Timing advance forwarding method, communication apparatus, and storage medium

Abstract

The present application provides a timing advance forwarding method, a communication apparatus, and a storage medium. The method comprises: a first centralized unit of a candidate network device sends first information to a candidate distributed unit, the first information being used for indicating a serving distributed unit providing a service for a terminal device among a plurality of second distributed units of a serving network device, and the serving network device being different from the candidate network device; the first centralized unit receives second information sent by the candidate distributed unit, the second information carrying a timing advance and first indication information, and the first indication information being used for indicating the serving distributed unit; the first centralized unit sends third information to a second centralized unit of the serving network device, the third information carrying the timing advance and second indication information, and the second indication information being used for indicating the serving distributed unit, so that the terminal device can receive the timing advance by means of the serving distributed unit, thereby ensuring the normal progress of cell handover and avoiding increase of a cell handover delay.

Description

Time advance forwarding method, communication apparatus and storage medium

[0001] The present application claims priority from the Chinese patent application No. 2024109847572 filed on July 22, 2024, and entitled "Time advance forwarding method, communication apparatus and storage medium", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to a time advance forwarding method, a communication apparatus and a storage medium. BACKGROUND

[0003] Cell switching refers to the process of switching a terminal device (user equipment, UE) from a currently accessed cell to another cell. During the cell switching process, the UE needs to complete uplink synchronization with the candidate cell.

[0004] In the related art, in the uplink synchronization process, the service distributed unit (DU) of the source base station requests the random access channel (RACH) resource of the candidate cell from the candidate DU of the source base station. When the candidate DU receives the RACH resource request information, the candidate DU sends the time advance (TA) of the candidate cell to the UE through the centralized unit (CU) and the service DU of the source base station. The UE receives the TA, thereby completing the uplink synchronization.

[0005] However, if the above uplink synchronization process occurs between different base stations, i.e., the service DU of the source base station needs to request the RACH resource of the candidate cell from the DU of the candidate base station, wherein the source base station and the candidate base station are two different base stations, then the DU of the candidate base station may not be able to distinguish which CU of the source base station the service DU of the source base station is under, resulting in that the DU of the candidate base station cannot send the TA to the UE through the CU of the source base station and the service DU of the source base station, thereby making the UE unable to obtain the TA. The UE needs to reacquire the TA, thereby increasing the time delay of cell switching. SUMMARY

[0006] The present application provides a time advance forwarding method, a communication apparatus and a storage medium to solve the problem that the DU of the candidate base station cannot send the TA to the UE through the CU of the source base station and the service DU of the source base station, thereby making the UE unable to obtain the TA. The UE needs to reacquire the TA, thereby increasing the time delay of cell switching. The present application ensures that the UE normally performs cell switching.

[0007] In a first aspect, the present application provides a time advance forwarding method, applied to a first centralized unit of a candidate network device, the candidate network device further comprising a plurality of first distributed units, the method comprising:

[0008] Before the first centralized unit receives a preamble sequence sent by a terminal device, the first centralized unit sends first information to a candidate distributed unit, the candidate distributed unit being a distributed unit corresponding to a first candidate cell in the plurality of first distributed units, the first candidate cell being a cell in a second candidate cell allowing the terminal device to access, the second candidate cell being a cell of the candidate network device, the second candidate cell being determined by a serving network device according to layer 3 measurement results, the first information being used to indicate a serving distributed unit in a plurality of second distributed units of the serving network device providing service for the terminal device, the serving network device being different from the candidate network device;

[0009] The first centralized unit receives second information sent by the candidate distributed unit, the second information carrying a time advance of the first candidate cell and first indication information, the time advance being determined by an active antenna unit of the candidate network device according to the preamble sequence sent by the terminal device, the first indication information being used to indicate the serving distributed unit, wherein the first indication information is determined according to the first information;

[0010] The first centralized unit sends third information to a second centralized unit of the serving network device, the third information carrying the time advance and second indication information, the second indication information being used to indicate the serving distributed unit, so that the terminal device can receive the time advance through the serving distributed unit, wherein the second indication information is determined according to the second information.

[0011] In a possible design, the method further comprises:

[0012] The first centralized unit receives handover request information sent by the second centralized unit, the handover request information being used to request a time advance of the second candidate cell, the handover request information carrying an identifier of the second candidate cell and an identifier of a serving cell, the serving cell belonging to the serving distributed unit, the serving cell providing service for the terminal device, or the handover request information carrying an identifier of the second candidate cell and an identifier of the serving distributed unit;

[0013] The first centralized unit determines the first information according to the handover request information.

[0014] In a second aspect, the present application provides a time advance forwarding method, applied to a candidate distribution unit of a candidate network device, wherein the candidate network device comprises a first centralized unit and a plurality of first distribution units, the candidate distribution unit is a distribution unit corresponding to a first candidate cell in the plurality of first distribution units, the first candidate cell is a cell allowing a terminal device to access in a second candidate cell, the second candidate cell is a cell of the candidate network device, the second candidate cell is determined by a serving network device according to a layer 3 measurement result, and the method comprises the following steps:

[0015] The candidate distribution unit receives first information sent by the first centralized unit before the first candidate cell receives a preamble sequence sent by the terminal device, wherein the first information is used to indicate a service distribution unit providing service for the terminal device in a plurality of second distribution units of the serving network device, and the serving network device is different from the candidate network device.

[0016] The candidate distribution unit sends second information to the first centralized unit, wherein the second information carries a time advance of the first candidate cell and first indication information, the time advance is determined by an active antenna unit of the candidate network device according to the preamble sequence sent by the terminal device, and the first indication information is used to indicate the service distribution unit, wherein the first indication information is determined according to the first information.

[0017] In a possible design, the method further comprises the following steps:

[0018] The candidate distribution unit receives fourth information sent by the active antenna unit, wherein the fourth information carries the time advance.

[0019] In a third aspect, the present application provides a time advance forwarding method, applied to a second centralized unit of a serving network device, wherein the serving network device further comprises a plurality of second distribution units, and the method comprises the following steps:

[0020] The second centralized unit receives third information sent by the first centralized unit of the candidate network device, the third information carrying time advance of the first candidate cell and second indication information, the time advance being determined by the active antenna unit of the candidate network device according to the preamble sequence sent by the terminal device, and the second indication information being used for indicating a serving distributed unit of the terminal device in the plurality of second distributed units, wherein the second indication information is determined according to second information sent by the candidate distributed unit to the first centralized unit, the candidate network device further comprising a plurality of first distributed units, the candidate distributed unit being a distributed unit corresponding to the first candidate cell in the plurality of first distributed units, the first candidate cell being a cell in the second candidate cell that allows the terminal device to access, the second candidate cell being a cell of the candidate network device, the second candidate cell being determined by the serving network device according to layer 3 measurement results, the second information carrying the time advance of the first candidate cell and first indication information, the first indication information being used for indicating the serving distributed unit of the terminal device in the plurality of second distributed units, the first indication information being determined according to first information, and the first information being sent by the first centralized unit to the candidate distributed unit before the first centralized unit receives the preamble sequence sent by the terminal device in the first candidate cell, the first information being used for indicating the serving distributed unit of the terminal device in the plurality of second distributed units, the serving network device being different from the candidate network device.

[0021] The second centralized unit sends fifth information to the serving distributed unit, the fifth information carrying the time advance, so that the terminal device can receive the time advance through the serving distributed unit.

[0022] In a possible design, the first information is determined by the first centralized unit according to handover request information, and the method further includes:

[0023] The second centralized unit sends handover request information to the first centralized unit, the handover request information being used for requesting time advance of the second candidate cell, the handover request information carrying an identifier of the second candidate cell and an identifier of a serving cell, the serving cell belonging to the serving distributed unit, and the serving cell providing service for the terminal device, or the handover request information carrying an identifier of the second candidate cell and an identifier of the serving distributed unit.

[0024] In the first aspect to the third aspect and any possible design of the first aspect to the third aspect, the first information carries an identity of a serving cell, the serving cell belongs to the serving distribution unit, the serving cell serves the terminal device, and the identity of the serving cell is unique among different network devices.

[0025] In the first aspect to the third aspect and any possible design of the first aspect to the third aspect, the first indication information carries the identity of the serving cell, and the second indication information carries the identity of the serving cell.

[0026] In the first aspect to the third aspect and any possible design of the first aspect to the third aspect, the first information carries an identity of the serving distribution unit and an identity of the serving network device.

[0027] In the first aspect to the third aspect and any possible design of the first aspect to the third aspect, the first indication information carries the identity of the serving distribution unit and the identity of the serving network device, and the second indication information carries the identity of the serving distribution unit.

[0028] In the present application, before a first candidate cell receives a preamble sequence sent by a terminal device, a first centralized unit sends first information to a candidate distribution unit, so that the candidate distribution unit knows that the terminal device requesting a time advance comes from which distribution unit of which network device or which cell. The candidate distribution unit sends second information to the first centralized unit, the second information carries a time advance of the first candidate cell and first indication information, wherein the first indication information is used to indicate a serving distribution unit, and the first centralized unit can know that the terminal device requesting the time advance comes from which distribution unit of which network device, so that the first centralized unit can send the time advance to the correct distribution unit. The first centralized unit sends third information to a second centralized unit of a serving network device, the third information carries the time advance of the first candidate cell and second indication information, and the second indication information is used to indicate the serving distribution unit, so that the terminal device can receive the time advance through the serving distribution unit. The second centralized unit can know the identity of the serving distribution unit corresponding to the terminal device requesting the time advance or the identity of the serving cell through the third information, so that the second centralized unit sends the time advance to the correct distribution unit, and ensures that the terminal device can receive the time advance. Based on this, the terminal device can receive the time advance through the serving distribution unit, and the terminal device does not need to acquire the time advance again, and the terminal device can perform cell switching through the time advance, so as to avoid increasing the time delay of cell switching and ensure normal cell switching.

[0029] In a fourth aspect, the present application provides a communication apparatus, comprising: a module for performing the time advance forwarding method in the first aspect and any possible design of the aspect.

[0030] In a fifth aspect, the present application provides a communication apparatus, comprising: a module for performing the time advance forwarding method in the second aspect and any possible design of the aspect.

[0031] In a sixth aspect, the present application provides a communication apparatus, comprising: a module for performing the time advance forwarding method in the third aspect and any possible design of the aspect.

[0032] In a seventh aspect, the present application provides a communication system, comprising: a serving network device, a candidate network device and a terminal device, wherein the serving network device comprises a second centralized unit and a serving distributed unit, the candidate network device comprises a candidate distributed unit and a first centralized unit for performing the time advance forwarding method in the first aspect and any possible design of the aspect; or the serving network device comprises a second centralized unit and a serving distributed unit, the candidate network device comprises a first centralized unit and a candidate distributed unit for performing the time advance forwarding method in the second aspect and any possible design of the aspect; or the candidate network device comprises a first centralized unit and a candidate distributed unit, the serving network device comprises a serving distributed unit and a second centralized unit for performing the time advance forwarding method in the third aspect and any possible design of the aspect.

[0033] In an eighth aspect, the present application provides a communication apparatus, comprising a processor. The processor is configured to invoke a computer program or computer instructions stored in the memory, so that the processor implements the method in any possible design of any one of the first aspect to the third aspect.

[0034] Optionally, the communication apparatus further comprises a transceiver, and the processor is configured to control the transceiver to transceive signals.

[0035] In a ninth aspect, the present application provides a communication apparatus, comprising at least one memory and at least one processor. The memory is configured to store computer executable programs or instructions. The processor is configured to invoke the computer executable programs or instructions in the memory, so that the communication apparatus implements the method in any possible design of any one of the first aspect to the third aspect.

[0036] Optionally, the processor is coupled with the memory through an interface.

[0037] In a tenth aspect, the present application provides a computer readable storage medium having stored thereon computer executable programs or instructions that, when executed by a processor, cause a communication apparatus to perform the method in any possible implementation of any one of the first aspect to the third aspect.

[0038] In an eleventh aspect, the present application provides a chip, comprising: an interface circuit and a logic circuit, the interface circuit is configured to receive a signal from another chip outside the chip and transmit the signal to the logic circuit, or send a signal from the logic circuit to another chip outside the chip, and the logic circuit is configured to implement the method in any possible implementation of any one of the first aspect to the third aspect.

[0039] In a twelfth aspect, the present application provides a computer program product, comprising: execution instructions stored in a readable storage medium, at least one processor of a communication apparatus can read the execution instructions from the readable storage medium, and the at least one processor executes the execution instructions to cause the communication apparatus to implement the method in any possible implementation of any one of the first aspect to the third aspect. BRIEF DESCRIPTION OF DRAWINGS

[0040] FIG. 1 is a signaling interaction diagram of an uplink synchronization method of an LTM cell according to an embodiment of the present application.

[0041] FIG. 2 is an architecture diagram of a communication system according to an embodiment of the present application.

[0042] FIG. 3 is a signaling interaction diagram of a TA forwarding method according to an embodiment of the present application.

[0043] FIG. 4 is a signaling interaction diagram of a method for determining first information according to an embodiment of the present application.

[0044] FIG. 5 is a structure diagram of a communication apparatus according to an embodiment of the present application.

[0045] FIG. 6 is a structure diagram of a communication apparatus according to an embodiment of the present application.

[0046] FIG. 7 is a structure diagram of a communication apparatus according to an embodiment of the present application.

[0047] FIG. 8 is a hardware structure diagram of a communication apparatus according to an embodiment of the present application. DETAILED DESCRIPTION

[0048] In the present application, "at least one" means one or more, and "multiple" means two or more. The term "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the following three cases: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c alone can represent: a alone, b alone, c alone, combination of a and b, combination of a and c, combination of b and c, or combination of a, b and c, where a, b, c can be single or multiple. In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0049] The terms "center", "longitudinal", "transverse", "upper", "lower", "left", "right", "front", "back", and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0050] The terms "connected" and "connected" should be broadly understood, for example, the "connected" or "connected" of the circuit structure can mean not only physical connection, but also electrical connection or signal connection, for example, it can be directly connected, that is, physically connected, or indirectly connected through at least one element in the middle, as long as the circuit is connected, it can also be the internal connection of two elements; In addition to signal connection through the circuit, signal connection through media medium, such as radio waves, can also be referred to. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] In the related art, as shown in FIG. 1, the uplink synchronization method of the L1 / L2-triggered mobility (LTM) cell triggered by layer 1 and layer 2 includes the following S11-S26.

[0052] S11, the UE sends a layer 3 (L3) measurement report to the serving DU of the source base station.

[0053] Correspondingly, the serving DU of the source base station receives the L3 measurement report sent by the UE.

[0054] Among them, the source base station includes a CU and multiple DUs. The multiple DUs are connected with the CU respectively, and the multiple DUs are independent of each other.

[0055] The serving DU of the source base station provides services for the UE.

[0056] S12, the serving DU of the source base station sends the L3 measurement report to the CU of the source base station.

[0057] Correspondingly, the CU of the source base station receives the L3 measurement report sent by the DU of the source base station.

[0058] S13, the CU of the source base station sends the context establishment request information to the candidate DU of the source base station.

[0059] Correspondingly, the candidate DU of the source base station receives the context establishment request information sent by the CU of the source base station.

[0060] The candidate DU of the source base station is the DU corresponding to the first cell, and the first cell is a cell of the source base station, which is determined by the CU of the source base station according to the L3 measurement report.

[0061] The number of the first cells is one or more, and for each first cell, the CU of the source base station sends the context establishment request information to the DU corresponding to the first cell.

[0062] The context establishment request information carries the identity document (ID) of one first cell, the LTM configuration ID of the candidate cell, the LTM configuration ID mapping table, the channel state information (CSI) resource configuration, and the physical random access channel (PRACH) resource request information.

[0063] The PRACH resource request information is used to request the PRACH resource from the candidate DU of the source base station, and the PRACH resource request information carries the ID of the serving DU of the source base station.

[0064] The CU of the source base station can initiate the LTM configuration through the context establishment request information.

[0065] S14, when the candidate DU of the source base station receives the context establishment request, the candidate DU of the source base station sends the context establishment response information to the CU of the source base station.

[0066] Correspondingly, the CU of the source base station receives the context establishment response information sent by the candidate DU of the source base station.

[0067] The context establishment response information carries the RACH resource configuration of the second cell and the LTM configuration ID.

[0068] The second cell is a cell allowed to be accessed by the UE in the first cell.

[0069] S15, the CU of the source base station sends context modification request information to the serving DU of the source base station.

[0070] Correspondingly, the serving DU of the source base station receives the context modification request information sent by the CU of the source base station.

[0071] The context modification request information carries the RACH resource configuration and the LTM configuration ID of the second cell.

[0072] S16, the serving DU of the source base station sends context modification response information to the CU of the source base station.

[0073] Correspondingly, the CU of the source base station receives the context modification response information sent by the serving DU of the source base station.

[0074] S17, the CU of the source base station sends context adjustment request information to the candidate DU of the source base station.

[0075] Correspondingly, the candidate DU of the source base station receives the context adjustment request information sent by the CU of the source base station.

[0076] The context adjustment request information carries the RACH resource configuration and the CSI resource configuration.

[0077] S18, the candidate DU of the source base station sends context adjustment response information to the CU of the source base station.

[0078] Correspondingly, the CU of the source base station receives the context adjustment response information sent by the candidate DU of the source base station.

[0079] The context adjustment response information carries the CSI report update information of the second cell.

[0080] S19, the CU of the source base station sends downlink radio resource control message transfer (DL RRC MESSAGE TRANSFER) information to the serving DU of the source base station.

[0081] Correspondingly, the serving DU of the source base station receives the DL RRC MESSAGE TRANSFER information sent by the CU of the source base station.

[0082] The DL RRC MESSAGE TRANSFER information carries RRC reconfiguration information.

[0083] The RRC reconfiguration information carries the LTM configuration.

[0084] S20, the serving DU of the source base station sends RRC reconfiguration information to the UE.

[0085] Correspondingly, the UE receives the RRC reconfiguration information sent by the serving DU of the source base station.

[0086] S21, the UE sends RRC reconfiguration completion information to the serving DU of the source base station.

[0087] Correspondingly, the serving DU of the source base station receives the RRC reconfiguration completion information sent by the UE.

[0088] S22, the serving DU of the source base station sends the RRC reconfiguration completion information to the CU of the source base station.

[0089] Correspondingly, the CU of the source base station receives the RRC reconfiguration completion information sent by the serving DU of the source base station.

[0090] S23, the UE initiates downlink synchronization and uplink synchronization.

[0091] In the uplink synchronization process, the UE sends a RACH preamble sequence to the candidate DU of the source base station according to the configured RACH resource.

[0092] S24, the candidate DU of the source base station sends the TA, non-contention random access resource related information, the ID of the second cell and the ID of the serving DU of the source base station to the CU of the source base station.

[0093] Correspondingly, the CU of the source base station receives the TA, non-contention random access resource related information, the ID of the second cell and the ID of the serving DU of the source base station sent by the candidate DU of the source base station.

[0094] The TA is obtained by the candidate DU of the source base station according to the RACH preamble sequence sent by the UE.

[0095] S25, the CU of the source base station sends the TA to the serving DU of the source base station according to the ID of the serving DU of the source base station.

[0096] Correspondingly, the serving DU of the source base station receives the TA sent by the CU of the source base station according to the ID of the serving DU of the source base station.

[0097] S26, the serving DU of the source base station sends the TA to the UE.

[0098] Correspondingly, the UE receives the TA sent by the serving DU of the source base station.

[0099] Based on this, the UE can determine whether to switch to the first cell based on the TA, so as to select a target cell from the first cell and switch to the target cell, thereby completing cell switching.

[0100] In the related technology, uplink synchronization occurs between different DUs of the same base station, and the CU of the source base station sends the ID of the serving DU of the source base station to the candidate DU of the source base station when requesting the RACH resource of the first cell from the candidate DU of the source base station, so that the candidate DU of the source base station knows from which DU the UE initiates the RACH.

[0101] However, since the ID of the DU is unique only under the CU of the same base station, if the uplink synchronization occurs between different base stations, that is, the serving DU of the source base station needs to request the RACH resource from the DU of the candidate base station, and the source base station and the candidate base station are two different base stations, the DU of the candidate base station may not be able to distinguish the serving DU of the source base station under which CU of which base station, resulting in that the DU of the candidate base station cannot send the TA to the UE through the CU of the source base station and the serving DU of the source base station, so that the UE cannot obtain the TA, and the UE needs to re-acquire the TA, increasing the time delay of cell switching.

[0102] Based on the above problems, the present application provides a time advance forwarding method, a communication device, a computer storage medium, a computer program product and a chip, when the serving DU of the source base station requests the RACH resource from the DU of the candidate base station, the ID of the serving DU of the source base station and the ID of the source base station are sent to the DU of the candidate base station at the same time, so that the DU of the candidate base station knows the serving DU of the source base station where the UE is located when initiating the RACH, so that the UE can quickly obtain the TA, and the smooth progress of cell switching is ensured.

[0103] Next, in combination with FIG. 2, the application scenario of the TA forwarding method provided by the embodiment of the present application will be described in detail.

[0104] Please refer to FIG. 2, which is an architecture schematic diagram of a communication system provided by an embodiment of the present application. As shown in FIG. 2, the communication system 1 of the present application can include a first network device 10, a second network device 20 and a UE 30.

[0105] The first network device 10 is the network device currently accessed by the UE 30, and the first network device 10 can provide service for the UE 30.

[0106] The first network device 10 includes one CU and multiple DUs, the CU is connected with the multiple DUs respectively, and the DUs are independent from each other. FIG. 2 is a schematic diagram taking the first network device including three DUs as an example, and the number of DUs included in the first network device 10 is not limited by the present application.

[0107] For each DU, the DU includes one or more cells.

[0108] The first network device 10 provides service for the UE 30 through a DU corresponding to a serving cell.

[0109] The serving cell is a cell currently accessed by the UE 30.

[0110] The second network device 20 is a network device to which the UE 30 can perform cell switching. The number of the second network device 20 can be one or more, and the number of the second network device 20 is not limited in the present application.

[0111] For example, the second network device 20 can include one or more network devices adjacent to the first network device.

[0112] The second network device 20 includes one CU and multiple DUs, the CU is connected with the multiple DUs respectively, and the DUs are independent from each other. FIG. 2 is a schematic diagram taking the second network device 20 including three DUs as an example, and the number of the DUs included in the second network device 20 is not limited in the present application.

[0113] For each DU, the DU includes one or more cells.

[0114] After the UE 30 successfully performs cell switching and switches to a target cell, the second network device 20 can provide service for the UE 30 through a DU corresponding to the target cell.

[0115] The CU of the first network device 10 and the CU of the second network device 20 can communicate through an Xn interface.

[0116] The first network device 10 and the second network device 20 can be base stations, or access points, or access network devices, or can refer to devices in an access network that communicate with wireless terminals over one or more sectors on an air interface. The network devices can be configured to convert received air frames to and from IP packets, as routers between wireless terminals and the rest of the access network, which can include an Internet Protocol (IP) network. The network devices can also coordinate management of properties of the air interface. For example, the network devices can be satellites, unmanned aerial vehicles, base transceiver stations (BTSs) in global system of mobile communication (GSM) or code division multiple access (CDMA), NodeBs (NBs) in wideband code division multiple access (WCDMA), evolutional node Bs (eNBs or eNodeBs) in long term evolution (LTE), or terminals or relays or access points that perform the functions of base stations in vehicular to everything (V2X), device-to-device (D2D), and machine-to-machine (M2M) communications, or base stations in 5G networks, such as gNBs, or base stations in future 6G networks, without limitation.

[0117] The UE 30 can be a user equipment, an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent, or a user device. The UE 30 can also be a satellite phone, a cellular phone, a smartphone, a wireless data card, a wireless modem, a machine type communication device, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having wireless communication function, a computing device, or other processing device connected to a wireless modem, a vehicle-mounted device, or a wearable device, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical treatment, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a terminal device in a 5G mobile communication system, a terminal device in a 6G mobile communication system, or a terminal device in a future mobile communication system, and the like. In addition, the UE 30 can also be a terminal device in an internet of things (IoT) system.

[0118] Based on the foregoing description, the following embodiments of the present application will take the communication system with the structure shown in FIG. 2 as an example to describe in detail the time advance forwarding method provided by the embodiments of the present application in combination with the drawings.

[0119] Please refer to FIG. 3, which is a signaling interaction diagram of a TA forwarding method provided by an embodiment of the present application.

[0120] In FIG. 3, the serving network device can be the first network device 10 shown in FIG. 2, the candidate network device can be a network device in the second network device 20 shown in FIG. 2, and the UE can be the UE 30 shown in FIG. 2.

[0121] As shown in FIG. 3, the time advance forwarding method can include:

[0122] S101, before the first candidate cell receives the preamble sequence sent by the UE, the first CU sends first information to the candidate DU.

[0123] Correspondingly, the candidate DU receives the first information sent by the first CU.

[0124] The second CU is a CU of a serving network device. The serving network device further includes a plurality of second DUs. Among the plurality of second DUs, a DU currently providing service for the UE is a serving DU.

[0125] The first CU is a CU of a candidate network device. The candidate network device further includes a plurality of first DUs.

[0126] In the process of performing cell switching, the UE needs to request a TA of a second candidate cell. Therefore, the second CU sends a switching request to the first CU, and informs the first CU of an ID of the second candidate cell.

[0127] The second candidate cell is determined by the serving network device according to an L3 measurement result.

[0128] The second candidate cell is a cell of the candidate network device, that is, the candidate network device is a network device corresponding to the second candidate cell.

[0129] Therefore, after receiving the switching request, the first CU can learn the ID of the second candidate cell from the switching request.

[0130] Since there can be a cell in the second candidate cell that does not allow the UE to access, based on this, for each second candidate cell, the first CU can determine whether the second candidate cell allows the UE to access, and filter out the second candidate cell that does not allow access. The UE does not need to request a TA of the second candidate cell that does not allow access.

[0131] Specifically, the first CU can determine whether the second candidate cell allows the UE to access according to a current network load or a network load in a future period of time, and an attribute of the second candidate cell.

[0132] For example, for a second candidate cell, when a current network load or a network load in a future period of time of the second candidate cell is good, and the second candidate cell is not a dedicated cell, the second candidate cell allows the UE to access. When the current network load or the network load in the future period of time of the second candidate cell is poor, or the second candidate cell is a dedicated cell, it indicates that the second candidate cell does not allow the UE to access.

[0133] The first CU can filter the second candidate cell, and determine the first candidate cell, that is, filter out the cell that allows the UE to access from the second candidate cell.

[0134] Thus, in the uplink synchronization process of the UE, the UE can acquire the TA of the first candidate cell, and complete uplink synchronization and cell switching according to the TA of the first candidate cell.

[0135] Since the first CU does not store information related to the switching request after determining the first candidate cell, based on this, the first CU can send the first information to the candidate DU before the first candidate cell receives the preamble sequence sent by the UE, so that the candidate DU knows which service DU the UE requesting TA comes from.

[0136] The candidate DU is a DU corresponding to the first candidate cell in the plurality of first DUs.

[0137] When the number of first candidate cells is one, the first CU sends the first information to the DU corresponding to the first candidate cell.

[0138] When the number of first candidate cells is a plurality, the first CU sends the first information to the DUs corresponding to the plurality of first candidate cells respectively.

[0139] The first information is used to indicate a service DU in a plurality of second DUs of a service network device that provides service for the UE.

[0140] Thus, the candidate DU can know which service DU the UE requesting TA comes from.

[0141] The first information sent by the first CU to the candidate DU has multiple forms.

[0142] In some examples, the first information carries an ID of a service cell.

[0143] The ID of the service cell is unique among different network devices.

[0144] The first CU can obtain the ID of the service cell through the above switching request.

[0145] Since the ID of the cell is unique in a communication system, the candidate DU can determine which DU the UE requesting TA comes from according to the ID of the service cell.

[0146] As shown in Table 1, network device A includes cell 1 and cell 2, and network device B includes cell 3, cell 4 and cell 5.

[0147] Table 1

[0148] When the first information carries the ID of cell 1, the candidate DU can know that cell 1 is a cell of network device A.

[0149] In some examples, the first information carries the ID of the serving DU and the ID of the serving network device.

[0150] In some examples, the first CU can learn the ID of the serving DU and the ID of the serving network device through the above-mentioned switching request.

[0151] Since the ID of the DU is unique only when it is under the same network device, the ID of the DU can be the same between different network devices.

[0152] As shown in Table 2, the network device A includes the DU 1 and the DU 2, and the network device B includes the DU 1, the DU 2 and the DU 3.

[0153] Table 2

[0154] When the candidate DU learns the ID of the DU 1, if the ID of the network device A is not learned at the same time, the candidate DU cannot distinguish whether the DU 1 is the DU of the network device A or the DU of the network device B.

[0155] Therefore, when the first information carries the ID of the DU 1 and the ID of the network device A, the candidate DU can learn that the DU 1 belongs to the network device A.

[0156] Based on this, the first CU sends the first information to the candidate DU, the first information carries the ID of the serving DU and the ID of the serving network device, or the first information carries the ID of the serving cell, so that the candidate DU can learn which DU of which network device the UE requesting the TA comes from.

[0157] S102, the candidate DU sends the second information to the first CU.

[0158] Correspondingly, the first CU receives the second information sent by the candidate DU.

[0159] After the candidate DU receives the first information, the candidate DU can learn which DU of which network device the UE requesting the TA comes from.

[0160] Based on this, after the first candidate cell receives the preamble sequence sent by the UE, the active antenna unit (AAU) of the candidate network device calculates the TA of the first candidate cell based on the preamble sequence.

[0161] The AAU sends the TA to the candidate DU.

[0162] Therefore, the candidate DU can obtain the TA from the AAU, and the candidate DU sends the second information to the first CU, so that the first CU learns the TA of the first candidate cell.

[0163] The second information carries the TA of the first candidate cell and first indication information.

[0164] The first indication information is used for indicating the serving DU.

[0165] The first indication information includes multiple forms.

[0166] In some examples, the first indication information carries the ID of the serving cell.

[0167] The candidate DU can determine the ID of the serving cell according to the first information, so that the candidate DU can obtain the first indication information.

[0168] The first CU can know the cell corresponding to the UE requesting the TA through the first indication information after receiving the second information.

[0169] In other examples, the first indication information carries the ID of the serving DU and the ID of the serving network device.

[0170] The candidate DU can determine the ID of the serving cell according to the first information, so that the candidate DU can obtain the first indication information.

[0171] The first CU can know the ID of the serving network device and the ID of the serving DU corresponding to the UE requesting the TA through the first indication information after receiving the second information.

[0172] Based on this, the first CU receives the second information sent by the candidate DU, and the first CU can know which DU of which network device the UE requesting the TA comes from, so that the first CU can send the TA to the correct network device and DU.

[0173] S103, the first CU sends third information to the second CU of the serving network device.

[0174] Correspondingly, the second CU receives the third information sent by the first CU.

[0175] The first CU can know which network device needs to forward the TA according to the ID of the serving cell, or according to the ID of the serving network device and the ID of the serving DU after receiving the second information.

[0176] Therefore, the first CU sends the third information to the second CU.

[0177] The first CU can send the third information to the second CU through an Xn interface.

[0178] The third information carries the TA and second indication information.

[0179] The second indication information is determined according to the second information.

[0180] The second indication information is used to indicate the serving DU, so that the UE can receive the TA through the serving DU.

[0181] The second indication information includes multiple forms.

[0182] In some examples, the second indication information carries an ID of the serving cell.

[0183] The first CU can determine the ID of the serving cell according to the second information.

[0184] Therefore, after receiving the third information, the second CU can know the cell corresponding to the UE requesting the TA through the second indication information. The second CU can determine the DU corresponding to the serving cell according to the ID of the serving cell, so that the second CU can send the TA to the correct DU, and ensure that the UE can receive the TA.

[0185] In other examples, the second indication information carries an ID of the serving DU.

[0186] The candidate DU can determine the ID of the serving DU according to the second information.

[0187] Therefore, after receiving the third information, the second CU can know the ID of the serving DU corresponding to the UE requesting the TA through the second indication information, so that the second CU can send the TA to the correct DU, and ensure that the UE can receive the TA.

[0188] S104, the second CU sends fifth information to the serving DU.

[0189] Correspondingly, the serving DU receives the fifth information sent by the second CU.

[0190] The fifth information carries the TA, so that the UE can receive the TA through the serving DU.

[0191] Based on this, the serving DU can obtain the TA and send the TA to the UE, so that the UE receives the TA.

[0192] After the UE receives the TA, the UE can determine the target cell for performing the handover in the first candidate cell according to the TA, so as to complete the cell handover.

[0193] In the embodiment of the present application, before the first candidate cell receives the preamble sequence sent by the UE, the first CU sends the first information to the candidate DU, so that the candidate DU knows which DU of which network device or which cell the UE requesting the TA comes from. The candidate DU sends the second information to the first CU, and the second information carries the TA and the first indication information, wherein the first indication information is used to indicate the serving DU, and the first CU can know which DU of which network device the UE requesting the TA comes from, so that the first CU can send the TA to the correct DU. The first CU sends the third information to the second CU of the serving network device, and the third information carries the TA and the second indication information, and the second indication information is used to indicate the serving DU, so that the UE can receive the TA through the serving DU. The second CU can know the ID of the serving DU corresponding to the UE requesting the TA or the ID of the serving cell through the third information, so that the second CU sends the TA to the correct DU, and ensures that the UE can receive the TA. Based on this, the UE can receive the TA through the serving DU, and the UE does not need to acquire the TA again, and the UE can perform cell switching through the TA, avoids increasing the time delay of cell switching, and ensures the normal switching of the cell.

[0194] Based on the above exemplary description, before S101, the first CU can determine the first information by the method shown in FIG. 4.

[0195] FIG. 4 is a signaling interaction diagram of a method for determining the first information according to an embodiment of the present application. As shown in FIG. 4, the method comprises the following steps.

[0196] S201, the second CU sends the switching request information to the first CU.

[0197] Correspondingly, the first CU receives the switching request information sent by the second CU.

[0198] The second CU is a CU of a serving network device. The serving network device further comprises a plurality of second DUs. The DU currently providing services for the UE in the plurality of second DUs is a serving DU.

[0199] The first CU is a CU of a candidate network device. The candidate network device further comprises a plurality of first DUs.

[0200] The candidate network device is a network device corresponding to the second candidate cell.

[0201] The serving network device is different from the candidate network device.

[0202] The second candidate cell is determined by the serving network device according to the L3 measurement report, and the second candidate cell is a cell capable of performing LTM cell switching for the UE.

[0203] Before initiating uplink synchronization, the UE needs to perform L3 measurement according to the L3 measurement reporting configuration configured by the serving network device to the UE, and send the L3 measurement report to the serving network device.

[0204] The L3 measurement includes one or more parameters such as reference signal receiving power (RSRP), reference signal received quality (RSRQ), or signal-to-noise and interference ratio (SINR). When the UE initially accesses the serving network device, the serving network device configures the L3 measurement reporting configuration for the UE, so that the UE can perform periodic or aperiodic L3 measurement on the serving cell and the neighbor cell according to the L3 measurement reporting configuration, and obtain the L3 measurement report.

[0205] The serving cell provides services for the UE, and the serving cell belongs to the serving DU, and the serving DU is the DU currently providing services for the UE.

[0206] The L3 measurement report includes one or more L3 measurement results, and the L3 measurement result is used to indicate the signal performance of the RRM-RS of the network device corresponding to the neighbor cell and the serving network device, such as the value of RSRP, the value of RSRQ, or the value of SINR.

[0207] The neighbor cell is a cell adjacent to the serving cell, and the number of neighbor cells can be one or more. The network device corresponding to the neighbor cell can be all or part of the network devices in the second network device.

[0208] Based on this, the serving network device learns the L3 measurement report, and the serving network device can determine the second candidate cell for the UE to perform LTM cell switching according to the L3 measurement report.

[0209] The serving network device can determine the second candidate cell in multiple ways.

[0210] As a feasible implementation manner, the serving network device can determine the second candidate cell according to the L3 measurement result.

[0211] For example, when the L3 measurement result is the value of RSRP, the second candidate cell is the cell corresponding to the maximum RSRP value in all L3 measurement results, so that the second CU can directly initiate a switching request to the second candidate cell, which helps to improve the success rate of the request TA, and further helps to improve the success rate of cell switching.

[0212] As another possible implementation, the serving network device can indicate the UE to send the beam level measurement results of each neighbor cell at the same time when the UE sends the L3 measurement report to the serving network device when configuring the L3 measurement report configuration for the UE. Thus, for each neighbor cell, the UE sends the beam level measurement results to the serving network device once when the UE performs a periodic measurement, and the serving network device stores the beam level measurement results of the periodic measurement. After multiple periods, the serving network device stores the beam level measurement results of multiple periods.

[0213] Thus, the serving network device can obtain the motion trajectory of the UE based on the changes of the beam level measurement results of multiple periods in different coverage directions. The serving network device determines one or more cells that the UE is likely to pass through when the UE moves at a future time according to the motion trajectory of the UE, and the serving network device can determine the one or more cells as the second candidate cells.

[0214] In the above implementation, the second candidate cells include all the cells that the UE is likely to pass through when the UE moves at a future time, and the second CU requests the TA from the second candidate cells, so that the selection range of the cells when requesting the TA can be increased, which helps to improve the success rate of requesting the TA.

[0215] As another possible implementation, after the serving network device determines the one or more cells that the UE is likely to pass through when the UE moves at a future time according to the motion trajectory of the UE, the serving network device can group the one or more cells according to the respective network devices, and in each group, determine the second candidate cells according to the L3 measurement results.

[0216] For example, when the L3 measurement result is the value of RSRP, the one or more cells that the UE is likely to pass through when the UE moves at a future time according to the motion trajectory of the UE include cell 1, cell 2 and cell 3, cell 1 belongs to network device A, and cell 2 and cell 3 belong to network device B, and the cell with the maximum value of RSRP in cell 2 and cell 3 is cell 2. Then, the second candidate cells include cell 1 and cell 2.

[0217] Based on this, the serving network device determines the second candidate cells, and determines the network device corresponding to the second candidate cells as the candidate network device.

[0218] There are various cases for the number of candidate network devices.

[0219] When the number of second candidate cells is one, the number of candidate network devices is one, and the candidate network device includes the network device corresponding to the second candidate cell.

[0220] For example, the second candidate cells include cell 1, and cell 1 belongs to network device A. Then, the candidate network device includes network device A.

[0221] When the number of the second candidate cells is multiple and the second candidate cells belong to the same network device, the number of the candidate network devices is one, and the candidate network devices include the network device corresponding to the second candidate cells.

[0222] For example, the second candidate cells include cell 1 and cell 2, and both cell 1 and cell 2 belong to network device A. Then, the candidate network devices include network device A.

[0223] When the number of the second candidate cells is multiple and the second candidate cells belong to different network devices, the number of the candidate network devices is also multiple, and the candidate network devices include all the network devices corresponding to the second candidate cells respectively.

[0224] For example, the second candidate cells include cell 1, cell 2 and cell 3, cell 1 belongs to network device A, and cell 2 and cell 3 belong to network device B. Then, the candidate network devices include network device A and network device B.

[0225] Based on this, when the candidate network devices are different from the serving network device, the second CU sends the handover request information to the first CU.

[0226] When the number of the candidate network devices is one, the second CU sends the handover request information to the first CU of the candidate network device.

[0227] When the number of the candidate network devices is multiple, the second CU sends the handover request information to the first CU of each candidate network device respectively.

[0228] The handover request information is used to request the TA of the second candidate cell.

[0229] The handover request information has multiple cases.

[0230] In some examples, the handover request information carries the ID of the second candidate cell and the ID of the serving cell.

[0231] In other examples, the handover request information carries the ID of the second candidate cell and the ID of the serving distribution unit.

[0232] In the above two examples, the handover request information does not carry the ID of the serving network device, which can save network resources.

[0233] Of course, the handover request information can also carry the ID of the serving network device, so that the candidate network device knows which network device the handover request information comes from.

[0234] In addition, the handover request information can also carry the L1 and L2 configuration request messages. The L1 and L2 configuration request messages are used to request the LTM configuration from the second candidate cell.

[0235] In addition, when the candidate network device and the serving network device are the same network device, the serving network device can perform cell switching based on means in the related art, which will not be described herein.

[0236] S202, the first CU determines the first information according to the switching request information.

[0237] After the first CU receives the switching request information, the first CU can learn the ID of the serving DU or the ID of the serving cell through the switching request information.

[0238] Based on this, the first CU can determine the first information according to the switching request information.

[0239] The first information is used to indicate a serving DU of a plurality of second DUs of the serving network device that provides services for the UE.

[0240] In some examples, the first information carries the ID of the serving DU and the ID of the serving network device.

[0241] The first CU can obtain the ID of the serving DU and the ID of the serving network device from the switching request information.

[0242] Of course, the first CU can also obtain the ID of the serving DU from the switching request information, and determine the ID of the serving network device according to the network device that receives the switching request information. The first CU can pre-know the ID of the serving network device. When the first CU receives the switching request information sent by the serving network device, the first CU can determine the ID of the serving network device.

[0243] In other examples, the first information carries the ID of the serving cell.

[0244] The first CU can obtain the ID of the serving cell from the switching request information.

[0245] Based on this, the first CU determines the first information.

[0246] Based on the above exemplary description, the candidate DU can determine the TA in the following manner.

[0247] The AAU sends fourth information to the DU.

[0248] Correspondingly, the candidate DU receives the fourth information sent by the AAU.

[0249] The fourth information carries the TA of the first candidate cell.

[0250] The AAU can obtain the TA of the first candidate cell based on the preamble sequence after receiving the preamble sequence sent by the UE, so that the AAU can send the TA to the candidate DU, so that the candidate DU obtains the TA.

[0251] Exemplarily, the present application further provides a communication device.

[0252] Fig. 5 is a structural schematic diagram of a communication device according to an embodiment of the present application.

[0253] As shown in Fig. 5, the communication device 100 can exist independently or be integrated in other devices, and can communicate with the candidate distribution unit or the second centralized unit mentioned above to implement the operation corresponding to the first centralized unit in any of the above method embodiments.

[0254] The communication device 100 can include a transceiver 101. The transceiver 101 can implement the corresponding communication function. The transceiver 101 can also be referred to as a communication interface or a communication unit.

[0255] Optionally, the communication device 100 can further include a storage unit and a processing unit. The storage unit can be used to store instructions and / or data, and the processing unit can read the instructions and / or data in the storage unit to enable the communication device 100 to implement the above method embodiments.

[0256] The communication device 100 can be used to perform the actions performed by the first centralized unit in the above method embodiments. The communication device 100 can be the first centralized unit or a component configurable to the first centralized unit. The transceiver 101 is used to perform the receiving related operations of the first centralized unit in the above method embodiments.

[0257] Optionally, the transceiver 101 can include a sending unit and a receiving unit. The sending unit is used to perform the sending operations in the above method embodiments. The receiving unit is used to perform the receiving operations in the above method embodiments.

[0258] It should be noted that the communication device 100 can include the sending unit and not include the receiving unit. Alternatively, the communication device 100 can include the receiving unit and not include the sending unit. Specifically, whether the sending unit and the receiving unit are included in the communication device 100 can depend on whether the sending action and the receiving action are included in the above scheme performed by the communication device 100.

[0259] As an example, the communication device 100 is used to perform the actions performed by the first centralized unit in the embodiments shown in Figs. 3-4.

[0260] The communication device 100 can include a transceiver 101.

[0261] The transceiver unit 101 is configured to send first information to a candidate distribution unit before the first candidate cell receives a preamble sequence sent by a terminal device, the candidate distribution unit being a distribution unit corresponding to the first candidate cell in a plurality of first distribution units, the first candidate cell being a cell in a second candidate cell that allows the terminal device to access, the second candidate cell being a cell of a candidate network device, the second candidate cell being determined by a serving network device according to a layer 3 measurement result, the first information being used to indicate a service distribution unit in a plurality of second distribution units of the serving network device that provides service for the terminal device, the serving network device being different from the candidate network device;

[0262] The transceiver unit 101 is configured to receive second information sent by the candidate distribution unit, the second information carrying a time advance of the first candidate cell and first indication information, the time advance being determined by an active antenna unit of the candidate network device according to the preamble sequence sent by the terminal device, the first indication information being used to indicate the service distribution unit, wherein the first indication information is determined according to the first information;

[0263] The transceiver unit 101 is configured to send third information to a second centralized unit of the serving network device, the third information carrying the time advance and second indication information, the second indication information being used to indicate the service distribution unit, so that the terminal device can receive the time advance through the service distribution unit, wherein the second indication information is determined according to the second information.

[0264] It should be understood that each unit performs the corresponding process described above, which has been described in detail in the above method embodiments. For the sake of brevity, it will not be repeated here.

[0265] The processing unit in the foregoing embodiments can be implemented by at least one processor or processor-related circuit. The transceiver unit 101 can be implemented by a transceiver or transceiver-related circuit. The transceiver unit 101 can also be referred to as a communication unit or a communication interface. The storage unit can be implemented by at least one memory.

[0266] In some examples, the communication apparatus 100 further includes a processing unit;

[0267] The transceiver unit 101 is further configured to receive handover request information sent by the second centralized unit, the handover request information being used to request a time advance of the second candidate cell, the handover request information carrying an identifier of the second candidate cell and an identifier of a service cell, the service cell belonging to the service distribution unit, the service cell providing service for the terminal device, or the handover request information carrying an identifier of the second candidate cell and an identifier of the service distribution unit;

[0268] The processing unit is further configured to determine the first information according to the handover request information.

[0269] In some examples, the first information carries an identity of a serving cell, the serving cell belongs to the serving distribution unit, the serving cell provides service to the terminal device, and the identity of the serving cell is unique among different network devices.

[0270] In some examples, the first indication information carries the identity of the serving cell, and the second indication information carries the identity of the serving cell.

[0271] In some examples, the first information carries an identity of the serving distribution unit and an identity of the serving network device.

[0272] In some examples, the first indication information carries the identity of the serving distribution unit and the identity of the serving network device, and the second indication information carries the identity of the serving distribution unit.

[0273] Exemplarily, the present application further provides a communication apparatus.

[0274] FIG. 6 is a structural schematic diagram of a communication apparatus according to an embodiment of the present application.

[0275] As shown in FIG. 6, the communication apparatus 200 can exist independently or can be integrated in other devices, and can communicate with the first centralized unit mentioned above to implement the operations of the candidate distribution unit in any of the above method embodiments.

[0276] The communication apparatus 200 can include a transceiver 201. The transceiver 201 can implement corresponding communication functions. The transceiver 201 can also be referred to as a communication interface or a communication unit.

[0277] Optionally, the communication apparatus 200 can further include a storage unit, which can be used to store instructions and / or data. The processing unit 201 can read the instructions and / or data in the storage unit, so that the communication apparatus 200 implements the above method embodiments.

[0278] The communication apparatus 200 can be used to perform the operations of the candidate distribution unit in the above method embodiments. The communication apparatus 200 can be the candidate distribution unit or a component configurable to the candidate distribution unit. The transceiver 201 is used to perform the receiving related operations of the candidate distribution unit in the above method embodiments.

[0279] Optionally, the transceiver 201 can include a transmitter and a receiver. The transmitter is configured to perform the transmitting operations in the foregoing method embodiments. The receiver is configured to perform the receiving operations in the foregoing method embodiments.

[0280] It should be noted that the communication apparatus 200 can include the transmitter but not the receiver. Alternatively, the communication apparatus 200 can include the receiver but not the transmitter. Specifically, whether the transmitter and the receiver are included in the communication apparatus 200 can depend on whether the communication apparatus 200 performs the transmitting action and the receiving action in the foregoing schemes.

[0281] As an example, the communication apparatus 200 is configured to perform the action performed by the candidate distribution unit in the embodiments shown in FIG. 3 to FIG. 4.

[0282] The communication apparatus 200 can include a transceiver 201.

[0283] The transceiver 201 is configured to receive first information sent by the first centralized unit before the first candidate cell receives a preamble sequence sent by the terminal device, where the first information is used to indicate a service distribution unit in a plurality of second distribution units of a service network device, and the service network device is different from the candidate network device.

[0284] The transceiver 201 is configured to send, to the first centralized unit, second information carrying a time advance of the first candidate cell and first indication information, where the time advance is determined by an active antenna unit of the candidate network device according to the preamble sequence sent by the terminal device, and the first indication information is used to indicate the service distribution unit, and the first indication information is determined according to the first information.

[0285] In some examples, the transceiver 201 is further configured to receive fourth information sent by the active antenna unit, where the fourth information carries the time advance.

[0286] In some examples, the first information carries an identifier of a serving cell, the serving cell belongs to the service distribution unit, the serving cell provides service to the terminal device, and the identifier of the serving cell is unique among different network devices.

[0287] In some examples, the first indication information carries the identifier of the serving cell, and the second indication information carries the identifier of the serving cell.

[0288] In some examples, the first information carries an identifier of the service distribution unit and an identifier of the service network device.

[0289] In some examples, the first indication information carries an identity of the service distribution unit and an identity of the service network device, and the second indication information carries the identity of the service distribution unit.

[0290] Exemplarily, the present application further provides a communication apparatus.

[0291] Fig. 7 is a structural schematic diagram of a communication apparatus according to an embodiment of the present application.

[0292] As shown in Fig. 7, the communication apparatus 300 can exist independently or be integrated in other devices, and can communicate with the first centralized unit or the service distribution unit mentioned above to implement the operations of the second centralized unit in any of the above method embodiments.

[0293] The communication apparatus 300 can include a transceiver 301. The transceiver 301 can implement corresponding communication functions. The transceiver 301 can also be referred to as a communication interface or a communication unit.

[0294] Optionally, the communication apparatus 300 can further include a storage unit and a processing unit. The storage unit can be used to store instructions and / or data, and the processing unit can read the instructions and / or data in the storage unit to enable the communication apparatus 300 to implement the above method embodiments.

[0295] The communication apparatus 300 can be used to perform the actions performed by the first network device in the above method embodiments. The communication apparatus 300 can be the second centralized unit or a component configurable to the second centralized unit. The transceiver 301 is used to perform the receiving operations of the second centralized unit in the above method embodiments.

[0296] Optionally, the transceiver 301 can include a sending unit and a receiving unit. The sending unit is used to perform the sending operations in the above method embodiments. The receiving unit is used to perform the receiving operations in the above method embodiments.

[0297] It should be noted that the communication apparatus 300 can include the sending unit and not include the receiving unit. Alternatively, the communication apparatus 300 can include the receiving unit and not include the sending unit. Whether the sending unit and the receiving unit are included in the communication apparatus 300 can depend on whether the communication apparatus 300 performs the sending action and the receiving action in the above schemes.

[0298] As an example, the communication apparatus 300 is used to perform the actions performed by the second centralized unit in the embodiments shown in Figs. 3 to 4.

[0299] The communication apparatus 300 can include a transceiver 301.

[0300] The transceiver unit 301 is configured to receive third information sent by the first centralized unit of the candidate network device, wherein the third information carries time advance of the first candidate cell and second indication information, the time advance is determined by the active antenna unit of the candidate network device according to the preamble sequence sent by the terminal device, and the second indication information is used to indicate a service distribution unit of the plurality of second distribution units that provides service for the terminal device, wherein the second indication information is determined according to second information sent by the candidate distribution unit to the first centralized unit, the candidate network device further comprises a plurality of first distribution units, the candidate distribution unit is a distribution unit corresponding to the first candidate cell in the plurality of first distribution units, the first candidate cell is a cell in the second candidate cell that allows the terminal device to access, the second candidate cell is a cell of the candidate network device, the second candidate cell is determined by the service network device according to layer 3 measurement result, the second information carries the time advance of the first candidate cell and first indication information, the first indication information is used to indicate the service distribution unit of the plurality of second distribution units that provides service for the terminal device, the first indication information is determined according to first information, and the first information is sent by the first centralized unit to the candidate distribution unit before the first centralized unit receives the preamble sequence sent by the terminal device in the first candidate cell, the first information is used to indicate the service distribution unit of the plurality of second distribution units that provides service for the terminal device, and the service network device is different from the candidate network device.

[0301] The transceiver unit 301 is configured to send fifth information to the service distribution unit, wherein the fifth information carries the time advance, so that the terminal device can receive the time advance through the service distribution unit.

[0302] In some examples, the transceiver unit 301 is further configured to send handover request information to the first centralized unit, wherein the handover request information is used to request time advance of the second candidate cell, the handover request information carries an identifier of the second candidate cell and an identifier of a service cell, the service cell belongs to the service distribution unit, and the service cell provides service for the terminal device, or the handover request information carries an identifier of the second candidate cell and an identifier of the service distribution unit.

[0303] In some examples, the first information carries an identifier of a service cell, the service cell belongs to the service distribution unit, the service cell provides service for the terminal device, and the identifier of the service cell is unique between different network devices.

[0304] In some examples, the first indication information carries an identity of the serving cell, and the second indication information carries the identity of the serving cell.

[0305] In some examples, the first information carries an identity of the serving distribution unit and an identity of the serving network device.

[0306] In some examples, the first indication information carries an identity of the serving distribution unit and an identity of the serving network device, and the second indication information carries the identity of the serving distribution unit.

[0307] Exemplarily, the present application also provides a communication apparatus.

[0308] Fig. 8 is a schematic diagram of a hardware structure of a communication apparatus according to an embodiment of the present application.

[0309] The communication apparatus 400 comprises a processor 401 coupled with a memory 402, the memory 402 being configured to store computer programs or instructions and / or data, and the processor 401 being configured to execute the computer programs or instructions and / or data stored in the memory 402, so that the method in the foregoing method embodiments is executed.

[0310] Optionally, the processor 401 comprised by the communication apparatus 400 is one or more.

[0311] Optionally, as shown in Fig. 8, the communication apparatus 400 can further comprise the memory 402.

[0312] Optionally, the memory 402 comprised by the communication apparatus 400 can be one or more.

[0313] Optionally, the memory 402 can be integrated with the processor 401 or separately arranged.

[0314] The communication apparatus 400 can further comprise a transceiver configured to receive and / or transmit signals. For example, the processor 401 is configured to control the transceiver to receive and / or transmit signals.

[0315] As an option, the communication apparatus 400 is configured to implement the operations performed by any one of the second centralized unit, the candidate distribution unit, and the first centralized unit in the foregoing method embodiments.

[0316] For example, the processor 401 is configured to implement the processing-related operations performed by any one of the second centralized unit, the candidate distribution unit, and the first centralized unit in the foregoing method embodiments, and the transceiver is configured to implement the transceiving-related operations performed by any one of the second centralized unit, the candidate distribution unit, and the first centralized unit in the foregoing method embodiments.

[0317] In the communication apparatus shown in FIG. 8, the device for receiving power in the transceiver can be regarded as a receiving unit, and the device for transmitting function in the transceiver can be regarded as a transmitting unit. That is, the transceiver can include a receiver and a transmitter. The transceiver can also be referred to as a transceiver, a transceiving unit, or a transceiving circuit, etc. The receiver can also be referred to as a receiver, a receiving unit, a receiver, or a receiving circuit, etc. The transmitter can also be referred to as a transmitter, a transmitting unit, or a transmitting circuit, etc. The processor 401 has a processing function, and the processor 401 can be referred to as a processing unit. The memory 402 is used for storing computer program codes and data, and the memory 402 can also be referred to as a storage unit.

[0318] When the communication apparatus is a chip, the chip includes a transceiver, a memory and a processor. The transceiver can be an input / output circuit or a communication interface. The processor is a processor or a microprocessor integrated on the chip or an integrated circuit. The transmitting operation of any one of the second concentrating unit, the candidate distributing unit and the first concentrating unit in the method embodiment can be understood as the output of the chip, and the receiving operation of any one of the second concentrating unit, the candidate distributing unit and the first concentrating unit in the method embodiment can be understood as the input of the chip.

[0319] Exemplarily, the present application further provides a computer readable storage medium, which stores computer instructions for implementing the method executed by any one of the second concentrating unit, the candidate distributing unit and the first concentrating unit in the method embodiment.

[0320] For example, when the computer program is executed by a computer, the computer can implement the method executed by any one of the second concentrating unit, the candidate distributing unit and the first concentrating unit in the method embodiment.

[0321] Exemplarily, the present application further provides a computer program product including instructions, which are executed by a computer to make the computer implement the method executed by any one of the second concentrating unit, the candidate distributing unit and the first concentrating unit in the method embodiment.

[0322] Exemplarily, the present application further provides a communication system, which includes a service network device, a candidate network device and a terminal device. The service network device includes a concentrating unit and a distributing unit. The candidate network device includes a distributing unit and a concentrating unit.

[0323] The processor mentioned in any of the above can be a general central processing unit, a microprocessor, a baseband processor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs of the method of the preceding embodiments. The memory mentioned in any of the above can be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM), and the like.

[0324] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the explanation and beneficial effects of the related content in any of the above communication devices can refer to the corresponding method embodiments provided in the foregoing, which will not be repeated here.

[0325] In the present application, any of the second centralized unit, the candidate distribution unit, and the first centralized unit can include a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. The hardware layer can include a central processing unit (CPU), a memory management unit (MMU), and a memory (also known as main memory), and the like. The operating system of the operating system layer can be any one or more computer operating systems that implement business processing through processes, such as Linux operating system, Unix operating system, Android operating system, iOS operating system, or windows operating system, and the like. The application layer can include browsers, address books, word processing software, instant messaging software, and the like.

[0326] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described system, device, and unit can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0327] In several embodiments provided in the present application, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed mutual units can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0328] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e. may be located in one place, or may be distributed to multiple network units. Part or all of the units may be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0329] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present alone, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0330] If the integrated unit is realized in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the part of the technical scheme of the present application that essentially contributes or the whole or part of the technical scheme can be embodied in the form of a software product, which is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the processes of the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk, and various program code storage media.

[0331] The above embodiments are only used to illustrate the technical scheme of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical scheme recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the corresponding technical scheme deviate from the scope of the technical scheme of the embodiments of the present application.

Claims

1. A time advance forwarding method, characterized by, The method is applied to a first centralized unit of a candidate network device, the candidate network device further comprising a plurality of first distributed units, and the method comprises the following steps of: Before a first candidate cell receives a preamble sequence sent by a terminal device, the first centralized unit sends first information to a candidate distributed unit, the candidate distributed unit being a distributed unit corresponding to the first candidate cell in the plurality of first distributed units, the first candidate cell being a cell in a second candidate cell allowing the terminal device to access, the second candidate cell being a cell of the candidate network device, the second candidate cell being determined by a serving network device according to a layer 3 measurement result, the first information being used for indicating a serving distributed unit providing service for the terminal device in a plurality of second distributed units of the serving network device, the serving network device being different from the candidate network device; The first centralized unit receives second information sent by the candidate distributed unit, the second information carrying a time advance of the first candidate cell and first indication information, the time advance being determined by an active antenna unit of the candidate network device according to the preamble sequence sent by the terminal device, the first indication information being used for indicating the serving distributed unit, wherein the first indication information is determined according to the first information; The first centralized unit sends third information to a second centralized unit of the serving network device, the third information carrying the time advance and second indication information, the second indication information being used for indicating the serving distributed unit, so that the terminal device can receive the time advance through the serving distributed unit, wherein the second indication information is determined according to the second information.

2. The method of claim 1, wherein, The method further comprises the following steps of: The first centralized unit receives handover request information sent by the second centralized unit, the handover request information being used for requesting a time advance of the second candidate cell, the handover request information carrying an identifier of the second candidate cell and an identifier of a serving cell, the serving cell belonging to the serving distributed unit, the serving cell providing service for the terminal device, or the handover request information carrying an identifier of the second candidate cell and an identifier of the serving distributed unit; The first centralized unit determines the first information according to the handover request information.

3. A time advance forwarding method, characterized by, The method is applied to a candidate distributed unit of a candidate network device, the candidate network device comprising a first centralized unit and a plurality of first distributed units, the candidate distributed unit being a distributed unit corresponding to a first candidate cell in the plurality of first distributed units, the first candidate cell being a cell in a second candidate cell allowing a terminal device to access, the second candidate cell being a cell of the candidate network device, the second candidate cell being determined by a serving network device according to a layer 3 measurement result, and the method comprises the following steps of: The candidate distribution unit receives first information sent by the first centralized unit before the first candidate cell receives a preamble sequence sent by the terminal device, and the first information is used to indicate a serving distribution unit of a plurality of second distribution units of the serving network device that provides service for the terminal device, and the serving network device is different from the candidate network device; The candidate distribution unit sends second information to the first centralized unit, and the second information carries a time advance of the first candidate cell and first indication information, the time advance is determined by an active antenna unit of the candidate network device according to the preamble sequence sent by the terminal device, and the first indication information is used to indicate the serving distribution unit, wherein the first indication information is determined according to the first information.

4. The method of claim 3, wherein, The method further comprises: The candidate distribution unit receives fourth information sent by the active antenna unit, and the fourth information carries the time advance.

5. A time advance forwarding method, characterized by, The second centralized unit of the serving network device further comprises a plurality of second distribution units, and the method comprises: The second centralized unit receives third information sent by the first centralized unit of the candidate network device, and the third information carries a time advance of a first candidate cell and second indication information, the time advance is determined by an active antenna unit of the candidate network device according to a preamble sequence sent by a terminal device, and the second indication information is used to indicate a serving distribution unit of the plurality of second distribution units that provides service for the terminal device, wherein the second indication information is determined according to second information, the second information is sent by a candidate distribution unit to the first centralized unit, the candidate network device further comprises a plurality of first distribution units, the candidate distribution unit is a distribution unit corresponding to a first candidate cell in the plurality of first distribution units, the first candidate cell is a cell in a second candidate cell that allows the terminal device to access, the second candidate cell is a cell of the candidate network device, the second candidate cell is determined by the serving network device according to a layer 3 measurement result, the second information carries the time advance and first indication information, the first indication information is used to indicate a serving distribution unit of the plurality of second distribution units that provides service for the terminal device, and the first indication information is determined according to first information, the first information is sent by the first centralized unit to the candidate distribution unit before the first candidate cell receives the preamble sequence sent by the terminal device, and the first information is used to indicate a serving distribution unit of the plurality of second distribution units that provides service for the terminal device, and the serving network device is different from the candidate network device; The second centralized unit sends fifth information to the serving distribution unit, and the fifth information carries the time advance, so that the terminal device can receive the time advance through the serving distribution unit.

6. The method of claim 5, wherein, The first information is determined by the first centralized unit according to handover request information, and the method further comprises: The second centralized unit sends switching request information to the first centralized unit, the switching request information is used for requesting a time advance of the second candidate cell, the switching request information carries an identifier of the second candidate cell and an identifier of a serving cell, the serving cell belongs to the serving distributed unit, the serving cell provides service for the terminal device, or the switching request information carries an identifier of the second candidate cell and an identifier of the serving distributed unit.

7. The method according to any one of claims 1 to 6, characterized in that, The first information carries an identifier of a serving cell, the serving cell belongs to the serving distributed unit, the serving cell provides service for the terminal device, and the identifier of the serving cell is unique between different network devices.

8. The method of claim 7, wherein, The first indication information carries the identifier of the serving cell, and the second indication information carries the identifier of the serving cell.

9. The method according to any one of claims 1 to 6, characterized in that, The first information carries an identifier of the serving distributed unit and an identifier of the serving network device.

10. The method of claim 9, wherein, The first indication information carries the identifier of the serving distributed unit and the identifier of the serving network device, and the second indication information carries the identifier of the serving distributed unit.

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