Information transmission method and device

Abstract

The invention discloses an information transmission method and device. The method comprises the following steps: a network device CU of a candidate cell sends a first F1 message comprising information for obtaining uplink synchronization on the candidate cell to a first network device DU;

Description

Information transmission method and device Technical Field

[0001] The present application relates to the field of communications. Background Art

[0002] Currently, network equipment (e.g., gNB) determines the expected timing advance (TA) setting and provides it to the user equipment (UE). The UE uses the provided TA to determine its uplink transmit time relative to the downlink receive time observed by the UE.

[0003] FIG1 is a schematic diagram of the uplink and downlink timing relationship on the UE side. As shown in FIG1, for example, the uplink advance between uplink frame i and downlink frame i can be based on (N TA +N TA,offset )T c Calculation, N TA For example, it is an absolute time advance value.

[0004] In order to establish time alignment of a secondary timing advance group (TAG), a random access procedure is triggered.

[0005] There are two types of random access procedures: 4-step random access (4-step RA) using MSG1 and 2-step random access (2-step RA) using MSGA. Both random access procedures support contention-based random access (CBRA) and contention-free random access (CFRA).

[0006] FIG2 is a schematic diagram of information interaction between 4-step random access and 2-step random access.

[0007] The 4-step RA type MSG1 includes a preamble on the PRACH (Physical Random Access Channel). After the MSG1 is transmitted, the UE listens for a response from the network within a configured window.

[0008] For CFRA, the network allocates a dedicated preamble for MSG1 transmission, and once the random access response is received from the network, the UE ends the random access procedure (as shown in (c) in Figure 2);

[0009] For CBRA, upon receiving a random access response, the UE sends MSG3 using the UL grant scheduled in the response and monitors contention resolution (as shown in (a) in Figure 2 ). If contention resolution is unsuccessful after MSG3 transmission / retransmission, the UE returns to MSG1 transmission.

[0010] The 2-step RA type of MSGA consists of a preamble on the PRACH and a data (payload) on the PUSCH. After the MSGA is transmitted, the UE listens for a response from the network within a configured window;

[0011] For CFRA, dedicated preamble and PUSCH resources for MSGA transmission are configured, and once the network response is received, the UE ends the random access procedure (as shown in (d) in Figure 2);

[0012] For CBFA, if the contention resolution is successful when receiving the network response, the UE ends the random access procedure (as shown in (b) of FIG2 ).

[0013] When carrier aggregation (CA) is configured, for 2-step RA type random access, random access is performed only on the primary cell (PCell), and contention resolution can be cross-scheduled by the PCell.

[0014] When CA is configured, for a 4-step RA type random access procedure, the first three steps of CBRA always occur in the PCell, and contention resolution can be cross-scheduled by the PCell. All three steps of CFRA initiated on the PCell occur on the PCell. CFRA on the secondary cell (SCell) is initiated only by the gNB to establish the timing advance of the secondary TAG: this procedure is initiated by the gNB with a PDCCH order (step 0) sent on a scheduling cell of an activated SCell of the secondary TAG. The preamble transmission (step 1) occurs on the indicated SCell, and the random access response (step 2) occurs on the PCell.

[0015] The gNB provides the TA to the UE via the Random Access Response (RAR) or the MAC payload of the MSGB.

[0016] FIG3 is a schematic diagram of MAC RAR; FIG4 is a schematic diagram of fallbackRAR of MSGB's MAC payload; FIG5 is a schematic diagram of successRAR of MSGB's MAC payload.

[0017] As shown in Figure 3, MAC RAR is the RAR in the 4-step RA type, which indicates the TA through 12 bits. As shown in Figure 4, fallbackRAR is applicable to the situation where the network only receives the preamble but not the payload in the 2-step RA type, and it indicates the TA through 12 bits. As shown in Figure 5, successRAR is applicable to the situation where contention is resolved in the 2-step RA type, and it indicates the TA through 12 bits.

[0018] When a terminal device moves from the coverage area of ​​one cell to the coverage area of ​​another, at some point a serving cell change needs to be performed. Currently, serving cell changes are triggered by Layer 3 (L3) measurements and completed by RRC signalling, with the addition of Reconfiguration with Synchronisation triggered for PCell and Primary Secondary Cell (PSCell) changes, and the release of SCells when applicable. All cases involve a full Layer 1, i.e. L1 (and Layer 2, i.e. L2) reset, resulting in longer latency, greater overhead and longer disruption times than beam switching mobility. The goal of L1 / L2 mobility enhancements is to ensure that serving cell changes via L1 / L2 signalling reduce latency, overhead and disruption times.

[0019] To reduce mobility delay, the mechanisms and processes for inter-cell mobility based on L1 / L2 include:

[0020] Configuration and maintenance of multiple candidate cells to allow for rapid application of candidate cell configurations;

[0021] For potentially applicable scenarios, a dynamic handover mechanism between candidate serving cells (including special cells and secondary cells) based on L1 / L2 signaling;

[0022] L1 enhancements for inter-cell beam management, including L1 measurement and reporting, and beam indication;

[0023] Timed advance management;

[0024] CU-DU interface signaling to support L1 / L2 mobility.

[0025] It should be noted that the above introduction to the technical background is merely for convenience, to provide a clear and complete description of the technical solutions of this application and to facilitate understanding by those skilled in the art. It should not be assumed that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of this application.

[0026] Summary of the Invention

[0027] Timing advance management is part of the mechanisms and procedures for enabling L1 / L2 inter-cell mobility. It has been agreed to support TA acquisition for candidate cells during the L1 / L2 triggered mobility (LTM) process, prior to receiving a cell switch command. One mechanism for acquiring the TA for a candidate cell is PDCCH ordered RACH. TA updates for candidate cells, i.e., reacquisition of the TA, can be triggered by the network, reusing the same triggering mechanism for initial TA acquisition: PDCCH ordered random access on the candidate cell.

[0028] The PDCCH ordered RACH acquires the TA of the LTM candidate cell. The PDCCH order is triggered only by the source cell. Its DCI includes an indication of the candidate cell and / or the PRACH occasion of the candidate cell. The RACH resource configuration of the candidate cell is provided before the PDCCH order.

[0029] The inventors discovered that when the source cell and the candidate cell are different gNB-DUs, the source cell cannot know the random access configuration (RO configuration) of the candidate cell and therefore cannot trigger the PDCCH ordered RA on the candidate cell.

[0030] In addition, according to the current mechanism, the candidate cell determines the TA value of the terminal through the RA preamble sent by the terminal. If the source cell and the candidate cell are not in the same gNB-DU, the source cell cannot know the TA value of the candidate cell and cannot provide it to the terminal device.

[0031] In order to solve one or more of the above problems, embodiments of the present application provide an information transmission method and apparatus.

[0032] According to a first aspect of an embodiment of the present application, an information transmission device is provided, comprising: a first sending unit, configured for a network device CU of a candidate cell to send a first F1 message including information for obtaining uplink synchronization on the candidate cell to a first network device DU.

[0033] According to a second aspect of an embodiment of the present application, an information transmission device is provided, comprising: a fifth receiving unit, for a first network device DU to receive a first F1 message including information for obtaining uplink synchronization on a candidate cell from a network device CU of a candidate cell; and a third sending unit, for the first network device DU to send DCI to a terminal device.

[0034] According to a third aspect of an embodiment of the present application, an information transmission device is provided, which is arranged in a terminal device, and the device includes: a sixth receiving unit, which receives DCI from a first network device DU, and the DCI includes a random access configuration of a candidate cell and / or information of the candidate cell.

[0035] According to a fourth aspect of the embodiments of the present application, a network device is provided, wherein the network device includes the apparatus according to the first aspect and / or the second aspect of the embodiments of the present application.

[0036] According to a fifth aspect of an embodiment of the present application, a terminal device is provided, wherein the terminal device includes the apparatus according to the third aspect of an embodiment of the present application.

[0037] According to the sixth aspect of the embodiment of the present application, a communication system is provided, which includes the network device according to the fourth aspect of the embodiment of the present application and / or the terminal device according to the fifth aspect of the embodiment of the present application.

[0038] According to a seventh aspect of an embodiment of the present application, an information transmission method is provided, the method comprising: a network device CU of a candidate cell sends a first F1 message including information for obtaining uplink synchronization on the candidate cell to a first network device DU.

[0039] According to an eighth aspect of an embodiment of the present application, an information transmission method is provided, wherein a first network device DU receives a first F1 message including information for obtaining uplink synchronization on a candidate cell from a network device CU of a candidate cell; and the first network device DU sends a DCI to a terminal device.

[0040] According to a ninth aspect of an embodiment of the present application, a method for information transmission is provided, the method comprising: a terminal device receiving a DCI from a first network device DU, the DCI comprising a random access configuration of a candidate cell and / or information of the candidate cell.

[0041] According to the tenth aspect of the embodiment of the present application, a computer-readable program is provided, wherein when the program is executed in an information transmission device or a network device, the program enables the information transmission device or the network device to execute the information transmission method described in the seventh aspect and / or the eighth aspect of the embodiment of the present application.

[0042] According to the eleventh aspect of the embodiment of the present application, a computer-readable program is provided, wherein when the program is executed in an information transmission apparatus or a terminal device, the program enables the information transmission apparatus or the terminal device to execute the information transmission method described in the ninth aspect of the embodiment of the present application.

[0043] According to the twelfth aspect of the embodiment of the present application, a storage medium storing a computer-readable program is provided, wherein the computer-readable program enables an information transmission device or a network device to execute the information transmission method described in the seventh aspect and / or the eighth aspect of the embodiment of the present application.

[0044] According to the thirteenth aspect of the embodiment of the present application, a storage medium storing a computer-readable program is provided, wherein the computer-readable program enables an information transmission device or a terminal device to execute the information transmission method described in the ninth aspect of the embodiment of the present application.

[0045] One of the advantageous effects of the embodiments of the present application is that a first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to a first network device DU serving as a source gNB-DU via a network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering a PDCCH ordered RA on the candidate cell.

[0046] Furthermore, when the information used to obtain uplink synchronization on the candidate cell includes a TA value, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, thereby being able to provide the TA value of the candidate cell to the terminal device, reducing the interruption time in LTM.

[0047] With reference to the following description and accompanying 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. Within the spirit and scope of the appended claims, the embodiments of the present application include many variations, modifications and equivalents.

[0048] 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.

[0049] It should be emphasized that the terms “include / comprising / having” when used herein refer to the presence of features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps or components. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] 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.

[0051] 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 skilled in the art, other drawings can be obtained based on these drawings without inventive work. In the drawings:

[0052] FIG1 is a schematic diagram of the uplink and downlink timing relationship on the UE side;

[0053] FIG2 is a schematic diagram of information interaction between 4-step random access and 2-step random access;

[0054] FIG3 is a schematic diagram of MAC RAR;

[0055] FIG4 is a schematic diagram of the fallbackRAR of the MSGB MAC payload;

[0056] FIG5 is a schematic diagram of the successRAR of the MSGB MAC payload;

[0057] FIG6 is a schematic diagram of a communication system according to an embodiment of the present application;

[0058] FIG7 is a schematic diagram of a Repeater / RIS deployment scenario;

[0059] FIG8 is a schematic diagram of a multi-TRP operation scenario;

[0060] FIG9 is a schematic diagram of an inter-cell mobility scenario based on L1 / L2;

[0061] FIG10 is a schematic diagram of the L1 / L2 triggered mobility process within a gNB-DU;

[0062] FIG11 is a schematic diagram of the L1 / L2 triggered mobility process between gNB and DU;

[0063] FIG12 is a schematic diagram of the information transmission method according to Example 1 of the present application;

[0064] FIG13 is a schematic diagram of an implementation of the information transmission method of Example 1 of the present application;

[0065] FIG14 is a process diagram of an implementation method of the information transmission method of Example 1 of the present application;

[0066] FIG15 is a schematic diagram of another implementation of the information transmission method of Example 1 of the present application;

[0067] FIG16 is a process diagram of another implementation of the information transmission method of Example 1 of the present application;

[0068] FIG17 is a schematic diagram of the TA value transmission process of Example 1 of the present application;

[0069] FIG18 is a schematic diagram of an information transmission method according to Example 2 of the present application;

[0070] FIG19 is a schematic diagram of an information transmission method according to Example 3 of the present application;

[0071] FIG20 is a schematic diagram of an information transmission device according to Example 4 of the present application;

[0072] FIG21 is a schematic diagram of an information transmission device according to Example 5 of the present application;

[0073] FIG22 is a schematic diagram of an information transmission device according to Example 6 of the present application;

[0074] FIG23 is a schematic block diagram of a system structure of a network device according to Embodiment 7 of the present application;

[0075] Figure 24 is a schematic block diagram of the system structure of the terminal device of Example 8 of the present application. DETAILED DESCRIPTION

[0076] The above and other features of the present application will become apparent through the following description with reference to the accompanying drawings. In the description and the accompanying drawings, specific embodiments of the present application are disclosed in detail, which illustrate some embodiments in which the principles of the present application can be adopted. 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 that fall within the scope of the appended claims.

[0077] 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.

[0078] 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.

[0079] 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, Wideband Code Division Multiple Access), High-Speed ​​Packet Access (HSPA, High-Speed ​​Packet Access), New Radio (NR, New Radio), etc.

[0080] 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 and future 5G, etc., and / or other communication protocols currently known or to be developed in the future.

[0081] In the embodiments of the present application, the term "network device" or "network node" refers to, for example, a device in a communication system that connects a user equipment to a communication network and provides services to the user equipment. Network devices or network nodes may include, but are not limited to, the following devices: "node" and / or "donor" under the IAB architecture, 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.

[0082] Base stations may include, but are not limited to, NodeBs (NBs), evolved NodeBs (eNodeBs or eNBs), and 5G base stations (gNBs). 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 encompass some or all of their functions. Each base station provides communication coverage for a specific geographic area. For example, a 5G gNB may include a gNB CU and one or more gNB DUs, where a CU / DU is a logical node within the gNB that also performs some of the gNB's functions. The term "cell" may refer to a base station and / or its coverage area, depending on the context in which the term is used. A gNB-DU supports one or more cells, and a cell is supported by only one gNB-DU.

[0083] In the embodiments of the present application, the term "user equipment" (UE) refers to, for example, a device that accesses a communication network through a network device and receives network services, and may also be referred to as "terminal equipment" (TE). A terminal device 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. For example, a terminal device under the IAB architecture served by an IAB node or an IAB host.

[0084] Among them, terminal 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.

[0085] For another example, in scenarios such as the Internet of Things (IoT), the terminal device can also be a machine or device for monitoring or measurement, including but not limited to: machine type communication (MTC) terminal, vehicle-mounted communication terminal, device-to-device (D2D) terminal, machine-to-machine (M2M) terminal, and so on.

[0086] In the embodiments of the present application, "when...", "under the circumstances of...", "for the circumstances of..." and "if..." all mean based on one or certain conditions or states, etc. In addition, these expressions can be replaced with each other.

[0087] The following describes the scenarios of the embodiments of the present application through examples, but the present application is not limited thereto.

[0088] Figure 6 is a schematic diagram of a communication system according to an embodiment of the present application, which schematically illustrates a situation taking a terminal device and a network device as an example. As shown in Figure 6, a communication system 100 includes a network device 101 and a terminal device 102. The network device 101 includes a network device CU (gNB-CU), a first network device DU, and a second network device DU. The first network device DU and the second network device DU both belong to the network device CU.

[0089] When the terminal device 102 performs an inter-gNB-DU cell change, the first network device DU is the source gNB-DU, also known as the serving gNB-DU; the second network device DU is the candidate gNB-DU, also known as the candidate target gNB-DU or target candidate gNB-DU.

[0090] For simplicity, FIG6 only takes one terminal device as an example for description, but it may also include a case where multiple terminal devices are included.

[0091] In some embodiments, Figure 6 can also represent an IAB network, wherein the terminal device 102 can be either a UE or an IAB-MT: for a cell change between an IAB-donor-DU or an IAB-node-DU within an IAB-donor-CU, the first network device DU and the second network device DU are different IAB-donor-DUs or IAB-node-DUs within the same IAB-donor-CU, that is, when the terminal device 102 needs to perform a cell change, the first network device DU is the source IAB-donor-DU, also known as a serving IAB-donor-DU, and the second network device DU is a target / candidate IAB-donor-DU / IAB-node-DU, also known as a candidate target IAB-donor-DU / IAB-node-DU or a target candidate IAB-donor-DU / IAB-node-DU.

[0092] In the embodiment of the present application, existing services or future services can be carried out between the first network device DU and / or the second network device DU and the terminal device 102. For example, these services include but are not limited to: enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable and low-latency communication (URLLC), etc.

[0093] In current communication systems, in order to increase coverage, etc., an additional node, device, or entity is added between the base station (e.g., gNB or gNB-CU) and the mobile terminal (terminal device). The node or device has a simplified protocol stack and / or function for processing (e.g., amplifying, routing, etc.) signals and / or symbols received from the base station and / or mobile terminal and transmitting them to the mobile terminal and / or base station.

[0094] The additional nodes, devices or entities may be Repeaters, RISs (Reconfigurable Intelligent Surfaces), TRPs (Transmit / Receive Points), etc.

[0095] Scenarios in which an additional node, device, or entity is used between a base station and a mobile terminal are all applicable to the embodiments of the present application, including, for example:

[0096] (1) Repeater / RIS scenario

[0097] FIG7 is a schematic diagram of a Repeater / RIS deployment scenario.

[0098] As shown in Figure 7, a Repeater / RIS is a device that receives, processes, and transmits radiated or conducted RF carriers in the downlink direction (from the base station to the mobile area) and the uplink direction (from the mobile terminal to the base station).

[0099] For a Repeater, the processing includes power amplification; the Repeater is, for example, an NCR (Network Controlled Repeater).

[0100] For RIS, the processing includes beamforming, reshaping the propagation environment, etc. In an operating frequency band where only downlink or uplink is designated, only the designated uplink or downlink is repeated.

[0101] (2) Multi-TRP Operation Scenario

[0102] The TRP is the part of the gNB that receives signals from and / or sends signals to the terminal UE.

[0103] Figure 8 is a schematic diagram of a scenario of multi-TRP operation. As shown in Figure 8, in multi-TRP operation, a serving cell can schedule UE from 2 TRPs to provide better PDSCH coverage, reliability and / or data rate. For multi-TRP, there are 2 different operation modes, namely single DCI and multi-DCI. For these two modes, the control of uplink and downlink operations is performed by the physical layer and MAC within the configuration provided by the RRC layer. In single DCI mode, the UE is scheduled by two TRPs through the same DCI; in multi-DCI mode, the UE is scheduled by a separate DCI for each TRP. The embodiments of the present application are applicable to multi-DCI mode.

[0104] In an embodiment of the present application, the two TRPs may belong to the same cell or different cells.

[0105] As shown in Figure 8, the gNB where TRP-2 resides is an additional node, device, or entity, while the gNB where TRP-1 resides is a base station. TRP-2 and TRP-1 can belong to different gNBs and exchange information over the X2 interface. Alternatively, TRP-2 and TRP-1 can be part of the same gNB and exchange information using an internal interface.

[0106] FIG9 is a schematic diagram of an inter-cell mobility scenario based on L1 / L2.

[0107] When a terminal device moves from the coverage area of ​​one cell to the coverage area of ​​another cell, at some point it needs to perform an L1 / L2 triggered serving cell change. The scenarios supported by L1 / L2 based inter-cell mobility include:

[0108] Inter-DU and intra-DU scenarios: The designs of intra-DU and inter-DU L1 / L2-based mobility should share as much commonality as possible under reasonable circumstances.

[0109] Handover, i.e. mobility / change of PCell, involves both non-CA (i.e. PCell only) and CA scenarios (i.e. PCell and SCell(s)). This includes:

[0110] The target PCell / target SCell(s) is not the current serving cell (i.e., CA->CA scenario with PCell change), such as the LTM from terminal B to terminal D in Figure 9;

[0111] The target SCell is the current PCell, such as the LTM from terminal A to terminal B in Figure 9;

[0112] The target PCell is a current SCell, such as the LTM from terminal B to C in Figure 9;

[0113] CA scenarios support PCell changes without SCell changes and PCell changes with SCell changes;

[0114] Support NR-DC scenarios, at least for PSCell changes that do not involve the MN, i.e., intra-SN;

[0115] Basically, inter-frequency scenarios are supported (including mobility to inter-frequency cells other than the current serving cell), and inter-frequency L1 measurements are supported if feasible.

[0116] In the embodiment of the present application, the source and target cells may be synchronous or asynchronous, and may operate in FR1 and FR2.

[0117] Figure 10 illustrates the L1 / L2-triggered mobility process within a gNB-DU. As shown in Figure 10, when a terminal moves within the same gNB-DU, the NR operations for L1 / L2-triggered mobility include:

[0118] 1. The UE sends a MeasurementReport message containing neighbor cell measurements to the gNB-DU. The gNB-DU sends an UL RRC MESSAGE TRANSFER message carrying the received MeasurementReport message to the gNB-CU.

[0119] 2. The gNB-CU decides to initiate the configuration of L1 / L2 inter-cell mobility;

[0120] 3. Assumption: The gNB-CU sends a UE CONTEXT MODIFICATION REQUEST message to the gNB-DU to include the target candidate cell.

[0121] 4. Assumption: If the request to configure L1 / L2 inter-cell mobility is accepted, the gNB-DU responds with a UE CONTEXT MODIFICATION RESPONSE message including the generated lower layer RRC configuration of the agreed candidate cells.

[0122] 5. The gNB-CU sends a DL RRC MESSAGE TRANSFER message to the gNB-DU, including a generated RRCReconfiguration message carrying the L1 / L2 inter-cell mobility configuration.

[0123] 6. The gNB-DU passes the received RRCReconfiguration message to the UE.

[0124] 7. The UE responds to the gNB-DU with an RRCReconfigurationComplete message.

[0125] 8. The gNB-DU transmits the RRCReconfigurationComplete message to the gNB-CU using the UL RRC MESSAGE TRANSFER message.

[0126] 9. The UE sends the L1 measurement result to the gNB-DU. The gNB-DU decides to perform L1 / L2 inter-cell mobility.

[0127] 10. The gNB-DU sends an L1 / L2 inter-cell mobility command to the UE.

[0128] 11. FFS: How the gNB-DU detects the UE accessing the cell depends on RAN2.

[0129] 12. The gNB-DU sends an Access Success message to the gNB-CU to indicate that the UE has successfully accessed the target cell. This message includes the target cell ID.

[0130] 13.FFS: The gNB-CU may send a UE Context Modification message to the gNB-DU to release the resources of the prepared cell.

[0131] 14.FFS: The gNB-DU responds with the UE CONTEXT MODIFICATION RESPONSE message.

[0132] Figure 11 illustrates the L1 / L2-triggered mobility process between gNB-DUs. As shown in Figure 11, when a terminal moves from one gNB-DU to another within the same gNB-CU, the NR operation process for L1 / L2-triggered mobility includes:

[0133] 1. The UE sends a MeasurementReport message containing neighbor cell measurements to the source gNB-DU. The source gNB-DU sends an UL RRC MESSAGE TRANSFER message carrying the received MeasurementReport message to the gNB-CU.

[0134] 2. The gNB-CU decides to initiate the configuration of L1 / L2 inter-cell mobility;

[0135] 3. The gNB-CU sends a UE CONTEXT SETUP REQUEST message to the candidate gNB-DU to include the target candidate cell.

[0136] 4. If the candidate gNB-DU decides to accept the request for LTM configuration, it responds to the gNB-CU with a UE CONTEXT SETUP RESPONSE message including the generated lower layer RRC configuration of the accepted target candidate cell.

[0137] 5. The gNB-CU sends a DL RRC MESSAGE TRANSFER (or UE CONTEXT MODIFICATION REQUEST) message to the source gNB-DU, including the generated RRCReconfiguration message carrying the L1 / L2 inter-cell mobility configuration.

[0138] 6. The source gNB-DU passes the received RRCReconfiguration message to the UE.

[0139] 7. The UE responds to the source gNB-DU with an RRCReconfigurationComplete message.

[0140] 8. The source gNB-DU delivers the RRCReconfigurationComplete message to the gNB-CU via the UL RRC MESSAGE TRANSFER (or UE CONTEXT MODIFICATION RESPONSE) message.

[0141] 9. The UE sends the low-layer measurement results to the source gNB-DU.

[0142] 10. The source gNB-DU decides to perform L1 / L2 triggered mobility towards a candidate target cell.

[0143] 11. The source gNB-DU sends an L1 / L2 triggered mobility cell switch command to the UE.

[0144] In the embodiments of the present application, L1 refers to layer 1, for example, including the physical layer;

[0145] L2 refers to layer 2, for example, including the MAC layer or MAC sublayer, the PDCP layer or PDCP sublayer, and the RLC layer or RLC sublayer;

[0146] L3 refers to layer 3, including, for example, an RRC layer.

[0147] The following describes various implementations of the present application in conjunction with the accompanying drawings. These implementations are merely illustrative and are not intended to limit the present application.

[0148] Example 1

[0149] An embodiment of the present application provides an information transmission method, which is applied to a network device CU, such as the network device CU in Figure 6, the base station (BS) in Figure 7, the gNB-CU to which TRP1 / TRP2 belongs in Figure 8, or the gNB-CU in Figure 9.

[0150] FIG12 is a schematic diagram of the information transmission method of Example 1 of the present application. As shown in FIG12 , the method includes:

[0151] Step 1201: The network device CU of the candidate cell sends a first F1 message including information for obtaining uplink synchronization on the candidate cell to the first network device DU.

[0152] In this way, the first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to the first network device DU serving as the source gNB-DU through the network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering the PDCCH ordered RA on the candidate cell.

[0153] In some embodiments, a candidate cell may be substituted as a target candidate cell or candidate configuration.

[0154] In some embodiments, the source cell may be replaced by the serving cell.

[0155] In some embodiments, the network equipment CU of the candidate cell and the network equipment CU of the serving cell are the same network equipment CU, for example, the same gNB-CU.

[0156] In some embodiments, the first network device DU is a source network device DU, such as a source gNB-DU (serving gNB-DU), i.e., a gNB-DU to which the source cell belongs.

[0157] In some embodiments, the information for obtaining uplink synchronization on the candidate cell is included in the first F1 message, that is, the network device CU of the candidate cell sends a message to the first network device DU through the F1 interface, including the information for obtaining uplink synchronization on the candidate cell.

[0158] In some embodiments, the information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a timing advance (TA) value.

[0159] In some embodiments, the random access configuration includes at least one of the following information:

[0160] Random access time-frequency resource information, such as PRACH MASK index;

[0161] Random access preamble information, such as RA preamble index; and

[0162] Downlink reference signal (DL RS) information, such as SSB index and CSI-RS resource ID.

[0163] In some embodiments, the random access configuration includes one random access configuration, or the random access configuration includes multiple random access configurations and corresponding candidate cell information.

[0164] In some embodiments, for the case where the information used to obtain uplink synchronization on the candidate cell includes the random access configuration of the candidate cell, that is, the first F1 message includes the random access configuration of the candidate cell, FIG13 is a schematic diagram of an implementation of the information transmission method of Example 1 of the present application. As shown in FIG13, the method includes:

[0165] Step 1301: The network device CU of the candidate cell receives a request message for random access configuration of the candidate cell from the first network device DU;

[0166] Step 1302: The network device CU sends a message indicating one or more candidate cells to the second network device DU to request the random access configuration of the indicated candidate cells;

[0167] Step 1303: The network device CU receives the random access configuration of the candidate cell from the second network device DU;

[0168] Step 1304: The CU sends a first F1 message including information for obtaining uplink synchronization on the candidate cell to the first network device DU; and

[0169] Step 1305: The network device CU receives a response message to the first F1 message from the first network device DU.

[0170] In some embodiments, the above steps 1301-1303 and step 1305 are optional steps.

[0171] In some embodiments, the second network device DU is a candidate network device DU, such as a candidate gNB-DU (target candidate gNB-DU), i.e., a gNB-DU to which the candidate cell belongs.

[0172] The first network device DU and the second network device DU belong to the same network device CU.

[0173] FIG14 is a process diagram of an implementation of the information transmission method of Example 1 of the present application, which corresponds to the method shown in FIG13 . In FIG14 , the gNB-CU corresponds to the network device CU, the source gNB-DU corresponds to the first network device DU, and the candidate gNB-DU corresponds to the second network device DU.

[0174] As shown in FIG14 , the method includes:

[0175] Step 1401: The source gNB-DU decides to initiate random access configuration. For example, the source gNB-DU decides to initiate random access configuration based on L1 measurement results.

[0176] Step 1402: The source gNB-DU sends an F1 message to the gNB-CU to request random access configuration for the candidate cell.

[0177] Step 1403: The gNB-CU sends a UE CONTEXT SETUP REQUEST message to the candidate gNB-DU, including the random access configuration of the indicated candidate cell.

[0178] Step 1404: The candidate gNB-DU sends a UE CONTEXT SETUP RESPONSE response message to the gNB-CU. The response message includes the random access configuration of the indicated candidate cell.

[0179] Step 1405: The gNB-CU sends a UE CONTEXT MODIFICATION REQUEST message to the source gNB-DU, which includes the random access configuration.

[0180] In addition, if random access configurations of multiple candidate cells are requested, the message includes the multiple random access configurations and corresponding candidate cell information;

[0181] In addition, the message may also be a new F1 message or an existing F1 message other than the UE CONTEXT MODIFICATION REQUEST message;

[0182] Step 1406: The source gNB-DU includes information about a candidate cell and the random access configuration of the candidate cell in the DCI, triggering the UE to initiate a random access procedure based on the random access configuration of the candidate cell, e.g., to obtain the TA value of the candidate cell.

[0183] Step 1407: The source gNB-DU sends a UE CONTEXT MODIFICATION RESPONSE message to the gNB-CU.

[0184] In addition, when step 1405 uses a new F1 message or other existing F1 message instead of the UE CONTEXT MODIFICATION REQUEST message, the response message may be a response message of the new F1 message or the existing F1 message instead of the UE CONTEXT MODIFICATION RESPONSE.

[0185] In some embodiments, steps 1401-1404 and steps 1406 and 1407 are optional steps. In addition, the order of steps 1406 and 1407 is not restricted, that is, step 1406 can be executed first and then step 1407, or step 1407 can be executed first and then step 1406, or steps 1406 and 1407 can be executed simultaneously.

[0186] For a case where the information for obtaining uplink synchronization on the candidate cell includes the random access configuration of the candidate cell, that is, the first F1 message includes the random access configuration of the candidate cell, FIG15 is a schematic diagram of another implementation of the information transmission method of Example 1 of the present application. As shown in FIG15 , the method includes:

[0187] Step 1501: The network device CU decides to initiate random access configuration;

[0188] Step 1502: The network device CU sends a message indicating one or more candidate cells to the second network device DU to request the random access configuration of the indicated candidate cells;

[0189] Step 1503: The network device CU receives the random access configuration of the candidate cell from the second network device DU;

[0190] Step 1504: The CU sends a first F1 message including information for obtaining uplink synchronization on the candidate cell to the first network device DU; and

[0191] Step 1505: The network device CU receives a response message to the first F1 message from the first network device DU.

[0192] In some embodiments, the above steps 1501-1503 and step 1505 are optional steps.

[0193] FIG16 is a process diagram of another implementation of the information transmission method of Example 1 of the present application, which corresponds to the method shown in FIG15 . In FIG16 , the gNB-CU corresponds to the network device CU, the source gNB-DU corresponds to the first network device DU, and the candidate gNB-DU corresponds to the second network device DU.

[0194] As shown in FIG16 , the method includes:

[0195] Step 1601: The gNB-CU decides to initiate random access configuration.

[0196] Step 1602: The gNB-CU sends a UE CONTEXT SETUP REQUEST message to the accepted candidate gNB-DU to include the random access configuration of the candidate cell.

[0197] Step 1603: The candidate gNB-DU responds to the gNB-CU with a UE CONTEXT SETUP RESPONSE message, including the random access configuration of one or more candidate cells.

[0198] Step 1604: The gNB-CU sends a UE CONTEXT MODIFICATION REQUEST message to the source gNB-DU, including information about one or more candidate cells and the random access configuration of the candidate cells.

[0199] In addition, the message may also be a new F1 message or an existing F1 message other than the UE CONTEXT MODIFICATION REQUEST message;

[0200] Step 1605: The source gNB-DU includes a candidate cell and the random access configuration of the candidate cell in the DCI, triggering the UE to initiate a random access procedure based on the random access configuration of the candidate cell, e.g., to obtain the TA value of the candidate cell.

[0201] Step 1606: The source gNB-DU sends a UE CONTEXT MODIFICATION RESPONSE message to the gNB-CU.

[0202] In addition, when step 1604 uses a new F1 message or an existing F1 message other than UE CONTEXT MODIFICATION REQUEST, the response message may be a response message of the new F1 message or the existing F1 message instead of UE CONTEXT MODIFICATION RESPONSE.

[0203] In some embodiments, steps 1601-1603 and steps 1605 and 1606 are optional steps. In addition, the order of steps 1605 and 1606 is not restricted, that is, step 1605 can be executed first and then step 1606, or step 1606 can be executed first and then step 1605, or steps 1605 and 1606 can be executed simultaneously.

[0204] In some embodiments, for the random access process on the candidate cell, the terminal device determines to perform random access based on the random access configuration indicated by the DCI and / or the candidate cell information. For example, in the above steps 1406 and 1605, the source gNB-DU includes a candidate cell information and the random access configuration of the candidate cell in the DCI, triggering the terminal device to initiate a random access process on the random access configuration of the candidate cell.

[0205] In some embodiments, different from the embodiments shown in Figures 13 to 16, the information sent by the gNB-CU to the source gNB-DU for obtaining uplink synchronization on the candidate cell includes the candidate cell information but does not include the random access configuration of the candidate cell. Accordingly, the DCI sent by the source gNB-DU to the terminal device includes the candidate cell information but does not include the random access configuration of the candidate cell. In this case, the candidate cell information is used by the terminal device to determine the random access configuration of the candidate cell.

[0206] In some embodiments, the random access configuration determined by the terminal device according to the candidate cell information includes at least one of the following:

[0207] Random access configuration included in the candidate cell configuration;

[0208] The random access configuration for obtaining timing advance included in the candidate cell configuration;

[0209] The first random access configuration included in the candidate cell configuration, for example, the first random access configuration is the random access configuration used to obtain the TA;

[0210] The first random access configuration for acquiring timing advance included in the candidate cell configuration;

[0211] The random access configuration included in the candidate cell configuration, and the L1 measurement result of the downlink reference signal corresponding to the random access configuration is better than the configured threshold; and

[0212] The candidate cell configuration includes the next available random access configuration after receiving the DCI. For example, "available" means that there is no conflict or overlap with the serving cell transmission.

[0213] In some embodiments, for example, in steps 1406 and 1605, the source gNB-DU (first network device DU) includes candidate cell information and the random access configuration of the candidate cell in the DCI, triggering the terminal device to initiate a random access procedure based on the random access configuration of the candidate cell to obtain the TA value of the candidate cell;

[0214] In this case, the second network device DU (candidate gNB-DU) may receive the random access preamble code sent by the terminal device on the candidate cell and determine the TA value of the terminal device; and the first network device DU (source gNB-DU) includes the TA value of one or more candidate cells in the RAR or cell switching command and sends it to the terminal device.

[0215] In some embodiments, the TA value of the candidate cell includes TA values ​​of one or more candidate cells.

[0216] In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, and thus can provide the TA value of the candidate cell to the terminal device.

[0217] FIG17 is a schematic diagram illustrating the TA value transfer process according to Example 1 of the present application. In FIG17 , the gNB-CU corresponds to the network device CU, the source gNB-DU corresponds to the first network device DU, and the candidate gNB-DU corresponds to the second network device DU.

[0218] As shown in Figure 17, the transfer process includes:

[0219] Step 1701: The candidate gNB-DU receives a random access preamble sent by a terminal device on a candidate cell.

[0220] Step 1702: The candidate gNB-DU determines the TA value of the UE.

[0221] Step 1703: The candidate gNB-DU indicates the TA value to the gNB-CU via the F1 interface, and may also indicate UE information.

[0222] Step 1704: The gNB-CU indicates the TA value to the source gNB-DU via the F1 interface. Additionally, it may indicate UE information and / or candidate cell information.

[0223] Step 1705: The source gNB-DU includes the TA values ​​of one or more candidate cells in the RAR or cell handover command and sends it to the terminal device.

[0224] In some embodiments, the candidate cell is a cell with downlink, i.e., not a UL only cell;

[0225] And / or, the candidate cell is a timing reference of the candidate cell and / or candidate cells in the same TA group.

[0226] In some embodiments, the TA value is an absolute time advance value, such as an initial TA value or a TA updated value;

[0227] In this case, for example, the downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell that can be a special cell in the same TA group. The source cell is, for example, the source cell that sends the PDCCH order.

[0228] For example, the configuration of the timing reference is sent via an RRC message, for example, included in the candidate configuration;

[0229] Alternatively, the configuration of the timing reference is sent via MAC signaling, for example, RAR or MSGB or cell handover command MAC CE or TAC MAC CE;

[0230] Alternatively, the configuration of the timing reference is sent via DCI, for example, a PDCCH order that triggers a random access procedure.

[0231] In some embodiments, the TA value may also be a variable of an absolute time advance value, such as a TA update value.

[0232] In some embodiments, the time advance value is used by the terminal device to determine the uplink advance.

[0233] For example, the TA value is used by the terminal device to determine the uplink advance based on the absolute time advance value, or the time advance value is used by the terminal device to determine the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0234] For example, N in the formula in Figure 1 TA It is the absolute time advance value, or the sum of the absolute time advance value and the absolute time advance value variable. TA Confirm the upward movement in advance.

[0235] As can be seen from the above embodiment, the first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to the first network device DU serving as the source gNB-DU via the network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering a PDCCH ordered RA on the candidate cell.

[0236] Furthermore, when the information used to obtain uplink synchronization on the candidate cell includes a TA value, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, thereby being able to provide the TA value of the candidate cell to the terminal device, reducing the interruption time in LTM.

[0237] Example 2

[0238] The present application provides an information transmission method, which is applied to a first network device DU, such as the first network device DU in Figure 6, the base station (BS) in Figure 7, the TRP1 in Figure 8, or the candidate DU in Figure 9. The method described in Example 2 corresponds to the method described in Example 1, and for the same or corresponding contents, reference can be made to the description in Example 1.

[0239] FIG18 is a schematic diagram of an information transmission method according to Example 2 of the present application. As shown in FIG18 , the method includes:

[0240] Step 1801: A first network device DU receives a first F1 message including information for obtaining uplink synchronization on a candidate cell from a network device CU of a candidate cell; and

[0241] Step 1802: The first network device DU sends DCI to the terminal device.

[0242] In some embodiments, a candidate cell may be substituted as a target candidate cell or candidate configuration.

[0243] In some embodiments, the source cell may be replaced by the serving cell.

[0244] In some embodiments, the network equipment CU of the candidate cell and the network equipment CU of the serving cell are the same network equipment CU, for example, the same gNB-CU.

[0245] In some embodiments, the first network device DU is a source network device DU, such as a source gNB-DU (serving gNB-DU), i.e., a gNB-DU to which the source cell belongs.

[0246] In some embodiments, the second network device DU is a candidate network device DU, such as a candidate gNB-DU (target candidate gNB-DU), i.e., a gNB-DU to which the candidate cell belongs.

[0247] The first network device DU and the second network device DU belong to the same network device CU.

[0248] In some embodiments, the information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a timing advance (TA) value.

[0249] In some embodiments, the method further comprises at least one of the following steps:

[0250] The first network device DU decides to initiate random access configuration;

[0251] The first network device DU sends a request message for random access configuration of the candidate cell to the network device CU; and

[0252] The first network device DU sends a response message to the first F1 message to the network device CU.

[0253] In some embodiments, the DCI includes the random access configuration of the candidate cell and / or information of the candidate cell.

[0254] In some embodiments, the DCI triggers the terminal device to initiate a random access process on the candidate cell.

[0255] In some embodiments, the DCI includes information about the candidate cell, and the information about the candidate cell is used by the terminal device to determine the random access configuration of the candidate cell.

[0256] In some embodiments, the timing advance value is an absolute timing advance value or a variation of an absolute timing advance value.

[0257] In some embodiments, the time advance value is used by the terminal device to determine the uplink advance.

[0258] In some embodiments, the time advance value is used by the terminal device to determine the uplink advance according to the absolute time advance value, or,

[0259] The time advance value is used by the terminal device to determine the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0260] In some embodiments, the candidate cell is a cell with downlink; and / or,

[0261] The candidate cell is a timing reference for the candidate cell and / or candidate cells in the same TA group.

[0262] In some embodiments, the downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be a special cell.

[0263] In some embodiments, the configuration of the timing reference is sent via RRC message or MAC signaling or DCI.

[0264] In some embodiments, the method further comprises:

[0265] Step 1803: The first network device DU sends the timing advance value of the candidate cell to the terminal device through a random access response (RAR) or a cell switching command.

[0266] In some embodiments, step 1803 is an optional step.

[0267] In some embodiments, the specific contents of steps 1801-1803 can refer to the relevant records in Example 1, for example, the records in Figures 14 and 16.

[0268] In some embodiments, the timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0269] As can be seen from the above embodiment, the first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to the first network device DU serving as the source gNB-DU via the network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering a PDCCH ordered RA on the candidate cell.

[0270] Furthermore, when the information used to obtain uplink synchronization on the candidate cell includes a TA value, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, thereby being able to provide the TA value of the candidate cell to the terminal device, reducing the interruption time in LTM.

[0271] Example 3

[0272] The present application provides an information transmission method, which is applied to a terminal device, such as the terminal device 102 in Figures 6 or 8, the UE in Figure 7, or the terminal in Figure 9. The method described in Example 3 corresponds to the method described in Example 1, and for the same or corresponding content, reference can be made to the description in Example 1.

[0273] FIG19 is a schematic diagram of an information transmission method according to Example 3 of the present application, which is applied to a terminal device. As shown in FIG19 , the method includes:

[0274] Step 1901: The terminal device receives DCI from the first network device DU, where the DCI includes the random access configuration of the candidate cell and / or information of the candidate cell.

[0275] In some embodiments, the DCI includes a random access configuration of a candidate cell and information about the candidate cell. In this case, as shown in FIG19 , the method may further include:

[0276] Step 1902: The terminal device initiates a random access process on the candidate cell according to the candidate cell information and the random access configuration of the candidate cell to obtain a timing advance (TA) value of the candidate cell.

[0277] In some embodiments, the DCI includes information about the candidate cell but does not include a random access configuration of the candidate cell. In this case, as shown in FIG19 , the method may further include:

[0278] Step 1903: The terminal device determines the random access configuration of the candidate cell based on the information of the candidate cell.

[0279] In some embodiments, the random access configuration determined by the terminal device according to the candidate cell information includes at least one of the following:

[0280] Random access configuration included in the candidate cell configuration;

[0281] The random access configuration for obtaining timing advance included in the candidate cell configuration;

[0282] The first random access configuration included in the candidate cell configuration;

[0283] The first random access configuration for acquiring timing advance included in the candidate cell configuration;

[0284] The random access configuration included in the candidate cell configuration, and the L1 measurement result of the downlink reference signal corresponding to the random access configuration is better than the configured threshold; and

[0285] The candidate cell configuration includes the next available random access after receiving DCI.

[0286] In some embodiments, step 1903 is an optional step, indicated by a dotted box in FIG19 .

[0287] In addition, after the random access configuration of the candidate cell is determined in step 1903, step 1902 may be performed, ie, a random access process is initiated on the candidate cell.

[0288] In some embodiments, the timing advance value is an absolute timing advance value or a variation of an absolute timing advance value.

[0289] In some embodiments, as shown in FIG19 , the method may further include:

[0290] Step 1904: The terminal device receives a random access response (RAR) or a cell switching command from the first network device DU, where the random access response or the cell switching command includes a timing advance value of the candidate cell.

[0291] In some embodiments, the timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0292] In some embodiments, as shown in FIG19 , the method may further include:

[0293] Step 1905: The terminal device determines the uplink advance based on the time advance value.

[0294] In some embodiments, the terminal device determines the uplink advance based on the time advance value, including: the terminal device determines the uplink advance based on the absolute time advance value, or the terminal device determines the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0295] In some embodiments, the candidate cell is a cell with downlink; and / or,

[0296] The candidate cell is a timing reference for the candidate cell and / or candidate cells in the same TA group.

[0297] In some embodiments, the downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be a special cell.

[0298] In some embodiments, the configuration of the timing reference is sent via RRC message or MAC signaling or DCI.

[0299] In some embodiments, steps 1902-1905 are optional steps.

[0300] In some embodiments, the specific implementation of steps 1901-1905 can refer to the relevant records in Example 1 and will not be repeated here.

[0301] As can be seen from the above embodiment, the first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to the first network device DU serving as the source gNB-DU via the network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering a PDCCH ordered RA on the candidate cell.

[0302] Furthermore, when the information used to obtain uplink synchronization on the candidate cell includes a TA value, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, thereby being able to provide the TA value of the candidate cell to the terminal device, reducing the interruption time in LTM.

[0303] Example 4

[0304] The embodiment of the present application provides an information transmission device, which is provided in a network device CU. Since the principle of solving the problem of the device is similar to that of the method in Example 1, its specific implementation can refer to the implementation of the method described in Example 1, and the same or related contents will not be repeated.

[0305] FIG20 is a schematic diagram of an information transmission device according to Example 4 of the present application. As shown in FIG20 , the device 2000 includes:

[0306] The first sending unit 2001 is configured to send a first F1 message including information for obtaining uplink synchronization on the candidate cell to a first network device DU in a network device CU of a candidate cell.

[0307] In some embodiments, the information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a timing advance (TA) value.

[0308] In some embodiments, the random access configuration includes at least one of the following information:

[0309] Random access time and frequency resource information;

[0310] Random access preamble information; and

[0311] Downlink reference signal (DL RS) information.

[0312] In some embodiments, as shown in FIG20 , the apparatus 2000 further includes at least one of the following units:

[0313] A second sending unit 2002 is configured to send, by the network device CU, a message indicating one or more candidate cells to a second network device DU, to request the random access configuration of the indicated candidate cells;

[0314] A first receiving unit 2003 is configured for the network device CU to receive the random access configuration of the candidate cell from the second network device DU; and

[0315] The second receiving unit 2004 is configured to receive, by the network device CU, a response message to the first F1 message from the first network device DU.

[0316] In some embodiments, as shown in FIG20 , the apparatus 2000 further includes at least one of the following units:

[0317] The third receiving unit 2005 is configured to receive, by the network device CU, a request message for random access configuration of the candidate cell from the first network device DU; or

[0318] The first decision unit 2006 is configured for the network device CU to decide to initiate random access configuration.

[0319] In some embodiments, the random access configuration comprises a random access configuration, or,

[0320] The random access configuration includes multiple random access configurations and corresponding candidate cell information.

[0321] In some embodiments, the information used to obtain uplink synchronization on the candidate cell includes candidate cell information, including: the candidate cell information is used by the terminal device to determine the random access configuration of the candidate cell.

[0322] In some embodiments, the timing advance value is an absolute timing advance value or a variation of an absolute timing advance value.

[0323] In some embodiments, the time advance value is used by the terminal device to determine the uplink advance.

[0324] In some embodiments, the time advance value is used by the terminal device to determine the uplink advance according to the absolute time advance value, or,

[0325] The time advance value is used by the terminal device to determine the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0326] In some embodiments, the candidate cell is a cell with downlink; and / or,

[0327] The candidate cell is a timing reference for the candidate cell and / or candidate cells in the same TA group.

[0328] In some embodiments, the downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be a special cell.

[0329] In some embodiments, the configuration of the timing reference is sent via RRC message or MAC signaling or DCI.

[0330] In some embodiments, as shown in FIG20 , the apparatus 2000 further includes:

[0331] The fourth receiving unit 2007 is configured to receive, by the network device CU, the timing advance value of the candidate cell from the second network device DU.

[0332] Alternatively, the first receiving unit 2003 may be reused to receive the timing advance value of the candidate cell from the second network device DU.

[0333] In addition, the fourth receiving unit 2007 or the reused first receiving unit 2003 may also be connected to other units to perform transmission and / or processing related to time advance.

[0334] In some embodiments, the timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0335] In some embodiments, the above units 2002-2007 are optional units.

[0336] In some embodiments, the specific implementation of the functions of the above-mentioned units can refer to the relevant steps in Example 1 and will not be repeated here.

[0337] As can be seen from the above embodiment, the first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to the first network device DU serving as the source gNB-DU via the network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering a PDCCH ordered RA on the candidate cell.

[0338] Furthermore, when the information used to obtain uplink synchronization on the candidate cell includes a TA value, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, thereby being able to provide the TA value of the candidate cell to the terminal device, reducing the interruption time in LTM.

[0339] Example 5

[0340] The present embodiment provides an information transmission device, which is provided in a first network device DU. Since the principle of solving the problem of the device is similar to that of the method in Example 2, its specific implementation can refer to the implementation of the method described in Example 2, and the same or related contents will not be repeated.

[0341] FIG21 is a schematic diagram of an information transmission device according to Example 5 of the present application. As shown in FIG21 , the device 2100 includes:

[0342] A fifth receiving unit 2101 is configured for the first network device DU to receive a first F1 message including information for obtaining uplink synchronization on the candidate cell from the network device CU of the candidate cell; and

[0343] The third sending unit 2102 is used for the first network device DU to send DCI to the terminal device.

[0344] In some embodiments, the information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a timing advance (TA) value.

[0345] In some embodiments, as shown in FIG21 , the apparatus 2100 further includes at least one of the following units:

[0346] A second decision unit 2103, which is used by the first network device DU to decide to initiate random access configuration;

[0347] The fourth sending unit 2104 is configured for the first network device DU to send a request message for random access configuration of the candidate cell to the network device CU; and

[0348] The fifth sending unit 2105 is configured to send, by the first network device DU, a response message to the first F1 message to the network device CU.

[0349] In some embodiments, the DCI includes the random access configuration of the candidate cell and / or information of the candidate cell.

[0350] In some embodiments, the DCI triggers the terminal device to initiate a random access process on the candidate cell.

[0351] In some embodiments, the DCI includes information of the candidate cell.

[0352] The information of the candidate cell is used by the terminal device to determine the random access configuration of the candidate cell.

[0353] In some embodiments, the timing advance value is an absolute timing advance value or a variation of an absolute timing advance value.

[0354] In some embodiments, the time advance value is used by the terminal device to determine the uplink advance.

[0355] In some embodiments, the time advance value is used by the terminal device to determine the uplink advance according to the absolute time advance value, or,

[0356] The time advance value is used by the terminal device to determine the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0357] In some embodiments, the candidate cell is a cell with downlink; and / or,

[0358] The candidate cell is a timing reference for the candidate cell and / or candidate cells in the same TA group.

[0359] In some embodiments, the downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be a special cell.

[0360] In some embodiments, the configuration of the timing reference is sent via RRC message or MAC signaling or DCI.

[0361] In some embodiments, as shown in FIG21 , the apparatus 2100 further includes:

[0362] The sixth sending unit 2106 is configured for the first network device DU to send the timing advance value of the candidate cell to the terminal device through a random access response (RAR) or a cell handover command.

[0363] In some embodiments, the timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0364] In some embodiments, the above-mentioned units 2103-2106 are optional units.

[0365] In some embodiments, the specific implementation of the functions of the above-mentioned units can refer to the relevant steps in Example 1 and Example 2, and will not be repeated here.

[0366] As can be seen from the above embodiment, the first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to the first network device DU serving as the source gNB-DU via the network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering a PDCCH ordered RA on the candidate cell.

[0367] Furthermore, when the information used to obtain uplink synchronization on the candidate cell includes a TA value, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, thereby being able to provide the TA value of the candidate cell to the terminal device, reducing the interruption time in LTM.

[0368] Example 6

[0369] The embodiment of the present application provides an information transmission device, which is provided in a terminal device. Since the principle of solving the problem of the device is similar to that of the method of Example 3, its specific implementation can refer to the implementation of the method described in Example 3, and the same or related contents will not be repeated.

[0370] FIG22 is a schematic diagram of an information transmission device according to Example 6 of the present application. As shown in FIG22 , the device 2200 includes:

[0371] The sixth receiving unit 2201 receives DCI from the first network device DU, where the DCI includes the random access configuration of the candidate cell and / or information of the candidate cell.

[0372] In some embodiments, as shown in FIG22 , the apparatus 2200 further includes:

[0373] The first initiating unit 2202 is configured to initiate a random access process on the candidate cell according to the candidate cell information and the random access configuration of the candidate cell, so as to obtain a timing advance (TA) value of the candidate cell.

[0374] In some embodiments, as shown in FIG22 , the apparatus 2200 further includes:

[0375] The first determining unit 2203 is configured to determine the random access configuration of the candidate cell according to the information of the candidate cell.

[0376] In some embodiments, the random access configuration determined by the first determining unit 2203 according to the candidate cell information includes at least one of the following:

[0377] Random access configuration included in the candidate cell configuration;

[0378] The random access configuration for obtaining timing advance included in the candidate cell configuration;

[0379] The first random access configuration included in the candidate cell configuration;

[0380] The first random access configuration for acquiring timing advance included in the candidate cell configuration;

[0381] The random access configuration included in the candidate cell configuration, and the L1 measurement result of the downlink reference signal corresponding to the random access configuration is better than the configured threshold; and

[0382] The candidate cell configuration includes the next available random access after receiving DCI.

[0383] In some embodiments, the first determining unit 2203 is an optional unit, which is represented by a dotted box in FIG22 .

[0384] In some embodiments, the timing advance value is an absolute timing advance value or a variation of an absolute timing advance value.

[0385] In some embodiments, as shown in FIG22 , the apparatus 2200 further includes:

[0386] The seventh receiving unit 2204 is configured to receive a random access response (RAR) or a cell switching command from the first network device DU, where the random access response or the cell switching command includes the timing advance value of the candidate cell.

[0387] In some embodiments, the timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0388] In some embodiments, as shown in FIG22 , the apparatus 2200 further includes:

[0389] The second determining unit 2205 is configured to determine an uplink advance according to the time advance value.

[0390] In some embodiments, the second determining unit 2205 determines the uplink advance according to the timing advance value, including:

[0391] The second determining unit 2205 determines the uplink advance according to the absolute time advance value, or,

[0392] The second determining unit 2205 determines the uplink advance according to the absolute time advance value and a variable of the absolute time advance value.

[0393] In some embodiments, the candidate cell is a cell with downlink; and / or,

[0394] The candidate cell is a timing reference for the candidate cell and / or candidate cells in the same TA group.

[0395] In some embodiments, the downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be a special cell.

[0396] In some embodiments, the configuration of the timing reference is sent via RRC message or MAC signaling or DCI.

[0397] As can be seen from the above embodiment, the first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to the first network device DU serving as the source gNB-DU via the network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering a PDCCH ordered RA on the candidate cell.

[0398] Furthermore, when the information used to obtain uplink synchronization on the candidate cell includes a TA value, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, thereby being able to provide the TA value of the candidate cell to the terminal device, reducing the interruption time in LTM.

[0399] Example 7

[0400] An embodiment of the present application provides a network device, which includes the information transmission device as described in Example 4 and / or Example 5.

[0401] For example, the information transmission device described in Example 4 is set in the gNB-CU of the candidate cell, and the information transmission device described in Example 5 is set in the source gNB-DU. The embodiments of the present application involve LTM within the gNB-CU, that is, the gNB-CU of the candidate cell is also the gNB-CU of the source cell.

[0402] The network device (e.g., gNB) includes the information transmission device described in Example 4 (e.g., gNB-CU of the candidate cell / source cell), or the network device (e.g., gNB) includes the information transmission device described in Example 5 (e.g., source gNB-DU), or the network device (e.g., gNB) includes the information transmission device described in Example 4 (e.g., gNB-CU of the candidate cell / source cell) and the information transmission device described in Example 5 (e.g., source gNB-DU).

[0403] Figure 23 is a schematic block diagram of the system configuration of a network device according to Example 7 of the present application. As shown in Figure 23, network device 2300 may include a processor 2310 and a memory 2320; the memory 2320 is coupled to the processor 2310. The memory 2320 may store various data and may also store an information processing program 2330. This program 2330 is executed under the control of the processor 2310 to receive various information sent by terminal devices and to send various information to the terminal devices.

[0404] In one embodiment, the functionality of the information delivery device may be integrated into the processor 2310 .

[0405] Corresponding to embodiment 4, the processor 2310 may be configured to: the network device CU of the candidate cell sends a first F1 message including information for obtaining uplink synchronization on the candidate cell to the first network device DU.

[0406] Corresponding to embodiment 5, the processor 2310 may be configured to: receive a first F1 message including information for obtaining uplink synchronization on the candidate cell from the network device CU of the candidate cell by the first network device DU; and send DCI to the terminal device by the first network device DU.

[0407] In another embodiment, the information transmission device may be configured separately from the processor 2310 . For example, the information transmission device may be configured as a chip connected to the processor 2310 , and the functions of the information transmission device may be implemented under the control of the processor 2310 .

[0408] In addition, as shown in Figure 23, network device 2300 may also include: a transceiver 2340 and an antenna 2350; wherein, the functions of the above components are similar to those in the prior art and are not described here in detail. It is worth noting that network device 2300 does not necessarily include all the components shown in Figure 23; in addition, network device 2300 may also include components not shown in Figure 23, and reference may be made to the prior art for details.

[0409] As can be seen from the above embodiment, the first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to the first network device DU serving as the source gNB-DU via the network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering a PDCCH ordered RA on the candidate cell.

[0410] Furthermore, when the information used to obtain uplink synchronization on the candidate cell includes a TA value, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, thereby being able to provide the TA value of the candidate cell to the terminal device, reducing the interruption time in LTM.

[0411] Example 8

[0412] An embodiment of the present application provides a terminal device, which includes the information transmission device as described in Example 6.

[0413] Figure 24 is a schematic block diagram of the system structure of a terminal device according to Example 8 of the present application. As shown in Figure 24, terminal device 2400 may include a processor 2410 and a memory 2420; memory 2420 is coupled to processor 2410. It should be noted that this diagram is exemplary; other types of structures may be used to supplement or replace this structure to implement telecommunication functions or other functions.

[0414] In one embodiment, the functionality of the information delivery device may be integrated into the processor 2410 .

[0415] In some embodiments, the processor 2410 is configured to: the terminal device receives DCI from the first network device DU, where the DCI includes a random access configuration of a candidate cell and / or information about the candidate cell.

[0416] In another embodiment, the information transmission device may be configured separately from the processor 2410 . For example, the information transmission device may be configured as a chip connected to the processor 2410 , and the functions of the information transmission device may be implemented under the control of the processor 2410 .

[0417] As shown in FIG24 , terminal device 2400 may further include: a communication module 2430, an input unit 2440, a display 2450, and a power supply 2460. It is worth noting that terminal device 2400 does not necessarily include all the components shown in FIG24 ; in addition, terminal device 2400 may also include components not shown in FIG24 , and reference may be made to related art for details.

[0418] As shown in FIG. 24 , the processor 2410 is sometimes also referred to as a controller or an operation control, and may include a microprocessor or other processor device and / or logic device. The processor 2410 receives input and controls the operation of various components of the terminal device 2400 .

[0419] Memory 2420 may be, for example, one or more of a cache, flash memory, a hard drive, removable media, volatile memory, non-volatile memory, or other suitable devices. It may store various data and programs for executing related information. Processor 2410 may execute the programs stored in memory 2420 to implement information storage or processing. The functions of other components are similar to those of existing devices and are not further described here. Each component of terminal device 2400 may be implemented using dedicated hardware, firmware, software, or a combination thereof without departing from the scope of the present invention.

[0420] As can be seen from the above embodiment, the first F1 message including information for obtaining uplink synchronization on the candidate cell is sent to the first network device DU serving as the source gNB-DU via the network device CU of the candidate cell. In this way, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the information for obtaining uplink synchronization on the candidate cell, thereby triggering a PDCCH ordered RA on the candidate cell.

[0421] Furthermore, when the information used to obtain uplink synchronization on the candidate cell includes a TA value, when the source cell and the candidate cell are different gNB-DUs, the source cell can obtain the TA value of the candidate cell, thereby being able to provide the TA value of the candidate cell to the terminal device, reducing the interruption time in LTM.

[0422] Example 9

[0423] The embodiment of the present application provides a communication system, including the terminal device according to embodiment 8 and / or the network device according to embodiment 7. For specific details, please refer to the description in embodiment 8 and embodiment 7.

[0424] For example, the structure of the communication system can refer to Figure 6. As shown in Figure 2, the communication system 100 includes a network device 101 and a terminal device 102. The terminal device 102 can be the same as the terminal device recorded in Example 8, and / or, the network device 101 can be the same as the network device recorded in Example 7. The repeated content will not be repeated.

[0425] 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 logic component is, for example, a field programmable logic component, a microprocessor, a processor used in a computer, etc. 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.

[0426] 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 Figure 20 and / or one or more combinations of functional block diagrams can correspond to various software modules of a computer program flow or to various hardware modules. These software modules can correspond to the various steps shown in Figures 12, 13, and 15, respectively. These hardware modules can be implemented by solidifying these software modules using, for example, a field programmable gate array (FPGA).

[0427] 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.

[0428] One or more of the functional blocks and / or one or more combinations of functional blocks described in FIG20 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 suitable 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 FIG20 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.

[0429] 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.

[0430] According to various implementations disclosed in the examples of this application, the following notes are also disclosed:

[0431] Note 1:

[0432] 1. An information transmission device, comprising:

[0433] The first sending unit is used for the network device CU of the candidate cell to send a first F1 message including information for obtaining uplink synchronization on the candidate cell to the first network device DU.

[0434] 2. The device according to Note 1, wherein:

[0435] The information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a timing advance (TA) value.

[0436] 3. The device according to Note 2, wherein:

[0437] The random access configuration includes at least one of the following information:

[0438] Random access time and frequency resource information;

[0439] Random access preamble information; and

[0440] Downlink reference signal (DL RS) information.

[0441] 4. The device according to Note 2 or 3, wherein the device further comprises at least one of the following units:

[0442] a second sending unit, configured to send, by the network device CU, a message indicating one or more candidate cells to a second network device DU, to request the random access configuration of the indicated candidate cells;

[0443] a first receiving unit, configured for the network device CU to receive the random access configuration of the candidate cell from a second network device DU; and

[0444] The second receiving unit is configured to receive, by the network device CU, a response message to the first F1 message from the first network device DU.

[0445] 5. The device according to any one of Notes 2 to 4, further comprising at least one of the following units:

[0446] a third receiving unit, configured for the network device CU to receive a request message for random access configuration of the candidate cell from the first network device DU; or

[0447] The first decision unit is configured to enable the network device CU to decide to initiate random access configuration.

[0448] 6. The device according to any one of Notes 2 to 4, wherein:

[0449] The random access configuration includes a random access configuration, or,

[0450] The random access configuration includes multiple random access configurations and corresponding candidate cell information.

[0451] 7. The apparatus according to Note 2, wherein the information used to obtain uplink synchronization on the candidate cell includes candidate cell information, including:

[0452] The candidate cell information is used by the terminal device to determine the random access configuration of the candidate cell.

[0453] 8. The device according to Note 2, wherein:

[0454] The timing advance value is an absolute timing advance value or a variation of the absolute timing advance value.

[0455] 9. The device according to Note 2 or 8, wherein:

[0456] The time advance value is used by the terminal device to determine the uplink advance.

[0457] 10. The device according to Note 9, wherein:

[0458] The time advance value is used by the terminal device to determine the uplink advance according to the absolute time advance value, or,

[0459] The time advance value is used by the terminal device to determine the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0460] 11. The device according to any one of Notes 2, 8-10, wherein:

[0461] The candidate cell is a cell with downlink; and / or,

[0462] The candidate cell is a timing reference of the candidate cell and / or candidate cells in the same TA group.

[0463] 12. The device according to any one of Notes 2, 8-11, wherein:

[0464] The downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be used as a special cell.

[0465] 13. The device according to any one of Notes 2, 8-12, wherein:

[0466] The configuration of the timing reference is sent via RRC message, MAC signaling or DCI.

[0467] 14. The device according to any one of Notes 2, 8-13, further comprising:

[0468] The fourth receiving unit is configured to receive, by the network device CU, the timing advance value of the candidate cell from the second network device DU.

[0469] 15. The device according to any one of Notes 2, 8-14, wherein:

[0470] The timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0471] 16. An information transmission device, comprising:

[0472] a fifth receiving unit, configured for the first network device DU to receive, from the network device CU of the candidate cell, a first F1 message including information for obtaining uplink synchronization on the candidate cell; and

[0473] The first network device DU sends DCI to the terminal device.

[0474] 17. The device according to Note 16, wherein:

[0475] The information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a timing advance (TA) value.

[0476] 18. The device according to Note 17, wherein the device further comprises at least one of the following units:

[0477] a second decision unit, configured for the first network device DU to decide to initiate random access configuration;

[0478] a third sending unit, configured for the first network device DU to send a request message for random access configuration of the candidate cell to the network device CU; and

[0479] A fourth sending unit is configured to send, by the first network device DU, a response message to the first F1 message to the network device CU.

[0480] 19. The device according to any one of Notes 16 to 18, wherein:

[0481] The DCI includes the random access configuration of the candidate cell and / or information of the candidate cell.

[0482] 20. The device according to Note 19, wherein:

[0483] The DCI triggers the terminal device to initiate a random access process on the candidate cell.

[0484] 21. The apparatus according to Note 19, wherein the DCI includes information about the candidate cell, including:

[0485] The information of the candidate cell is used by the terminal device to determine the random access configuration of the candidate cell.

[0486] 22. The device according to Note 17, wherein:

[0487] The timing advance value is an absolute timing advance value or a variation of the absolute timing advance value.

[0488] 23. The device according to Note 17 or 22, wherein:

[0489] The time advance value is used by the terminal device to determine the uplink advance.

[0490] 24. The device according to Note 23, wherein:

[0491] The time advance value is used by the terminal device to determine the uplink advance according to the absolute time advance value, or,

[0492] The time advance value is used by the terminal device to determine the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0493] 25. The device according to any one of Notes 17, 22-24, wherein:

[0494] The candidate cell is a cell with downlink; and / or,

[0495] The candidate cell is a timing reference of the candidate cell and / or candidate cells in the same TA group.

[0496] 26. The device according to any one of Notes 17, 22-25, wherein:

[0497] The downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be used as a special cell.

[0498] 27. The device according to any one of Notes 17, 22-26, wherein:

[0499] The configuration of the timing reference is sent via RRC message, MAC signaling or DCI.

[0500] 28. The device according to any one of Notes 16, 17, 22-27, further comprising:

[0501] The fifth sending unit is used for the first network device DU to send the timing advance value of the candidate cell to the terminal device through a random access response (RAR) or a cell switching command.

[0502] 29. The device according to any one of Notes 16, 17, 22-28, wherein:

[0503] The timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0504] 30. An information transmission device, the device being provided in a terminal device, the device comprising:

[0505] A sixth receiving unit is configured to receive DCI from the first network device DU, where the DCI includes a random access configuration of a candidate cell and / or information about the candidate cell.

[0506] 31. The device according to Note 30, further comprising:

[0507] A first initiating unit is configured to initiate a random access process on the candidate cell according to the candidate cell information and the random access configuration of the candidate cell, so as to obtain a timing advance (TA) value of the candidate cell.

[0508] 32. The device according to Note 30, further comprising:

[0509] A first determining unit is configured to determine a random access configuration of the candidate cell according to the information of the candidate cell.

[0510] 33. The apparatus according to note 32, wherein the random access configuration determined by the first determining unit according to the candidate cell information comprises at least one of the following:

[0511] Random access configuration included in the candidate cell configuration;

[0512] The random access configuration for obtaining timing advance included in the candidate cell configuration;

[0513] The first random access configuration included in the candidate cell configuration;

[0514] The first random access configuration for acquiring timing advance included in the candidate cell configuration;

[0515] The random access configuration included in the candidate cell configuration, and the L1 measurement result of the downlink reference signal corresponding to the random access configuration is better than the configured threshold; and

[0516] The candidate cell configuration includes the next available random access after receiving DCI.

[0517] 34. The device according to Note 31, wherein:

[0518] The timing advance value is an absolute timing advance value or a variation of the absolute timing advance value.

[0519] 35. The device according to Note 31 or 34, wherein the device further comprises:

[0520] A second determining unit is configured to determine an uplink advance according to the timing advance value.

[0521] 36. The apparatus according to note 35, wherein the second determining unit determines the uplink advance according to the timing advance value, comprising:

[0522] The second determining unit determines the uplink advance according to the absolute time advance value, or,

[0523] The second determining unit determines the uplink advance according to the absolute time advance value and a variable of the absolute time advance value.

[0524] 37. The device according to any one of Notes 31, 34-36, wherein:

[0525] The candidate cell is a cell with downlink; and / or,

[0526] The candidate cell is a timing reference of the candidate cell and / or candidate cells in the same TA group.

[0527] 38. The device according to any one of Notes 31, 34-37, wherein:

[0528] The downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be used as a special cell.

[0529] 39. The device according to any one of Notes 31, 34-38, wherein:

[0530] The configuration of the timing reference is sent via RRC message, MAC signaling or DCI.

[0531] 40. The apparatus according to any one of Notes 31, 34-39, further comprising:

[0532] A seventh receiving unit is configured to receive a random access response (RAR) or a cell switching command from the first network device DU, where the random access response or the cell switching command includes a timing advance value of the candidate cell.

[0533] 41. The device according to any one of Notes 31, 34-40, wherein:

[0534] The timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0535] 42. A network device, comprising the apparatus described in any one of Notes 1-29.

[0536] 43. A terminal device, comprising the apparatus described in any one of Notes 30-41.

[0537] 44. A communication system, comprising the network device described in Note 42 and / or the terminal device described in Note 43.

[0538] Note 2:

[0539] 1. A method for transmitting information, comprising:

[0540] The network device CU of the candidate cell sends a first F1 message including information for obtaining uplink synchronization on the candidate cell to the first network device DU.

[0541] 2. The method according to Note 1, wherein:

[0542] The information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a timing advance (TA) value.

[0543] 3. The method according to Note 2, wherein:

[0544] The random access configuration includes at least one of the following information:

[0545] Random access time and frequency resource information;

[0546] Random access preamble information; and

[0547] Downlink reference signal (DL RS) information.

[0548] 4. The method according to Note 2 or 3, wherein the method further comprises at least one of the following steps:

[0549] The network device CU sends a message indicating one or more candidate cells to the second network device DU to request the random access configuration of the indicated candidate cells;

[0550] The network device CU receives the random access configuration of the candidate cell from the second network device DU; and

[0551] The network device CU receives a response message to the first F1 message from the first network device DU.

[0552] 5. The method according to any one of Notes 2 to 4, wherein the method further comprises at least one of the following steps:

[0553] The network device CU receives a request message for random access configuration of the candidate cell from the first network device DU; or,

[0554] The network device CU decides to initiate random access configuration.

[0555] 6. The method according to any one of Notes 2 to 4, wherein:

[0556] The random access configuration includes a random access configuration, or,

[0557] The random access configuration includes multiple random access configurations and corresponding candidate cell information.

[0558] 7. The method according to Note 2, wherein the information used to obtain uplink synchronization on the candidate cell includes candidate cell information, including:

[0559] The candidate cell information is used by the terminal device to determine the random access configuration of the candidate cell.

[0560] 8. The method according to Note 2, wherein:

[0561] The timing advance value is an absolute timing advance value or a variation of the absolute timing advance value.

[0562] 9. The method according to Note 2 or 8, wherein:

[0563] The time advance value is used by the terminal device to determine the uplink advance.

[0564] 10. The method according to Note 9, wherein:

[0565] The time advance value is used by the terminal device to determine the uplink advance according to the absolute time advance value, or,

[0566] The time advance value is used by the terminal device to determine the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0567] 11. The method according to any one of Notes 2, 8-10, wherein:

[0568] The candidate cell is a cell with downlink; and / or,

[0569] The candidate cell is a timing reference of the candidate cell and / or candidate cells in the same TA group.

[0570] 12. The method according to any one of Notes 2, 8-11, wherein:

[0571] The downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be used as a special cell.

[0572] 13. The method according to any one of Notes 2, 8-12, wherein:

[0573] The configuration of the timing reference is sent via RRC message, MAC signaling or DCI.

[0574] 14. The method according to any one of Notes 2, 8-13, wherein the method further comprises:

[0575] The network device CU receives the timing advance value of the candidate cell from the first network device DU.

[0576] 15. The method according to any one of Notes 2, 8-14, wherein:

[0577] The timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0578] 16. A method for transmitting information, the method comprising:

[0579] The first network device DU receives a first F1 message including information for obtaining uplink synchronization on the candidate cell from the network device CU of the candidate cell; and

[0580] The first network device DU sends DCI to the terminal device.

[0581] 17. The method according to Note 16, wherein:

[0582] The information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a timing advance (TA) value.

[0583] 18. The method according to Note 17, wherein the method further comprises at least one of the following steps:

[0584] The first network device DU decides to initiate random access configuration;

[0585] The first network device DU sends a request message for random access configuration of the candidate cell to the network device CU; and

[0586] The first network device DU sends a response message to the first F1 message to the network device CU.

[0587] 19. The method according to any one of Notes 16 to 18, wherein:

[0588] The DCI includes the random access configuration of the candidate cell and / or information of the candidate cell.

[0589] 20. The method according to Note 19, wherein:

[0590] The DCI triggers the terminal device to initiate a random access process on the candidate cell.

[0591] 21. The method according to Note 19, wherein the DCI includes information about the candidate cell, including:

[0592] The information of the candidate cell is used by the terminal device to determine the random access configuration of the candidate cell.

[0593] 22. The method according to Note 17, wherein:

[0594] The timing advance value is an absolute timing advance value or a variation of the absolute timing advance value.

[0595] 23. The method according to Note 17 or 22, wherein:

[0596] The time advance value is used by the terminal device to determine the uplink advance.

[0597] 24. The method according to Note 23, wherein:

[0598] The time advance value is used by the terminal device to determine the uplink advance according to the absolute time advance value, or,

[0599] The time advance value is used by the terminal device to determine the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0600] 25. The method according to any one of Notes 17, 22-24, wherein:

[0601] The candidate cell is a cell with downlink; and / or,

[0602] The candidate cell is a timing reference of the candidate cell and / or candidate cells in the same TA group.

[0603] 26. The method according to any one of Notes 17, 22-25, wherein:

[0604] The downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be used as a special cell.

[0605] 27. The method according to any one of Notes 17, 22-26, wherein:

[0606] The configuration of the timing reference is sent via RRC message, MAC signaling or DCI.

[0607] 28. The method according to any one of Notes 16, 17, 22-27, further comprising:

[0608] The first network device DU sends the timing advance value of the candidate cell to the terminal device through a random access response (RAR) or a cell switching command.

[0609] 29. The method according to any one of Notes 16, 17, 22-28, wherein:

[0610] The timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

[0611] 30. A method for transmitting information, the method comprising:

[0612] The terminal device receives DCI from the first network device DU, where the DCI includes a random access configuration of a candidate cell and / or information of the candidate cell.

[0613] 31. The method according to Note 30, further comprising:

[0614] The terminal device initiates a random access process on the candidate cell according to the candidate cell information and the random access configuration of the candidate cell to obtain a timing advance (TA) value of the candidate cell.

[0615] 32. The method according to Note 30, further comprising:

[0616] The terminal device determines the random access configuration of the candidate cell according to the information of the candidate cell.

[0617] 33. The method according to note 32, wherein the random access configuration determined by the terminal device according to the candidate cell information includes at least one of the following:

[0618] Random access configuration included in the candidate cell configuration;

[0619] The random access configuration for obtaining timing advance included in the candidate cell configuration;

[0620] The first random access configuration included in the candidate cell configuration;

[0621] The first random access configuration for acquiring timing advance included in the candidate cell configuration;

[0622] The random access configuration included in the candidate cell configuration, and the L1 measurement result of the downlink reference signal corresponding to the random access configuration is better than the configured threshold; and

[0623] The candidate cell configuration includes the next available random access after receiving DCI.

[0624] 34. The method according to Note 31, wherein:

[0625] The timing advance value is an absolute timing advance value or a variation of the absolute timing advance value.

[0626] 35. The method according to Note 31 or 34, wherein the method further comprises:

[0627] The terminal device determines the uplink advance according to the time advance value.

[0628] 36. The method according to note 35, wherein the terminal device determines the uplink advance according to the timing advance value, comprising:

[0629] The terminal device determines the uplink advance according to the absolute time advance value, or,

[0630] The terminal device determines the uplink advance based on the absolute time advance value and a variable of the absolute time advance value.

[0631] 37. The method according to any one of Notes 31, 34-36, wherein:

[0632] The candidate cell is a cell with downlink; and / or,

[0633] The candidate cell is a timing reference of the candidate cell and / or candidate cells in the same TA group.

[0634] 38. The method according to any one of Notes 31, 34-37, wherein:

[0635] The downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be used as a special cell.

[0636] 39. The method according to any one of Notes 31, 34-38, wherein:

[0637] The configuration of the timing reference is sent via RRC message, MAC signaling or DCI.

[0638] 40. The method according to any one of Notes 31, 34-39, wherein the method further comprises:

[0639] The terminal device receives a random access response (RAR) or a cell switching command from the first network device DU, where the random access response or the cell switching command includes a timing advance value of the candidate cell.

[0640] 41. The method according to any one of Notes 31, 34-40, wherein:

[0641] The timing advance value of the candidate cell includes the timing advance value of one or more candidate cells.

Claims

1. An information transmission device, comprising: The first sending unit is used for the network device CU of the candidate cell to send a first F1 message including information for obtaining uplink synchronization on the candidate cell to the first network device DU.

2. The device according to claim 1, wherein: The information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a time advance (TA) value.

3. The device according to claim 2, wherein: The device further comprises at least one of the following units: A second sending unit, configured for the network device CU to send a message indicating one or more candidate cells to the second network device DU to request the random access configuration of the indicated candidate cells; A first receiving unit, configured for the network device CU to receive the random access configuration of the candidate cell from the second network device DU; as well as The second receiving unit is configured to receive, by the network device CU, a response message to the first F1 message from the first network device DU.

4. The device according to claim 2, wherein: The device further comprises at least one of the following units: A third receiving unit is configured for the network device CU to receive a request message for random access configuration of the candidate cell from the first network device DU; or, A first decision unit is used for the network device CU to decide to initiate a random access configuration.

5. The device according to claim 2, wherein: The time advance value is an absolute time advance value or a variation of the absolute time advance value.

6. An information transmission device, comprising: A fifth receiving unit, configured for the first network device DU to receive, from the network device CU of the candidate cell, a first F1 message including information for obtaining uplink synchronization on the candidate cell; as well as A third sending unit is used for the first network device DU to send DCI to a terminal device.

7. The device according to claim 6, wherein: The information used to obtain uplink synchronization on the candidate cell includes at least one of a random access configuration of the candidate cell, information of the candidate cell, and a time advance (TA) value.

8. The device according to claim 7, wherein: The device further comprises at least one of the following units: A second decision unit, which is used for the first network device DU to decide to initiate a random access configuration; A fourth sending unit, configured for the first network device DU to send a request message for random access configuration of the candidate cell to the network device CU; as well as A fifth sending unit is configured to enable the first network device DU to send a response message of the first F1 message to the network device CU.

9. The device according to claim 6, wherein: The DCI includes the random access configuration of the candidate cell and / or the information of the candidate cell.

10. The device according to claim 9, wherein: The DCI triggers the terminal device to initiate a random access process on the candidate cell.

11. The device according to claim 7, wherein: The time advance value is an absolute time advance value or a variation of the absolute time advance value.

12. The device according to claim 6, further comprising: The sixth sending unit is used for the first network device DU to send the time advance value of the candidate cell to the terminal device through a random access response (RAR) or a cell switching command.

13. An information transmission device, the device being arranged in a terminal device, the device comprising: A sixth receiving unit is configured to receive DCI from the first network device DU, where the DCI includes a random access configuration of a candidate cell and / or information of the candidate cell.

14. The device according to claim 13, wherein: The device also includes: The first initiating unit is configured to initiate a random access process on the candidate cell according to the candidate cell information and the random access configuration of the candidate cell, so as to obtain a timing advance (TA) value of the candidate cell.

15. The device according to claim 13, wherein: The device also includes: A first determining unit is configured to determine a random access configuration of the candidate cell according to the information of the candidate cell.

16. The device according to claim 15, wherein: The random access configuration determined by the first determining unit according to the candidate cell information includes at least one of the following: The random access configuration included in the candidate cell configuration; The random access configuration for obtaining the timing advance included in the candidate cell configuration; The first random access configuration included in the candidate cell configuration; The first random access configuration for acquiring timing advance included in the candidate cell configuration; A random access configuration included in the candidate cell configuration, and an L1 measurement result of a downlink reference signal corresponding to the random access configuration is better than a configured threshold; and The candidate cell configuration includes the next available random access after receiving the DCI.

17. The device according to claim 14, wherein: The device also includes: A second determining unit is configured to determine an uplink advance according to the time advance value.

18. The device according to claim 17, wherein: The second determining unit determines the uplink advance according to the time advance value, including: The second determining unit determines the uplink advance according to the absolute time advance value, or, The second determining unit determines the uplink advance according to the absolute time advance value and a variable of the absolute time advance value.

19. The device according to claim 14, wherein: The candidate cell is a cell with downlink; and / or, The candidate cell is a timing reference of the candidate cell and / or candidate cells in the same TA group.

20. The device according to claim 14, wherein: The downlink timing reference is the candidate cell or the source cell or another candidate cell in the same TA group or a candidate cell in the same TA group that can be used as a special cell.

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