A method and device for transmitting system information

Abstract

An embodiment of the present application provides a method for transmitting system information. The method includes: a terminal device sends a first request to a radio access network RAN ​​device, the first request is used for the terminal device to establish a radio resource control RRC connection with a first cell controlled by the RAN device; wherein the first request includes first information, and the first information is used to indicate at least one of the following: the terminal device expects to access a second cell, the second cell the terminal device expects to access, and at least a partial identification of the terminal device. The terminal device receives a first response from the RAN device, wherein the first response includes a cell identification of each second cell in one or more second cells and partial system information. Using this method, the terminal device can effectively be enabled to access the second cell.

Description

Technical Field

[0001] The present invention relates to the field of wireless communications, and in particular to a method and device for transmitting system information. Background Art

[0002] With the rapid development of wireless communication technology, the fifth generation (5G) wireless communication technology has become a hot topic in the industry. 5G will support a variety of application requirements, including access capabilities that support higher speed experience and larger bandwidth, lower latency and highly reliable information interaction, and access and management of larger-scale and low-cost machine-type communication devices. Supporting the ubiquitous needs of various vertical industries and ensuring energy saving are key factors for the application of 5G.

[0003] When a terminal device accesses a mobile network, it searches for and accesses a cell on a carrier frequency within a certain frequency range, which can also be called a carrier. The terminal device uses resources within a certain bandwidth range corresponding to the carrier to communicate data with the mobile network, and the bandwidth range can include multiple subcarriers. Usually, a cell sends public broadcast signaling, such as synchronization signals and system information, on some subcarriers corresponding to its carrier, so that the terminal device can access the cell. The terminal device synchronizes with the cell through the synchronization signal, and accesses the cell by reading the system information to obtain the necessary information for accessing the cell. For some cells, due to the need for energy saving, some public broadcast signaling may not be sent or even no public broadcast signaling may be sent. For example, some system information may be sent, or system information may not be sent at all, or synchronization signals may not be sent further, so as to reduce the power consumption and transmission time of the transmitter. For these cells, there is currently no appropriate solution for how to enable terminal devices to access. Summary of the invention

[0004] An embodiment of the present application provides a method for transmitting system information, which effectively enables terminal equipment to access an energy-saving cell.

[0005] The present application is introduced from multiple aspects below. It is easy to understand that the implementation methods of the following multiple aspects can refer to each other.

[0006] In a first aspect, the present application provides a method for transmitting system information, including: a terminal device sends a first request to a wireless access network RAN ​​device, the first request including first information, the first information being used to indicate at least one of the following: the terminal device expects to access a second cell, the second cell the terminal device expects to access, and at least a partial identification of the terminal device, the first request being used for the terminal device to establish a radio resource control RRC connection with the first cell controlled by the RAN device; the terminal device receives a first response to the first request from the RAN device, the first response including a cell identification of each second cell in one or more second cells and partial system information SI.

[0007] It can be seen that the method provided in the embodiment of the present application enables the terminal device to obtain partial SI of the second cell when accessing the RAN, thereby enabling the terminal device to access the second cell.

[0008] In a possible implementation, before the terminal device sends a first request to a radio access network RAN ​​device, the method further includes: the terminal device sends a random access preamble to the RAN device; and the terminal device receives a random access response from the RAN device.

[0009] Through this step, the terminal device can obtain part of the SI of the second cell when randomly accessing the first cell.

[0010] In a possible implementation, when the first information is used to indicate a second cell that the terminal device expects to access, the first information includes identifiers of one or more second cells.

[0011] In this way, when the terminal device accesses the first cell, it informs the second cell it wishes to access, so that the first cell can send partial SI of the specific second cell desired by the terminal device to the terminal device, thereby improving the efficiency of information transmission.

[0012] In a possible implementation, when the first information is used to indicate at least a partial identification of the terminal device, the first information includes at least a partial identification of a temporary terminal device identification provided by the 5G core network for the terminal device.

[0013] In this way, the terminal device only needs to carry at least a partial identifier of the terminal device in the RRC request, thereby saving air interface signaling overhead.

[0014] In a possible implementation, the first cell sends the system information required for the terminal device to initially access the first cell, and the second cell partially sends or does not send the system information required for the terminal device to initially access the second cell.

[0015] In one possible implementation, the first information is used to at least partially identify the terminal device, including: the first information contains at least part of the temporary terminal device identification provided by the fifth generation 5G core network for the terminal device.

[0016] In a possible implementation manner, the partial system information of the second cell includes remaining minimum system information RMSI of the second cell.

[0017] In a possible implementation manner, the partial system information of the second cell includes the RMSI and other system information OSI of the second cell.

[0018] In a possible implementation manner, the first request is an RRC connection request message or an RRC establishment request message.

[0019] In a possible implementation manner, the first response is an RRC reject message or an RRC connection reject message.

[0020] In one possible implementation, the first cell and / or the second cell is a new wireless NR cell (or a cell controlled by a gNB).

[0021] In one possible implementation, the first cell and / or the second cell is an LTE cell (or a cell controlled by a gNB).

[0022] In one possible implementation, the first cell and / or the second cell is an eLTE cell (or a cell controlled by an ng-eNB).

[0023] In one possible implementation, the terminal device sends a first request to a wireless access network RAN ​​device, including the terminal device sending the first request to a centralized unit CU of the RAN device through a distributed unit DU of the RAN device; the terminal device receives a first response to the first request from the RAN device, including the terminal device receiving the first response sent from the CU through the DU; and the DU is connected to the CU.

[0024] In a second aspect, the present application provides a method for transmitting system information, including: a wireless access network RAN ​​device receives a first request from a terminal device, the first request includes first information, and the first information is used to indicate at least one of the following: the terminal device expects to access a second cell, the second cell that the terminal device expects to access, and at least a partial identification of the terminal device, and the first request is used for the terminal device to establish a radio resource control RRC connection with the first cell controlled by the RAN device; the RAN device sends a first response to the first request to the terminal device, and the first response includes a cell identification of each second cell in one or more second cells and partial system information.

[0025] It can be seen that the method provided in the embodiment of the present application enables the terminal device to obtain partial SI of the second cell when accessing the RAN, thereby enabling the terminal device to access the second cell.

[0026] In a possible implementation, before the RAN device receives the first request from the terminal device, the method further includes: the RAN device receiving a random access preamble from the terminal device; and the RAN device sending a random access response to the terminal device.

[0027] Through this step, the terminal device can obtain part of the SI of the second cell when initially accessing the first cell.

[0028] In a possible implementation, when the first information is used to indicate a second cell that the terminal device expects to access, the first information includes identifiers of one or more second cells.

[0029] Through this step, the terminal device informs the second cell it wishes to access when accessing the first cell, so that the first cell can send partial SI of the specific second cell desired by the terminal device to the terminal device, thereby improving the efficiency of information transmission.

[0030] In a possible implementation, when the first information is used to indicate at least a partial identification of the terminal device, the first information includes at least a partial identification of a temporary terminal device identification provided by the 5G core network for the terminal device.

[0031] In this way, the terminal device only needs to carry at least a partial identifier of the terminal device in the RRC request, thereby saving air interface signaling overhead.

[0032] In a possible implementation manner, before the radio access network RAN ​​device receives the first request from the terminal device, the method further includes: the RAN device acquiring a cell identifier and part of the system information of each second cell in the one or more second cells.

[0033] In a possible implementation, the first cell sends the system information required for the terminal device to initially access the first cell, and the second cell partially sends or does not send the system information required for the terminal device to initially access the second cell.

[0034] In one possible implementation, the first information is used to at least partially identify the terminal device, including: the first information contains at least part of the temporary terminal device identification provided by the fifth generation 5G core network for the terminal device.

[0035] In a possible implementation manner, the partial system information of the second cell includes remaining minimum system information RMSI of the second cell.

[0036] In a possible implementation manner, the partial system information of the second cell includes the RMSI and other system information OSI of the second cell.

[0037] In a possible implementation manner, the first request is an RRC connection request message or an RRC establishment request message.

[0038] In a possible implementation manner, the first response is an RRC reject message or an RRC connection reject message.

[0039] In one possible implementation, the first cell and / or the second cell is a new wireless NR cell (or a cell controlled by a gNB).

[0040] In one possible implementation, the first cell and / or the second cell is an LTE cell (or a cell controlled by a gNB).

[0041] In one possible implementation, the first cell and / or the second cell is an eLTE cell (or a cell controlled by an ng-eNB).

[0042] In one possible implementation, the radio access network RAN ​​device receives a first request from a terminal device, including the centralized unit CU of the RAN device receiving the first request from the terminal device through the distributed unit DU; the RAN device sends a first response to the first request to the terminal device, including the CU sending the first response to the terminal device through the DU; the DU is connected to the CU.

[0043] In a third aspect, the present application provides a method for transmitting system information, including: a terminal device sends a radio resource control RRC re-establishment request to a radio access network RAN ​​device, the RRC re-establishment request includes first information, and the first information is used to indicate at least one of the following: the terminal device expects to access a second cell, the second cell that the terminal device expects to access, and the first request is used for the terminal device to perform RRC re-establishment with the first cell controlled by the RAN device; the terminal device receives an RRC re-establishment response message from the RAN device, and the RRC re-establishment response message includes a cell identifier of each second cell in one or more second cells and part of the system information SI.

[0044] It can be seen that the method provided in the embodiment of the present application enables a terminal device in an RRC connected state to actively request to obtain partial SI of a DCC cell, thereby enabling the terminal device to access the DCC cell.

[0045] In a possible implementation, when the first information is used to indicate a second cell that the terminal device expects to access, the first information includes identifiers of one or more second cells.

[0046] In this way, the terminal device informs the second cell it wishes to access when re-establishing RRC, so that the first cell can send partial SI of the specific second cell desired by the terminal device to the terminal device, thereby improving the efficiency of information transmission.

[0047] In a possible implementation, the first cell sends the system information required for the terminal device to initially access the first cell, and the second cell partially sends or does not send the system information required for the terminal device to initially access the second cell.

[0048] In one possible implementation, the first cell and / or the second cell is a new wireless NR cell (or a cell controlled by a gNB).

[0049] In one possible implementation, the first cell and / or the second cell is an LTE cell (or a cell controlled by a gNB).

[0050] In one possible implementation, the first cell and / or the second cell is an eLTE cell (or a cell controlled by an ng-eNB).

[0051] In one possible implementation, the terminal device sends an RRC re-establishment request to a wireless access network RAN ​​device, including the terminal device sending the RRC re-establishment request to a centralized unit CU of the RAN device through a distributed unit DU of the RAN device; the terminal device receives an RRC re-establishment response message from the RAN device, including the terminal device receiving the RRC re-establishment response message sent from the CU through the DU; and the DU is connected to the CU.

[0052] In a fourth aspect, the present application provides a method for transmitting system information, including: a radio access network RAN ​​device receives a radio resource control RRC re-establishment request from a terminal device, the RRC re-establishment request includes first information, and the first information is used to indicate at least one of the following: the terminal device expects to access a second cell, the second cell that the terminal device expects to access, and the first request is used for the terminal device to perform RRC re-establishment with the first cell controlled by the RAN device; the RAN device sends an RRC re-establishment response message to the terminal device, and the RRC re-establishment response message includes a cell identifier of each second cell in one or more second cells and part of the system information SI.

[0053] It can be seen that the method provided in the embodiment of the present application enables a terminal device in an RRC connected state to actively request to obtain partial SI of a DCC cell, thereby enabling the terminal device to access the DCC cell.

[0054] In a possible implementation, when the first information is used to indicate a second cell that the terminal device expects to access, the first information includes identifiers of one or more second cells.

[0055] In this way, the terminal device informs the second cell it wishes to access when re-establishing RRC, so that the first cell can send partial SI of the specific second cell desired by the terminal device to the terminal device, thereby improving the efficiency of information transmission.

[0056] In a possible implementation, the first cell sends the system information required for the terminal device to initially access the first cell, and the second cell partially sends or does not send the system information required for the terminal device to initially access the second cell.

[0057] In one possible implementation, the first cell and / or the second cell is a new wireless NR cell (or a cell controlled by a gNB).

[0058] In one possible implementation, the first cell and / or the second cell is an LTE cell (or a cell controlled by a gNB).

[0059] In one possible implementation, the first cell and / or the second cell is an eLTE cell (or a cell controlled by an ng-eNB).

[0060] In one possible implementation, the radio access network RAN ​​device receives an RRC re-establishment request from a terminal device, including a centralized unit CU of the RAN device receiving the RRC re-establishment request from the terminal device through a distributed unit DU; the RAN device sends an RRC re-establishment response message to the terminal device, including the CU sending the RRC re-establishment response message to the terminal device through the DU; and the DU is connected to the CU.

[0061] In a fifth aspect, the present application provides a method for transmitting system information, including: a terminal device receives a radio resource control RRC reconfiguration message sent by a radio access network RAN ​​device, the RRC reconfiguration message includes second information, the second information includes a cell identifier of each second cell in one or more second cells and part of the system information SI, and the terminal device establishes an RRC connection with a first cell controlled by the RAN device; the terminal device sends an RRC reconfiguration response message to the RAN device.

[0062] Through the above steps of the embodiment of the present application, the first cell actively sends the SI of the second cell to the terminal device in the RRC connection state, thereby enabling the terminal device to access the second cell.

[0063] In a possible implementation, the first cell sends the system information required for the terminal device to initially access the first cell, and the second cell partially sends or does not send the system information required for the terminal device to initially access the second cell.

[0064] In one possible implementation, the first cell and / or the second cell is a new wireless NR cell (or a cell controlled by a gNB).

[0065] In one possible implementation, the first cell and / or the second cell is an LTE cell (or a cell controlled by a gNB).

[0066] In one possible implementation, the first cell and / or the second cell is an eLTE cell (or a cell controlled by an ng-eNB).

[0067] In one possible implementation, the terminal device receives an RRC reconfiguration message from a RAN device, including the terminal device receiving the RRC reconfiguration message sent by a centralized unit CU of the RAN device to the terminal device through a distributed unit DU; the terminal device sends an RRC reconfiguration response message to the RAN device, including the terminal device sending the RRC reconfiguration response message to the CU through the DU; and the DU is connected to the CU.

[0068] In a sixth aspect, the present application provides a method for transmitting system information, including: a wireless access network RAN ​​device sends a radio resource control RRC reconfiguration message to a terminal device, the RRC reconfiguration message including second information, the second information including a cell identifier of each second cell in one or more second cells and part of the system information SI, and the terminal device establishes an RRC connection with a first cell controlled by the RAN device; the RAN device receives an RRC reconfiguration response message from the terminal device.

[0069] Through the above steps of the embodiment of the present application, the first cell actively sends the SI of the second cell to the terminal device in the RRC connection state, thereby enabling the terminal device to access the second cell.

[0070] In a possible implementation, the first cell sends the system information required for the terminal device to initially access the first cell, and the second cell partially sends or does not send the system information required for the terminal device to initially access the second cell.

[0071] In one possible implementation, the first cell and / or the second cell is a new wireless NR cell (or a cell controlled by a gNB).

[0072] In one possible implementation, the first cell and / or the second cell is an LTE cell (or a cell controlled by a gNB).

[0073] In one possible implementation, the first cell and / or the second cell is an eLTE cell (or a cell controlled by an ng-eNB).

[0074] In one possible implementation, the RAN device sends an RRC reconfiguration message to the terminal device, including the RRC reconfiguration message sent by the centralized unit CU of the RAN device to the terminal device through the distributed unit DU; the RAN device receives an RRC reconfiguration response message from the terminal device, including the CU receiving the RRC reconfiguration response message from the terminal device through the DU; the DU is connected to the CU.

[0075] In a seventh aspect, the present application provides a method for transmitting system information, including: a first wireless access network RAN ​​device sends second information to a second RAN device, the second information being used to indicate a cell identifier and partial system information SI of each second cell in one or more second cells controlled by the first RAN device; the first RAN device receives a response to the second information from the second RAN device; the second RAN device controls one or more first cells; the first cell sends the system information required for the terminal device to initially access the first cell, and the second cell partially sends or does not send the system information required for the terminal device to initially access the second cell.

[0076] Through the above steps of the embodiment of the present application, the first cell can obtain partial SI of the second cell, enabling the first cell to send partial SI of the second cell to the terminal device.

[0077] In a possible implementation manner, the first RAN device sends third information to the second RAN device, where the third information is used to indicate that one or more cells controlled by the first RAN device are second cells.

[0078] In a possible implementation manner, the first RAN device receives a response to the third information from the second RAN device.

[0079] In this way, the first cell can know which second cells are around it, and provide auxiliary information for the first cell to send partial SI of the second cell to the terminal device.

[0080] In a possible implementation manner, the third information includes information used to indicate what type of second cell the second cell is.

[0081] In this way, the first cell can know what type of second cell the second cell is, and further provide auxiliary information for the first cell to send partial SI of the second cell to the terminal device.

[0082] In one possible implementation, the first cell and / or the second cell is a new wireless NR cell (or a cell controlled by a gNB).

[0083] In one possible implementation, the first cell and / or the second cell is an LTE cell (or a cell controlled by a gNB).

[0084] In one possible implementation, the first cell and / or the second cell is an eLTE cell (or a cell controlled by an ng-eNB).

[0085] In a possible implementation manner, the centralized unit CU of the first RAN device sends the second information to the second RAN device; and the CU of the first RAN device receives a response to the second information from the second RAN device.

[0086] In an eighth aspect, the present application provides a method for transmitting system information, including: a second radio access network RAN ​​device receives second information from a first RAN device, the second information being used to indicate a cell identifier and partial system information SI of each second cell in one or more second cells controlled by the first RAN device; the second RAN device sends a response to the second information to the first RAN device; the second RAN device controls one or more first cells; the first cell sends the system information required for the terminal device to initially access the first cell, and the second cell partially sends or does not send the system information required for the terminal device to initially access the second cell.

[0087] Through the above steps of the embodiment of the present application, the first cell can obtain partial SI of the second cell, enabling the first cell to send partial SI of the second cell to the terminal device.

[0088] In a possible implementation manner, the second RAN device receives third information from the first RAN device, where the third information is used to indicate that one or more cells controlled by the first RAN device are second cells.

[0089] In a possible implementation manner, the second RAN device sends a response of the third information to the first RAN device.

[0090] In this way, the first cell can know which second cells are around it, and provide auxiliary information for the first cell to send partial SI of the second cell to the terminal device.

[0091] In a possible implementation manner, the third information includes information used to indicate what type of second cell the second cell is.

[0092] In this way, the first cell can know what type of second cell the second cell is, and further provide auxiliary information for the first cell to send partial SI of the second cell to the terminal device.

[0093] In one possible implementation, the first cell and / or the second cell is a new wireless NR cell (or a cell controlled by a gNB).

[0094] In one possible implementation, the first cell and / or the second cell is an LTE cell (or a cell controlled by a gNB).

[0095] In one possible implementation, the first cell and / or the second cell is an eLTE cell (or a cell controlled by an ng-eNB).

[0096] In a possible implementation manner, the centralized unit DU of the second RAN device receives the second information from the second RAN device through the centralized unit CU to which the DU is connected; and the DU of the second RAN device sends a response to the second information to the second RAN device through the CU.

[0097] In the ninth aspect, a terminal device is provided for executing the method in the first aspect or any possible implementation of the first aspect, or the third aspect or any possible implementation of the third aspect, or the fifth aspect or any possible implementation of the fifth aspect. Specifically, the terminal device may include a unit for executing the method in the first aspect or any possible implementation of the first aspect, or the third aspect or any possible implementation of the third aspect, or the fifth aspect or any possible implementation of the fifth aspect.

[0098] In the tenth aspect, a radio access network RAN ​​device is provided for executing the method in the second aspect or any possible implementation of the second aspect, or the fourth aspect or any possible implementation of the fourth aspect, or the sixth aspect or any possible implementation of the sixth aspect, or the seventh aspect or any possible implementation of the seventh aspect, or the eighth aspect or any possible implementation of the eighth aspect. Specifically, the RAN device may include a unit for executing the method in the second aspect or any possible implementation of the second aspect, or the fourth aspect or any possible implementation of the fourth aspect, or the sixth aspect or any possible implementation of the sixth aspect, or the seventh aspect or any possible implementation of the seventh aspect, or the eighth aspect or any possible implementation of the eighth aspect.

[0099] In the eleventh aspect, a computer program product is provided, which includes: a computer program code, when the computer program code is executed by a communication unit, a processing unit or a transceiver, or a processor of a communication device (for example, an access network device or a terminal device), the communication device executes the method in the first to eighth aspects or any possible implementation of the first to eighth aspects.

[0100] In a twelfth aspect, a computer-readable storage medium is provided, which stores a program, and the program enables a computer to execute the method in the first to eighth aspects or any possible implementation of the first to eighth aspects.

[0101] In the ninth aspect, an embodiment of the present application provides a chip, which is coupled to a memory and executes the method of the first aspect or any possible design of the first aspect, the second aspect or any possible design of the second aspect, the third aspect or any possible design of the third aspect, the fourth aspect or any possible design of the fourth aspect, the fifth aspect or any possible design of the fifth aspect, the sixth aspect or any possible design of the sixth aspect, the seventh aspect or any possible design of the seventh aspect, or the eighth aspect or any possible design of the eighth aspect.

[0102] These and other aspects of the invention will become more apparent from the following description of the embodiment(s). BRIEF DESCRIPTION OF THE DRAWINGS

[0103] The following is a brief introduction to the drawings used in the embodiments of the present application or the description of the prior art:

[0104] Figure 1 is a schematic diagram of a wireless communication system provided in an embodiment of the present application;

[0105] Figure 2 This is a schematic diagram of the architecture of a gNB divided into a CU and a DU provided in an embodiment of the present application;

[0106] Figure 3 This is a schematic diagram of the difference in physical frame information transmission between a BCC cell and a DCC cell in an NR provided in an embodiment of the present application;

[0107] Figure 4 It is a flowchart of a method for a terminal device to randomly access a RAN device and establish an RRC connection provided by an embodiment of the present application;

[0108] Figure 5 It is a flowchart of another method for a terminal device to randomly access a RAN device and establish an RRC connection provided by an embodiment of the present application;

[0109] Figure 6It is a flowchart of a method provided by an embodiment of the present application in which a terminal device requests a RAN device to send partial SI of a DCC cell;

[0110] Figure 7 It is a flowchart of a method provided by an embodiment of the present application in which a RAN device actively sends partial SI of a DCC cell to a terminal device;

[0111] Figure 8 It is a flowchart of a method provided by an embodiment of the present application for a terminal device to request SI of a DCC cell from a RAN device;

[0112] Fig. 9 It is a flowchart of a method for information interaction between a first RAN device controlling a DCC cell and a second RAN device controlling a BCC cell provided by an embodiment of the present application;

[0113] Fig.10 is a schematic block diagram of a terminal device provided in an embodiment of the present application;

[0114] Fig.11 is another schematic block diagram of a terminal device provided in an embodiment of the present application;

[0115] Fig.12 is a schematic block diagram of a first network device provided in an embodiment of the present application;

[0116] Fig.13 is another schematic block diagram of a first network device provided in an embodiment of the present application;

[0117] Fig.14 is a schematic block diagram of a second network device provided in an embodiment of the present application;

[0118] Fig.15 It is another schematic block diagram of the second network device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0119] The embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0120] In this application, the word "exemplary" is used to mean "serving as an example, illustration, or illustration." Any embodiment described in this application as "exemplary" is not necessarily to be construed as being preferred or advantageous over other embodiments. The following description is given to enable any person skilled in the art to implement and use the invention. In the following description, details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the invention can be implemented without using these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in this application.

[0121] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0122] The terms "system" and "network" are often used interchangeably herein.

[0123] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0124] The technical solutions of the embodiments of the present application can be applied to various wireless communication systems, such as: Long Term Evolution (LTE) system, fifth generation (5G) mobile communication system, new radio (NR) communication system, next generation (NG) communication system and future mobile communication systems.

[0125] In a wireless communication system, a terminal device is connected to a radio access network (RAN) device through a wireless link, and communicates with other terminal devices or accesses the wireless Internet through the core network (CN) device connected to the RAN device. Usually, a terminal device is wirelessly connected to a RAN device to achieve communication. Furthermore, a terminal device can also be wirelessly connected to two or more RAN devices to achieve communication. Figure 1 A schematic diagram of a wireless communication system 100 provided in an embodiment of the present application is shown. Among them, the terminal device 120 is wirelessly connected to the RAN device 140 via the air interface 160. Optionally, the wireless communication system also includes the terminal device 120 being wirelessly connected to the RAN device 142 via the air interface 162. In one possible implementation, data transmission between the terminal device 120 and the core network 180 can be transmitted through the interface between the RAN device 140 and the core network 180, and data between the terminal device 120 and the RAN device 142 is transmitted to the core network 180 via the RAN device 140 through the interface between the RAN device 140 and the RAN device 142; in another possible implementation, data transmission between the terminal device 120 and the core network 180 can be transmitted through the interface between the RAN device 140 and the core network 180 and the interface between the RAN device 142 and the core network 180, respectively. It should be noted that Figure 1 The RAN device 140 and the RAN device 142 may be deployed at different geographical locations respectively; or they may be deployed at the same geographical location, that is, the RAN device 140 and the RAN device 142 are deployed at the same site.

[0126] In the actual system, Figure 1The RAN device shown may be a next-generation base station, such as a next-generation Node B (gNB) or a next-generation evolved Node B (ng-eNB), or an access point (AP) in a wireless local area network (WLAN), or an evolved Node B (eNB or eNodeB) in LTE, or a relay station or access point, or an in-vehicle device, a wearable device, and a transmission and reception point (TRP), etc. It should be understood that the terminal device communicates with the RAN device through the transmission resources (for example, frequency domain resources, time domain resources, code domain resources, etc.) used by one or more cells managed by the RAN device. The cell may belong to a macro cell, a hyper cell, or a small cell. The small cells here may include: metro cells, micro cells, pico cells, femto cells, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services. Figure 1The terminal device in the WLAN may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device may be a station (ST) in a WLAN, a cellular phone, a cordless phone, a SIP phone, a wireless local loop (WLL) station, a personal digital assistant (PDA) device, a handheld device with wireless communication function, a relay device, a computing device or other processing device coupled to a wireless modem, a vehicle-mounted device, a wearable device, and a next-generation communication system, for example, a terminal device in a 5G network or a terminal device in a future-evolved public land mobile network (PLMN) network. As an example and not a limitation, in an embodiment of the present application, the terminal device may also be a wearable device. Wearable devices may also be referred to as wearable smart devices, which are a general term for wearable devices that are intelligently designed and developed using wearable technology for daily wear, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothes or accessories. Wearable devices are not just hardware devices, but also realize powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those with full functions, large size, and can realize complete or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that only focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0127] Optionally, in a 5G system, a RAN device (such as a gNB) can be further divided into a central unit (CU) and a distributed unit (DU) according to the protocol stack, where the CU and DU can be deployed on different physical devices. The CU is responsible for the operation of the RRC layer, SDAP layer, and PDCP layer, and the DU is responsible for the operation of the RLC layer, MAC layer, and PHY layer. Figure 2(a) in the figure shows an architecture of a gNB divided into CU and DU. Among them, a gNB may include a CU and one or more DUs, and the one or more DUs are controlled by the one CU. A DU is connected to the CU through a control plane interface (such as F1-C) for transmitting control plane data; a DU is connected to the CU through a user plane interface (such as F1-U) for transmitting user plane data. Furthermore, the CU can also be divided into a centralized unit of the control plane (i.e., a centralized unit control plane CU-CP network element) and a centralized unit of the user plane (i.e., a centralized unit user plane CU-UP network element), wherein the CU-CP and CU-UP can also be deployed on different physical devices respectively, the CU-CP is responsible for the processing of the control plane of the RRC layer and the PDCP layer, and the CU-UP is responsible for the processing of the user plane of the SDAP layer and the PDCP layer. Figure 2 (b) in the figure shows an architecture of a gNB divided into CU-CP, CU-UP and DU. Among them, a gNB may include a CU-CP, one or more CU-UPs and one or more DUs. A CP-UP is connected to only one CU-CP through a control plane interface (such as E1) for transmitting control plane data; a DU is connected to only one CU-CP through a control plane interface (such as F1-C) for transmitting control plane data; under the control of the CU-CP, a DU can be connected to one or more CU-UPs, and a CU-UP can also be connected to one or more DUs. The CU-UP and DU are connected through a user plane interface (such as F1-U) for transmitting user plane data. It is worth noting that in order to maintain the resilience of the network, a DU or a CU-UP can also be connected to multiple CU-CPs. At this time, multiple CU-CPs serve as backups for each other; in actual applications, only one CU-CP is running at the same time. It should be understood that for the RAN device architecture divided into CU and DU, the protocol stack division method based on which the above-mentioned RAN device is divided into CU and DU is only exemplary, and the RAN device can also divide CU and DU according to other division methods. For example, the CU can be responsible for the operations of the RRC layer, SDAP layer, PDCP layer and RLC layer, and the DU can be responsible for the operations of the MAC layer and the PHY layer; or the CU can be responsible for the operations of the RRC layer and the SDAP layer, and the DU can be responsible for the operations of the PDCP layer, RLC layer, MAC layer and PHY layer, etc.; similarly, the protocol stack division method between CU-CP and CU-UP in the CU is also variable; the application does not make specific limitations on this.

[0128] For ease of understanding, several concepts involved in the embodiments of the present application are first introduced. It should be understood that the following concept explanations may be limited due to the specific circumstances of the embodiments of the present application, but it does not mean that the present application is limited to the specific circumstances, and the explanations of the following concepts may also differ with the specific circumstances of different embodiments.

[0129] System information (SI): SI generally includes a master information block (MIB) and multiple system information blocks (SIB). Among them, MIB and each SIB can be broadcast using the same or different periods. MIB is sent on the physical broadcast channel (PBCH), and each SIB can be sent on the downlink shared channel. Multiple SIBs are divided into SIB1 and other SIBs, and other SIBs include SIB2, SIB3, SIB4, etc. Different SIBs contain different contents and have different functions. For example, SIB1 contains the information required for initial access to the system, SIB2 contains information for cell reselection, SIB3 contains service frequency information and neighboring cell information related to same-frequency cell reselection, SIB4 contains other frequency information and neighboring cell information related to different-frequency cell reselection, etc.

[0130] Base component carrier (BCC) cell: A BCC cell refers to a cell that periodically sends public broadcast signaling, which includes synchronization signals and SI. The public broadcast signaling may also include paging signaling, etc. Specifically, the RAN device that controls the BCC cell periodically sends public broadcast signaling on the resources corresponding to the carrier of the BCC cell. For the convenience of description, in the following, the broadcast signal / message of the RAN device that controls a cell is also referred to as the cell broadcast signal / message. Since the BCC cell broadcasts SI, the BCC cell allows terminal devices to access. The terminal device obtains the necessary information for accessing the BCC cell by reading the SI, so that it can access the BCC cell.

[0131] Data component carrier (DCC) cell: A DCC cell refers to a cell that does not send at least part of the public broadcast signaling on the resources corresponding to its carrier, for example, does not send SI or sends part of SI. A DCC cell may also not send paging signaling, etc. Since the sending of public broadcast signaling is reduced, the transmission time and / or transmission power of the DCC cell can be reduced, thereby achieving the purpose of energy saving. Since the DCC cell does not send the necessary SI to obtain access to the DCC cell, the DCC cell does not allow new terminal devices to access, but can provide data transmission for the terminal devices that have already accessed. It should be noted that the terminal devices that have already accessed may obtain the necessary SI to access the DCC cell through other means, or access the DCC cell before the DCC cell is converted from a BCC cell to a DCC cell. Furthermore, the DCC cell may not send all public broadcast signaling, that is, it does not send synchronization signals and SI, thereby further saving energy.

[0132] Synchronization signal block (SSB): SSB contains the primary synchronization signal (PSS), the secondary synchronization signal (SSS) and the physical broadcast channel (PBCH). Among them, SSB occupies 4 symbols in the time domain and 240 subcarriers in the frequency domain, and can be broadcast using a period of 5ms to 160ms. PSS is transmitted in the first OFDM symbol of SSB and occupies 127 subcarriers; SSS is transmitted in the third OFDM symbol of SSB and also occupies 127 subcarriers; PBCH is transmitted in the second and fourth OFDM symbols of SSB and occupies 240 subcarriers; in addition, PBCH is also transmitted using 48 subcarriers on both sides of SSS. It is worth noting that the resources transmitted by PBCH also include the demodulation reference signal (DMRS) used to demodulate PBCH. In addition, for multi-beam scenarios, each beam can correspond to one SSB, and SSBs of different beams can be sent using beam scanning in a time-division multiplexing manner. The collection of SSBs of multiple beams is called an SS burst set. At this time, the broadcast period of the above SSB refers to the broadcast period of the SSB of one beam, and an SS burst set is always sent within 5ms.

[0133] For the initial access of NR, when the UE enters the coverage area of ​​the mobile network, it will first perform a cell search based on SSB, obtain the physical cell identify (PCI), frequency synchronization and downlink time synchronization through PSS and SSS detection; MIB can be obtained by decoding PBCH, which contains a small amount of information required by the terminal to obtain the remaining system information broadcast by the network, such as system frame number, SSB time index, DMRS position, SIB1 configuration, etc. Among them, the MIB configuration provides the search space, control resource sets (CORESET) and other physical downlink control channel (PDCCH) related parameters required by the UE to detect SIB1. SIB1 is also called the remaining minimum system information (RMSI). RMSI contains the system information that the UE needs to know to access the network, such as the information that the UE must know for random access, that is, the necessary SI for accessing the cell. For the convenience of description, SIB1 is equivalent to RMSI in the following text, and the two can be used interchangeably. NR cells usually broadcast RMSI periodically to enable UEs to access the network. The other system information (OSI) in the SIB, except SIB1, contains system information that the UE does not need to know before accessing the system. These OSIs can be broadcast periodically or transmitted on demand, that is, they are sent only when the UE requests them. It should be noted that for DCC cells that do not send RMSI, their MIB may not include SIB1 configuration.

[0134] Figure 3 The figure shows the difference between the physical frame information transmission of BCC cell and DCC cell in NR. Figure 3 (a) in FIG. 1 shows information transmitted by a physical frame of a BCC cell, which may correspond to a subframe or a time slot and may be transmitted periodically. In the physical frame, the BCC cell broadcasts public broadcast signaling SSB, RMSI and OSI, which may provide access for terminal devices. Figure 3 (b) to Figure 3 (d) in the figure represents three types of DCC cells: Figure 3 In (b), the DCC1 cell corresponding to the above figure broadcasts some public broadcast signaling such as SSB, but does not broadcast RMSI and OSI; Figure 3 The DCC2 cell corresponding to (c) broadcasts SSB and OSI, but not RMSI; Figure 3 The DCC3 cell corresponding to (d) in FIG. 1 does not broadcast public broadcast signaling. It is worth noting that Figure 3 (a) to Figure 3 The transmission of various public broadcast signaling in (d) is illustrative only, and the specific physical resources used by each cell to transmit these public broadcast signaling are not described in detail; Figure 3 (a) to Figure 3 In the physical frame (c), except for the resources occupied by public broadcast signaling, other unlabeled physical frame resources can be used for data transmission and transmission of other control signaling. In an actual communication system, one possible scenario is that the BCC cell serves as the coverage layer of a heterogeneous network, mainly providing control plane data transmission and small-capacity user plane data transmission; the DCC cell serves as the capacity layer of a heterogeneous network, and its coverage is smaller than that of the BCC cell. The capacity layer is superimposed on the coverage layer, and mainly provides large-capacity user plane data transmission. In this case, the DCC cell can provide data plane transmission, and since RMSI is not broadcast, the periodic public broadcast signaling is reduced to achieve energy saving. Another possible scenario is that the BCC cell and the DCC cell jointly provide data transmission for the terminal device, realizing dual connection between the terminal device and the network, such as Figure 1 The terminal device 120 is connected to the RAN device 140 and the RAN device 142 at the same time. In this case, the DCC cell can be used as a secondary cell (group) of the BCC cell to provide data transmission for the terminal device, and the DCC cell itself does not accept the access of the terminal device, reducing the control plane signaling to achieve energy saving. The BCC cell may also have other application scenarios, which are not specifically limited in this application.

[0135] The inventors found that because the DCC cell did not send RMSI, the terminal device could not access the DCC cell. When a UE needed to access the network, the existing technology could not use the DCC cell to access the UE, thereby increasing the capacity of the network and improving the UE service quality. To this end, an embodiment of the present application provides a technical solution for transmitting system information. Furthermore, the technical solution of the embodiment of the present application is also applied to a RAN device architecture with a CU and a DU, wherein the CU may also include a case where the CU-CP and the CU-UP are separated.

[0136] This article specifically provides the following embodiments. Figures 4 to 9 , the technical solution of the present application is described in detail with specific method embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. It should be noted that Figures 4 to 9 is a schematic flow chart of a method embodiment of the present application, showing detailed communication steps or operations of the method, but these steps or operations are only examples, and the present application embodiment may also perform other operations or Figures 4 to 9 In addition, Figures 4 to 9 The steps in Figures 4 to 9 are executed in a different order than those presented, and may not be executed in the order Figures 4 to 9 All operations in .

[0137] In a possible implementation, when a terminal device in the RRC idle state attempts to access a BCC cell, the BCC cell sends the SI of the DCC cell to the terminal device. This implementation may be applied to a terminal device that expects to access a DCC cell, but because the DCC cell does not send the system information required for initial access to the DCC cell, the terminal device can only attempt to access the BCC cell and inform the network that it expects to access the DCC cell when accessing the BCC cell.

[0138] Figure 4 A flow chart of a method for randomly accessing a RAN device and establishing a radio resource control (RRC) connection provided in an embodiment of the present application. The method 400 can be applied to randomly accessing an LTE eNB by a terminal device, or to randomly accessing an eLTE ng-eNB or a NR gNB by a terminal device. Figure 4 The process includes the following steps:

[0139] S401. The terminal device sends a random access preamble to the RAN device.

[0140] Accordingly, the RAN device receives a random access preamble from the terminal device.

[0141] In this step, the terminal device sends a random access preamble to the RAN device to attempt to access a cell controlled by the RAN device. It should be noted that the RAN device controls one or more BCC cells, and the cell that the terminal device attempts to access is a BCC cell.

[0142] Typically, the terminal device randomly selects a random access preamble from the random access preamble set, selects an appropriate PRACH resource from the preconfigured physical random access channel (PRACH) resource pool, and sends the random access preamble to the RAN device. For the convenience of description, in the following, the terminal device sending a signal or information to the RAN device controlling the BCC cell may also be referred to as the terminal device sending a signal or information to the BCC cell.

[0143] It should be noted that the terminal device is in an RRC idle state before executing step S401. When the terminal device receives a network-side paging or initiates a service, step S401 is executed to access the cell and establish an RRC connection.

[0144] S402: The RAN device sends a random access response to the terminal device.

[0145] Correspondingly, the terminal device receives a random access response from the RAN device.

[0146] After receiving the random access preamble sent by the terminal device, the RAN device calculates the timing advance (TA) sent by the terminal device according to the time when the random access preamble is received, and sends the TA and the uplink resource grant allocated to the terminal device to send the RRC request to the UE through the random access response. For the convenience of description, in the following, the RAN device controlling the BCC cell to send a signal or information to the terminal device may also be referred to as the BCC cell sending a signal or information to the terminal device.

[0147] S403: The terminal device sends an RRC request message to the RAN device.

[0148] Accordingly, the RAN device receives the RRC request message from the terminal device.

[0149] The RRC request message is used by the terminal device to request to establish an RRC connection with the RAN device. The RRC request message includes first information, and the first information is used to indicate that the terminal device expects to access the DCC cell. Optionally, the first information may use a one-bit information element to indicate whether the terminal device expects to access the DCC cell, such as when the bit value is 1, it indicates that the terminal device expects to access the DCC cell, or when the bit value is 0, it indicates that the terminal device expects to access the DCC cell.

[0150] Optionally, in this step, the terminal device randomly selects a number within a preset digital range as its own identification (such as ue-Identity), and sends an RRC request message to the RAN device according to the TA sent by the RAN device.

[0151] Optionally, the RRC request message is an RRC connection request (RRCConnectionRequest) message or an RRC establishment request (RRCSetupRequest) message.

[0152] S404. The RAN device sends an RRC reject message to the terminal device.

[0153] Accordingly, the terminal device receives an RRC reject message from the RAN device.

[0154] The RRC rejection message is used by the RAN device to indicate the rejection of the RRC request of the terminal device. Among them, the RRC rejection message includes the second information, and the second information includes the cell identifier of the DCC cell and the partial SI of the DCC cell. The partial SI of the DCC cell includes the RMSI of the DCC cell, and may also include the OSI of the DCC cell. It should be noted that the second information may include the cell identifier of each DCC cell in one or more DCC cells and the partial SI of each DCC cell. For the convenience of description, in the following, the partial SI of the DCC cell includes the RMSI of the DCC cell, and further, may also include the OSI of the DCC cell.

[0155] Optionally, the RRC reject message is an RRC reject (RRCReject) message or an RRC connection reject (RRCConnectionReject) message.

[0156] It should be noted that in the above steps S401 to S404, the terminal device performs contention-based random access, that is, if multiple terminal devices select the same random access preamble in step S401 and send the random access preamble on the same PRACH resource, the random access of these terminal devices may conflict and require contention resolution. The terminal device that successfully competes correctly receives the message of step S404, and the terminal device that fails in the competition cannot decode the message of step S404 and needs to initiate random access again. The above steps S401 and S402 are optional and are used in the process of random access of the terminal device to the RAN device. If the terminal device accesses the RAN device and establishes an RRC connection by other means, the above steps S401 and S402 may not be performed.

[0157] In another embodiment, in step S403, the first information included in the RRC request message is used to indicate one or more DCC cells. For example, the first information may include the cell identifiers of one or more DCC cells. In this case, the first information is equivalent to indicating which DCC cell(s) the terminal device expects to access. For example, a DCC cell is searched before the terminal device accesses the BCC cell. In this way, when the terminal device establishes an RRC connection with the BCC cell, the cell identifier of the DCC cell can be carried in the RRC request message to indicate that the terminal device expects to access the DCC cell. Accordingly, in step S404, the second information includes the cell identifiers of each DCC cell in the one or more DCC cells and partial SI of each DCC cell. Optionally, the second information only includes partial SI of each DCC cell in the one or more DCC cells. For example, if the first information includes a cell identifier of a DCC cell, the second information does not include the cell identifier of the DCC cell; or if the first information includes the cell identifiers of multiple DCC cells, and the arrangement order of the partial SI of each DCC cell in the multiple DCC cells included in the second information corresponds to the arrangement order of the cell identifiers of each DCC cell in the multiple DCC cells in the first information, the second information may not include the cell identifiers of the multiple DCC cells. It should be noted that in step S404, the information of one or more DCC cells included in the second information may be part or all of the information of one or more DCC cells included in the first information; in addition, the information of one or more DCC cells included in the second information may not correspond to the one or more DCC cells indicated in the first information. Exemplarily, the first information includes the identifier of the second cell A and the identifier of the second cell B; the information of the second cell included in the second information may include the information of the second cell A or the second cell B, or may include the information of the second cell A and the second cell B, or may include the information of the second cell C.

[0158] In the case where the RAN device is a CU-DU separation architecture, some messages in the above steps S401 to S404 are interactions between the terminal device and the DU, and some messages are interactions between the terminal device and the CU. Specifically, in step S401, the terminal device sends a random access preamble to the DU attempting to access. In step S402, the DU sends a random access response to the terminal device. In step S403, the terminal device sends an RRC request to the CU connected to the DU through the DU. Among them, the terminal device sends an RRC request to the DU through the air interface, and the DU then sends the RRC request to the CU through the F1-C interface. In step S404, the CU sends an RRC rejection to the terminal device through the DU. Among them, the CU sends an RRC rejection to the DU through the F1-C interface, and the DU then sends the RRC rejection to the terminal device through the air interface. In the case where the CU is further divided into CU-CP and CU-UP, steps S403 and S404 are interactions between the terminal device and the CU-CP of the CU.

[0159] Through the above steps in the embodiment of the present application, it is achieved that when the UE accesses the RAN, it obtains part of the SI of the DCC cell, thereby enabling the UE to access the DCC cell.

[0160] Optionally, after receiving the second information in step S404, the terminal device may execute a cell reselection process and select a suitable cell for access, and the suitable cell may be a BCC cell or a DCC cell. Exemplarily, the BCC cell controlled by the eNB broadcasts a cell reference signal (cell-specific reference signal, CRS), and the DCC cell controlled by the gNB broadcasts SSB. If the terminal device detects that the signal strength of a DCC cell is higher than the CRS strength of the BCC cell that the terminal device attempts to access, the terminal device may attempt to access the DCC cell. The criteria for the terminal device to select a suitable cell may be based on the strength of the reference signal of each cell, or other criteria, such as the terminal device giving priority to accessing a DCC cell, etc., which is not specifically limited in this application.

[0161] Figure 5 A flowchart of another method for randomly accessing a RAN device and establishing an RRC connection provided by an embodiment of the present application. The method 500 can be applied to randomly accessing an LTE eNB by a terminal device, or to randomly accessing an eLTE ng-eNB or a NR gNB by a terminal device. Figure 5 The process includes the following steps:

[0162] S501. The terminal device sends a random access preamble to the RAN device.

[0163] Accordingly, the RAN device receives a random access preamble from the terminal device.

[0164] S502: The RAN device sends a random access response to the terminal device.

[0165] Correspondingly, the terminal device receives a random access response from the RAN device.

[0166] The above steps S501 and S502 are similar to the steps S401 and S402 of the above embodiment, and will not be described in detail here. It should be noted that steps S501 and S502 are also optional.

[0167] S503: The terminal device sends an RRC request message to the RAN device.

[0168] Accordingly, the RAN device receives the RRC request message from the terminal device.

[0169] The RRC request message is used by the terminal device to request to establish an RRC connection with the RAN device. Among them, the RRC request message includes a first identifier, and the first identifier includes at least a part of the identifier of the terminal device, for example, the first identifier includes at least a part of the temporary terminal device identifier provided by the 5G core network for the terminal device. It is worth noting that if the terminal device has registered with the 5G core network before step S501, the 5G core network allocates a temporary terminal device identifier to the terminal device in the registered tracking area, such as the 5G system architecture evolution temporary mobile station identifier (5G S-Temporary MobileSubscription Identifier, 5G-S-TMSI). In this step, the first identifier includes at least part of the 5G-S-TMSI, that is, the first identifier can include part or all of the 5G-S-TMSI, and can also include other information.

[0170] Optionally, the RRC request message may be an RRC connection request (RRCConnectionRequest) message or an RRC establishment request (RRCSetupRequest) message.

[0171] S504: The RAN device sends an RRC reject message to the terminal device.

[0172] Accordingly, the terminal device receives an RRC reject message from the RAN device.

[0173] The above step S504 is similar to step S404 in the above embodiment and will not be described again.

[0174] For the case where the RAN equipment is a CU-DU separation architecture, Figure 4The embodiment is similar, steps S501 and S502 are interactions between the terminal device and the DU; steps S503 and S504 are interactions between the terminal device and the CU. In the case where the CU is further divided into CU-CP and CU-UP, steps S503 and S504 are interactions between the terminal device and the CU-CP of the CU.

[0175] Through the above steps of the embodiment of the present application, the terminal device obtains part of the SI of the DCC cell when accessing the RAN, thereby enabling the terminal device to access the DCC cell. Since the terminal device has been registered with the 5G core network, only the first identifier of the terminal device needs to be carried in the RRC request, thereby saving air interface signaling overhead.

[0176] Optionally, after receiving the second information in step S504, the terminal device may execute a cell reselection process and select a suitable cell for access, and the suitable cell may be a BCC cell or a DCC cell. Exemplarily, the BCC cell controlled by the eNB broadcasts CRS, and the DCC cell controlled by the gNB broadcasts SSB. If the terminal device detects that the signal strength of a DCC cell is higher than the CRS strength of the BCC cell that the UE attempts to access, the terminal device may attempt to access the DCC cell. The criteria for the terminal device to select a suitable cell may be based on the strength of the reference signal of each cell, or other criteria, such as the terminal device giving priority to accessing a DCC cell, etc., which is not specifically limited in this application.

[0177] exist Figure 4 and Figure 5 In the illustrated embodiment, the terminal device obtains partial SI of the DCC cell during the process of accessing the BCC cell to establish an RRC connection so as to access the DCC cell. In another possible implementation, when the terminal device is in an RRC connection state, that is, the terminal device has established an RRC connection with the BCC cell, in this case, the terminal device may request the BCC cell to obtain partial SI of the DCC cell, or the BCC cell may actively send partial SI of the DCC cell to the terminal device.

[0178] Figure 6 A flow chart of a method for a terminal device to request a RAN device to send partial SI of a DCC cell provided in an embodiment of the present application. Exemplarily, a terminal device in an RRC connected state desires to switch from the RRC connection of a BCC cell to the RRC connection of a DCC cell, or to add an RRC connection of a DCC cell, due to the quality of service (QoS) requirements of the service. In this case, the terminal device may request the BCC cell to send partial SI of the DCC cell. The method 600 may be applied to the interaction between a terminal device and an eNB of LTE, an ng-eNB of eLTE, or a gNB of NR. Figure 6 The process includes the following steps:

[0179] S601. The terminal device sends an RRC re-establishment request message to the RAN device.

[0180] Accordingly, the RAN device receives an RRC re-establishment request message from the terminal device.

[0181] The RRC re-establishment request is used by the terminal device to request the re-establishment of the RRC connection with the RAN device. Among them, the RRC re-establishment request message includes the first information, and the first information is used to indicate that the terminal device expects to access the DCC cell. It should be noted that before the terminal device sends the RRC re-establishment request message to the RAN device, the terminal device has established an RRC connection with the BCC cell controlled by the RAN device, and requests to re-establish the RRC connection with the BCC cell in this step. Optionally, the first information can use a one-bit information element to indicate whether the terminal device expects to access the DCC cell, such as when the bit value is 1, it indicates that the terminal device expects to access the DCC cell, or when the bit value is 0, it indicates that the terminal device expects to access the DCC cell.

[0182] Optionally, the RRC reestablishment request message is an RRC reestablishment request (RRCReestablishmentRequest) message or an RRC connection reestablishment request (RRCConnectionReestablishmentRequest) message.

[0183] S602. The RAN device sends an RRC re-establishment response message to the terminal device.

[0184] Correspondingly, the terminal device receives an RRC re-establishment response message from the RAN device.

[0185] As a response to the RRC re-establishment request, the RRC re-establishment response message includes second information, and the second information includes the cell identifier of the DCC cell and part of the SI of the DCC cell. It should be noted that the second information may include the cell identifier and part of the SI of each DCC cell in one or more DCC cells.

[0186] Optionally, the RRC reestablishment response message is an RRC reestablishment (RRCReestablishment) message, an RRC setup (RRCSetup) message, an RRC connection reestablishment (RRCConnectionReestablishment) message, or an RRC connection reestablishment reject (RRCConnectionReestablishmentReject) message.

[0187] In another implementation, in step S601, the first information included in the RRC re-establishment request message is used to indicate one or more DCC cells. For example, the first information may include the cell identifiers of one or more DCC cells. In this case, the first information is equivalent to indicating which DCC cell(s) the terminal device expects to access. For example, the terminal device searches for or detects a DCC cell before RRC re-establishment, so that the terminal device can carry the cell identifier of the DCC cell in the RRC re-establishment request message when performing RRC re-establishment with the BCC cell to indicate that the terminal device expects to access the DCC cell. Accordingly, in step S602, the second information includes the cell identifiers of each DCC cell in the one or more DCC cells and partial SI of each DCC cell. Optionally, the second information only includes partial SI of each DCC cell in the one or more DCC cells. For example, if the first information includes a cell identifier of a DCC cell, the second information does not include the cell identifier of the DCC cell; or if the first information includes cell identifiers of multiple DCC cells, and the arrangement order of the partial SI of each DCC cell in the multiple DCC cells included in the second information corresponds to the arrangement order of the cell identifiers of each DCC cell in the multiple DCC cells in the first information, the second information may not include the cell identifiers of the multiple DCC cells. It should be noted that in step S602, the information of one or more DCC cells included in the second information may be part or all of the information of one or more DCC cells included in the first information; in addition, the information of one or more DCC cells included in the second information may not correspond to the one or more DCC cells indicated in the first information. Exemplarily, the first information includes the identifier of the second cell A and the identifier of the second cell B; the information of the second cell included in the second information may include the information of the second cell A or the second cell B, or may include the information of the second cell A and the second cell B, or may include the information of the second cell C.

[0188] In the case where the RAN device is a CU-DU separation architecture, steps S601 and S602 are interactions between the terminal device and the CU, and the CU is connected to the DU that has established an RRC connection with the terminal device. Specifically, in step S601, the terminal device sends an RRC re-establishment request to the CU through the DU. Among them, the terminal device sends an RRC re-establishment request to the DU through the air interface, and the DU then sends the RRC re-establishment request to the CU through the F1-C interface. In step S602, the CU sends an RRC re-establishment response to the terminal device through the DU. Among them, the CU sends an RRC re-establishment response to the DU through the F1-C interface, and the DU then sends the RRC re-establishment response to the terminal device through the air interface. In the case where the CU is further divided into CU-CP and CU-UP, steps S601 and S602 are interactions between the terminal device and the CU-CP of the CU.

[0189] Through the above steps of the embodiment of the present application, the terminal device in the RRC connection state actively requests to obtain partial SI of the DCC cell, thereby enabling the terminal device to access the DCC cell.

[0190] Figure 7 A flowchart of a method for a RAN device to actively send partial SI of a DCC cell to a terminal device provided in an embodiment of the present application. For example, due to excessive load on the BCC cell and in combination with the service QoS requirements of the terminal device, it is desired to switch the terminal device to the DCC cell, or to add a DCC cell to provide services for the terminal device. In this case, the BCC cell actively sends partial SI of the DCC cell to the terminal device in the RRC connected state. The method 700 can be applied to the interaction between the terminal device and the eNB of LTE, the ng-eNB of eLTE, or the gNB of NR. Figure 7 The process includes the following steps:

[0191] S701. The RAN device sends an RRC reconfiguration message to the terminal device.

[0192] Accordingly, the terminal device receives the RRC reconfiguration message from the RAN device.

[0193] RRC reconfiguration is used to modify the RRC connection of the terminal device, such as establishing / modifying / releasing a radio bearer, establishing / modifying / releasing a measurement, or adding / modifying / deleting a secondary cell, etc. Among them, the RRC reconfiguration message includes the second information, and the second information includes the cell identifier of the DCC cell and part of the SI of the DCC cell. It should be noted that the second information may include the cell identifier of each DCC cell in one or more DCC cells and part of the SI of each DCC cell. Before the RAN device sends the RRC reconfiguration message to the terminal device, the terminal device establishes an RRC connection with the BCC cell controlled by the RAN device, and the BCC cell initiates RRC reconfiguration to the terminal device in this step.

[0194] Optionally, the RRC reconfiguration message is an RRC reestablishment (RRCReconfiguration) message or an RRC connection reconfiguration request (RRCConnectionReconfiguration) message.

[0195] S702. The terminal device sends an RRC reconfiguration response message to the RAN device.

[0196] Accordingly, the RAN device receives an RRC reconfiguration response message from the terminal device.

[0197] The terminal device confirms whether the RRC reconfiguration message is successfully received by responding to the RRC reconfiguration message. Optionally, the response is included in an RRC reconfiguration complete (RRCReconfigurationComplete) message, and may also be included in an RRC connection reconfiguration complete (RRCConnectionReconfigurationComplete) message, and may also be included in an RRC connection re-establishment (RRC connection re-establishment) message.

[0198] For the case where the RAN equipment is a CU-DU separation architecture, Figure 6 Similar to the embodiment, steps S701 and S702 are interactions between the terminal device and the CU, which is connected to the DU that has established an RRC connection with the terminal device. In the case where the CU is further divided into a CU-CP and a CU-UP, steps S701 and S702 are interactions between the terminal device and the CU-CP of the CU.

[0199] Through the above steps of the embodiment of the present application, the BCC cell actively sends the SI of the DCC cell to the terminal device in the RRC connection state, thereby enabling the terminal device to access the DCC cell.

[0200] For the BCC to actively send partial SI of the DCC cell to the terminal device in the RRC connection state, another implementation method can also be adopted, that is, the BCC cell sends an RRC release message to the terminal device. The RRC release message includes the above-mentioned second information. Optionally, the RRC release message is an RRC release (RRCRelease) message or an RRC connection release (RRCConnectionRelease) message.

[0201] In the above embodiment, the terminal device and the BCC cell interact through RRC signaling, so that the terminal device can obtain part of the SI of the DCC cell to enable the terminal device to access the DCC cell. In another possible implementation, the BCC cell can send part of the SI of the DCC cell by broadcasting. Specifically, the BCC cell includes the cell identifier of the DCC cell and part of the SI of the DCC cell (that is, the above-mentioned second information) in the SI of the BCC cell for broadcasting; or, the BCC cell broadcasts the second information through other broadcast channels. The embodiment of the present application does not specifically limit how the BCC cell broadcasts the second information. It should be noted that the BCC cell can broadcast the cell identifiers of one or more DCC cells and their respective part of the SI. Exemplarily, when the BCC cell broadcasts part of the SI of the DCC cell through its own SI, the BCC cell needs to modify its own SI and notify the terminal device to read the modified SI. Among them, the SI of the BCC cell includes the configuration of the SI modification period. Optionally, the BCC cell indicates the modification of the SI of the BCC cell to the terminal device in the PDCCH. After receiving the indication, the terminal device reads the modified SI, ie, the SI of the BCC cell including the second information, in the next SI modification cycle.

[0202] In another possible implementation, when the terminal device randomly accesses the BCC cell, it obtains the above-mentioned second information by sending a specific random access preamble. The specific random access preamble refers to a preamble used to request SI, and the specific random access preamble can be used to request SI of the DCC cell, and can also be used to request SI of the BCC cell. In this implementation, the first random access preamble set used by the terminal device to request SI of the BCC and / or DCC cell can be pre-configured through a standard protocol, terminal device subscription information or other means. Optionally, the terminal device sends a specific random access preamble on a specific PRACH resource, and the specific PRACH resource is also pre-configured. The terminal device and the RAN device pre-acquire the first random access preamble set, and can further pre-acquire the PRACH resource pool for the terminal device to send the specific random access preamble. When the terminal device randomly accesses the BCC cell, the terminal device selects a specific random access preamble in the first random access preamble set and sends it to the RAN device on a specific PRACH resource. The selection can be a random selection by the terminal device in the first random access preamble set, or it can be pre-configured to the terminal device by the RAN device, or it can be selected by the terminal device using other criteria, and this application does not make specific limitations on this. Optionally, after correctly receiving the specific random access preamble, the RAN device learns that the terminal device requests to obtain SI of the BCC and / or DCC cell. Figure 8 A schematic flow chart of a method provided by an embodiment of the present application for a terminal device to request a RAN device for SI of a DCC cell. The method 800 process includes the following steps:

[0203] S801. The terminal device sends an SI request to the RAN device.

[0204] Accordingly, the RAN device receives the SI request from the terminal device.

[0205] In this step, the terminal device selects a specific random access preamble and sends the specific random access preamble to the RAN device.

[0206] It should be noted that the above step S801 is similar to the above step S401, the main difference being that in this step, the specific random access preamble sent by the terminal device to the RAN device is used to request SI. Generally, it can also be referred to as the terminal device sending an SI request to the RAN device to request the SI of the DCC cell. Specifically, it can be used to request the RMSI of the DCC cell, and further, it can also be used to request the OSI of the DCC cell. Optionally, the SI request can also request the SI of the BCC cell controlled by the RAN device, for example, other SIBs in the SI of the BCC cell except SIB1.

[0207] S802. The RAN device sends an SI request confirmation to the terminal device.

[0208] Correspondingly, the terminal device receives an SI request confirmation from the RAN device.

[0209] In this step, the RAN device sends a random access response to the terminal device, where the random access response is used to indicate an acknowledgement for the SI request.

[0210] Optionally, the RAN device includes only the random access preamble identifier (RAPID) of the UE in the MAC layer sub-PDU for the terminal device in the random access response to indicate confirmation of the SI request of the terminal device.

[0211] S803. The RAN device sends SI to the terminal device.

[0212] Accordingly, the terminal device receives SI from the RAN device.

[0213] In this step, the RAN device sends SI to the UE on the scheduled resources. The SI includes at least the cell identifier of each DCC cell of one or more DCC cells and part of the SI of each DCC cell. Optionally, the SI may also include other SIBs except SIB1 in the SI of the BCC cell controlled by the RAN device.

[0214] In the case where the RAN device is a CU-DU separation architecture, some messages in steps S801 to S803 are interactions between the terminal device and the DU, and some messages are interactions between the terminal device and the CU. Specifically, in step S801, the terminal device sends a system information request to the DU. In step S802, the DU sends a system information request confirmation to the terminal device. If the system information is stored in the CU connected to the DU, then in step S803, the CU connected to the DU sends the system information to the terminal device through the DU; wherein the CU sends the system information to the DU through the F1-C interface, and the DU then sends the system information to the terminal device through the air interface. If the CU is further divided into CU-CP and CU-UP, step S803 is the CU-CP of the CU sending the system information to the terminal device through the DU. If the system information is stored in the DU, then in step S803, the DU sends the system information to the terminal device.

[0215] Through the above steps of the embodiment of the present application, the terminal device can quickly obtain part of the SI of the DCC cell, thereby enabling the terminal device to access the DCC cell. The terminal device can obtain part of the SI of the DCC cell before establishing an RRC connection, thereby shortening the time for the terminal device to obtain part of the SI of the DCC cell, which is conducive to shortening the time for the terminal device to access the network.

[0216] The above-mentioned multiple embodiments describe various ways of how a terminal device obtains partial SI of a DCC cell from a BCC cell. It should be noted that before the RAN device controlling the BCC cell sends partial SI of the DCC cell to the UE, the RAN device has already obtained partial SI of one or more DCC cells. The one or more DCC cells may have a neighboring cell relationship with the BCC cell. The coverage of the DCC cell may partially overlap or completely overlap with the coverage of the BCC cell. There may be multiple ways for the RAN device to obtain partial SI of the DCC cell. For example, the RAN device may obtain partial SI of the DCC cell through the operation, administration and maintenance system (OAM) and save it; or, the BCC cell controlled by the RAN device and the adjacent DCC cell may establish an inter-cell interface (such as an X2 interface or an Xn interface) and update the interface during operation, and the RAN device may obtain partial SI of the DCC cell through the inter-cell interface and save it; the RAN device may also obtain partial SI of the DCC cell and save it in other ways, which is not specifically limited in this application.

[0217] Fig. 9 A flow chart of a method for information interaction between a first RAN device controlling a DCC cell and a second RAN device controlling a BCC cell provided in an embodiment of the present application. The method 900 flow includes the following steps:

[0218] S901. A first RAN device sends third information to a second RAN device, where the third information is used to indicate that one or more cells controlled by the first RAN device are DCC cells.

[0219] Accordingly, the second RAN device receives the third information from the first RAN device.

[0220] In this step, the first RAN device controlling the DCC cell indicates to the second RAN device controlling the BCC cell that the cell is a DCC cell. Generally, the DCC cell and the BCC cell have a neighboring cell relationship. The DCC cell may be Figure 3 (b) to Figure 3 Any DCC cell shown in (d) above.

[0221] In a possible implementation, the third information may include a cell identifier of at least one DCC cell. In this way, after receiving the third information, the second RAN device knows which cell(s) controlled by the first RAN device is a DCC cell. The third information may also be indicated by other information that can identify the identity of the DCC cell, which is not specifically limited in this application. Furthermore, the third information may also include an indication of what type of DCC cell the DCC cell is. For example, the DCC cell is a DCC cell that broadcasts SSB but does not broadcast RMSI and OSI (such as Figure 3 (b) in FIG. 1 ), or the DCC cell is a DCC cell that broadcasts SSB and OSI but does not broadcast RMSI (e.g. Figure 3 (c) in ), or the DCC cell is a DCC cell that does not broadcast public broadcast signaling (such as Figure 3 (d) in the above description, etc. Optionally, for a DCC cell, the third information includes a two-bit information element to indicate the type of the DCC cell.

[0222] In another possible implementation, the third information may be carried in a message with a cell identifier that is exchanged between existing RAN devices. Exemplarily, the message sent by the existing first RAN device to the second RAN device includes the cell identifier of at least one cell controlled by the first RAN device. In this case, if a cell is a DCC cell, an information element corresponding to the cell identifier of the cell may be added to the existing message to represent the third information. Specifically, the third information may be a one-bit information element, such as when the bit value is 1, it indicates that the cell is a DCC cell, or when the bit value is 0, it indicates that the cell is a DCC cell; further, the third information may also include an indication of what type of DCC cell the DCC cell is.

[0223] The third information may be transmitted when the first RAN device and the second RAN device establish a RAN side interface, or may be transmitted when the interface information between the first RAN device and the second RAN device is updated. Optionally, the third information is included in an Xn setup request message, or may be included in an NG-RAN node configuration update message.

[0224] S902: The second RAN device sends a response of third information to the first RAN device.

[0225] Accordingly, the first RAN device receives a response of the third information from the second RAN device.

[0226] The second RAN device confirms whether the third information sent by the first RAN device is successfully received by responding to the third information. Optionally, the response may be included in an Xn setup response message or in an NG-RAN node configuration update acknowledgement message.

[0227] It should be noted that step S902 is optional.

[0228] The second RAN device may save the correctly received third information.

[0229] Through the above steps S901 and S902, the BCC cell can learn which DCC cells are around it, and further, can learn what type of DCC cells they are, so as to provide auxiliary information for the BCC cell to send partial SI of the DCC cell to the terminal device.

[0230] S903: The first RAN device sends second information to the second RAN device.

[0231] Accordingly, the second RAN device receives the second information from the first RAN device.

[0232] The second information includes a cell identifier of a DCC cell and a partial SI of the DCC cell. The partial SI of the DCC cell includes the RMSI of the DCC cell and may also include the OSI of the DCC cell. It should be noted that the second information may include a cell identifier of one or more DCC cells controlled by the first RAN device and a partial SI of each.

[0233] Further, in this step, the information of part of SI included in the second information corresponds to the DCC cell type in S901. Figure 3 For a DCC cell of type (b) in the above, the second information includes the RMSI of the DCC cell and may further include the OSI; Figure 3 For a DCC cell of type (c), the second information includes the RMSI of the DCC cell.

[0234] The second information may be transmitted when the first RAN device and the second RAN device establish a RAN side interface, or may be transmitted when the interface information between the first RAN device and the second RAN device is updated. Optionally, the second information is included in an Xn setup request message, or may be included in an NG-RAN node configuration update message.

[0235] S904: The second RAN device sends a response of the second information to the first RAN device.

[0236] Accordingly, the first RAN device receives a response of the second information from the second RAN device.

[0237] The second RAN device confirms whether the second information sent by the first RAN device is successfully received by responding to the second information. Optionally, the response may be included in an Xn setup response message or in an NG-RAN node configuration update acknowledgement message.

[0238] It should be noted that step S904 is optional.

[0239] The second RAN device may save the correctly received second information.

[0240] Through the above steps S903 and S904, the BCC cell can obtain partial SI of the DCC cell, enabling the BCC cell to send partial SI of the DCC cell to the terminal device.

[0241] It should be noted that step S901 and optional S902 are the first sub-process, and step S903 and optional S904 are the second sub-process. The first sub-process and the second sub-process can be executed independently. The above two sub-processes can also be combined together, that is, the first RAN device uses one message to send the third information and the second information to the second RAN device, and the second RAN device uses another message to send the third information and the response to the second information to the first RAN device.

[0242] In the case where the RAN device is a CU-DU separation architecture, in a possible implementation, the second information and the third information are stored in the CU connected to the DU controlling the DCC cell in the first RAN device. Then, in step S901, the CU connected to the DU controlling the DCC cell in the first RAN device sends the third information to the CU connected to the DU controlling the BCC cell in the second RAN device through the Xn / X2 interface. Optionally, the CU of the second RAN device sends the third information to the DU of the second RAN device through the F1-C interface. In step S902, the CU connected to the DU controlling the BCC cell in the second RAN device sends a response to the third information to the CU connected to the DU controlling the DCC cell in the first RAN device through the Xn / X2 interface. Optionally, the DU of the second RAN device sends a response to the third information to the CU of the second RAN device through the F1-C interface, and then the CU of the second RAN device sends a response to the third information to the CU of the first RAN device through the Xn / X2 interface. The transmission process of the second information in step S903 is similar to the transmission process of the third information in step S901, and the transmission process of the response to the second information in step S904 is similar to the transmission process of the response to the third information in step S902, which will not be described in detail in this application. In another possible implementation, the second information and the third information are stored in the DU controlling the DCC cell in the first RAN device. In step S901, the DU controlling the DCC cell in the first RAN device sends the third information to the CU connected to the DU through the F1-C interface, and then the CU of the first RAN device sends the third information to the CU connected to the DU controlling the BCC cell in the second RAN device through the Xn / X2 interface. Optionally, the CU of the second RAN device sends the third information to the DU of the second RAN device through the F1-C interface. In step S902, the CU connected to the DU controlling the BCC cell in the second RAN device sends a response to the third information to the CU connected to the DU controlling the DCC cell in the first RAN device through the Xn / X2 interface, and then the CU of the first RAN device sends a response to the third information to the DU of the first RAN device through the F1-C interface. Optionally, the DU of the second RAN device sends a response to the third information to the CU of the second RAN device through the F1-C interface, and the CU of the second RAN device sends a response to the third information to the CU of the first RAN device through the Xn / X2 interface, and the CU of the first RAN device sends a response to the third information to the DU of the first RAN device through the Xn / X2 interface. The transmission process of the second information in step S903 is similar to the transmission process of the third information in step S901, and the transmission process of the response to the second information in step S904 is similar to the transmission process of the response to the third information in step S902, and this application will not repeat them again.In the case where the CU is further divided into CU-CP and CU-UP, the steps performed by the CU in steps S901 to S904 are performed by the CU-CP of the CU. It should be noted that, in the case where one of the two RAN devices is a CU-CP architecture, steps S901 to S904 are interactions between one RAN device and the CU of another RAN device, or the CU-CP of another RAN device, and this application will not go into details.

[0243] In the above-mentioned multiple embodiments, the BCC cell obtains part of the SI of the DCC cell, and can send part of the SI of the DCC cell to the terminal device in multiple ways, thereby enabling the terminal device to access the DCC cell. In another implementation, the BCC cell can instruct the DCC cell to be converted into a BCC cell, which can also be called the BCC cell activating the DCC cell. For example, when the number of terminal devices accessing the BCC cell is large, causing the load of the BCC cell to be too high, the BCC cell can instruct one or more adjacent DCC cells to be converted into BCC cells, so that some terminal devices in the network can access the BCC cell converted from the DCC cell, thereby reducing the load of the existing BCC cell and improving the QoS of the terminal device. To this end, the second RAN device controlling the BCC cell can send fourth information to the first RAN device controlling the DCC cell, and the fourth information is used to indicate that the DCC cell is converted into a BCC cell, and the fourth information can also be considered to be used to activate the DCC cell. Optionally, the fourth information can include the cell identifier of the DCC cell. In this way, after receiving the fourth information, the first RAN device knows which DCC cell it controls is converted into a BCC cell. The fourth information may also be indicated by other information that can identify the DCC cell, and this application does not specifically limit this. Optionally, the BCC cell may transmit the fourth information to the DCC cell through an NG-RAN node configuration update message. The DCC cell may also be confirmed through an NG-RAN node configuration update acknowledgement message. For the case where the RAN device is a CU-DU separation architecture, the fourth information may be an interaction between the DU of the first RAN device and the DU of the second RAN device, or an interaction between the DU of the first RAN device and the CU of the second RAN device, or an interaction between the CU of the first RAN device and the DU of the second RAN device, or an interaction between the CU of the first RAN device and the CU of the second RAN device. In the case where the CU is further divided into CU-CP and CU-UP, the operations performed by the above CU are performed by the CU-CP of the CU. In the case where one of the two RAN devices is a CU-CP architecture, the above operation is an interaction between a RAN device and the DU of another RAN device, or a CU of another RAN device, or a CU-CP of another RAN device. Through this operation, the BCC cell can instruct the DCC cell to convert to the BCC cell, thereby enabling the access of the terminal device, which can help to reduce the load of the existing BCC cell and improve the service quality of the terminal device.

[0244] Optionally, the BCC cell can also instruct other BCC cells to convert into DCC cells, which can also be called the BCC cell deactivating another BCC cell. For example, when the number of terminal devices accessing the BCC cell is small and the network load is low, the BCC cell can instruct one or more adjacent BCC cells to convert into DCC cells, so that some BCC cells in the network can achieve energy saving and reduce network energy consumption. To this end, the second RAN device controlling the BCC cell can send the fifth information to the first RAN device controlling another BCC cell, and the fifth information is used to indicate that the BCC cell is converted into a DCC cell, and the fifth information can also be considered to be used to deactivate the BCC cell. Optionally, the fifth information may include the cell identifier of the BCC cell. In this way, after receiving the fifth information, the first RAN device knows which BCC cell it controls to convert into a DCC cell. The fifth information can also be indicated by other information that can identify the BCC cell, and this application does not make specific limitations on this. Optionally, the BCC cell can transmit the fifth information to another BCC cell through an NG-RAN node configuration update message. The other BCC cell can also be confirmed through the NG-RAN node configuration update acknowledgement message. For the case where the RAN device is a CU-DU separation architecture, the fifth information can be an interaction between the DU of the first RAN device and the DU of the second RAN device, or an interaction between the DU of the first RAN device and the CU of the second RAN device, or an interaction between the CU of the first RAN device and the DU of the second RAN device, or an interaction between the CU of the first RAN device and the DU of the second RAN device, or an interaction between the CU of the first RAN device and the CU of the second RAN device. In the case where the CU is further divided into CU-CP and CU-UP, the operations performed by the above CU are performed by the CU-CP of the CU. In the case where one of the two RAN devices is a CU-CP architecture, the above operation is an interaction between a RAN device and the DU of another RAN device, or the CU of another RAN device, or the CU-CP of another RAN device. Through this operation, the BCC cell can instruct another BCC cell to convert to a DCC cell, so that the other BCC cell can achieve energy saving, thereby reducing network energy consumption.

[0245] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)), etc. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this patent application.

[0246] Combination of the above Figures 4 to 9 The method embodiment of the present application is described in detail below. Figures 10 to 15 , describes in detail the device embodiment of the present application. It should be understood that the device embodiment corresponds to the method embodiment, and similar descriptions can refer to the method embodiment. It is worth noting that the device embodiment can be used in conjunction with the above method or alone.

[0247] Fig.10A schematic block diagram of a terminal device 1000 of an embodiment of the present application is shown, and the terminal device 1000 may correspond to (for example, may be configured in or itself be) the terminal device described in the above method 400, or the terminal device described in the above method 500, or the terminal device described in the above method 600, or the terminal device described in the above method 700, or the terminal device described in the above method 800, or the terminal device described in other embodiments. The terminal device 1000 may include: a processor 1001 and a transceiver 1002, and the processor 1001 and the transceiver 1002 are communicatively coupled. Optionally, the terminal device 1000 also includes a memory 1003, and the memory 1003 is communicatively coupled to the processor 1001. Optionally, the processor 1001, the memory 1003 and the transceiver 1002 may be communicatively coupled, and the memory 1003 may be used to store instructions, and the processor 1001 is used to execute the instructions stored in the memory 1003 to control the transceiver 1002 to receive and / or send information or signals. The processor 1001 and the transceiver 1002 are respectively used to execute the actions or processing procedures performed by the terminal device described in the above method 400, or the terminal device described in the above method 500, or the terminal device described in the above method 600, or the terminal device described in the above method 700, or the terminal device described in the above method 800, or the terminal device described in other embodiments. Here, in order to avoid redundancy, the detailed description is omitted.

[0248] Fig.11 Another schematic block diagram of a terminal device 1100 according to an embodiment of the present application is shown. The terminal device 1100 may correspond to (for example, may be configured in or may be) the terminal device described in the above method 400, or the terminal device described in the above method 500, or the terminal device described in the above method 600, or the terminal device described in the above method 700, or the terminal device described in the above method 800, or the terminal device described in other embodiments. The terminal device 1100 may include: a receiving module 1101, a processing module 1102, and a sending module 1103. The processing module 1102 is communicatively coupled to the receiving module 1101 and the sending module 1103, respectively. The terminal device 1100 may adopt Fig.10 The processing module 1102 can be Fig.10 The processor 1001 in the embodiment can be implemented by the receiving module 1101 and / or the sending module 1103. Fig.10The terminal device 1100 may further include a storage unit for storing programs or data to be executed by the processing module 1102, or storing information received by the receiving module 1101 and / or sent by the sending module 1103. Each module or unit in the terminal device 1100 is used to execute the actions or processing procedures performed by the terminal device described in the above method 400, or the terminal device described in the above method 500, or the terminal device described in the above method 600, or the terminal device described in the above method 700, or the terminal device described in the above method 800, or the terminal device described in other embodiments. Here, in order to avoid redundancy, the detailed description is omitted.

[0249] Fig.12 A schematic block diagram of a first RAN device 1200 according to an embodiment of the present application is shown. The first RAN device 1200 may correspond to (for example, may be configured in or may be) the first RAN device described in the above method 900, or a RAN device for controlling a DCC cell described in other embodiments. The first RAN device 1200 may include: a processor 1201 and a transceiver 1202, the processor 1201 and the transceiver 1202 being communicatively coupled. Optionally, the first RAN device 1200 further includes a memory 1203, the memory 1203 being communicatively coupled to the processor 1201. Optionally, the processor 1201, the memory 1203 and the transceiver 1202 may be communicatively coupled, the memory 1203 may be used to store instructions, and the processor 1201 is used to execute the instructions stored in the memory 1203 to control the transceiver 1202 to receive and / or send information or signals. The processor 1201 and the transceiver 1202 are respectively used to execute the actions or processing procedures performed by the first RAN device described in the above method 900, or the RAN device controlling the DCC cell described in other embodiments. Here, in order to avoid redundancy, the detailed description is omitted. In the case where the first RAN device 1200 is a CU-DU separated architecture, Fig.12 The illustrated first RAN device 1200 may be a CU of the first RAN device 1200 , or a DU of the first RAN device 1200 , or a CU-CP of the first RAN device 1200 .

[0250] Fig.13Another schematic block diagram of a first RAN device 1300 according to an embodiment of the present application is shown. The first RAN device 1300 may correspond to (for example, may be configured in or may be) the first RAN device described in the above method 900, or a RAN device for controlling a DCC cell described in other embodiments. The first RAN device 1300 may include: a receiving module 1301, a processing module 1302, and a sending module 1303. The processing module 1302 is communicatively coupled to the receiving module 1301 and the sending module 1303, respectively. The first RAN device 1300 may adopt Fig.12 The processing module 1302 can be Fig.12 The processor 1201 in the embodiment can be implemented by the receiving module 1301 and / or the sending module 1303. Fig.12 The first RAN device 1300 may further include a storage unit for storing programs or data to be executed by the processing module 1302, or for storing information received by the receiving module 1301 and / or sent by the sending module 1303. Each module or unit in the first RAN device 1300 is used to execute the actions or processing procedures performed by the first RAN device described in the above method 900, or the RAN device controlling the DCC cell described in other embodiments. Here, in order to avoid redundancy, the detailed description is omitted. In the case where the first RAN device 1300 is a CU-DU separated architecture, Fig.13 The illustrated first RAN device 1300 may be a CU of the first RAN device 1300 , or a DU of the first RAN device 1300 , or a CU-CP of the first RAN device 1300 .

[0251] Fig.14A schematic block diagram of a second RAN device 1400 according to an embodiment of the present application is shown. The second RAN device 1400 may correspond to (for example, may be configured in or may be) the RAN device described in the method 400, the RAN device described in the method 500, the RAN device described in the method 600, the RAN device described in the method 700, the RAN device described in the method 800, the second RAN device described in the method 900, or the RAN device controlling the BCC cell described in other embodiments. The second RAN device 1400 may include: a processor 1401 and a transceiver 1402, the processor 1401 and the transceiver 1402 being communicatively coupled. Optionally, the second RAN device 1400 further includes a memory 1403, the memory 1403 being communicatively coupled to the processor 1401. Optionally, the processor 1401, the memory 1403 and the transceiver 1402 may be communicatively coupled, the memory 1403 may be used to store instructions, and the processor 1401 is used to execute the instructions stored in the memory 1403 to control the transceiver 1402 to receive and / or send information or signals. Among them, the processor 1401 and the transceiver 1402 are respectively used to execute the actions or processing procedures performed by the RAN device described in the above method 400, or the RAN device described in the above method 500, or the RAN device described in the above method 600, or the RAN device described in the above method 700, or the RAN device described in the above method 800, the second RAN device described in the above method 900, or the RAN device controlling the BCC cell described in other embodiments. Here, in order to avoid redundancy, the detailed description is omitted. In the case where the second RAN device 1400 is a CU-DU separated architecture, Fig.14 The second RAN device 1400 shown may be a CU of the second RAN device 1400 , or a DU of the second RAN device 1400 , or a CU-CP of the second RAN device 1400 .

[0252] Fig.15Another schematic block diagram of a second RAN device 1500 of an embodiment of the present application is shown. The second RAN device 1500 may correspond to (for example, may be configured in or may be) the RAN device described in the above method 400, or the RAN device described in the above method 500, or the RAN device described in the above method 600, or the RAN device described in the above method 700, or the RAN device described in the above method 800, the second RAN device described in the above method 900, or the RAN device controlling the BCC cell described in other embodiments. The second RAN device 1500 may include: a receiving module 1501, a processing module 1502, and a sending module 1503. The processing module 1502 is communicatively coupled to the receiving module 1501 and the sending module 1503, respectively. The second RAN device 1500 may adopt Fig.14 The processing module 1502 can be Fig.14 The processor 1401 in the embodiment can be implemented by the receiving module 1501 and / or the sending module 1503. Fig.14 The second RAN device 1500 may further include a storage unit for storing programs or data to be executed by the processing module 1502, or storing information received by the receiving module 1501 and / or sent by the sending module 1503. Each module or unit in the second RAN device 1500 is used to execute the actions or processing procedures performed by the RAN device described in the above method 400, or the RAN device described in the above method 500, or the RAN device described in the above method 600, or the RAN device described in the above method 700, or the RAN device described in the above method 800, the second RAN device described in the above method 900, or the RAN device controlling the BCC cell described in other embodiments. Here, in order to avoid redundancy, the detailed description is omitted. In the case where the second RAN device 1500 is a CU-DU separation architecture, Fig.15 The second RAN device 1500 shown may be a CU of the second RAN device 1500 , or a DU of the second RAN device 1500 , or a CU-CP of the second RAN device 1500 .

[0253] It should be understood that the processor (1001, 1201, 1401) in the device embodiment of the present application can be a central processing unit (CPU), a network processor (NP), a hardware chip or any combination thereof. The above-mentioned hardware chip can be an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The above-mentioned PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof.

[0254] The memory (1003, 1203, 1403) in the device embodiments of the present application can be a volatile memory (volatile memory), such as a random-access memory (random-access memory, RAM); it can also be a non-volatile memory (non-volatile memory), such as a read-only memory (read-only memory, ROM), a flash memory (flash memory), a hard disk drive (HDD) or a solid-state drive (solid-state drive, SSD); it can also be a combination of the above types of memory.

[0255] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication coupling shown or discussed can be through some interfaces, indirect coupling or communication coupling of devices or units, which can be electrical, mechanical or other forms.

[0256] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0257] In addition, each functional unit in each embodiment of the present patent application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0258] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this patent application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and contains several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the various embodiments of the method of this patent application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0259] The above are only specific implementations of this patent application, but the protection scope of this patent application is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in this patent application, which should be included in the protection scope of this patent application. Therefore, the protection scope of this patent application should be based on the protection scope of the claims.

Claims

1. A method for transmitting system information, characterized in that: include: The terminal device sends a random access preamble to a radio access network RAN ​​device, where the random access preamble is used to indicate a first request, where the first request includes first information, where the first information is used to indicate that: the terminal device expects to access a second cell, and / or, the second cell that the terminal device expects to access, the second cell partially sends or does not send system information required for the terminal device to initially access the second cell; The terminal device receives a random access response from the RAN device, where the random access response is used to indicate confirmation of the first request; The terminal device receives a first response to the first request from the RAN device, where the first response includes a cell identifier and remaining minimum system information RMSI of each second cell in the one or more second cells.

2. The method according to claim 1, characterized in that The RAN device is a RAN device that controls the first cell, The first cell sends system information required for the terminal device to initially access the first cell, and the first cell is adjacent to the second cell.

3. The method according to claim 1 or 2, characterized in that: The first request is also used to request other system information OSI of the second cell; the first response also includes the OSI of each second cell in the one or more second cells.

4. The method according to claim 3, characterized in that The terminal device sends a random access preamble to a wireless access network RAN ​​device, including the terminal device sending the random access preamble to a distributed unit DU of the RAN device; the terminal device receives a first response to the first request from the RAN device, including the terminal device receiving the first response sent from a centralized unit CU in the RAN device through the DU; the DU is connected to the CU.

5. The method according to claim 1 or 2, characterized in that: The terminal device sends a random access preamble to a wireless access network RAN ​​device, including the terminal device sending the random access preamble to a distributed unit DU of the RAN device; the terminal device receives a first response to the first request from the RAN device, including the terminal device receiving the first response sent from a centralized unit CU in the RAN device through the DU; the DU is connected to the CU.

6. A method for transmitting system information, characterized in that: include: A radio access network RAN ​​device receives a random access preamble from a terminal device, where the random access preamble is used to indicate a first request, where the first request includes first information, where the first information is used to indicate that: the terminal device expects to access a second cell, and / or, the second cell that the terminal device expects to access, the second cell partially sends or does not send system information required for the terminal device to initially access the second cell; The RAN device sends a random access response to the terminal device, where the random access response is used to indicate confirmation of the first request; The RAN device sends a first response to the first request to the terminal device, where the first response includes a cell identifier and remaining minimum system information RMSI of each second cell in the one or more second cells.

7. The method according to claim 6, characterized in that The RAN device is a RAN device that controls a first cell. The first cell sends system information required for the terminal device to initially access the first cell. The first cell is adjacent to the second cell.

8. The method according to claim 7, characterized in that Before the RAN device receives a random access preamble from the terminal device, the method further includes: The RAN device obtains a cell identity and a RMSI of each second cell among the one or more second cells.

9. The method according to any one of claims 6 to 8, characterized in that The first request is also used to request other system information OSI of the second cell; the first response also includes the OSI of each second cell in the one or more second cells.

10. The method according to claim 9, characterized in that The wireless access network RAN ​​device receives a random access preamble from a terminal device, including the distributed unit DU of the RAN device receiving the random access preamble from the terminal device; the RAN device sends a first response to the first request to the terminal device, including the centralized unit CU of the RAN device sending the first response to the terminal device through the DU; the DU is connected to the CU.

11. The method according to any one of claims 6 to 8, characterized in that: The wireless access network RAN ​​device receives a random access preamble from a terminal device, including the distributed unit DU of the RAN device receiving the random access preamble from the terminal device; the RAN device sends a first response to the first request to the terminal device, including the centralized unit CU of the RAN device sending the first response to the terminal device through the DU; the DU is connected to the CU.

12. A terminal device, characterized in that: The terminal device includes a processor and a transceiver, wherein: The processor is configured to determine a random access preamble, where the random access preamble is used to indicate a first request, where the first request includes first information, where the first information is used to indicate that: the terminal device expects to access a second cell, and / or, the second cell that the terminal device expects to access, the second cell partially sends or does not send system information required for the terminal device to initially access the second cell; The transceiver is communicatively coupled to the processor, and is configured to send the random access preamble to a radio access network RAN ​​device; The transceiver is configured to receive a random access response from the RAN device, where the random access response is used to indicate confirmation of the first request; The transceiver is further configured to receive a first response to the first request from the RAN device, where the first response includes a cell identifier and remaining minimum system information RMSI of each second cell in the one or more second cells.

13. The terminal device according to claim 12, characterized in that: The RAN device is a RAN device that controls a first cell. The first cell sends system information required for the terminal device to initially access the first cell. The first cell is adjacent to the second cell.

14. The terminal device according to claim 12 or 13, characterized in that: The first request is also used to request other system information OSI of the second cell; the first response also includes the OSI of each second cell in the one or more second cells.

15. The terminal device according to claim 14, characterized in that: The transceiver sends a random access preamble to a wireless access network RAN ​​device, including the transceiver sending the random access preamble to a distributed unit DU of the RAN device; the transceiver receives a first response to the first request from the RAN device, including the transceiver receiving the first response sent by a centralized unit CU of the RAN device through the DU; the DU is connected to the CU.

16. The terminal device according to claim 12 or 13, characterized in that: The transceiver sends a random access preamble to a wireless access network RAN ​​device, including the transceiver sending the random access preamble to a distributed unit DU of the RAN device; the transceiver receives a first response to the first request from the RAN device, including the transceiver receiving the first response sent by a centralized unit CU of the RAN device through the DU; the DU is connected to the CU.

17. A radio access network RAN ​​device, the RAN device comprising a processor and a transceiver, characterized in that: The transceiver is configured to receive a random access preamble from a terminal device, the random access preamble is used to indicate a first request, the first request includes first information, and the first information is used to indicate that: the terminal device expects to access a second cell, and / or, the second cell that the terminal device expects to access, the second cell partially sends or does not send system information required for the terminal device to initially access the second cell; The processor is coupled to the transceiver, and is configured to determine a random access response and a first response to the first request, the random access response being used to indicate confirmation of the first request, the first response comprising a cell identifier and remaining minimum system information RMSI of each second cell in one or more second cells; The transceiver is used to send the random access response to the terminal device; The transceiver is further used to send the first response to the terminal device.

18. The RAN device according to claim 17, characterized in that: The RAN device is a RAN device that controls a first cell. The first cell sends system information required for the terminal device to initially access the first cell. The first cell is adjacent to the second cell.

19. The RAN device according to claim 18, characterized in that: Also includes: The processor is configured to obtain a cell identifier and a RMSI of each second cell among the one or more second cells.

20. The RAN device according to any one of claims 17 to 19, characterized in that: The first request is also used to request other system information OSI of the second cell; the first response also includes the OSI of each second cell in the one or more second cells.

21. The RAN device according to claim 20, characterized in that: The transceiver receives a random access preamble from a terminal device, including the distributed unit DU of the RAN device receiving the random access preamble from the terminal device; the transceiver sends the first response to the terminal device, including the centralized unit CU of the RAN device sending the first response to the terminal device through the DU; the DU is connected to the CU.

22. The RAN device according to any one of claims 17 to 19, characterized in that: The transceiver receives a random access preamble from a terminal device, including the distributed unit DU of the RAN device receiving the random access preamble from the terminal device; the transceiver sends the first response to the terminal device, including the centralized unit CU of the RAN device sending the first response to the terminal device through the DU; the DU is connected to the CU.

23. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the instructions are executed on a computer, the computer is caused to perform the method according to any one of claims 1 to 5.

24. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the instructions are executed on a computer, the computer is caused to perform the method according to any one of claims 6 to 11.

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