied to both uplink carriers and supplementary uplink carriers.

[0214] ■ Information relating to the usage / remaining status of the resources allocated by the first node to the second node for uplink synchronization. The second node can use this information to understand the usage of these resources. For example, if the utilization rate of the uplink synchronization resources allocated by the first node to the second node is high, the second node may consider allocating more uplink synchronization resources to the first node; conversely, if the utilization rate of the uplink synchronization resources allocated by the first node to the second node is low, the second node may consider releasing some of the uplink synchronization resources allocated to the first node. This information may include, for example, at least one of the following information or a list of information:

[0215] ◆Information related to used resources, indicating the usage of resources allocated by the first node to the second node for uplink synchronization. This information can be an integer between 0 and 100, representing the percentage of uplink synchronization resources used relative to the total uplink synchronization resources allocated by the second node to the first node. Alternatively, this information can be an absolute value representing the amount of resources used.

[0216] ◆ Information related to unused resources, indicating the remaining resources allocated by the first node to the second node for uplink synchronization. This information can be an integer between 0 and 100, representing the percentage of unused uplink synchronization resources relative to the total uplink synchronization resources allocated by the second node to the first node. Alternatively, this information can be an absolute value representing the amount of unused resources.

[0217] The implementation of the first notification message described above can be applied to each cell in one or more cells of the second node. That is, the first notification message may include one or more of the above-mentioned information for each cell (e.g., "information related to the identifier of the cell for which the requested allocation of resources for uplink synchronization is made", "seventh information related to the type of the requested resources for uplink synchronization", "eighth information related to the number of the requested resource set for uplink synchronization", "ninth information related to assisting the second node in allocating resources for uplink synchronization", "information related to the operation type of the requested resources", "information related to the requested release of resources for uplink synchronization", "information related to the requested modification / update of resources for uplink synchronization", "information related to the usage / remaining status of the resources for uplink synchronization allocated by the first node to the second node"). In other words, one or more of the above-mentioned information are included for each cell. As an alternative implementation, the first notification message may not be per cell of one or more cells of the second node. For example, "ninth information related to assisting the second node in allocating resources for uplink synchronization" may be included only once in the first notification message, rather than for each cell. Other than "ninth information related to assisting the second node in allocating resources for uplink synchronization", the aforementioned information may be per cell of one or more cells of the second node.

[0218] The aforementioned first notification message can be a non-UE-related message, such as an XnAP establishment request message, an NG-RAN node configuration update message, or other existing or newly defined XnAP messages. This message can also be a UE-related message.

[0219] Upon receiving the first notification message, the second node assumes that the UE served by the first node may move to the second node's service area and require network resources, such as uplink synchronization for potential subsequent mobility events. The second node then sends a second request message to the fourth node based on the first notification message. See step 302 for details.

[0220] Step 302: The second node sends a second request message to the fourth node. This second request message may include one or more of the first notification messages from step S301. For example, it may include at least one of the following: sixteenth information related to the type of the requested uplink synchronization resource; seventeenth information related to the number of the requested uplink synchronization resource set; and eighteenth information related to assisting the fourth node in allocating resources for uplink synchronization. The purpose of this message is to send information related to the requested uplink synchronization resources to the fourth node. The content of this message can be referred to the description in step 301.

[0221] The aforementioned second request message can be a non-UE-related message, such as an F1AP establishment request message, a gNB-CU configuration update message, or other existing or newly defined F1AP messages. This message can also be a UE-related message.

[0222] After receiving the above message, the fourth node will determine the resources to be allocated to the first node for uplink synchronization based on the content of the second request message, and will send the information related to the allocated resources to the second node in the second request response message, as detailed in step 303.

[0223] Step 303: The fourth node sends a second request response message to the second node. This message provides feedback to the second node regarding information related to the uplink synchronization resources allocated by the fourth node. In this invention, the resources used for uplink synchronization can all be used for the UE's advance synchronization. This message may, for example, contain at least one of the following information or a list of information:

[0224] ■ Nineteenth information related to the tenth resource used for uplink synchronization, such as a list of information related to the first resource used for uplink synchronization. This information can be used to provide information related to the resources allocated / reserved by the fourth node for uplink synchronization. The reserved resources can be used for subsequent uplink synchronization of the UE during movement, including advance synchronization. For each cell (in a CU-DU separation architecture, it is the cell of the fourth node; in an aggregated architecture, ...), Figure 3a As shown, this is the cell of the second node. This information may include, for example, at least one of the following information or a list of information:

[0225] ◆Community signage information.

[0226] ◆ This information applies to uplink carrier resource-related information. This information may include, for example, at least one of the following:

[0227] ● Information related to the number of the resource used for uplink synchronization, such as the number of the resource assigned for uplink synchronization. This information can be an integer value or a string.

[0228] ● Information related to the type of time-frequency resources used for uplink synchronization, such as resource types like TDD, FDD, CDMA, SBFD, etc.

[0229] ●Information related to the purpose of using resources for uplink synchronization, such as for HO, for CHO, for LTM, for C-LTM, for secondary cell activation, etc.

[0230] ● Information related to the validity period of resources used for uplink synchronization. This information can be a point in time, such as an absolute time, or a difference relative to an absolute time. For example, it can be used to indicate that the resources used for uplink synchronization were valid before the time indicated by the information. This information can also be a period of time, for example, it can be used to indicate that the resources used for uplink synchronization were valid within the period of time indicated by the information.

[0231] ● Subcarrier spacing.

[0232] ●Starting frequency or starting frequency band. This information can be an integer value, such as INTEGER(0..maxNrofPhysicalResourceBlocks-1), where maxNrofPhysicalResourceBlocks is the maximum number of physical resource blocks.

[0233] ● The number of RACH random access opportunities, which can be an enumeration type, such as ENUMERATED{1, 2, 4, 8}.

[0234] ● The RACH random access configuration entry (index) can be an integer value, such as INTEGER(0..255, ...) or INTEGER(263..299, ...). The maximum value defined in the encoding of this information can be any integer greater than 0.

[0235] ● The number of SSBs for each random access opportunity. This information can be an enumeration type value, such as ENUMERATED(1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, 16, ...).

[0236] ● The frequency domain length of the random access timing. This information can be a selectable value, with options including L839, L139, L571, L1151, etc. For example, if the value is L139, it means the prach-RootSequenceIndex L = 139.

[0237] ● The zero-correlation interval configuration for random access can be an integer value, such as INTEGER(0..15, ...). The maximum value defined in this information encoding can be any integer greater than 0.

[0238] ● Random access response window: This information indicates the length of the SBFD random access response time window.

[0239] ◆ This information is applicable to supplementing uplink carrier resource-related information. This information may include, for example, at least one of the following:

[0240] ● Information related to the type of time-frequency resources used for uplink synchronization, such as resource types like TDD, FDD, CDMA, SBFD, etc.

[0241] ●Information related to the purpose of using resources for uplink synchronization, such as for HO, for CHO, for LTM, for C-LTM, for secondary cell activation, etc.

[0242] ● Information related to the validity period of resources used for uplink synchronization.

[0243] ● Subcarrier spacing.

[0244] ●Starting frequency or starting frequency band. This information can be an integer value, such as INTEGER(0..maxNrofPhysicalResourceBlocks-1), where maxNrofPhysicalResourceBlocks is the maximum number of physical resource blocks.

[0245] ● The number of RACH random access opportunities, which can be an enumeration type, such as ENUMERATED{1, 2, 4, 8}.

[0246] ● The RACH random access configuration entry (index) can be an integer value, such as INTEGER(0..255, ...) or INTEGER(263..299, ...). The maximum value defined in the encoding of this information can be any integer greater than 0.

[0247] ● The number of SSBs for each random access opportunity. This information can be an enumeration type value, such as ENUMERATED(1 / 8, 1 / 4, 1 / 2, 1, 2, 4, 8, 16, ...).

[0248] ● The frequency domain length of the random access timing. This information can be a selectable value, with options including L839, L139, L571, L1151, etc. For example, if the value is L139, it means the prach-RootSequenceIndex L = 139.

[0249] ● The zero-correlation interval configuration for random access can be an integer value, such as INTEGER(0..15, ...). The maximum value defined in this information encoding can be any integer greater than 0.

[0250] ● Random access response window: This information indicates the length of the SBFD random access response time window.

[0251] ■ Information related to the type of operation on the resources used for uplink synchronization, such as allocating, releasing, or modifying / updating the resources used for uplink synchronization. This information can be an enumeration type containing the operation mode on the uplink synchronization resources determined by the fourth node, such as ENUMERATED(mode 1, mode 2, mode 3, ...), where mode 1, mode 2, and mode 3 can be any one of allocation, release, modification, update, or rejection.

[0252] ■ A twentieth piece of information related to the release of the eleventh resource used for uplink synchronization, such as information indicating the release of a second resource used for uplink synchronization. This information can be a value of type ENUMERATED, such as ENUMERATED(true, ...). As one implementation, the aforementioned twentieth information can be indicated by the name of a cell; for example, if a cell is named "Instruction to Release Resources Used for Uplink Synchronization," then when this cell appears as a true value, it indicates the release of the resources used for uplink synchronization.

[0253] ■ The twenty-first piece of information related to updating the twelfth resource used for uplink synchronization, such as indicating the modification / update of information related to the third resource used for uplink synchronization, if the second request response message contains this information, then the receiving end, upon receiving the second request response message, can consider the resource-related information in the message to be the updated resource allocation information. The modification / update methods can be, for example, the following two:

[0254] ◆The previously stored resource allocation information is replaced by new resource allocation information.

[0255] ◆Add or modify existing stored resource information.

[0256] ■ Information related to the rejection of the requested resources for uplink synchronization. This information can be a value of type ENUMERATED, such as ENUMERATED(true, ...). Upon receiving this information, the second node should assume that the fourth node has rejected the request for resources for uplink synchronization and notify the first node of this information.

[0257] The aforementioned second request response message can be a non-UE-related message, such as an F1AP establishment request response message, a gNB-CU configuration update confirmation message, or other existing or newly defined F1AP messages. This message can also be a UE-related message.

[0258] After receiving the second request response message, the second node can regard the message as the fourth node's response to the resource request for uplink synchronization, and forward the content of the message to the first node, as detailed in step 304.

[0259] Step 304: The second node sends a second notification message to the first node. This message forwards information about the resources allocated to the second node or its DU to the first node. The content of this second notification message can be referred to in step 303.

[0260] The aforementioned second notification message can be a non-UE-related message, such as an XnAP establishment request response message, an NG-RAN node configuration update confirmation message, or other existing or newly defined XnAP interface messages. This message can also be a UE-related message.

[0261] Upon receiving the second notification message, the first node (if supported) can use the resource-related information corresponding to the first request response for subsequent UE mobility-related processes, such as the uplink synchronization process.

[0262] The methods provided in various embodiments of this disclosure, by pre-allocating / reserving resources for uplink synchronization between base stations, enable the source base station to notify the UE of the pre-allocated / reserved resources for uplink synchronization in UE mobility scenarios, thereby achieving uplink synchronization without random access. This reduces UE interruptions caused by random access during movement. Furthermore, by pre-allocating / reserving uplink synchronization resources between base stations, the methods provided in various embodiments of this disclosure eliminate the need to request uplink synchronization resources from candidate cells based on the UE's request when a cell handover occurs. Compared to UE-request-based schemes, this reduces signaling overhead related to uplink synchronization, thereby reducing the load on the network interface. Furthermore, compared to existing LTM schemes where resources for uplink synchronization can only be requested during the handover preparation process related to the UE (e.g., including requests for resources for uplink synchronization in the handover request message), the methods provided by various embodiments of this disclosure request resources for uplink synchronization in advance before handover preparation (e.g., before sending a sixth request message related to requesting configuration of the target cell and / or candidate cell of the UE). This allows the methods of this disclosure to perform per-node interactions between networks without relying on the mobility preparation process with the UE. Moreover, the pre-allocated resources for uplink synchronization can be used not only for LTM but also for HO / CHO / C-LTM / secondary cell activation, etc., thus providing a general uplink synchronization resource allocation scheme that is not limited to LTM scenarios (Layer 1 / Layer 2 triggered mobility) and makes the methods provided by various embodiments of this disclosure applicable to a wider range of scenarios.

[0263] In the above embodiment, the second base station is a CU-DU separated architecture, wherein the second node is the CU of the second base station, and the fourth node is the DU of the second base station. As another embodiment, the second base station can be an aggregated architecture. Please refer to... Figure 3a , Figure 3a This is a schematic diagram illustrating the interaction between a first node and a second node according to various embodiments of the present disclosure, wherein the first node is a first base station and the second node is a second base station. In this embodiment, a second request message and a second request response message may not exist.

[0264] like Figure 3a As shown, in step 301a, the first node sends a first notification message to the second node related to the request for resources used for uplink synchronization. The specific message content can be found in step 301.

[0265] After the second node makes a decision to allocate / update / release resources for uplink synchronization, in step 304a, the second node sends a second notification message to the first node. The second notification message may include information related to the identifier of the second node's first cell and at least one of the following information corresponding to the first cell: first information related to the first resource used for uplink synchronization; second information related to the release of the second resource used for uplink synchronization; and third information related to the update of the third resource used for uplink synchronization. The specific content can be found in step 304. The second and third resources may be different, and the second / third resource may be the same as or different from the first resource. In one embodiment, if the resource to be released is indicated by the first information related to the first resource used for uplink synchronization, then the first and second resources are the same; if the first information related to the first resource used for uplink synchronization indicates a newly allocated resource, and the second information related to the release of the second resource used for uplink synchronization indicates a released resource, then the first and second resources are different. In another implementation, if the resource to be updated is indicated by first information associated with a first resource used for uplink synchronization, then the first resource and the third resource are the same; if the first information associated with the first resource used for uplink synchronization indicates a newly allocated resource, and the third information associated with updating the third resource used for uplink synchronization indicates an updated resource, then the first resource and the third resource are different.

[0266] It is important to note that Figure 3 and Figure 3a The first and second notification messages can be two independent messages or a set of related request and response messages. When the first and second notification messages are independent, the second node can proactively send the second notification message to the first node without receiving the first notification message; that is, the first notification message is optional. When the first and second notification messages are related request and response messages, in this invention, the first notification message can also be called the first request message, and the second notification message can also be called the first request-response message.

[0267] The methods provided in various embodiments of this disclosure, by pre-allocating / reserving resources for uplink synchronization between base stations, enable the source base station to notify the UE of the pre-allocated / reserved resources for uplink synchronization in UE mobility scenarios, thereby achieving uplink synchronization without random access. This reduces UE interruptions caused by random access during movement. Furthermore, by pre-allocating / reserving uplink synchronization resources between base stations, the methods provided in various embodiments of this disclosure eliminate the need to request uplink synchronization resources from candidate cells based on the UE's request when a cell handover occurs. Compared to UE-request-based schemes, this reduces signaling overhead related to uplink synchronization, thereby reducing the load on the network interface. Furthermore, compared to existing LTM schemes where resources for uplink synchronization can only be requested during the handover preparation process related to the UE (e.g., including requests for resources for uplink synchronization in the handover request message), the methods provided by various embodiments of this disclosure request resources for uplink synchronization in advance before handover preparation (e.g., before sending a sixth request message related to requesting configuration of the target cell and / or candidate cell of the UE). This allows the methods of this disclosure to perform per-node interactions between networks without relying on the mobility preparation process with the UE. Moreover, the pre-allocated resources for uplink synchronization can be used not only for LTM but also for HO / CHO / C-LTM, thus providing a universal uplink synchronization resource allocation scheme that is not limited to (Layer 1 / Layer 2 triggered mobility) LTM scenarios, making the methods provided by various embodiments of this disclosure applicable to a wider range of scenarios.

[0268] After receiving resource allocation information from neighboring base stations, if the first base station has a CU-DU separation architecture, the first node (the CU of the first base station) can allocate these resources to the third node (the DU of the first base station), or allocate resources based on DU requests. Please refer to [link / reference]. Figure 4 , Figure 4 This is a schematic diagram illustrating the interaction between a first node, a third node, and a fifth node according to various embodiments of the present disclosure, wherein the first node is the CU of the first base station, the third node is the DU of the first base station, and the fifth node is the UE. Figure 4 The method shown may include one or more of steps 401 to 403:

[0269] Step 401: The first node sends a third request message to the third node, wherein the third request message includes eleventh information related to the seventh resource for uplink synchronization determined by the first node for the third node. As one implementation, the seventh resource for uplink synchronization may be received by the first node from a neighboring base station (e.g., Figure 3 In step 304, the second notification message, which includes the first resource for uplink synchronization, is received from the second node and allocated to the third node. The content of the third request message is as described in the second notification message in step 304.

[0270] As another approach, the eleventh information included in the third request message may be a subset of the first information included in step 304 (in this embodiment, the first resource for uplink synchronization and the seventh resource for uplink synchronization may be different, and the seventh resource for uplink synchronization is a subset of the first resource for uplink synchronization; in another embodiment, the first resource for uplink synchronization and the seventh resource for uplink synchronization may be the same, that is, the first node determines all the first resources for uplink synchronization allocated by the second node as the seventh resources for uplink synchronization used by the third node), and may also include resources for uplink synchronization allocated by other base stations besides the second base station.

[0271] The aforementioned third request message can be a non-UE-related message, such as an F1AP establishment request message, a gNB-CU configuration update message, or other existing or newly defined F1AP messages. It can also be a UE-related message. Upon receiving the third request message, the third node, if supported, can use the seventh resource carried in the third request message for uplink synchronization in subsequent UE mobility-related processes, such as the uplink synchronization process.

[0272] Step 402: The third node sends a third request response message to the first node. This message is the third node's response to the third request message sent by the first node. For each cell (which can be a cell of the second node or a cell of the fourth node, depending on whether the base station has a CU-DU separation structure), this message may include, for example, at least one of the following information or a list of information:

[0273] ■ Community signage.

[0274] ■ Confirmation information related to accepting resources used for uplink synchronization.

[0275] ■ Information related to resources that are refused for uplink synchronization.

[0276] ■ Information related to the usage of the eighth resource for uplink synchronization, determined by the first node for the third node, which can be used to notify the first node of the usage of the eighth resource for uplink synchronization. The eighth resource for uplink synchronization may be the same as or different from the seventh resource for uplink synchronization. For example, the third request response message may provide feedback on the usage of the seventh resource for uplink synchronization in the third request message; in this case, the eighth resource for uplink synchronization may be the same as the seventh resource for uplink synchronization. Alternatively, the third request response message may provide feedback not only on the usage of the seventh resource for uplink synchronization in the third request message, but also on the usage of previously determined / allocated resources for uplink synchronization; in this case, the eighth resource for uplink synchronization may be different from the seventh resource for uplink synchronization. Furthermore, if the third node's utilization rate of the uplink synchronization resources allocated to the second node is low, the first node can notify the second base station or request the second base station to release some of the uplink synchronization resources. Conversely, if the third node's utilization rate of the uplink synchronization resources allocated to the second node is high, the first node can consider requesting more uplink synchronization resources from the second base station. This information may include, for example, the following:

[0277] At least one of the following: information or list of information:

[0278] ◆Used resource information: This information indicates the usage status of resources used by the third node for uplink synchronization. This information can be an integer between 0 and 100, representing the percentage of uplink synchronization resources used out of all uplink synchronization resources received by the third node; it can also be an absolute value representing the amount of resources used.

[0279] ◆Unused resource information: This information indicates the remaining resources used by the third node for uplink synchronization. This information can be an integer between 0 and 100, representing the percentage of unused resources relative to the total uplink synchronization resources allocated to the third node; it can also be an absolute value representing the number of unused resources.

[0280] ◆A list of numbers corresponding to the resources used for uplink synchronization. The number can be an integer or a string.

[0281] ◆A list of unused IDs for uplink synchronization resources. The ID can be an integer or a string.

[0282] The aforementioned third request response message can be a non-UE-related message, such as an F1AP establishment request response message, a gNB-CU configuration update confirmation message, or other existing or newly defined F1AP messages.

[0283] As another implementation method Figure 4 The method shown may include steps 401' to 402', but may not include steps 401 to 402. The specific contents of steps 401' to 402' are described in detail below.

[0284] Step 401': The third node sends a fourth request message to the first node. This message can be used to send a request to the first node regarding resources, such as a request for uplink synchronization resources. This message may include, for example, at least one of the following information or a list of information:

[0285] ■ Information related to UEs that need to use resources for uplink synchronization, such as UE identifiers or a list of identifiers that need to use resources for uplink synchronization.

[0286] ■ Twelfth piece of information relating to the type of resource requested for uplink synchronization. The type of resource for uplink synchronization can be classified in several different ways. For example, the type of resource for uplink synchronization can be classified based on the following methods, and it is understood that regardless of the classification method, it falls within the scope of this disclosure.

[0287] ◆If classified according to the purpose of resource use, resources used for uplink synchronization can be one or more of the following types:

[0288] ● Synchronization resources used for Layer 3 (L3) switching;

[0289] ● Synchronization resources used for LTM;

[0290] ● Synchronization resources used for Conditional Hitch (CHO);

[0291] ● Synchronization resources for the type of Conditional LTM (C-LTM);

[0292] ● Synchronization resources used for secondary cell activation (Scell ​​activation).

[0293] ◆If classified according to the type of time-frequency resources, the resources used for uplink synchronization can be one or more of the following types:

[0294] ●Time-division multiplexed synchronization resources;

[0295] ●Frequency division multiplexing synchronization resources;

[0296] ● Synchronization resources for Code Division Multiple Access;

[0297] ●Synchronization resources for full-duplex sub-bands.

[0298] ◆If classified according to the type of uplink carrier, the resources used for uplink synchronization can be one or more of the following types:

[0299] ● Synchronization resources for the uplink carrier;

[0300] ●Supplement the synchronization resources of the uplink carrier.

[0301] ■ Thirteenth piece of information related to the number of resource sets requested. A detailed description of this thirteenth piece of information can be found in the description of the eighth piece of information, and will not be repeated here.

[0302] ■ Information related to the type of operation requested for the resources used for uplink synchronization, such as requesting allocation, requesting release, or requesting modification / update of the resources used for uplink synchronization. This information can be an enumeration type containing the operation method requested by the first node for the second node to use for the resources used for uplink synchronization, for example, ENUMERATED(Method 1, Method 2, Method 3, ...), where Method 1, Method 2, and Method 3 can be any one of allocation, release, modification, and update, respectively.

[0303] ■ The number corresponding to the resource used for uplink synchronization that is requested to be released / modified / updated. This information can be an integer value or a string.

[0304] The aforementioned fourth request message can be a non-UE-related message, such as a gNB-DU configuration update message, or other existing or newly defined F1AP messages. It can also be a UE-related message.

[0305] Step 402': The first node sends a fourth request response message to the third node, wherein the fourth request response message includes fourteenth information related to the ninth resource for uplink synchronization determined by the first node for the third node. As one implementation, the ninth resource for uplink synchronization may be obtained by the first node from a neighboring base station (e.g., Figure 3 In step 304, the second notification message received from the second node includes the first resource (used for uplink synchronization) and is allocated to the third node. The content of this message is as described in step 401.

[0306] In another manner, the fourteenth information contained in the fourth request response message may be a subset of the first information contained in step 304 (in this embodiment, the first resource for uplink synchronization and the ninth resource for uplink synchronization may be different, and the ninth resource for uplink synchronization is a subset of the first resource for uplink synchronization; in another embodiment, the first resource for uplink synchronization and the ninth resource for uplink synchronization may be the same, that is, the first node determines all the first resources for uplink synchronization allocated by the second node as the ninth resources for uplink synchronization used by the third node), and may also include resources for uplink synchronization allocated by other base stations besides the second base station.

[0307] The aforementioned fourth request response message can be a non-UE-related message, such as a gNB-DU configuration update confirmation message, or other existing or newly defined F1AP messages. This message can also be a UE-related message.

[0308] Step 403: The first node sends a first reconfiguration message to the fifth node. This message can be used to send resources that the UE may need during mobility (e.g., resources for uplink synchronization) to the UE in advance, thereby reducing interaction during mobility and alleviating interface load. This message may include, for example, at least one of the following information or a list of information:

[0309] ■ Fourth information related to the fourth resource used for uplink synchronization. The specific content of this information is as described in step 401. It should be noted that the fourth resource used for uplink synchronization in step 403 may be a subset of the seventh resource used for uplink synchronization in step 401 or the ninth resource used for uplink synchronization in step 402', or it may include resources used for uplink synchronization allocated by cells served by other neighboring base stations besides the second base station.

[0310] ■ Fifth information related to the release of the fifth resource used for uplink synchronization. For details regarding the fifth information, please refer to the description of the second information; it will not be repeated here.

[0311] ■ The sixth piece of information relates to updating the sixth resource used for uplink synchronization. For details regarding the sixth piece of information, please refer to the description of the third piece of information; it will not be repeated here.

[0312] The aforementioned first configuration message can be an RRC reconfiguration message or other RRC messages.

[0313] The methods provided in various embodiments of this disclosure, by pre-allocating / reserving resources for uplink synchronization between base stations, enable the source base station to notify the UE of the pre-allocated / reserved resources for uplink synchronization in UE mobility scenarios, thereby achieving uplink synchronization without random access. This reduces UE interruptions caused by random access during movement. Furthermore, by pre-allocating / reserving uplink synchronization resources between base stations, the methods provided in various embodiments of this disclosure eliminate the need to request uplink synchronization resources from candidate cells based on the UE's request when a cell handover occurs. Compared to UE-request-based schemes, this reduces signaling overhead related to uplink synchronization, thereby reducing the load on the network interface. Furthermore, compared to existing LTM schemes where resources for uplink synchronization can only be requested during the handover preparation process related to the UE (e.g., including requests for resources for uplink synchronization in the handover request message), the methods provided by various embodiments of this disclosure request resources for uplink synchronization in advance before handover preparation (e.g., before sending a sixth request message related to requesting configuration of the target cell and / or candidate cell of the UE). This allows the methods of this disclosure to perform per-node interactions between networks without relying on the mobility preparation process with the UE. Moreover, the pre-allocated resources for uplink synchronization can be used not only for LTM but also for HO / CHO / C-LTM / secondary cell activation, etc., thus providing a general uplink synchronization resource allocation scheme that is not limited to LTM scenarios (Layer 1 / Layer 2 triggered mobility) and makes the methods provided by various embodiments of this disclosure applicable to a wider range of scenarios.

[0314] In the above embodiments, the first base station is a CU-DU separated architecture, wherein the first node is the CU of the first base station, and the third node is the DU of the first base station. As another embodiment, the first base station can be an aggregated architecture. Please refer to... Figure 4a , Figure 4a This is a schematic diagram illustrating the interaction between a first node and a fifth node according to various embodiments of the present disclosure, wherein the first node is a first base station and the fifth node is a UE served by the first base station.

[0315] After the first node receives the resources allocated by the second base station for uplink synchronization (e.g., after step 304a), it can send a first reconfiguration message to the fifth node in step 403a. This first reconfiguration message may include information related to the identifier of the second cell determined by the first node for the UE, and at least one of the following information corresponding to the second cell: fourth information related to the fourth resource for uplink synchronization; fifth information related to releasing the fifth resource for uplink synchronization; and sixth information related to updating the sixth resource for uplink synchronization, as described in step 403. In this embodiment, the third request message, third request response message, fourth request message, and fourth request response message may not be present.

[0316] The methods provided in various embodiments of this disclosure, by pre-allocating / reserving resources for uplink synchronization between base stations, enable the source base station to notify the UE of the pre-allocated / reserved resources for uplink synchronization in UE mobility scenarios, thereby achieving uplink synchronization without random access. This reduces UE interruptions caused by random access during movement. Furthermore, by pre-allocating / reserving uplink synchronization resources between base stations, the methods provided in various embodiments of this disclosure eliminate the need to request uplink synchronization resources from candidate cells based on the UE's request when a cell handover occurs. Compared to UE-request-based schemes, this reduces signaling overhead related to uplink synchronization, thereby reducing the load on the network interface. Furthermore, compared to existing LTM schemes where resources for uplink synchronization can only be requested during the handover preparation process related to the UE (e.g., including requests for resources for uplink synchronization in the handover request message), the methods provided by various embodiments of this disclosure request resources for uplink synchronization in advance before handover preparation (e.g., before sending a sixth request message related to requesting configuration of the target cell and / or candidate cell of the UE). This allows the methods of this disclosure to perform per-node interactions between networks without relying on the mobility preparation process with the UE. Moreover, the pre-allocated resources for uplink synchronization can be used not only for LTM but also for HO / CHO / C-LTM / secondary cell activation, etc., thus providing a general uplink synchronization resource allocation scheme that is not limited to LTM scenarios (Layer 1 / Layer 2 triggered mobility) and makes the methods provided by various embodiments of this disclosure applicable to a wider range of scenarios.

[0317] It should be noted that the steps in the various embodiments of this invention do not have a predetermined order. For example, Figure 4 Step 401' in the process can occur Figure 3This can occur before step 301 or after step 304. In other words, if the first base station has a CU-DU separation architecture, the first node (the CU of the first base station) can proactively initiate a request for resources for uplink synchronization to the second base station, or it can send a request for resources for uplink synchronization to the second base station based on a request from the third node (the DU of the first base station).

[0318] After the base station makes a handover decision for the UE, it can notify the UE to perform uplink synchronization using pre-allocated resources before or during the handover preparation process. Please refer to [reference needed]. Figure 5 , Figure 5 This is a schematic diagram illustrating the interaction between the first to fifth nodes according to various embodiments of the present disclosure, wherein the first node is the CU of the first base station, the third node is the DU of the first base station, the second node is the CU of the second base station, the fourth node is the DU of the second base station, and the fifth node is the UE. Figure 5 The method shown may include one or more of steps 501 to 509:

[0319] Step 501: The first node sends a fifth request message to the third node. This message can be used to notify the DU to trigger the UE to perform uplink synchronization. This fifth request message may contain, for example, the following information:

[0320] ■ Information related to triggering UE uplink synchronization, such as information instructing the UE to perform uplink synchronization. This information is used to notify the third node to trigger the UE to send a preamble to the target cell for uplink synchronization. For example, during L3 handover, the first node selects a target cell for the UE based on L3 measurement information and notifies the corresponding DU to trigger the UE to perform early uplink synchronization. After receiving this message, the third node should send a PDCCH command (order) to the UE to trigger the UE to perform early uplink synchronization.

[0321] The aforementioned fifth request message can be a non-UE-related message, such as a gNB-CU configuration update message, or other existing or newly defined F1AP messages; or it can be a UE-related message, such as a UE text creation message, a UE text modification message, or other existing or newly defined messages.

[0322] Step 502: The third node sends a PDCCH command to the fifth node. This information is used to instruct the UE about resources related to uplink synchronization.

[0323] Step 503: The third node sends a fifth request response message to the first node. This fifth request response message can be used to notify the first node of the uplink synchronization-related resource information used by the UE, wherein the uplink synchronization-related resource information used by the UE is sent to the UE via the PDCCH command in step 502. After receiving the message, the first node can forward the content of the message to the second base station, and the second base station should determine the UE corresponding to the timing advance (TA) value based on the message. The message may contain at least one of the following information or a list of information:

[0324] ■ Fifteenth piece of information related to the Random Access Channel (RACH) resources used for uplink synchronization by the UE. This fifteenth piece of information may, for example, include at least one of the following information or a list of information:

[0325] ◆Target cell or candidate cell identifier.

[0326] ◆Information related to the preamble entry used by the UE for uplink synchronization, which can be used to indicate the preamble entry used by the UE for uplink synchronization.

[0327] ◆ UE Identifier Based on Random Access (RA-RNTI).

[0328] ◆Information related to the source entity of the handover, such as the identifier of the source base station (e.g., global NG-RAN node ID) and the identifier of the source DU (gNB-DU ID);

[0329] ◆ Information related to the Timing Advance Group (TAG), which relates to the Transmission Configuration Indication (TCI) state, can be included in the TCI-UL-State or TCI-state.

[0330] The aforementioned fifth request response message can be a non-UE-related message, such as a gNB-CU configuration update confirmation message, or other existing or newly defined messages; it can also be a UE-related message, such as a UE text establishment response message, a UE text modification response message, or other existing or newly defined messages.

[0331] Optionally, the third node may send step 503 to the first node without step 501. In this case, the message of step 503 may be a gNB-DU configuration update message, a UE text modification request message, or other existing or newly defined UE-related or non-UE-related messages.

[0332] Step 504: The fifth node sends a preamble to the fourth node. The preamble information used by the fifth node is indicated in step 502.

[0333] Step 505: The first node sends a sixth request message to the second node (e.g., the sixth request message may be a handover request message), wherein the sixth request message may include tenth information related to the Random Access Channel (RACH) resources used by the UE for uplink synchronization. This sixth request message can be used to request configuration of the user's target cell or candidate cell. In L3 HO, this message is used to request configuration of the user's target cell; in CHO, LTM, and C-LTM, this information is used to request configuration of the user's candidate cell. During L3 handover preparation, this message contains tenth information related to the RACH resources used by the UE for uplink synchronization, and the second base station can determine the UE corresponding to the TA value based on this information. The specific content of the tenth information is as described in the fifteenth information in step 503.

[0334] The sixth request message mentioned above can be a UE-related message, such as a handover request message, or other existing or newly defined XnAP messages. It can also be a non-UE-related message.

[0335] Step 506: The second node sends a seventh request message to the fourth node, wherein the seventh request message includes twenty-second information related to the Random Access Channel (RACH) resources used for uplink synchronization with the UE. This message can be used to establish context information related to the UE experiencing mobility with the fourth node. The fourth node can determine the UE corresponding to the TA value based on the twenty-second information. The specific content of the twenty-second information can be found in the description of the fifteenth information in step 503.

[0336] The aforementioned seventh request message can be a UE-related message, such as a UE text establishment message, or other existing or newly defined F1AP messages. It can also be a non-UE-related message.

[0337] Step 507: The fourth node sends a seventh request response message to the second node. This message can be used to send a context-related response to the second node regarding the UE that has experienced mobility. During L3 handover, this message may include the TA value required for UE uplink synchronization. This TA value is measured by the base station and the corresponding UE is determined based on the twenty-second information related to the RACH resources used by the UE for uplink synchronization in the seventh request message. The seventh request response message may, for example, contain at least one of the following information or a list of information:

[0338] ■The TA value represents the time lead required for the UE to achieve uplink synchronization, as measured by the base station. This information is an integer between 0 and 4095, or an integer greater than 4095. Upon receiving this information, the second node should forward it to the first node so that the first node can send the TA value required for uplink synchronization to the UE.

[0339] The seventh request response message mentioned above can be a UE-related message, such as a UE text establishment response message, or other existing or newly defined F1AP messages. This message can also be a non-UE-related message.

[0340] Step 508: The second node sends a sixth request response message to the first node. This message can be used to send a response to the sixth request message for the target cell and / or candidate cell of the UE requesting configuration. During L3 handover, this message may include the TA value required by the UE for uplink synchronization, and the description of the TA value can be found in step 507.

[0341] The sixth request response message mentioned above can be a UE-related message, such as a handover request confirmation message, or other existing or newly defined XnAP messages. It can also be a non-UE-related message.

[0342] Step 509: The first node sends a second reconfiguration message to the UE. This message can be used to notify the UE of the TA value used for uplink synchronization. After receiving the TA value, the UE can use it to perform uplink synchronization with the target cell, reducing interruptions during mobility. This second reconfiguration message may contain at least one of the following information or a list of information:

[0343] ■The TA value represents the time lead required for the UE to achieve uplink synchronization, as measured by the base station. This information is an integer between 0 and 4095, or an integer greater than 4095.

[0344] The aforementioned second-level configuration message can be an RRC message, such as an RRC-Reconfiguration message, or a MACCE message, or other lower-level messages.

[0345] The methods provided in various embodiments of this disclosure, by pre-allocating / reserving resources for uplink synchronization between base stations, enable the source base station to notify the UE of the pre-allocated / reserved resources for uplink synchronization in UE mobility scenarios, thereby achieving uplink synchronization without random access. This reduces UE interruptions caused by random access during movement. Furthermore, by pre-allocating / reserving uplink synchronization resources between base stations, the methods provided in various embodiments of this disclosure eliminate the need to request uplink synchronization resources from candidate cells based on the UE's request when a cell handover occurs. Compared to UE-request-based schemes, this reduces signaling overhead related to uplink synchronization, thereby reducing the load on the network interface. Furthermore, compared to existing LTM schemes where resources for uplink synchronization can only be requested during the handover preparation process related to the UE (e.g., including requests for resources for uplink synchronization in the handover request message), the methods provided by various embodiments of this disclosure request resources for uplink synchronization in advance before handover preparation (e.g., before sending a sixth request message related to requesting configuration of the target cell and / or candidate cell of the UE). This allows the methods of this disclosure to perform per-node interactions between networks without relying on the mobility preparation process with the UE. Moreover, the pre-allocated resources for uplink synchronization can be used not only for LTM but also for HO / CHO / C-LTM / secondary cell activation, etc., thus providing a general uplink synchronization resource allocation scheme that is not limited to LTM scenarios (Layer 1 / Layer 2 triggered mobility) and makes the methods provided by various embodiments of this disclosure applicable to a wider range of scenarios.

[0346] In the above embodiments, the first base station and the second base station are in a CU-DU separate architecture. In another embodiment, the first base station and the second base station are in an aggregated architecture. Please refer to... Figure 5a , Figure 5a This is a schematic diagram illustrating the interaction between a first node, a second node, and a fifth node according to various embodiments of this disclosure, wherein the first node is a first base station, the second node is a second base station, and the fifth node is a UE served by the first base station. In this embodiment, the fifth request message, the fifth request response message, the seventh request message, and the seventh request response message may not exist.

[0347] Taking L3 handover under a CU-DU separation architecture as an example, the steps related to uplink synchronization, which are combined in the above embodiments, are as follows: Figure 6 As shown. Please refer to. Figure 6 , Figure 6This is a schematic diagram of interaction between a UE and a network node according to various embodiments of the present disclosure, wherein the first node is the CU of the first base station, the third node is the DU of the first base station, the second node is the CU of the second base station, the fourth node is the DU of the second base station, and the fifth node is the UE. Figure 6 The method shown may include one or more of steps 601 to 617:

[0348] Step 601: The first node sends a first notification message to the second node, see step 301 for details;

[0349] Step 602: The second node sends a second request message to the fourth node, see step 302 for details;

[0350] Step 603: The fourth node sends a second request response message to the second node, see step 303 for details;

[0351] Step 604: The second node sends a second notification message to the first node, see step 304 for details;

[0352] Step 605: The first node sends a third request message to the third node, see step 401 for details;

[0353] Step 606: The third node sends a third request response message to the first node, see step 402 for details;

[0354] Step 605': The third node sends a fourth request message to the first node, see step 401' for details;

[0355] Step 606': The first node sends a fourth request response message to the third node, see step 402' for details;

[0356] Step 607: The first node sends the first reconfiguration message to the fifth node, see step 403 for details;

[0357] Step 608: The first node sends a fifth request message to the third node, see step 501 for details;

[0358] Step 609: The third node sends a PDCCH command to the fifth node, see step 502 for details;

[0359] Step 610: The third node sends the fifth request response message to the first node, see step 503 for details;

[0360] Step 611: The fifth node sends a preamble to the fourth node, see step 504 for details;

[0361] Step 612: The first node sends a sixth request message to the second node, requesting configuration of the target cell. See step 505 for details.

[0362] Step 613: The second node sends the seventh request message to the fourth node, see step 506 for details;

[0363] Step 614: The fourth node sends the seventh request response message to the second node, see step 507 for details;

[0364] Step 615: The second node sends the sixth request response message to the first node, see step 508 for details;

[0365] Step 616: The first node sends a second configuration message to the fifth node, see step 509 for details;

[0366] Step 617: After the UE successfully synchronizes and accesses the second base station, it sends an RRC reconfiguration complete message to the second node.

[0367] The methods provided in various embodiments of this disclosure, by pre-allocating / reserving resources for uplink synchronization between base stations, enable the source base station to notify the UE of the pre-allocated / reserved resources for uplink synchronization in UE mobility scenarios, thereby achieving uplink synchronization without random access. This reduces UE interruptions caused by random access during movement. Furthermore, by pre-allocating / reserving uplink synchronization resources between base stations, the methods provided in various embodiments of this disclosure eliminate the need to request uplink synchronization resources from candidate cells based on the UE's request when a cell handover occurs. Compared to UE-request-based schemes, this reduces signaling overhead related to uplink synchronization, thereby reducing the load on the network interface. Furthermore, compared to existing LTM schemes where resources for uplink synchronization can only be requested during the handover preparation process related to the UE (e.g., including requests for resources for uplink synchronization in the handover request message), the methods provided by various embodiments of this disclosure request resources for uplink synchronization in advance before handover preparation (e.g., before sending a sixth request message related to requesting configuration of the target cell and / or candidate cell of the UE). This allows the methods of this disclosure to perform per-node interactions between networks without relying on the mobility preparation process with the UE. Moreover, the pre-allocated resources for uplink synchronization can be used not only for LTM but also for HO / CHO / C-LTM / secondary cell activation, etc., thus providing a general uplink synchronization resource allocation scheme that is not limited to LTM scenarios (Layer 1 / Layer 2 triggered mobility) and makes the methods provided by various embodiments of this disclosure applicable to a wider range of scenarios.

[0368] Figure 6Taking L3 HO as an example, the base station will only select one target cell for the UE. However, in CHO / LTM / C-LTM, the base station can select multiple candidate cells for the UE. Therefore, the steps for requesting uplink synchronization resources for candidate cells may differ from those in other scenarios. Figure 6 The differences are as follows: This disclosure provides, Figure 7 The illustrated examples demonstrate a CHO / LTM / C-LTM scenario using a CU-DU decoupled architecture. Please refer to... Figure 7 , Figure 7 This is a schematic diagram of interaction between a UE and a network node according to various embodiments of the present disclosure, wherein the first node is the CU of the first base station, the third node is the DU of the first base station, the second node is the CU of the second base station, the fourth node is the DU of the second base station, and the fifth node is the UE.

[0369] Figure 7 The method shown may include one or more of steps 701 to 716:

[0370] Step 701: The first node sends a first notification message to the second node, see step 301 for details;

[0371] Step 702: The second node sends a second request message to the fourth node, see step 302 for details;

[0372] Step 703: The fourth node sends a second request response message to the second node, see step 303 for details;

[0373] Step 704: The second node sends a second notification message to the first node, see step 304 for details;

[0374] Step 705: The first node sends a third request message to the third node, see step 401 for details;

[0375] Step 706: The third node sends a third request response message to the first node, see step 402 for details;

[0376] Step 705': The third node sends a fourth request message to the first node, see step 401' for details;

[0377] Step 706': The first node sends a fourth request response message to the third node, see step 402' for details;

[0378] Step 707: The first node sends a sixth request message to the second node, requesting the configuration of candidate cells;

[0379] Step 708: The second node sends a seventh request message to the fourth node;

[0380] Step 709: The fourth node sends the seventh request response message to the second node;

[0381] Step 710: The second node sends a sixth request response message to the first node;

[0382] Step 711: The first node sends a first reconfiguration message to the fifth node, the content of which includes the content of the first reconfiguration message in step 403;

[0383] Step 712: When the switching type is CHO, the first node sends a fifth request message to the third node;

[0384] Step 713: The third node sends a PDCCH command to the fifth node, see step 502 for details;

[0385] Step 714: The third node sends the fifth request response message to the first node, see step 503 for details;

[0386] Step 715: The fifth node sends a preamble to the fourth node, see step 504 for details;

[0387] Step 716: When the handover type is LTM or C-LTM, the fourth node sends a cell handover command to the fifth node.

[0388] The methods provided in various embodiments of this disclosure, by pre-allocating / reserving resources for uplink synchronization between base stations, enable the source base station to notify the UE of the pre-allocated / reserved resources for uplink synchronization in UE mobility scenarios, thereby achieving uplink synchronization without random access. This reduces UE interruptions caused by random access during movement. Furthermore, by pre-allocating / reserving uplink synchronization resources between base stations, the methods provided in various embodiments of this disclosure eliminate the need to request uplink synchronization resources from candidate cells based on the UE's request when a cell handover occurs. Compared to UE-request-based schemes, this reduces signaling overhead related to uplink synchronization, thereby reducing the load on the network interface. Furthermore, compared to existing LTM schemes where resources for uplink synchronization can only be requested during the handover preparation process related to the UE (e.g., including requests for resources for uplink synchronization in the handover request message), the methods provided by various embodiments of this disclosure request resources for uplink synchronization in advance before handover preparation (e.g., before sending a sixth request message related to requesting configuration of the target cell and / or candidate cell of the UE). This allows the methods of this disclosure to perform per-node interactions between networks without relying on the mobility preparation process with the UE. Moreover, the pre-allocated resources for uplink synchronization can be used not only for LTM but also for HO / CHO / C-LTM / secondary cell activation, etc., thus providing a general uplink synchronization resource allocation scheme that is not limited to LTM scenarios (Layer 1 / Layer 2 triggered mobility) and makes the methods provided by various embodiments of this disclosure applicable to a wider range of scenarios.

[0389] It should be noted that the order of steps in all embodiments of the present invention is not limited to that shown in the accompanying drawings or message numbers.

[0390] Figure 8 This is a block diagram illustrating the structure of a first node 800 according to an embodiment of the present disclosure.

[0391] refer to Figure 8 The first node 800 includes a transceiver 801 and a controller 802. The transceiver 801 is configured to transmit signals to and / or receive signals from the outside. The controller 802 is configured to perform the methods described above by the second node. The first node 800 may be implemented in hardware, software, or a combination of hardware and software to enable it to perform the methods described herein.

[0392] Figure 9 This is a block diagram illustrating the structure of a second node 900 according to an embodiment of the present disclosure.

[0393] refer to Figure 9 The second node 900 includes a transceiver 901 and a controller 902. The transceiver 901 is configured to transmit signals to and / or receive signals from the outside. The controller 902 is configured to perform the methods described above by the third node. The second node 900 may be implemented in hardware, software, or a combination of hardware and software to enable it to perform the methods described herein.

[0394] Figure 10 This is a block diagram illustrating the structure of a user equipment 1000 according to an embodiment of the present disclosure.

[0395] refer to Figure 10 User equipment 1000 includes a transceiver 1001 and a controller 1002. The transceiver 1001 is configured to transmit signals to and / or receive signals from the outside. The controller 1002 is configured to perform the methods described above by the user equipment. User equipment 1000 may be implemented in hardware, software, or a combination of hardware and software to enable it to perform the methods described herein.

[0396] Those skilled in the art will understand that the illustrative embodiments described above are not intended to be limiting. It should be understood that any two or more of the embodiments disclosed herein can be combined in any combination. Furthermore, other embodiments may be utilized and other changes may be made without departing from the spirit and scope of the subject matter presented herein. It will be readily understood that aspects of the invention disclosed herein, as generally described herein and illustrated in the accompanying drawings, can be arranged, substituted, combined, separated, and designed in a variety of different configurations, all of which are contemplated herein.

[0397] Those skilled in the art will understand that the various illustrative logic blocks, modules, circuits, and steps described herein can be implemented in hardware, software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in the form of sets of functions. Whether such sets of functions are implemented in hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described sets of functions in different ways for each specific application, but such design decisions should not be construed as departing from the scope of this application.

[0398] The various illustrative logic blocks, modules, and circuits described in this application may be implemented or performed using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in alternatives, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0399] The steps of the methods or algorithms described in this application may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read and write information to / from the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0400] In one or more exemplary designs, the functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media, the latter including any medium that facilitates the transfer of a computer program from one location to another. Storage media may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0401] The above description is merely an exemplary embodiment of this application and is not intended to limit the scope of protection of this application. The scope of protection of this application is determined by the appended claims.

Claims

1. A method executed by a first node in a communication system, comprising: Send a first notification message to the second node related to the requested resources for uplink synchronization; The second notification message is received from the second node, wherein the second notification message includes information related to the identifier of the first cell of the second node and at least one of the following information corresponding to the first cell: first information related to a first resource for uplink synchronization; second information related to releasing a second resource for uplink synchronization; and third information related to updating a third resource for uplink synchronization. A first reconfiguration message is sent to the User Equipment (UE), wherein the first reconfiguration message includes information related to the identifier of a second cell determined by the first node for the UE, and at least one of the following information corresponding to the second cell: fourth information related to a fourth resource for uplink synchronization; fifth information related to releasing a fifth resource for uplink synchronization; sixth information related to updating a sixth resource for uplink synchronization; and... Send a sixth request message to the second node related to the request to configure the target cell and / or candidate cell of the UE.

2. The method according to claim 1, wherein, The first notification message includes at least one of the following: The seventh piece of information relating to the type of resource requested for uplink synchronization; The eighth piece of information relating to the number of resource sets requested for uplink synchronization; Ninth information related to assisting the second node in allocating resources for uplink synchronization.

3. The method according to claim 2, wherein, The ninth piece of information includes at least one of the following: Information related to the number of UEs that may move; Information related to the potential trajectory of a UE that may move; Information related to the usage status of wireless resources in the cell of the first node.

4. The method according to claim 1, wherein, The sixth request message includes tenth information related to the random access channel (RACH) resources used by the UE for uplink synchronization.

5. The method according to claim 1, wherein, The method further includes: Send a third request message to the third node, wherein the third request message includes eleventh information related to the seventh resource for uplink synchronization determined by the first node for the third node; and A third request response message is received from the third node, the third request response including information related to the usage of an eighth resource for uplink synchronization, as determined by the first node for the third node.

6. The method according to claim 1, wherein, The method further includes: A fourth request message is received from the third node, wherein the fourth request message includes at least one of the following: information related to the UE that needs to use resources for uplink synchronization; twelfth information related to the type of the requested resources for uplink synchronization; and thirteenth information related to the number of the requested resource set. A fourth request response message is sent to the third node, wherein the fourth request response message includes fourteenth information related to the ninth resource for uplink synchronization determined by the first node for the third node.

7. The method according to any one of claims 1, 5, or 6, wherein, At least one of the first, fourth, eleventh, and fourteenth messages includes at least one of the following: Information related to the resource number used for uplink synchronization; Information related to the type of time-frequency resources used for uplink synchronization; Information related to the purpose of using the resources for uplink synchronization; Information related to the validity period of resources used for uplink synchronization; Subcarrier spacing of resources used for uplink synchronization; The starting frequency or starting band of the resources used for uplink synchronization; The number of random access opportunities in the Random Access Channel (RACH); RACH random access configuration entries; The number of synchronization signal blocks (SSBs) for each random access opportunity; The frequency domain length of the random access opportunity; Zero-correlation interval configuration for random access; Random access response window.

8. The method according to claim 7, wherein, The intended use includes at least one of the following: Used for switching; Used for condition switching; Used for triggering mobility LTM in layer 1 / layer 2; Used for conditional LTM; Used for secondary cell activation.

9. The method according to any one of claims 1-6, wherein, Any one of the first to ninth resources used for uplink synchronization includes uplink carrier resources and / or supplementary uplink carrier resources.

10. The method according to claim 1, wherein, The method further includes: A fifth request message is sent to the third node, wherein the fifth request message includes: information related to triggering uplink synchronization of the UE; and The third node receives a fifth request response message, wherein the fifth request response message includes fifteenth information related to the random access channel (RACH) resources used by the UE for uplink synchronization.

11. The method according to claim 4 or 10, wherein, The tenth or fifteenth piece of information includes at least one of the following: Information related to the preamble entry used for uplink synchronization with the UE; Information related to the source entity being switched.

12. The method according to claim 1, wherein, The method further includes: Receive a sixth request response message from the second node, wherein the sixth request message includes the timing advance (TA) value used by the UE for uplink synchronization; and A second reconfiguration message is sent to the UE, wherein the second reconfiguration message includes the TA value.

13. The method according to any one of claims 1-6, 10, and 12, wherein, The first node is a first base station or a centralized unit of a first base station; and / or The second node is a second base station or a centralized unit of a second base station; and / or The third node is the distribution unit of the first base station.

14. A method performed by a second node in a communication system, comprising: Receive a first notification message from the first node related to the resource requested for uplink synchronization; Send a second notification message to the first node, wherein the second notification message includes information related to the identifier of the first cell of the second node and at least one of the following information corresponding to the first cell: first information related to a first resource for uplink synchronization; second information related to releasing a second resource for uplink synchronization; and third information related to updating a third resource for uplink synchronization. Receive a sixth request message from the first node related to the target cell and / or candidate cell for requesting configuration of the user equipment UE; The first reconfiguration message sent by the first node to the UE includes information related to the identifier of the second cell determined by the first node for the UE and at least one of the following information corresponding to the second cell: fourth information related to the fourth resource for uplink synchronization; fifth information related to the release of the fifth resource for uplink synchronization; and sixth information related to the update of the sixth resource for uplink synchronization.

15. The method according to claim 14, wherein, The method further includes: A second request message is sent to the fourth node, wherein the second request message includes at least one of the following: a sixteenth piece of information related to the type of the requested resources for uplink synchronization; a seventeenth piece of information related to the number of the requested resource set for uplink synchronization; and an eighteenth piece of information related to assisting the fourth node in allocating resources for uplink synchronization. The second request response message is received from the fourth node, wherein the second request response message includes information related to the identifier of the second cell and at least one of the following information corresponding to the second cell: nineteenth information related to the tenth resource for uplink synchronization; twentieth information related to the release of the eleventh resource for uplink synchronization; and twenty-first information related to the update of the twelfth resource for uplink synchronization.

16. The method of claim 14, wherein, The method further includes: Send a seventh request message to the fourth node, wherein the seventh request message includes twenty-second information related to the random access channel (RACH) resources used by the UE for uplink synchronization; The fourth node receives a seventh request response message, wherein the seventh request response message includes the timing advance TA value used by the UE for uplink synchronization.

17. A method performed by a user equipment (UE) in a communication system, comprising: A first reconfiguration message is received from a first node, wherein the first reconfiguration message includes information related to the identifier of a second cell determined by the first node for the UE, and at least one of the following information corresponding to the second cell: fourth information related to a fourth resource for uplink synchronization; fifth information related to releasing a fifth resource for uplink synchronization; and sixth information related to updating a sixth resource for uplink synchronization; and Send a preamble to the second node; The first reconfiguration message is based on a second notification message received by the first node from the second node. The second notification message includes information related to the identifier of the first cell of the second node and at least one of the following information corresponding to the first cell: first information related to a first resource for uplink synchronization; second information related to releasing a second resource for uplink synchronization; and third information related to updating a third resource for uplink synchronization. The second notification message is based on a first notification message sent by the first node to the second node that relates to the request for resources used for uplink synchronization; The sixth request message related to the request to configure the target cell and / or candidate cell of the UE is sent by the first node to the second node.

18. A first node, the first node comprising: A transceiver is configured to transmit and / or receive signals; as well as The controller is configured to control the transceiver to perform the method according to any one of claims 1-13.

19. A second node, the second node comprising: A transceiver is configured to transmit and / or receive signals; as well as The controller is configured to control the transceiver to perform the method according to any one of claims 14-16.

20. A user equipment (UE), the UE comprising: A transceiver is configured to transmit and / or receive signals; as well as The controller is configured to control the transceiver to perform the method according to claim 17.

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