Information receiving / sending method and apparatus

Abstract

The present application provides an information receiving / sending method and apparatus. The information receiving / sending method comprises: sending first signaling to a candidate cell, wherein the first signaling is used to request the candidate cell to send second signaling, and / or used to notify the candidate cell of or indicate to the candidate cell information related to TA.

Description

Information sending and receiving method and device Technical Field

[0001] The embodiments of the present application relate to the field of wireless communication technologies. Background Art

[0002] The 3rd Generation Partnership Project (3GPP) conducted in-depth discussions and research on the enhancement of mobility-related services in Release 18. Mobility management provides seamless connectivity for terminal devices and ensures service continuity. When the terminal location or channel environment changes, the service of an ongoing communication session can be transferred from one cell to another. The traditional process of changing the serving cell is triggered by Layer 3 (L3) measurements and implemented by Radio Resource Control (RRC) signaling. Release 18 introduces Layer 1 / Layer 2 (L1 / L2)-based mobility management, a mobility service triggered by the lower layer, namely Layer 1 / Layer 2 Triggered Mobility (LTM), which implements the change of serving cells through L1 / L2 signaling.

[0003] It should be noted that the above introduction to the technical background is merely intended to provide a clear and complete description of the technical solutions of this application and facilitate understanding by those skilled in the art. Simply because these solutions are described in the background technology section of this application, it should not be assumed that the above technical solutions are well known to those skilled in the art.

[0004] Summary of the Invention

[0005] The inventors discovered that before triggering LTM-based cell switching, the network side determines a candidate target cell for the terminal device based on the L1 measurement results reported by the terminal device, and the terminal device obtains the TA between the terminal device and the candidate target cell by triggering the Early Random Access (Early RACH) process. 3GPP Release 18 discussed and reached a consensus agreement that the Early RACH process does not include a Random Access Response (RAR) message, while the traditional RACH process includes the RAR message, and the network side will send the TA information to the terminal device through the RAR message. Therefore, the terminal device will not obtain the relevant TA from the target cell during the Early RACH process, nor will it maintain the TA of the candidate target cell.

[0006] The candidate target cell notifies the terminal device's serving cell of the TA between it and the terminal device. The serving cell then maintains the candidate target cell's TA and the corresponding time alignment timer (TAT). When the LTM process is triggered, if the target cell's TA maintained by the network is valid, the serving cell configures the TA information in the cell handover MAC CE and sends it to the terminal device. The terminal device then executes RACH-Less or RACH-Based LTM based on the TA configuration in the MAC CE. The terminal device cannot obtain the target cell's TA information before receiving the cell handover MAC CE.

[0007] During the LTM process, the serving cell needs to maintain the TA and the remaining effective time (TAT) between one or more candidate target cells and the terminal device to be switched. When the LTM switch is triggered, the serving cell configures the MAC CE according to the maintained TAT. If the TAT has not timed out, the TA of the target cell is considered valid, and the serving cell will configure the TA information in the MAC CE and send it to the terminal device. If the MAC CE indicates TA=0 or is consistent with the TA of the target cell maintained by the serving cell, the terminal device performs a RACH-Less mode switch, that is, the first uplink transmission is performed directly on the time-frequency resources of the allocated target cell. After receiving the first uplink transmission from the terminal device, the target cell considers the LTM process to be completed. During the entire LTM switch execution process, no additional RACH process is performed between the terminal device and the target cell, and the TA will not be re-acquired. During this period, there is no TA information maintenance between the terminal device and the target cell. Since the TA information of the candidate target cell is maintained by the serving cell, the serving cell and the candidate target cell may belong to different distributed units (DUs). The delay in communication between the two cells will cause the TAT to take effect in the serving cell with a delay, thereby causing the serving cell to misjudge the validity of the TA. When the candidate target cell notifies the serving cell that the TA has expired, the serving cell still considers the TA to be valid and configures it in the MAC CE that triggers LTM switching, so that the terminal device decides to perform RACH-Less cell switching based on this.

[0008] Furthermore, when the serving cell sends a MAC CE command to a terminal device, triggering an LTM cell handover, it no longer maintains the TA between the terminal device and the target cell. During the RACH-Less LTM process, the TAT (Time Alignment Timer) may have expired, but neither the target cell nor the source cell maintains this information. Therefore, the corresponding TA update process is not proactively triggered, ultimately leading to radio link failures and other issues.

[0009] In addition, according to the LTM discussion on RACH-Less in 3GPP Release 18, the terminal device sends the first uplink data on the CG or DG of the target cell according to the instruction of MAC CE. After the network successfully receives the uplink data, it needs to schedule a new transmission for the terminal device to confirm that the cell switching of this LTM is completed. The PDCCH used to schedule the new transmission addresses the C-RNTI of the terminal device in the target cell. After the terminal device successfully receives the new transmission scheduled by the target cell according to the first uplink data of the terminal device, it considers that the LTM process is completed. What content the new transmission sent by the network should indicate has not yet been determined.

[0010] In order to solve at least one of the above problems or other similar problems, an embodiment of the present application provides an information sending and receiving method and an apparatus thereof.

[0011] According to one aspect of an embodiment of the present application, a method for sending and receiving information is provided, which is applied to a serving cell of a terminal device, and the method includes:

[0012] Sending a first signaling to the candidate cell;

[0013] The first signaling is used to request the candidate cell to send a second signaling, and / or is used to notify or indicate information related to the candidate cell and the TA.

[0014] The content carried by the first signaling includes:

[0015] - request a second signalling indication; and / or

[0016] - the first time of the first TAT (Time Alignment Timer); and / or

[0017] - the initial value of the second TAT (Time Alignment Timer); and / or

[0018] - configuration of a second time of a second TAT (Time Alignment Timer); and / or

[0019] - Timing Advance; and / or

[0020] - a difference, where the difference is an offset between the configuration of the second time and the first time;

[0021] Among them, the first TAT is maintained by the serving cell; the first time is the remaining time of the first TAT or the time when the first TAT has been running; the second TAT is maintained by the candidate cell; the second time is the remaining time of the second TAT or the time when the second TAT has been running; the timing advance (TA) is the timing advance of the terminal device relative to the candidate cell.

[0022] Another aspect of the present application further provides a signaling receiving and sending method, which is applied to a candidate cell of a terminal device, and includes:

[0023] Receiving first signaling sent by a serving cell of a terminal device;

[0024] The first signaling is used to request the candidate cell to send a second signaling, and / or is used to notify or indicate information related to the candidate cell and the TA.

[0025] The content carried by the first signaling includes:

[0026] - request a second signalling indication; and / or

[0027] - the first time of the first TAT (Time Alignment Timer); and / or

[0028] - the initial value of the second TAT (Time Alignment Timer); and / or

[0029] - configuration of a second time of a second TAT (Time Alignment Timer); and / or

[0030] - Timing Advance; and / or

[0031] - a difference, where the difference is an offset between the configuration of the second time and the first time;

[0032] The first TAT is maintained by the serving cell; the first time is the remaining time of the first TAT or the time when the first TAT has been running; the second TAT is maintained by the candidate cell; the second time is the remaining time of the second TAT or the time when the second TAT has been running; the timing advance (TA) is the timing advance of the terminal device relative to the candidate cell.

[0033] Another aspect of the present application further provides an information sending and receiving method, which is applied to a target cell of an LTM cell handover, wherein the method includes:

[0034] Receive the first uplink data sent by the terminal device on the time-frequency resources of the configured target cell when performing RACH-Less LTM cell handover;

[0035] A new transmission is sent to the terminal device based on the first uplink data, where the new transmission indicates the latest timing advance (TA) between the target cell and the terminal device.

[0036] According to another aspect of an embodiment of the present application, there is provided an information transceiver device, which is applied to a serving cell of a terminal device. The device includes:

[0037] A first sending unit, configured to send a first signaling to a candidate cell;

[0038] The first signaling is used to request the candidate cell to send a second signaling, and / or is used to notify or indicate information related to the candidate cell and the TA.

[0039] Another aspect of the present application further provides a signaling transceiver device, which is applied to a candidate cell of a terminal device. The device includes:

[0040] A first receiving unit, configured to receive a first signaling sent by a serving cell of a terminal device;

[0041] The first signaling is used to request the candidate cell to send a second signaling, and / or is used to notify or indicate information related to the candidate cell and the TA.

[0042] Another aspect of the present application further provides an information transceiver device, which is applied to a target cell of an LTM cell handover, wherein the device includes:

[0043] A second receiving unit, configured to receive the first uplink data sent by the terminal device on the time-frequency resources of the configured target cell when performing RACH-Less LTM cell handover;

[0044] The second sending unit is configured to send a new transmission to the terminal device according to the first uplink data, where the new transmission indicates the latest timing advance (TA) between the target cell and the terminal device.

[0045] The beneficial effect of the embodiments of the present application is that the service cell of the terminal device sends a request message and / or a notification / indication message to the candidate cell, so that the service cell and / or the target cell promptly and effectively maintains the TA between the terminal device and the target cell, thereby avoiding the delayed effectiveness due to the communication delay between the cells (the problem of the service cell misjudging the validity of the TA). In addition, by maintaining the TA, problems such as wireless link failure that may be caused during the LTM execution process of RACH-Less can also be avoided.

[0046] With reference to the following description and drawings, specific embodiments of the present application are disclosed in detail, indicating the manner in which the principles of the present application can be employed. It should be understood that the embodiments of the present application are not limited in scope thereby. Within the scope of the terms of the appended claims, the embodiments of the present application include many variations, modifications, and equivalents.

[0047] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0048] It should be emphasized that the term "include / comprising" when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps or components. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The elements and features described in one figure or one embodiment of the present application can be combined with the elements and features shown in one or more other figures or embodiments. In addition, in the accompanying drawings, similar reference numerals represent corresponding parts in several figures and can be used to indicate corresponding parts used in more than one embodiment.

[0050] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without inventive work. In the drawings:

[0051] FIG1 is a schematic diagram of a communication system according to an embodiment of the present application;

[0052] FIG2 is a schematic diagram of LTM cell switching according to an embodiment of the present application;

[0053] FIG3 is a schematic diagram of a method for sending and receiving information according to an embodiment of the present application;

[0054] FIG4 is another schematic diagram of the information sending and receiving method according to an embodiment of the present application;

[0055] FIG5 is another schematic diagram of the information sending and receiving method according to an embodiment of the present application;

[0056] FIG6 is a signaling diagram of an embodiment of the present application;

[0057] FIG7 is another signaling diagram of an embodiment of the present application;

[0058] FIG8 is another signaling diagram of an embodiment of the present application;

[0059] FIG9 is another schematic diagram of the information sending and receiving method according to an embodiment of the present application;

[0060] FIG10 is another schematic diagram of the information sending and receiving method according to an embodiment of the present application;

[0061] FIG11 is another schematic diagram of the information sending and receiving method according to an embodiment of the present application;

[0062] FIG12 is a schematic diagram of an information transceiver device according to an embodiment of the present application;

[0063] FIG13 is another schematic diagram of the information transceiver according to an embodiment of the present application;

[0064] FIG14 is another schematic diagram of the information transceiver according to an embodiment of the present application;

[0065] FIG15 is another schematic diagram of the information transceiver according to an embodiment of the present application;

[0066] FIG16 is a schematic diagram of a network device according to an embodiment of the present application. DETAILED DESCRIPTION

[0067] The foregoing and other features of the present application will become apparent from the following description with reference to the accompanying drawings. In the description and drawings, specific embodiments of the present application are disclosed, which illustrate some embodiments in which the principles of the present application can be employed. It should be understood that the present application is not limited to the described embodiments. On the contrary, the present application includes all modifications, variations, and equivalents falling within the scope of the appended claims. Various embodiments of the present application are described below with reference to the accompanying drawings. These embodiments are merely illustrative and are not intended to limit the present application.

[0068] In the embodiments of the present application, the terms "first", "second", etc. are used to distinguish different elements from the name, but do not indicate the spatial arrangement or temporal order of these elements, and these elements should not be limited by these terms. The term "and / or" includes any one and all combinations of one or more of the associated listed terms. The terms "comprising", "including", "having", etc. refer to the presence of the stated features, elements, components or components, but do not exclude the presence or addition of one or more other features, elements, components or components.

[0069] In the embodiments of this application, the singular forms "a," "the," etc. include plural forms and should be broadly understood to mean "a" or "a type" rather than being limited to "one." Furthermore, the term "said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise. Furthermore, the term "according to" should be understood to mean "at least in part based on...", and the term "based on" should be understood to mean "at least in part based on...", unless the context clearly indicates otherwise.

[0070] In the embodiments of the present application, the term "communication network" or "wireless communication network" may refer to a network that complies with any of the following communication standards, such as Long Term Evolution (LTE), enhanced Long Term Evolution (LTE-A, LTE-Advanced), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), etc.

[0071] Furthermore, communication between devices in the communication system may be carried out according to communication protocols of any stage, for example, including but not limited to the following communication protocols: 1G (generation), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G, New Radio (NR) and future 6G, etc., and / or other currently known or future developed communication protocols.

[0072] In the embodiments of the present application, the term "network device" refers to, for example, a device in a communication system that connects a terminal device to the communication network and provides services to the terminal device. Network devices may include, but are not limited to, the following devices: base station (BS), access point (AP), transmission reception point (TRP), broadcast transmitter, mobile management entity (MME), gateway, server, radio network controller (RNC), base station controller (BSC), etc.

[0073] Base stations may include, but are not limited to, NodeB (NB), evolved NodeB (eNodeB or eNB), and 5G base stations (gNB), among others. They may also include remote radio heads (RRHs), remote radio units (RRUs), relays, or low-power nodes (e.g., femto, pico, etc.). The term "base station" may include some or all of their functions, and each base station may provide communication coverage for a specific geographic area. The term "cell" may refer to a base station and / or its coverage area, depending on the context in which the term is used.

[0074] In the embodiments of the present application, the term "user equipment" (UE) or "terminal equipment" (TE) refers to, for example, a device that accesses a communication network through a network device and receives network services. A user equipment may be fixed or mobile and may also be referred to as a mobile station (MS), a terminal, a subscriber station (SS), an access terminal (AT), a station, and so on.

[0075] Among them, user devices may include but are not limited to the following devices: cellular phones, personal digital assistants (PDAs), wireless modems, wireless communication devices, handheld devices, machine-type communication devices, laptop computers, cordless phones, smart phones, smart watches, digital cameras, etc.

[0076] For another example, in scenarios such as the Internet of Things (IoT), the user equipment may also be a machine or device for monitoring or measurement, such as but not limited to: machine type communication (MTC) terminals, vehicle-mounted communication terminals, device-to-device (D2D) terminals, machine-to-machine (M2M) terminals, terminals that support sidelink communication, and the like.

[0077] In addition, the term "network side" or "network device side" refers to one side of the network, which can be a base station or one or more network devices as described above. The term "user side" or "terminal side" or "terminal device side" refers to the user or terminal side, which can be a UE or one or more terminal devices as described above. Unless otherwise specified herein, "device" can refer to either network equipment or terminal equipment.

[0078] FIG1 is a schematic diagram of a communication system according to an embodiment of the present application, schematically illustrating a situation using a terminal device and a network device as an example. As shown in FIG1 , a communication system 100 may include a network device 101 and terminal devices 102 and 103. For simplicity, FIG1 illustrates only two terminal devices and one network device as an example, but the embodiments of the present application are not limited thereto.

[0079] In the embodiment of the present application, existing services or future services can be transmitted between the network device 101 and the terminal devices 102 and 103. For example, these services may include but are not limited to: enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable and low-latency communication (URLLC), etc.

[0080] Among them, terminal device 102 can send data to network device 101, for example, using authorized or unauthorized transmission. Network device 101 can receive data sent by one or more terminal devices 102 and feedback information to terminal device 102, such as confirmation ACK / non-confirmation NACK information, etc. HARQ-ACK can be replaced with positive HARQ-ACK or ACK. Terminal device 102 can confirm the end of the transmission process, or can continue new data transmission, or can retransmit data based on the feedback information.

[0081] It is worth noting that FIG1 shows that both terminal devices 102 and 103 are within the coverage range of network device 101, but the present application is not limited thereto. Both terminal devices 102 and 103 may not be within the coverage range of network device 101, or one terminal device 102 may be within the coverage range of network device 101 while the other terminal device 103 is outside the coverage range of network device 101.

[0082] Rel-18 studies Layer 1 / Layer 2 Triggered Mobility (LTM). Rel-18 LTM includes at least the following basic steps: a terminal device is provided with a candidate cell configuration, then receives a cell switch command indicating the TCI state, switches to the target cell according to the cell switch command, and applies the indicated TCI state to the target cell.

[0083] Figure 2 is a schematic diagram of cell switching of LTM in an embodiment of the present application. As shown in Figure 2, cell C0, cell C1, and cell C2 belong to serving cells. For example, cell C0, cell C1, and cell C2 are a group of cells aggregated by carriers, cell C0 is a primary cell (Pcell), and cell C1 and cell C2 are secondary cells (Scell). For example, a serving cell is at least one of the following: a special cell (SpCell), an Scell, an activated cell, or a deactivated cell. Cell C3, cell C4, cell C5, and cell C6 belong to non-serving cells. For example, cell C3, cell C4, cell C5, and cell C6 are a group of cells aggregated by carriers, cell C3 is a Pcell, and cell C4, cell C5, and cell C6 are Scells.

[0084] Currently, Rel-18LTM supports switching from one cell (for example, cell C0) to a serving cell, an intra-frequency cell, and an inter-frequency cell. For example, cell C0 can be switched to cell C2 (serving cell), cell C3 (intra-frequency), and cell C6 (inter-frequency cell). For example, a cell to which a terminal device may switch is called a candidate cell, or a candidate target cell, and the cell to which the terminal device actually switches is called a target cell. The terminal device can switch to one or more target cells, for example, from a group of carrier-aggregated serving cells (cell C0, cell C1, cell C2) to a group of carrier-aggregated non-serving cells (cell C3, cell C4, cell C5, cell C6). In addition, cell can be replaced by carrier or CC (Component Carrier).

[0085] In the following description, unless otherwise specified, a serving cell refers to the cell providing services to a terminal device before a cell handover. A serving cell may be replaced by a source cell. If a cell switch command instructs a terminal device to switch to a candidate cell, the candidate cell is also referred to as a target cell.

[0086] To address at least one of the above problems, the present invention provides an information sending and receiving method and apparatus. The present invention will be described in detail below with reference to the accompanying drawings.

[0087] Embodiments of the first aspect

[0088] FIG3 is a schematic diagram of an information receiving method according to an embodiment of the present application. As shown in FIG3 , the method is applied to a serving cell of a terminal device, and the method includes:

[0089] 301. Send a first signaling to a candidate cell; the first signaling is used to request the candidate cell to send a second signaling, and / or to notify or indicate information related to the candidate cell and the TA.

[0090] It is worth noting that FIG3 above is merely a schematic illustration of an embodiment of the present application, and the present application is not limited thereto. For example, the execution order of the various operations may be appropriately adjusted, other operations may be added or some operations may be reduced, and the objects of the aforementioned operations may be adjusted. Those skilled in the art may make appropriate modifications based on the above content, and are not limited to the description of FIG3 above.

[0091] According to the above embodiment, the service cell of the terminal device sends a request message and / or a notification / indication message to the candidate cell, so that the service cell and / or the target cell can promptly and effectively maintain the TA between the terminal device and the target cell, thereby avoiding the delayed effectiveness due to the communication delay between cells (the problem of the service cell misjudging the validity of the TA). In addition, by maintaining the TA, problems such as wireless link failure that may be caused during the LTM execution of RACH-Less can also be avoided.

[0092] In some embodiments, in 301, the candidate cell is a cell to which the terminal equipment (UE) may switch, that is, a candidate target cell. The candidate cell can be determined by the serving cell of the UE. The specific process is as described above and will not be repeated here.

[0093] In some embodiments, a first signaling is used to request the candidate cell to send a second signaling. The serving cell sends the first signaling to the candidate cell, and the candidate cell feeds back the second signaling to the serving cell based on the first signaling. The first signaling can be existing information that enables the candidate cell to feed back the second signaling, such as, for example, a signaling requesting Early RACH resources or a signaling requesting measurement resources. Alternatively, the first signaling can be separately defined information instructing the candidate cell to feed back the second signaling. The first signaling can contain no information or any information, and the second signaling fed back by the candidate cell can contain no information or any information. In this case, the first signaling only requests the candidate cell to feed back a signaling, regardless of the content carried by the second signaling. Thus, when the first signaling is an existing signaling requesting the candidate cell to feed back the second signaling, the serving cell can update (calibrate) the first time of its locally maintained first TAT based on the time difference between sending and receiving the signaling. This minimizes the impact on the existing signaling exchange process, saves signaling overhead, and resolves problems existing in the prior art.

[0094] In some embodiments, the first signaling is used to notify or indicate information related to the candidate cell and the TA.

[0095] In some embodiments, the content carried by the first signaling may be at least one of the following information:

[0096] (11) requesting a second signaling indication;

[0097] (12) a first time of a first TAT (Time Alignment Timer); the first TAT is maintained by the serving cell; the first time is the remaining time of the first TAT or the time when the first TAT has been running;

[0098] (13) an initial value of a second TAT (Time Alignment Timer); the second TAT is maintained by the candidate cell;

[0099] (14) Configuration of a second time of a second TAT (Time Alignment Timer), where the second time is the remaining time of the second TAT or the time during which the second TAT has been running; the configuration of the second time includes the value of the second time for which the serving cell is a candidate configuration;

[0100] (15) Timing Advance (TA); the timing advance is the timing advance of the terminal device relative to the candidate cell;

[0101] (16) A difference value, wherein the difference value is an offset between the configuration of the second time and the first time.

[0102] Among them, the above steps (12) to (16) are information related to TA, or can also be called TA information.

[0103] The above information (11) to (16) are described below.

[0104] In some embodiments, for the above information (11), the serving cell sends a first signaling including a request for a second signaling indication to the candidate cell, and after receiving the first signaling, the candidate cell sends a second signaling to the serving cell in response to the first signaling.

[0105] Regarding the above information (12), upon receiving the TA in the above information (11), the serving cell locally starts a first TAT. The first time of the first TAT represents the effective duration of the TA maintained locally by the serving cell. If the first TAT does not time out, the serving cell considers the TA to be valid. When the serving cell sends a first signaling to the candidate cell, the first signaling carries the first time of the first TAT. The content of the first TAT timeout is similar to the above content and is incorporated herein and will not be repeated here.

[0106] Regarding the above information (13), as mentioned above, the initial value of the second TAT is the value when the second TAT is started. As mentioned above, the initial value can be 0 (corresponding to the case where the second TAT is counting up), or a positive integer greater than 0 (corresponding to the case where the second TAT is counting down).

[0107] Corresponding to the above information (14), the second time of the second TAT is the effective duration of the TA in the above information (11) maintained locally by the candidate cell. The serving cell calculates the offset between the second time of the second TAT and the first time of the first TAT. The second time is configured by the serving cell, and the second time is, for example, the first time of the first TAT maintained locally by the serving cell, or another value determined by the serving cell.

[0108] Regarding the above information (15), the timing advance (TA) of the terminal device relative to the candidate cell is sent by the candidate cell to the serving cell during the early random access process. When the serving cell sends a first signaling to the candidate cell, the first signaling carries the TA.

[0109] Regarding the above information (16), as mentioned above, the serving cell configures the second time of the second TAT maintained locally by the candidate cell, that is, the configuration of the second time of the second TAT. The configuration of the second time can be the first time in the above information (12); or, the configuration of the second time can be the value after compensating the first time in the above information (12) based on the difference between the first time and the second time. For example, assuming that the difference is the communication delay between the serving cell and the candidate cell estimated, calculated or stored by the serving cell, and assuming that the first time is the remaining time of the first TAT, the serving cell subtracts the difference from the first time, and the resulting value is the value after compensating the first time, that is, the configuration of the second time; assuming that the first time is the time when the first TAT has already run, the serving cell adds the difference to the first time, and the resulting value is the value after compensating the first time, that is, the configuration of the second time. It is assumed here that the timing method of the serving cell and the candidate cell regarding TAT is the same, that is, both are positive timing or both are countdown.

[0110] In some embodiments, the first signaling sent by the serving cell to the candidate cell may include one of the above information (11) to (16), or may also include at least two of the above information (11) to (16), which will not be explained one by one here.

[0111] In some embodiments, the first signaling for notifying or indicating the information related to the candidate cell and the TA may be a new signaling different from the existing interactive signaling between the serving cell and the candidate cell, for example, the new signaling is a time alignment information request signaling, or a TAT calibration signaling. The first time of the first TAT and the TA are carried in the field of the existing signaling and sent to the candidate cell. The information contained in the time alignment information request signaling or the TAT calibration signaling is, for example, at least one of the above-mentioned information (11) to (16). The time alignment information request signaling or the TAT calibration signaling may include at least one of the above-mentioned information (11) to (16) but not other information, for example, the time alignment information request signaling or the TAT calibration signaling may include the first time of the first TAT and / or the timing advance (TA) but not other information. The time alignment information request signaling or TAT calibration signaling may also include at least one of the above-mentioned information (11) to (16) and other information at the same time. For example, the time alignment information request signaling or TAT calibration signaling may include the first time of the first TAT and / or timing advance (TA) and other information. The other information may be any information, and this application does not impose any restrictions on this.

[0112] In some embodiments, during the early random access process, the candidate cell sends the TA of the terminal device and the valid duration corresponding to the TA maintained locally by the candidate cell to the serving cell, and the serving cell starts to maintain the valid duration of the TA locally. The valid duration of the TA is related to the time of the TAT, and the serving cell maintains the TA by setting the TAT. For example, after receiving the TA, the serving cell starts the first TAT locally, and the first time of the first TAT is the valid duration of the TA maintained locally by the serving cell. The first TAT can be counted up or counted down. If the first TAT is counted down, the first time is the remaining time of the first TAT. At this time, the initial value of the first TAT is, for example, the maximum valid duration corresponding to the TA, which is, for example, configured by the network or sent by the candidate cell; when the first time of the first TAT is 0 or less than 0, it is considered that the first TAT has timed out. If the first TAT is counting, the first time is the time when the first TAT has been running. At this time, the initial value of the first TAT can be 0. When the first time of the first TAT reaches or exceeds a preset threshold, the first TAT is considered to have timed out. The preset threshold is, for example, the maximum valid duration corresponding to the TA, which is, for example, configured by the network or sent by the candidate cell.

[0113] Similarly, the candidate cell starts a second TAT locally, and the second time of the second TAT is the effective duration of the TA maintained locally by the candidate cell. The second TAT can be counted up or counted down. If the second TAT is counted down, the second time is the remaining time of the second TAT. At this time, the initial value of the second TAT is, for example, the maximum effective duration corresponding to the TA, and the maximum effective duration is, for example, configured by the network; when the first time of the first TAT is 0, the first TAT is considered to have timed out. If the first TAT is counted up, the first time is the time the first TAT has been running. At this time, the initial value of the first TAT can be 0 or less than 0. When the first time of the first TAT reaches or exceeds a preset threshold, the first TAT is considered to have timed out. The preset threshold is, for example, the maximum effective duration corresponding to the TA, and the maximum effective duration is, for example, configured by the network.

[0114] Therefore, the serving cell sends a first signaling to the candidate cell, and the first signaling carries the above-mentioned information related to the TA of the terminal device relative to the candidate cell. The candidate cell can calculate the update (calibration) information based on the first signaling and feed it back to the serving cell through the second signaling, so that the serving cell updates (calibrates) the first TAT maintained locally at the first time according to the signaling, thereby solving the problems existing in the prior art.

[0115] In some embodiments, the first signaling is used to request the candidate cell to feedback the second signaling, and the first signaling is used to notify or indicate information related to the candidate cell and the TA. The first signaling that notifies or indicates information related to the candidate cell and the TA can be an existing interactive signaling between the serving cell and the candidate cell, for example, the existing interactive signaling is an LTM handover preparation signaling, or an LTM cell handover notification signaling. At this time, the first time of the first TAT and the TA are carried in the field of the existing signaling and sent to the candidate cell. The field can be an existing field in the existing interactive signaling, or a newly added field in the existing interactive signaling, and this application does not impose any restrictions on this. In the existing interactive signaling, in addition to the first time of the first TAT and / or the timing advance (TA), other existing information is also included. Therefore, after carrying the first time and / or the timing advance (TA) of the first TAT, the original function of the existing interactive signaling is not affected.

[0116] Alternatively, the first signaling used to notify or indicate the candidate cell of information related to the TA may be new signaling different from existing signaling, which can request the candidate cell to feedback second signaling, and the new signaling carries at least the first time of the first TAT and / or the TA. In addition to the first time of the first TAT and / or the TA, the new signaling may also include other information, or may not include other information, which is not limited by this application. As a result, the original function of the existing interactive signaling sent by the serving cell to the candidate cell is not affected.

[0117] Therefore, the service cell of the terminal device sends a first signaling requesting feedback of the second signaling and including TA information to the candidate cell, so that the service cell and / or the target cell can promptly and effectively maintain the TA between the terminal device and the target cell, thereby avoiding delayed effectiveness due to communication delays between cells (the problem of misjudgment of TA validity by the service cell). In addition, by maintaining the TA, problems such as wireless link failure that may occur during the LTM execution of RACH-Less can also be avoided.

[0118] As a result, the service cell of the terminal device sends a message requesting the second signaling to the candidate cell, and / or a message notifying or indicating the TA information, so that the service cell and / or the target cell can promptly and effectively maintain the TA between the terminal device and the target cell, thereby avoiding the delayed effectiveness due to the communication delay between cells (the problem of the service cell misjudging the effectiveness of the TA). In addition, by maintaining the TA, problems such as wireless link failure that may be caused during the LTM execution of RACH-Less can also be avoided.

[0119] FIG4 is another schematic diagram of the information receiving method according to an embodiment of the present application. As shown in FIG4 , the method is applied to a serving cell of a terminal device, and the method includes:

[0120] 401. Send a first signaling to a candidate cell; the first signaling is used to request the candidate cell to send a second signaling, and / or to notify or indicate information related to the candidate cell and the TA.

[0121] 402: Receive second signaling sent by the candidate cell.

[0122] It is worth noting that FIG4 above is merely a schematic illustration of an embodiment of the present application, and the present application is not limited thereto. For example, the execution order of the various operations may be appropriately adjusted, other operations may be added or some operations may be reduced, and the objects of the aforementioned operations may be adjusted. Those skilled in the art may make appropriate modifications based on the above description, and are not limited to the description of FIG4 above.

[0123] As a result, the serving cell receives the second signaling sent by the candidate cell based on the first signaling. The serving cell can promptly and effectively maintain the TA between the terminal device and the target cell according to the second signaling, thereby avoiding the delayed effectiveness due to the communication delay between cells (the problem of the serving cell misjudging the effectiveness of the TA). In addition, by maintaining the TA, problems such as wireless link failure that may be caused during the LTM execution of RACH-Less can also be avoided.

[0124] In some embodiments, in 401, the first signaling sent to the candidate cell is similar to the above 301, and the above content is merged here and will not be repeated here.

[0125] In some embodiments, in step 402, the second signaling may not contain any information, or may contain arbitrary information. In this case, the first signaling only requires the candidate cell to feedback a signaling message, without regard to the content carried by the second signaling message. When the first signaling message is an existing signaling message requesting the candidate cell to feedback a second signaling message, the serving cell may update (calibrate) the first time of the locally maintained first TAT based on the time difference between sending and receiving the signaling message. This minimizes the impact on the existing signaling interaction process, saves signaling overhead, and resolves problems existing in the prior art.

[0126] In some embodiments, in 402, the serving cell receives second signaling sent by the candidate cell based on the first signaling. Information carried by the second signaling includes at least one of the following:

[0127] (21) a second time of a second TAT, the second TAT being maintained by the candidate cell, the second time being the remaining time of the second TAT or the time during which the second TAT has been running;

[0128] (22) the difference between the second time in the above information (22) and the first time in the above information (12);

[0129] (23)Invalid value.

[0130] Therefore, the serving cell can update the TA of the locally maintained first TAT according to the information in the second signaling, and can maintain the TA in a timely and effective manner, thereby avoiding the delayed effectiveness caused by inter-cell communication delays (the problem of the serving cell misjudging the validity of the TA).

[0131] In some embodiments, for the above information (21), the second time of the second TAT is the effective duration of the TA of the terminal device maintained locally by the candidate cell relative to the candidate cell. The second time of the second TAT is similar to the first time of the first TAT maintained by the serving cell. The above content is merged here and is not repeated here.

[0132] Regarding the above information (22), when the first signaling sent by the serving cell to the candidate cell includes the first time of the first TAT maintained locally by the serving cell, the candidate cell calculates the difference based on the second time of the second TAT maintained locally and the first time of the first TAT, and includes the information related to the difference in the second signaling and sends it to the serving cell. For example, it is assumed that the difference is the value of the first time minus the second time, or the difference is the value of the second time minus the first time. The difference represents the time of the TAT delay between the serving cell and the candidate cell. The information related to the difference is, for example, the difference. In this case, the information related to the difference represents the RTT delay of the communication return. Alternatively, the information related to the difference is, for example, half of the difference. In this case, the information related to the difference represents the one-way communication delay.

[0133] Regarding the above information (23), when the candidate cell receives the first signaling sent by the serving cell, if the second TAT maintained locally by the candidate cell times out, the candidate cell deems that the TA of the terminal device relative to the candidate cell times out. At this time, the second signaling fed back by the candidate cell to the serving cell includes information indicating that the TA is invalid, such as the second time invalid value of the second TAT; or if the candidate cell does not maintain the second TAT locally, at this time, the second signaling fed back by the candidate cell to the serving cell indicates an invalid value.

[0134] In some embodiments, the second signaling sent by the candidate cell to the serving cell may include one of the above information (21) to (23), or may also include at least two of the above information (21) to (23). For example, the second signaling includes the above information (21) and (22) at the same time, etc., which will not be explained one by one here.

[0135] In some embodiments, taking the first signaling as LTM cell handover preparation signaling as an example, the above 401 and 402 are performed, for example, in the following manner: the serving cell selects one of the candidate cells as the target cell for LTM handover, and sends information (first signaling) for preparing LTM handover to the target cell, and carries information related to the TA of the terminal device relative to the target cell, such as the first time of the first TAT maintained locally in the serving cell between the terminal user and the target cell, such as the remaining time or the time already run; after receiving the LTM handover preparation message and related TA information, the target cell not only feeds back to the serving cell the time-frequency resources available for the terminal device to access the target cell, the allocated preamble and other handover-related information, but also includes the second time of the second TAT of the terminal device maintained in the target cell, or the difference between the second time of the second TAT maintained by the target cell and the first time of the first TAT maintained by the serving cell, such as the offset between the second time of the second TAT and the first time of the first TAT, which can be a return deviation ΔRTT or a one-way deviation ΔDelay; after the target cell feeds back the LTM handover preparation signaling response (second signaling) to the serving cell, it releases the maintenance of the relevant TA.

[0136] In some embodiments, taking the first signaling as a separate TAT calibration signaling as an example, the above 401 and 402 are performed, for example, in the following manner: in order to obtain the delay of TAT validity, the serving cell sends a TAT validity time calibration request (first signaling) to the candidate cell of the TA, and the message carries the first duration status of the first TAT maintained locally in the serving cell between the terminal device and the candidate cell, such as the remaining duration, or the duration already running, etc.; after receiving the TAT validity time calibration request message, the candidate cell feeds back TAT calibration information to the serving cell, indicating the error between the second duration of the second TAT about the terminal device maintained in the candidate cell and the first duration of the first TAT maintained by the serving cell, such as the offset between the remaining valid duration or the started duration of the TA maintained by the candidate cell and the serving cell; the offset can be the backhaul deviation ΔRTT or the one-way deviation ΔDelay; after the candidate cell feeds back the TAT calibration information (second signaling) to the serving cell, it releases the maintenance of the relevant TA.

[0137] In the above embodiment, the candidate cell can be the target cell. After the candidate cell of LTM successfully receives the early RACH from the terminal device, it calculates the TA value. After notifying the serving cell of the terminal device of the TA value and the second time of the related second TAT, the candidate cell does not immediately release the maintenance of the TA. The candidate cell starts the valid timer TAT, maintains the valid timer TAT of the TA, and sets the maintenance time length to T2 to prevent resource hangs caused by problems such as inter-cell signaling loss. If the valid timer TAT times out, the candidate cell believes that the serving cell will not select it as the target cell for LTM switching, or there is a link problem between the serving cell and the candidate cell, resulting in a failure to receive the message. Therefore, the candidate cell no longer retains the TA information related to the terminal device, and the relevant storage and maintenance in the candidate cell are reset. For the candidate cell that no longer maintains the TA information with the terminal device, if it receives the TAT valid time calibration request (first signaling) sent by the serving cell again, it will feedback an invalid value of the second time of the second TAT, such as FFF. Alternatively, when the second TAT maintained locally by the candidate cell times out, the candidate cell considers the TA invalid. At this time, if it receives a TAT valid time calibration request (first signaling) sent by the serving cell, it will also feedback an invalid value of the second time of the second TAT, such as FFF.

[0138] FIG5 is another schematic diagram of the information receiving method according to an embodiment of the present application. As shown in FIG5 , the method is applied to a serving cell of a terminal device, and the method includes:

[0139] 501. Send a first signaling to a candidate cell; the first signaling is used to request the candidate cell to send a second signaling, and / or the first signaling includes a first time and / or timing advance (Timing Advance) of a first TAT (Time Alignment Timer); the first TAT is maintained by the serving cell, the timing advance is the timing advance of the terminal device relative to the candidate cell, and the first time is the remaining time of the first TAT or the time when the first TAT has been running.

[0140] 502. Receive second signaling sent by the candidate cell.

[0141] 503. Update the first time according to the second signaling.

[0142] It is worth noting that FIG5 above is merely a schematic illustration of an embodiment of the present application, and the present application is not limited thereto. For example, the execution order of the various operations may be appropriately adjusted, other operations may be added or some operations may be reduced, and the objects of the aforementioned operations may be adjusted. Those skilled in the art may make appropriate modifications based on the above description, and are not limited to the description of FIG5 above.

[0143] In some embodiments, in 501, the first signaling sent to the candidate cell is similar to 301 and 401 above, and the second signaling received from the candidate cell in 502 is similar to 402 above. The above contents are combined here and will not be repeated here.

[0144] In some embodiments, in 503 , the serving cell updates the first time of the first TAT maintained locally according to the second signaling fed back by the candidate cell.

[0145] In some embodiments, when the first signaling is used to request the candidate cell to send the second signaling, the serving cell can update the first time according to the time difference between the time when it sends the first signaling and the time when it receives the second signaling.

[0146] In some embodiments, when the first signaling is used to notify or indicate information related to TA of the candidate cell, the candidate cell calculates the error between the first TAT value of the serving cell and the second TAT value of the candidate cell based on the information related to TA carried by the first signaling, thereby enabling the serving cell to update the first time based on the error in the second signaling.

[0147] In some embodiments, the serving cell updates the first time according to the difference between the second time included in the second signaling and the first time included in the first signaling; and / or

[0148] The serving cell updates the first time according to the difference included in the second signaling; and / or

[0149] The serving cell updates the first time according to the difference between the time of receiving the second signaling and the time of sending the first signaling; and / or

[0150] The serving cell updates the first time according to the second time and the difference included in the second signaling.

[0151] In some embodiments, when the first signaling is used to request the candidate cell to send the second signaling and is used to notify or indicate the candidate cell's TA-related information, the candidate cell can calculate the error between the first TAT value of the serving cell and the second TAT value of the candidate cell based on the TA-related information in the first signaling. At the same time, the serving cell can also determine the time difference between the time it sends the first signaling and the time it receives the second signaling, so that the serving cell can update the first time with reference to the error and / or the time difference.

[0152] In some embodiments, the first signaling is LTM cell switching notification signaling. The serving cell decides to trigger LTM switching, sends a cell switching command carried by MAC CE to the terminal device, and then sends LTM cell switching notification signaling to the target cell. In addition to indicating the handover related information such as beamidx applied by the terminal to access the target cell, the signaling also indicates the time advance related information of the terminal device configured in the target cell, which includes time advance, and / or the initial value of the second TAT, and / or the second time of the second TAT, and / or the first time of the first TAT of the serving cell, and / or the difference between the second time of the second TAT configured by the target cell and the first time of the first TAT of the serving cell indicated in the information, such as the offset between the second time of the second TAT and the first time of the first TAT, which can be a return deviation ΔRTT or a one-way deviation ΔDelay; the target cell configures / updates / maintains the TA-related content of the target cell and the user based on this information; optionally, the target cell triggers uplink synchronization with the terminal device based on the configured / updated / maintained TA-related content, or sends a timing advance command TAC (Timing Advance) to the terminal device. Command), the TAC represents the TA, and the TAC is carried by the MAC CE.

[0153] The specific process related to updating the first time will be explained in the subsequent examples.

[0154] As mentioned above, the first signaling sent by the serving cell to the candidate cell is used to request the candidate cell to send a second signaling. The first signaling is, for example, an existing signaling that enables the candidate cell to feedback a signaling, such as a signaling requesting Early RACH resources, a signaling requesting measurement resources, etc.; the first signaling can also be a signaling containing the first time of the first TAT maintained locally by the terminal device and / or the TA of the terminal device relative to the candidate cell. At this time, the signaling can be a new signaling different from the existing signaling, or it can be a signaling after the existing signaling carries the above information. The first signaling can also be a signaling requesting the candidate cell to send a second signaling and containing the first time of the first TAT maintained locally by the terminal device and / or the TA of the terminal device relative to the candidate cell. The first signaling can also be a signaling indicating that the candidate cell configures the TA and the second TAT and the second time of the second TAT. Based on this, for different first signaling and second signaling, the present application provides the following examples to illustrate the interaction process shown in Figure 5 above and the specific method of updating the first time corresponding to each interaction process.

[0155] Example 1: The first signaling is a request for Early RACH resources signaling or a request for measurement resources signaling. Correspondingly, the second signaling is the Early RACH resources or measurement resources fed back by the candidate cell. Figure 6 is a signaling diagram of an embodiment of the present application. In Figure 6, the first signaling is a request for Early RACH resources signaling as an example. Optionally, the request for Early RACH resources signaling can also be replaced with a request for measurement resources signaling (shown in brackets in Figure 6).

[0156] As shown in FIG6 , the method includes:

[0157] 601, the serving cell sends a signaling requesting Early RACH resources (or a signaling requesting measurement resources) to the candidate cell;

[0158] 602. After receiving the Early RACH resource request signaling (or measurement resource request signaling), the candidate cell feeds back the Early RACH resource (or measurement resource) to the serving cell.

[0159] 603, the serving cell determines the communication delay between the candidate cell and the serving cell based on the received Early RACH resources (or measurement resources);

[0160] 604, the serving cell starts a first timer, and the initial value of the first timer is t11;

[0161] 605 : When necessary, update the first time of the locally maintained first TAT according to the communication delay.

[0162] In step 603, the serving cell calculates the communication delay between the serving cell and the candidate cell based on the value t2 of the first timer when the Early RACH resource (or measurement resource) is received and the initial value t1 of the first timer. For example, the communication delay can be the RRT delay of the communication return, that is, the difference between t2 and t1; the communication delay can also be the delay of one-way communication, that is, half of the difference between t2 and t1.

[0163] In 605, when necessary, the serving cell updates the first time of the locally maintained first TAT based on the communication delay in 603. When the communication delay is the RRT delay of the communication backhaul, the updated first time is the first time before the update minus half of the RRT delay of the communication backhaul; when the communication delay is the delay of one-way communication, the updated first time is the first time before the update minus the delay of the one-way communication.

[0164] The above 601 is the step corresponding to 501, 602 is the step corresponding to 502, and 605 is the step corresponding to 503. The above contents are combined here and will not be repeated here.

[0165] Therefore, when the first signaling is an existing signaling requesting the candidate cell to feedback the second signaling, the serving cell can update (calibrate) the first time of the first TAT maintained locally based on the time difference between sending and receiving the signaling, while having little impact on the existing signaling interaction process, saving signaling expenses, and solving problems existing in the existing technology.

[0166] Example 2: The first signaling may also include the first time of the first TAT maintained locally by the terminal device and / or the TA of the terminal device relative to the candidate cell. Accordingly, the second signaling includes at least one of the following information:

[0167] (21) a second time of a second TAT, the second TAT being maintained by the candidate cell, the second time being the remaining time of the second TAT or the time during which the second TAT has been running;

[0168] (22) the difference between the second time in the above information (22) and the first time in the above information (12);

[0169] (23)Invalid value.

[0170] The contents of the above information (21) to (23) are as described above, and the above contents are merged here and will not be repeated here.

[0171] FIG7 is a signaling diagram of an embodiment of the present application. As shown in FIG7 , the method includes:

[0172] 701. The serving cell sends a first signaling to the candidate cell. The first signaling includes the first time of the first TAT locally maintained by the terminal device and / or the TA of the terminal device relative to the candidate cell. For the content related to the first signaling, refer to the above description.

[0173] 702. The candidate cell feeds back a second signaling to the serving cell, where the second signaling includes at least one of the information (21) to (23) described above.

[0174] 703. The serving cell updates the first time of the locally maintained first TAT according to the information included in the second signaling.

[0175] The above steps 701-703 are steps corresponding to 501-503 respectively. The above contents are combined here and will not be repeated here.

[0176] In step 703, when the second signaling includes information about the second time of the second TAT, the serving cell determines the communication delay between the serving cell and the candidate cell based on the second time in the second signaling and the first time when the serving cell sent the first signaling, and updates the first time of the first TAT based on the communication delay. The communication delay in step 703 and the method for updating the first time based on the communication delay are similar to those in step 605 and are therefore incorporated herein.

[0177] In 703, when the second signaling includes the difference between the second time of the second TAT of the candidate cell and the first time in the first signaling, the serving cell updates the first time of the first TAT according to the difference, which is similar to the communication delay described above.

[0178] In 703, when the information contained in the second signaling is the second time of the second TAT of the candidate cell, and the second time is an invalid value, the serving cell updates the first time of the first TAT according to the error, that is, the first time of the first TAT is also updated to an invalid value, indicating that the TA of the corresponding candidate cell of the terminal device is invalid; or, the serving cell maintains the timing operation of the first TAT, and believes that the candidate cell has not maintained the relevant TA; or, the serving cell calculates the communication delay based on the time of sending the first signaling and the time of receiving the second signaling, and updates the first time of the first TAT.

[0179] The communication delay in 703, the difference between the second time of the second TAT of the candidate cell and the first time in the first signaling, and the method of updating the first time according to the communication delay are similar to 605, and the above contents are merged here.

[0180] Therefore, the serving cell can update the TA of the locally maintained first TAT according to the information in the second signaling, and can maintain the TA in a timely and effective manner, thereby avoiding the delayed effectiveness caused by inter-cell communication delays (the problem of the serving cell misjudging the validity of the TA).

[0181] Example 3: The first signaling may also be a signaling requesting the candidate cell to send a second signaling and notifying or indicating information related to the candidate cell and the TA. For example, the first signaling may be an LTM cell handover preparation signaling, in which case the second signaling may be an LTM cell handover preparation signaling response. Figure 8 is a signaling diagram according to an embodiment of the present application. In Figure 8, the first signaling is an LTM cell handover preparation signaling.

[0182] As shown in FIG8 , the method includes:

[0183] 801. The serving cell sends an LTM cell handover preparation signaling to the candidate cell. The LTM cell handover preparation signaling includes TA information. For contents related to the TA information and the LTM cell handover preparation signaling, refer to the above description.

[0184] 802. The candidate cell feeds back a second signaling to the serving cell, where the second signaling includes the UL Grant fed back by the candidate cell, the Preamble, and at least one of the information (21) to (23) as described above.

[0185] 803. The serving cell updates the first time of the locally maintained first TAT according to at least one of the information (21) to (23) described above contained in the second signaling.

[0186] The above steps 801-803 are steps corresponding to 501-503 respectively. The way in which the serving cell is updated for the first time in 803 is similar to 703. The above content is merged here and will not be repeated here.

[0187] The serving cell sends an LTM cell switching notification signaling to the candidate cell. The LTM cell switching notification signaling includes the first time of the first TAT and / or the TA of the terminal device relative to the candidate cell and / or the initial value configuration of the second TAT of the candidate cell and / or the configuration indicating the second time of the second TAT of the candidate cell. The content related to the LTM cell switching notification signaling is described above.

[0188] As a result, the maintenance of the TA of the terminal device relative to the target cell is switched from the serving cell to the target cell, and the target cell continues to maintain the TA.

[0189] Embodiments of the second aspect

[0190] An embodiment of the present application provides an information sending and receiving method, which is applied to the candidate cell side of a terminal device, corresponding to the embodiment of the first aspect. The contents different from the embodiment of the first aspect are described in detail, and the contents identical to the embodiment of the first aspect can be referred to the embodiment of the first aspect, which will not be repeated here.

[0191] FIG9 is a schematic diagram of an information sending and receiving method according to an embodiment of the present application, which is applied to a candidate cell. As shown in FIG9 , the method includes:

[0192] 901, receiving first signaling sent by a serving cell of a terminal device;

[0193] The first signaling is used to request the candidate cell to send a second signaling, and / or is used to notify or indicate information related to the candidate cell and the TA.

[0194] According to the above embodiment, the service cell of the terminal device sends a request and / or TA information to the candidate cell, so that the service cell and / or the target cell can timely and effectively maintain the TA between the terminal device and the target cell, thereby avoiding the delayed effectiveness due to the communication delay between cells (the problem of misjudgment of the effectiveness of the TA by the service cell). In addition, by maintaining the TA, problems such as wireless link failure that may be caused during the LTM execution of RACH-Less can also be avoided.

[0195] In some embodiments, the content carried by the first signaling may be at least one of the following information:

[0196] - requesting the candidate cell to send a second signaling indication;

[0197] -The first time of the first TAT (Time Alignment Timer);

[0198] - and or the initial value of the second TAT (Time Alignment Timer);

[0199] - and / or configuration of the second time of the second TAT (Time Alignment Timer)

[0200] - and / or Timing Advance;

[0201] - and / or a difference, the difference being an offset between the configuration of the second time and the first time;

[0202] The first TAT is maintained by the serving cell;

[0203] The first time is the remaining time of the first TAT or the time during which the first TAT has been running;

[0204] The second TAT is maintained by the candidate cell;

[0205] The second time is the remaining time of the second TAT or the time during which the second TAT has been running.

[0206] The first signaling is as described in the embodiment of the first aspect and will not be repeated here.

[0207] In some embodiments, the method further includes (not shown):

[0208] Sending a second signaling to the serving cell according to the first signaling, wherein the content carried by the second signaling includes at least one of the following:

[0209] - a second time of a second TAT, where the second TAT is maintained by the candidate cell, and the second time is a remaining time of the second TAT or a time during which the second TAT has been running;

[0210] - the difference between the second time and the first time;

[0211] -Invalid value.

[0212] The above second signaling is as described in the embodiment of the first aspect, and its content is merged here and will not be repeated here.

[0213] In some embodiments, the method further includes (not shown):

[0214] The timing advance obtained based on Early Rach and the maintenance of the TAT related to the timing advance are maintained.

[0215] For example, after successfully receiving the early RACH from the terminal device, the LTM candidate cell calculates the TA value and notifies the serving cell of the terminal device of the TA value and the second time of the associated second TAT. The candidate cell does not immediately release the maintenance of the TA.

[0216] Therefore, when the candidate cell receives the first signaling containing the first time and / or timing advance of the first TAT (Time Alignment Timer) sent by the serving cell, it can feedback information related to TA to the candidate, so that the serving cell and / or the target cell can maintain the TA between the terminal device and the target cell in a timely and effective manner, thereby avoiding the delayed effectiveness caused by the communication delay between cells (the problem of the serving cell misjudging the effectiveness of TA).

[0217] In some embodiments, the method further includes (not shown):

[0218] When the first signaling is not received within a preset time, or after the second signaling is sent to the serving cell, the maintenance of the time advance is released.

[0219] For example, after the candidate cell of LTM successfully receives the early RACH from the terminal device, it calculates the TA value. After notifying the serving cell of the terminal device of the TA value and the second time of the related second TAT, the candidate cell does not immediately release the maintenance of the TA. The candidate cell starts the valid timer TAT, maintains the valid timer TAT of the TA, and sets the maintenance time length to T2 to prevent resource hangs caused by problems such as inter-cell signaling loss. If the valid timer TAT times out, the candidate cell believes that the serving cell will not select it as the target cell for LTM switching, or there is a link problem between the serving cell and the candidate cell, resulting in a failure to receive the message. Therefore, the candidate cell no longer retains the TA information related to the terminal device, and the relevant storage and maintenance in the candidate cell are reset.

[0220] In some embodiments, the first signaling is LTM cell handover notification signaling or LTM cell handover signaling.

[0221] The above first signaling, LTM cell switching notification signaling, and LTM cell switching signaling are as described in the embodiment of the first aspect, and their contents are merged here and will not be repeated here.

[0222] In some embodiments, the method further includes (not shown):

[0223] According to the first signaling, the time advance and the second time are configured / updated / maintained.

[0224] For example, when a candidate cell receives first signaling from a serving cell, it indicates that the serving cell has selected the candidate cell as a target cell. At this point, if the target cell does not maintain TA information, the target cell configures a time advance and a second time corresponding to the time advance to facilitate the target cell maintaining the TA of the terminal device relative to the target cell. If the target cell maintains TA information, the time advance and the second time corresponding to the time advance are updated / maintained. This first signaling is, for example, LTM cell handover notification signaling.

[0225] In some embodiments, the method further includes (not shown): triggering uplink synchronization with the terminal device and / or sending the time advance to the terminal device based on the time advance and the second time. As a result, maintenance of the TA of the terminal device relative to the target cell is switched from the serving cell to the target cell, and the target cell continues to maintain the TA.

[0226] Through the above embodiment, when the candidate cell receives the first signaling sent by the serving cell containing the first time of the first TAT (Time Alignment Timer) and / or TA information such as timing advance (Timing Advance), it can feedback information related to TA to the candidate, so that the serving cell and / or the target cell can maintain the TA between the terminal device and the target cell in a timely and effective manner, thereby avoiding delayed effectiveness caused by communication delays between cells (the problem of misjudgment of TA validity by the serving cell).

[0227] Embodiments of the third aspect

[0228] Currently, the serving cell before LTM handover sends a MAC CE to the terminal device, instructing it to handover to the target cell. The serving cell then checks whether the locally maintained connection between the terminal device and the target cell is still valid. If not, the value of the Timing Advance Command contained in the MAC CE is set to FFF. Otherwise, the TAC value is configured with a valid TA index. Based on this configuration, the terminal user chooses to skip the random access process and directly access the configured target cell's uplink reserved resources to perform RACH-Less LTM serving cell handover.

[0229] The inventors found that after triggering the LTM handover of RACH-Less, there is no network maintenance and TA between the terminal device. If the TA between the switched terminal device and the target cell fails or is not updated during the handover process, it may cause loss of synchronization after the LTM handover and lead to wireless link failure.

[0230] To solve the above problems, the present application provides an information processing method, which is applied to a target cell.

[0231] FIG10 is a schematic diagram of an information processing method according to an embodiment of the present application. As shown in FIG10 , the information processing method is applied to a target cell, and the method includes:

[0232] 1001, receiving the first uplink data sent by the terminal device on the time-frequency resources of the configured target cell when performing RACH-Less LTM cell handover;

[0233] 1002. Send a new transmission to the terminal device according to the first uplink data, where the new transmission indicates the latest timing advance (TA) between the target cell and the terminal device.

[0234] In some embodiments, in 1001, the process of performing RACH-Less is similar to that in the prior art.

[0235] In some embodiments, in 1002, the TA is represented by a timing advance command TAC (Timing Advance Command), and the TAC is carried by a MAC CE.

[0236] Through the above embodiment, the RACH-Less-based LTM switching process is supplemented, and the TA information between the user and the network is filled in to indicate the first new downlink transmission completed by the terminal device LTM. This information is obtained by the new service cell based on the first uplink transmission accessed by the user after the terminal device executes the LTM service cell switching, so that the network and the terminal device obtain updated valid synchronization information, avoiding the problem of no TA maintenance between the new service cell and the terminal device after the RACH-Less LTM switching, and also providing the specific content of the first downlink transmission after the LTM is completed. In this way, the problem of no network maintenance and TA between the switching terminal device after the RACH-Less LTM switching is avoided, and the problem of TA failure or no update between the switched terminal user and the switched target cell during the switching process is avoided, as well as the impact of wireless link failure caused by loss of synchronization after the LTM switching.

[0237] Embodiments of the fourth aspect

[0238] Currently, when a terminal device's serving cell triggers an LTM cell handover, it sends a MAC CE to the terminal device, instructing it to execute the LTM process. It also sends an LTM cell handover notification to the target cell. If the terminal device's TA relative to the target cell is valid when the LTM handover is triggered, the terminal device directly performs uplink transmission on the allocated target cell's time-frequency resources in RACH-Less mode. Otherwise, the TA is considered invalid or time-out, and the LTM cell handover is completed using RACH-Based mode, performing random access in the target cell according to the configuration indicated by the handover MAC CE.

[0239] The inventors found that if the TA of the terminal device relative to the target cell fails during the LTM switching process, the LTM cell switching may fail, or even if the terminal device successfully switches to the target cell (new service cell), it will quickly lose synchronization with the new service cell; at this time, the terminal device still needs to initiate a random access process to resynchronize with the target cell (new service cell), which reduces the LTM cell switching efficiency and wastes time and frequency resources.

[0240] To solve the above problems, the present application provides an information processing method applied to a serving cell.

[0241] FIG11 is a schematic diagram of an information processing method according to an embodiment of the present application. As shown in FIG11 , the information processing method includes:

[0242] 1101, sending an LTM cell handover notification message to the target cell;

[0243] The LTM cell switching notification message includes information related to TA, and the information related to TA is information related to the TA of the terminal device relative to the target cell, such as the TA between the target cell and the terminal device maintained by the serving cell and / or information related to the first duration of the first TAT.

[0244] In some embodiments, the information related to the first duration of the first TAT includes the first time and / or error of the TA, and the error includes an offset between a second time of a second TAT maintained by the target cell and the time.

[0245] The above TA, the first duration of the first TAT, the second duration of the second TAT, the error, and the offset are as described in the embodiment of the first aspect, and their contents are incorporated here and will not be repeated here.

[0246] Through the above embodiment, when / after the serving cell decides to perform an LTM handover, the TA and TAT of the terminal device to be handed over and the target cell, which it maintains locally, are included in the message notifying the neighboring cell of the LTM cell handover trigger. This allows the network to transfer the maintenance of the TA from the original serving cell to the target cell. This TA and TAT thus provide a reference for TA synchronization in the target cell, reducing the probability of cell handover failure.

[0247] Embodiments of the fifth aspect

[0248] An embodiment of the present application provides an information transceiver device, which is applied to a service cell. Figure 12 is a schematic diagram of the information transceiver device. The information transceiver device and the information transceiver method in the embodiment of the first aspect provided by the present application are based on the same inventive concept and have similar principles for solving problems. Therefore, the implementation of the information transceiver device refers to the implementation of the information transceiver method in the embodiment of the first aspect provided by the present application, and repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceived.

[0249] As shown in FIG12 , the information transceiver device includes:

[0250] A first sending unit 1201, configured to send a first signaling to a candidate cell;

[0251] The first signaling is used to request the candidate cell to send a second signaling, and / or is used to notify or indicate information related to the candidate cell and the TA.

[0252] According to the above embodiment, the service cell of the terminal device sends a request and / or TA information to the candidate cell, so that the service cell and / or the target cell can timely and effectively maintain the TA between the terminal device and the target cell, thereby avoiding the delayed effectiveness due to the communication delay between cells (the problem of misjudgment of the effectiveness of the TA by the service cell). In addition, by maintaining the TA, problems such as wireless link failure that may be caused during the LTM execution of RACH-Less can also be avoided.

[0253] In some embodiments, the first signaling is as described in the embodiment of the first aspect and will not be repeated here.

[0254] In some embodiments, the apparatus further includes (as shown in the dashed box in FIG12 ):

[0255] The first receiving unit 1202 is configured to receive second signaling sent by the candidate cell, wherein the content carried by the second signaling includes at least one of the following:

[0256] - a second time of a second TAT, where the second TAT is maintained by the candidate cell, and the second time is a remaining time of the second TAT or a time during which the second TAT has been running;

[0257] - the difference between the second time and the first time;

[0258] -Invalid value.

[0259] In some embodiments, the second signaling is as described in the embodiment of the first aspect and will not be repeated here.

[0260] In some embodiments, the apparatus further includes (as shown in the dashed box in FIG12 ):

[0261] The first processing unit 1203 is configured to update the first time according to the second signaling.

[0262] In some embodiments, the first signaling is LTM cell switching notification signaling or LTM cell switching signaling, and the LTM cell switching notification signaling or LTM cell switching signaling includes the content carried in the above-mentioned first signaling. The first signaling is as described above and will not be repeated here.

[0263] According to the above embodiment, the service cell of the terminal device sends a request message and / or a TA information indication / notification message to the candidate cell, so that the service cell and / or the target cell can promptly and effectively maintain the TA between the terminal device and the target cell, thereby avoiding delayed effectiveness due to communication delays between cells (the problem of misjudgment of TA validity by the service cell). In addition, by maintaining the TA, problems such as wireless link failure that may occur during the LTM execution of RACH-Less can also be avoided.

[0264] The embodiment of the present application also provides an information transceiver device, which is applied to a candidate cell. Figure 13 is a schematic diagram of the information transceiver device. The information transceiver device and the information transceiver method in the embodiment of the second aspect provided by the present application are based on the same inventive concept and have similar principles for solving problems. Therefore, for the implementation of the information transceiver device, please refer to the implementation of the information transceiver method in the embodiment of the second aspect provided by the present application, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceived.

[0265] As shown in FIG13 , the information transceiver device includes:

[0266] The second receiving unit 1301 is configured to receive a first signaling sent by a serving cell of a terminal device;

[0267] The first signaling is used to request the candidate cell to send a second signaling, and / or is used to notify or indicate information related to the candidate cell and the TA.

[0268] In some embodiments, the apparatus further comprises (as shown in the dotted box in FIG13 ):

[0269] The second sending unit 1302 is configured to send a second signaling to the serving cell according to the first signaling, wherein the content carried by the second signaling includes at least one of the following:

[0270] - a second time of a second TAT, where the second TAT is maintained by the candidate cell, and the second time is a remaining time of the second TAT or a time during which the second TAT has been running;

[0271] - the difference between the second time and the first time;

[0272] -Invalid value.

[0273] In some embodiments, the apparatus further includes (as shown in the dotted box in FIG13 ):

[0274] The second processing unit 1303 is configured to maintain the timing advance obtained based on the Early Rach and the TAT related to the timing advance.

[0275] In some embodiments, the second processing unit 1303 is further configured to:

[0276] When the first signaling is not received within a preset time, or after the second signaling is sent to the serving cell, the maintenance of the time advance is released.

[0277] In some embodiments, the first signaling is LTM cell handover notification signaling or LTM cell handover preparation signaling, and the LTM cell handover notification signaling or LTM cell handover signaling includes the content carried in the above-mentioned first signaling. The first signaling is as described above and will not be repeated here.

[0278] In some embodiments, the second processing unit 1303 is further configured to:

[0279] The time advance and the second time are configured according to the first signaling. The first signaling is, for example, an LTM cell handover notification signaling.

[0280] According to the above embodiment, the service cell of the terminal device sends a request and / or TA information to the candidate cell, so that the service cell and / or the target cell can timely and effectively maintain the TA between the terminal device and the target cell, thereby avoiding the delayed effectiveness due to the communication delay between cells (the problem of misjudgment of the effectiveness of the TA by the service cell). In addition, by maintaining the TA, problems such as wireless link failure that may be caused during the LTM execution of RACH-Less can also be avoided.

[0281] The embodiment of the present application also provides an information transceiver device, which is applied to the target cell. Figure 14 is a schematic diagram of the information transceiver device. The information transceiver device and the information transceiver method in the embodiment of the third aspect provided by the present application are based on the same inventive concept and have similar principles for solving problems. Therefore, for the implementation of the information transceiver device, please refer to the implementation of the information transceiver method in the embodiment of the third aspect provided by the present application, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceived.

[0282] As shown in FIG14 , the information transceiver device includes:

[0283] The third receiving unit 1401 is configured to receive the first uplink data sent by the terminal device on the time-frequency resources of the configured target cell when performing RACH-Less LTM cell handover;

[0284] The third sending unit 1402 is configured to send a new transmission to the terminal device according to the first uplink data, where the new transmission indicates the latest timing advance (TA) between the target cell and the terminal device.

[0285] In some embodiments, the TA is represented by a timing advance command TAC (Timing Advance Command), and the TAC is carried by a MAC CE.

[0286] The above embodiment avoids the problem of no network maintenance and TA between the switching terminal devices after the LTM switching of RACH-Less is triggered. It also avoids the problem of TA failure or non-update between the switched terminal user and the target cell during the switching process, as well as the resulting impact of radio link failure caused by loss of synchronization after LTM switching.

[0287] The embodiment of the present application also provides an information transceiver device, which is applied to a service cell. Figure 15 is a schematic diagram of the information transceiver device. The information transceiver device and the information transceiver method in the embodiment of the fourth aspect provided by the present application are based on the same inventive concept and have similar principles for solving problems. Therefore, for the implementation of the information transceiver device, please refer to the implementation of the information transceiver method in the embodiment of the fourth aspect provided by the present application, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceived.

[0288] As shown in FIG15 , the information transceiver device includes:

[0289] The fourth sending unit 1501 is configured to send an LTM cell handover notification message to a target cell;

[0290] The LTM cell switching notification message includes the TA between the target cell and the terminal device maintained by the serving cell and / or information related to the first duration of the first TAT.

[0291] In some embodiments, the information related to the first duration of the first TAT includes the first time and / or error of the TA, and the error includes an offset between a second time of a second TAT maintained by the target cell and the time.

[0292] The above TA, the first duration of the first TAT, the second duration of the second TAT, the error, and the offset are as described in the embodiment of the first aspect, and their contents are incorporated here and will not be repeated here.

[0293] Through the above embodiment, when / after the serving cell decides to perform an LTM handover, the TA and TAT of the terminal device to be handed over and the target cell, which it maintains locally, are included in the message notifying the neighboring cell of the LTM cell handover trigger. This allows the network to transfer the maintenance of the TA from the original serving cell to the target cell. This TA and TAT thus provide a reference for TA synchronization in the target cell, reducing the probability of cell handover failure.

[0294] Embodiments of the sixth aspect

[0295] An embodiment of the present application also provides a communication system, and reference may be made to FIG1 . The contents identical to those in the first to fifth aspects of the embodiments will not be repeated.

[0296] In some embodiments, the communication system 100 may include at least: a network device 101 and / or a terminal device 102,

[0297] There may be multiple network devices 101, and at least one network device corresponds to the serving cell of the present application, and at least one network device corresponds to the candidate cell or target cell of the present application. The network device corresponding to the serving cell of the present application is used to perform the information transceiving methods of the first and fourth aspects of the present application. The network device corresponding to the candidate cell or target cell of the present application is used to perform the information transceiving methods of the second and third aspects of the present application.

[0298] Figure 16 is a schematic diagram illustrating the structure of a network device according to an embodiment of the present application. As shown in Figure 16 , network device 1600 may include a processor 1610 (e.g., a central processing unit (CPU)) and a memory 1620; memory 1620 is coupled to processor 1610. Memory 1620 may store various data and may also store an information processing program 1630, which is executed under the control of processor 1610.

[0299] For example, the processor 1610 may be configured to execute a program to implement the information sending and receiving methods as described in the embodiments of the first to fourth aspects.

[0300] In addition, as shown in FIG16 , network device 1600 may further include: a transceiver 1640 and an antenna 1650, etc.; wherein, the functions of the above components are similar to those in the prior art and are not described in detail here. It is worth noting that network device 1600 does not necessarily include all the components shown in FIG16 ; in addition, network device 1600 may also include components not shown in FIG16 , and reference may be made to the prior art for details.

[0301] An embodiment of the present application also provides a computer program, wherein when the program is executed in a network device, the program causes the network device to execute the information receiving method as described in the embodiments of the first to fourth aspects.

[0302] An embodiment of the present application also provides a storage medium storing a computer program, wherein the computer program enables a network device to execute the information receiving method as described in the embodiments of the first to fourth aspects.

[0303] The above devices and methods of the present application can be implemented by hardware or by a combination of hardware and software. The present application relates to such a computer-readable program that, when executed by a logic component, enables the logic component to implement the devices or components described above, or enables the logic component to implement the various methods or steps described above. The present application also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, etc.

[0304] The method / device described in conjunction with the embodiments of the present application can be directly embodied as hardware, a software module executed by a processor, or a combination of the two. For example, one or more of the functional block diagrams shown in the figure and / or one or more combinations of functional block diagrams can correspond to various software modules of the computer program flow or to various hardware modules. These software modules can respectively correspond to the various steps shown in the figure. These hardware modules can be implemented by solidifying these software modules, for example, using a field programmable gate array (FPGA).

[0305] The software module may be located in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. A storage medium may be coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium; or the storage medium may be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The software module may be stored in the memory of the mobile terminal or in a memory card that can be inserted into the mobile terminal. For example, if the device (such as a mobile terminal) uses a large-capacity MEGA-SIM card or a large-capacity flash memory device, the software module may be stored in the MEGA-SIM card or the large-capacity flash memory device.

[0306] One or more of the functional blocks and / or one or more combinations of functional blocks described in the accompanying drawings may be implemented as a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or any appropriate combination thereof for performing the functions described in this application. One or more of the functional blocks and / or one or more combinations of functional blocks described in the accompanying drawings may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in communication with a DSP, or any other such configuration.

[0307] The present application has been described above in conjunction with specific embodiments. However, those skilled in the art should understand that these descriptions are merely illustrative and are not intended to limit the scope of protection of the present application. Those skilled in the art may make various modifications and variations to the present application based on the spirit and principles of the present application, and such modifications and variations are also within the scope of the present application.

[0308] Regarding the implementation methods including the above embodiments, the following additional notes are also disclosed:

[0309] 1. A time alignment adjustment method, applied to a serving cell of a terminal device, the method comprising:

[0310] Sending a first signaling to the candidate cell;

[0311] receiving second signaling from the candidate cell, where the second signaling is used to respond to the first signaling;

[0312] Adjust the timer used to control the length of time the terminal device is in uplink synchronization with the candidate cell.

[0313] 2. The method according to Note 1, wherein the first signaling may be:

[0314] -LTM handover preparation signaling

[0315] - and / or request Early RACH resource signaling

[0316] - and / or request measurement resource signaling

[0317] 3. The method according to Note 1, wherein the second signaling may be:

[0318] -LTM handover preparation signaling response

[0319] - and / or request Early RACH resource signaling response

[0320] -and / or request measurement resource signaling response.

Claims

1. An information transceiver device, applied to a service cell of a terminal device, the device comprising: A first sending unit, configured to send a first signaling to a candidate cell; The first signaling is used to request the candidate cell to send a second signaling, and / or is used to notify or indicate information related to the candidate cell and the TA.

2. The device according to claim 1, wherein: The content carried by the first signaling includes at least one of the following: requesting a second signaling indication; The first time of the first TAT (Time Alignment Timer); The initial value of the second TAT (Time Alignment Timer); Second time configuration of the second TAT (Time Alignment Timer) Timing Advance; A difference, where the difference is an offset between the configuration of the second time and the first time; Among them, the first TAT is maintained by the serving cell; the first time is the remaining time of the first TAT or the time when the first TAT has been running; the second TAT is maintained by the candidate cell; the second time is the remaining time of the second TAT or the time when the second TAT has been running; the timing advance is the timing advance of the terminal device relative to the candidate cell.

3. The device according to claim 2, wherein: The second time is configured as the first time, or as a value after compensating the first time according to the difference.

4. The device according to claim 1, wherein: The device also includes: A first receiving unit is configured to receive a second signaling sent by the candidate cell, wherein the content carried by the second signaling includes: the second time; and / or A difference, which is the difference or offset between the second time and the first time; and / or Invalid value.

5. The device according to claim 2, wherein: The difference may be a communication backhaul offset between the serving cell and the candidate cell; or a communication one-way delay offset between the serving cell and the candidate cell.

6. The device according to claim 4, wherein: The device also includes: A first processing unit is configured to update the first time according to the second signaling.

7. The device according to claim 6, wherein: The first processing unit is further configured to: updating the first time according to the difference between the second time included in the second signaling and the first time included in the first signaling; and / or updating the first time according to the difference included in the second signaling; and / or updating the first time according to the difference between the time when the second signaling is received and the time when the first signaling is sent; and / or The first time is updated according to the second time and the difference included in the second signaling.

8. The device according to claim 6, wherein: The first processing unit is further configured to: According to the invalid value indication included in the second signaling, the operation of the first TAT is maintained and the timing of the first time is maintained; or the first time is updated according to the difference between the time when the second signaling is received and the time when the first signaling is sent.

9. The device according to claim 1, wherein: The first signaling is LTM cell switching preparation signaling and / or LTM cell switching notification signaling.

10. An information transceiver device, applied to a candidate cell of a terminal device, the device comprising: A second receiving unit, configured to receive a first signaling sent by a serving cell of a terminal device; The first signaling is used to request the candidate cell to send a second signaling, and / or is used to notify or indicate information related to the candidate cell and the TA.

11. The device according to claim 10, wherein: The content carried by the first signaling includes at least one of the following: Requesting the candidate cell to send a second signaling indication; The first time of the first TAT (Time Alignment Timer); The initial value of the second TAT (Time Alignment Timer); Second time configuration of the second TAT (Time Alignment Timer) Timing Advance; A difference, where the difference is an offset between the configuration of the second time and the first time; The first TAT is maintained by the serving cell; the first time is the remaining time of the first TAT or the time when the first TAT has been running; the second TAT is maintained by the candidate cell; The second time is the remaining time of the second TAT or the time when the second TAT has been running; the timing advance is the timing advance of the terminal device relative to the candidate cell.

12. The device according to claim 10, wherein: The device also includes: A second sending unit is configured to send a second signaling to the serving cell according to the first signaling, wherein the content carried by the second signaling includes: the second time; and / or A difference, which is the difference or offset between the second time and the first time; and / or Invalid value.

13. The device according to claim 11, wherein: The difference is a communication backhaul offset between the serving cell and the candidate cell; or a communication one-way delay offset between the serving cell and the candidate cell.

14. The device according to claim 10, wherein: The device also includes: The second processing unit is configured to maintain the timing advance obtained based on Early Rach and the TAT related to the timing advance.

15. The device according to claim 14, wherein: The second processing unit is further configured to: When the first signaling is not received within a preset time, or after the second signaling is sent to the serving cell, the maintenance of the time advance and the maintenance of the TAT related to the time advance are released.

16. The device according to claim 11, wherein The second processing unit is further configured to: Configure / update / maintain the time advance and the second time according to the content carried by the first signaling.

17. The device according to claim 16, wherein: The configuration of the second time includes: The first time indicated by the first signaling; and / or a value after compensating the first time indicated by the first signaling according to the difference indicated by the first signaling; and / or a value after compensating the first time indicated by the first signaling according to the locally estimated difference; and / or The second time indicated by the first signaling.

18. The device according to claim 16, wherein: The second processing unit is further configured to: According to the time advance and the second time, uplink synchronization with the terminal device is triggered and / or the time advance is sent to the terminal device.

19. An information transceiver device, applied to a target cell of LTM cell switching, wherein: The device comprises: A third receiving unit, which is used to receive the first uplink data sent by the terminal device on the time-frequency resources of the configured target cell when performing LTM cell switching of RACH-Less; A third sending unit is used to send a new transmission to the terminal device according to the first uplink data, and the new transmission indicates a timing advance (Timing Advance, TA) between the target cell and the terminal device.

20. The device according to claim 19, wherein The timing advance is represented by a timing advance command TAC (Timing Advance Command), and the TAC is carried by MAC CE.

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