Method and device for supporting on-demand system messages

Abstract

The present application discloses a method for supporting on-demand system messages, including: a base station distribution unit DU receives configuration information of a physical random access channel PRACH for requesting system messages from a base station concentration unit CU; the DU receives a random access preamble for requesting system messages from a user equipment UE; the DU determines information about the system message requested by the UE based on the random access preamble and the configuration information of the PRACH for requesting system messages, and sends the system message requested by the UE to the UE. The present application also discloses several other methods for supporting on-demand system messages and corresponding devices. By applying the technical solution disclosed in the present application, it is possible to support the sending of on-demand system messages through interaction between the CU and the DU.

Description

[0001] This application is a divisional application of an invention patent application with an application date of May 9, 2018, application number 201810437646.4, and invention name “Method and device for supporting system messages on-demand requests”. Technical Field

[0002] The present application relates to the field of wireless communication technology, and in particular to a method and device for supporting on-demand system messages. Background Art

[0003] In the next generation network or the fifth generation (5G) network, in order to support network function virtualization, more efficient resource management and scheduling, the base station (gNB) that provides a wireless network interface for the terminal (UE) can be further divided into a base station centralized unit gNB-CU (gNB central unit) and a base station distributed unit gNB-DU (gNB distributed unit) (referred to as CU and DU respectively in the present invention).

[0004] CU has at least Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP) protocol layers, and also includes Service Data Adaptation Protocol (SDAP: Service Data Adaptation Protocol).

[0005] DU has a radio link control protocol (RLC), a medium access control (MAC), a physical layer, etc.

[0006] The standardized public interface F1 interface is between CU and DU.

[0007] The F1 interface is divided into: F1 interface control plane (F1-C) and F1 interface user plane (F1-U).

[0008] The transmission network layer of F1-C is based on IP transmission. In order to transmit signaling more reliably, the Stream Control Transmission Protocol (SCTP) is added on top of IP. The protocol of the application layer is F1AP. SCTP can provide reliable application layer message transmission.

[0009] The transport layer of F1-U is UDP / IP, and GTP-U is used to carry user plane protocol data units (PDUs) over UDP / IP.

[0010] Figure 1 The structures of CU and DU are shown.

[0011] In addition, in order to reduce the system overhead caused by system messages, on-demand system messages are defined in the 5G network. The system messages are not broadcast in the cell all the time, but are sent according to the user's request. In order to support on-demand system messages, the user will send a specific random access preamble (PRACH preamble) or send a preamble on a specific random access resource (PRACH resource), or send a specific random access preamble on a specific random access resource. The base station (gNB) determines which one or several system messages (system information message) the user requests based on the received random access preamble and / or the resource receiving the random access preamble. The system message may contain one or more system information blocks (system information block), and then the base station sends the system message requested by the user to the user in a broadcast, multicast or unicast manner.

[0012] As mentioned above, in a 5G system, a gNB may consist of two independent functional entities, namely, CU and DU, with the interface between the two being the standardized F1. In such a structure, the CU is responsible for generating system messages, while the DU can receive random access preambles sent by users. If there is no support for on-demand system messages between the CU and DU, the CU cannot know that the user has sent a random access preamble related to the request system message. Therefore, in order to support on-demand system messages, a related mechanism needs to be defined between the CU and DU. There is no discussion on this yet. Summary of the invention

[0013] The present application provides several methods and devices for supporting on-demand system message requests, which can implement the sending of on-demand system message requests.

[0014] The present application discloses a method for supporting on-demand system messages, including:

[0015] A. The base station distribution unit DU receives configuration information of a physical random access channel PRACH for requesting system messages from the base station central unit CU;

[0016] B. The DU receives a random access preamble for requesting a system message from the user equipment UE;

[0017] C. The DU determines information about the system message requested by the UE according to the random access preamble and the configuration information of the PRACH used to request the system message, and sends the system message requested by the UE to the UE.

[0018] Preferably, before the C, the method further includes: the DU receives configuration information of the system message requested on demand from the CU, and the configuration information of the system message requested on demand includes at least one of the following information:

[0019] Each system message supporting user on-demand request includes at least one system information block SIB, or at least one SIB;

[0020] Scheduling information for each system message that supports user on-demand requests;

[0021] A correspondence between each system message supporting on-demand request of a user and the PRACH configuration information used to request the system message;

[0022] The PRACH configuration information used to request the system message includes: PRACH preamble information and / or PRACH resource information.

[0023] Preferably, the information about the system message requested by the UE is: the system message requested by the UE;

[0024] The C includes: the DU determines the corresponding PRACH configuration information according to the random access preamble, and determines the system message requested by the UE according to the corresponding relationship between each system message supporting user on-demand request and the PRACH configuration information used to request the system message.

[0025] Preferably, the information about the system message requested by the UE is: PRACH configuration information corresponding to the random access preamble;

[0026] The C includes: the DU determines corresponding PRACH configuration information according to the random access preamble, and sends the PRACH configuration information to the CU; the DU receives a system message requested by the UE from the CU, and sends the system message requested by the UE to the UE.

[0027] Preferably, before the C, the method further includes: the DU receives, from the CU, index information corresponding to each PRACH configuration information for requesting a system message;

[0028] The information about the system message requested by the UE is: index information corresponding to the PRACH configuration information;

[0029] The C includes: the DU determines the corresponding PRACH configuration information according to the random access preamble, determines the index information corresponding to the PRACH configuration information, and sends the index information to the CU; the DU receives the system message requested by the UE from the CU, and sends the system message requested by the UE to the UE.

[0030] Preferably, before the C, the method further includes: the DU receiving, from the CU, index information of the system message corresponding to each PRACH configuration information for requesting the system message;

[0031] The information about the system message requested by the UE is: index information of the system message;

[0032] The C includes: the DU determines the corresponding PRACH configuration information according to the random access preamble, determines the index information of the corresponding system message, and sends the index information to the CU; the DU receives the system message requested by the UE from the CU, and sends the system message requested by the UE to the UE.

[0033] Preferably, before the DU sends the system message requested by the UE to the UE, the method further includes:

[0034] The DU sends a confirmation message to the UE, where the confirmation message is used to indicate at least one of the following information:

[0035] Confirm that the network side will send the system message requested by the UE;

[0036] Acknowledge that the random access preamble sent by the UE has been received;

[0037] Confirming that the random access preamble sent by the UE has been received and that the UE is requesting a system message;

[0038] Confirm that the random access preamble sent by the UE has been received, and that the UE is requesting a system message, and sends a corresponding request message to the CU;

[0039] Confirm that the random access preamble sent by the UE has been received, and that the UE is requesting a system message, and has sent a corresponding request message to the CU, and the CU has confirmed the UE's request.

[0040] The present application also discloses a method for supporting on-demand system messages, including:

[0041] The CU sends configuration information of the physical random access channel PRACH used to request system messages to the DU.

[0042] Preferably, the method further comprises: the CU sends configuration information of the on-demand requested system message to the DU.

[0043] Preferably, the method further comprises:

[0044] The CU receives the PRACH configuration information corresponding to the random access preamble sent by the UE from the DU;

[0045] The CU determines the system message requested by the UE according to the PRACH configuration information, and sends the system message to the DU.

[0046] Preferably, the method further comprises:

[0047] The CU sends index information corresponding to each PRACH configuration for requesting system information to the DU;

[0048] The CU receives index information corresponding to the PRACH configuration information corresponding to the random access preamble sent by the UE from the DU;

[0049] The CU determines the system message requested by the UE according to the corresponding index information, and sends the system message to the DU.

[0050] Preferably, the method further comprises:

[0051] The CU sends the index information of the system message corresponding to each PRACH configuration information for requesting the system message to the DU;

[0052] The CU receives index information of a system message corresponding to the PRACH configuration information corresponding to the random access preamble sent by the UE from the DU;

[0053] The CU determines the system message requested by the UE according to the corresponding index information, and sends the system message to the DU.

[0054] The present application also discloses a base station distribution unit device, including: a CU interaction module, a UE interaction module and a storage module, wherein:

[0055] The CU interaction module is used to receive PRACH configuration information for requesting system messages from the CU;

[0056] The storage module is used to store the configuration information of the PRACH used to request the system message;

[0057] The UE interaction module is used to receive a random access preamble for requesting a system message from the UE, determine the system message requested by the UE according to the random access preamble and the configuration information of the PRACH for requesting the system message, and send the system message requested by the UE to the UE.

[0058] Preferably, the CU interaction module is further used to receive at least one of the following information from the CU:

[0059] Configuration information for system messages requested on demand;

[0060] Index information corresponding to each PRACH configuration;

[0061] Index information of the system message corresponding to each PRACH configuration information for requesting the system message.

[0062] The present application also discloses a base station centralized unit device, including: a DU interaction module and a processing module, wherein:

[0063] The DU interaction module is used to send the configuration information of the PRACH used to request the system message to the DU.

[0064] Preferably, the DU interaction module is further used to send at least one of the following information to the DU:

[0065] Configuration information for system messages requested on demand;

[0066] Index information corresponding to each PRACH configuration;

[0067] Index information of the system message corresponding to each PRACH configuration information for requesting the system message.

[0068] The present application also discloses a method for supporting on-demand system messages, including:

[0069] The base station distribution unit DU receives a system information request message from the user equipment UE;

[0070] Sending a message containing UE information to a base station centralized unit CU;

[0071] A confirmation message sent by the receiving CU indicating that the system information request message is correctly received;

[0072] Send the system information requested by the UE to the UE.

[0073] Preferably, the confirmation message includes at least one of the following information:

[0074] The identification information of the UE, the identification of the cell where the UE is located, and the indication information of the system information sent by the DU to the UE.

[0075] The present application discloses a method for supporting on-demand system messages, including:

[0076] The base station centralized unit CU receives a message containing UE information sent by the base station distributed unit DU, wherein the message containing UE information is sent by the DU after receiving a system information request message from the user equipment UE;

[0077] Send a confirmation message to the DU that the system information request message has been correctly received.

[0078] Preferably, the confirmation message includes at least one of the following information:

[0079] The identification information of the UE, the identification of the cell where the UE is located, and the indication information of the system information sent by the DU to the UE.

[0080] The present application discloses a base station distribution unit DU, comprising:

[0081] A first receiving module, configured to receive a system information request message from a user equipment UE;

[0082] A first sending module, configured to send a message containing UE information to a base station centralized unit CU;

[0083] A first receiving module is used to receive a confirmation message sent by the CU that the system information request message is correctly received;

[0084] The first sending module is used to send the system information requested by the UE to the UE.

[0085] The present application discloses a base station centralized unit CU, comprising:

[0086] A second receiving module is used to receive a message containing UE information sent by a base station distribution unit DU, wherein the message containing UE information is sent by the DU after receiving a system information request message from the user equipment UE;

[0087] The second sending module is used to send a confirmation message of correctly receiving the system information request message to the DU.

[0088] It can be seen from the above technical solutions that the method and device for supporting on-demand system messages provided in the present application can support the sending of on-demand system messages through the interaction between the CU and the DU. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 This is a structural diagram of the existing gNB-CU and gNB-DU;

[0090] Figure 2 A schematic diagram of a method for supporting on-demand request system messages between a CU and a DU according to the present invention;

[0091] Figure 3 A second schematic diagram of a method for supporting on-demand request system messages between a CU and a DU according to the present invention;

[0092] Figure 4 A third schematic diagram of a method for supporting on-demand request system messages between a CU and a DU according to the present invention;

[0093] Figure 5 A fourth schematic diagram of a method for supporting on-demand request system messages between a CU and a DU according to the present invention;

[0094] Figure 6 A schematic diagram of the structure of a preferred base station distribution unit device of the present invention;

[0095] Figure 7A schematic diagram of the structure of a preferred base station centralized unit device of the present invention;

[0096] Figure 8 A schematic diagram of the CU sending a confirmation message of receiving a system information request message to the DU according to the present invention;

[0097] Fig. 9 A fifth schematic diagram of a method for supporting on-demand request system messages between a CU and a DU according to the present invention;

[0098] Fig.10 Schematic diagram of the method for supporting on-demand request system messages between CU and DU according to the present invention. DETAILED DESCRIPTION

[0099] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples.

[0100] In a 5G network, a gNB may be composed of a CU and a DU, and the functions of the CU and the DU are different. In addition, the 5G network will also support a mechanism for requesting system messages on demand, in which the user will send a specific random access preamble (PRACH preamble), or send a preamble on a specific random access resource (PRACH resource), or send a specific random access preamble on a specific random access resource to request the required system message from the network side. If the gNB is divided into a CU and a DU, the DU can receive the random access preamble sent by the user, but the system message is generated by the CU, so in order to send the system message requested by the user to the user, interaction is required between the CU and the DU. The present invention proposes a method for supporting system messages requested by users through interaction between the CU and the DU.

[0101] In the present invention, the system message refers to a message including one or more system information blocks (SIB: system information block), or refers to one or more SIBs.

[0102] The technical solution of the present application is described in detail below through several preferred embodiments.

[0103] Embodiment 1

[0104] In this embodiment, the CU configures all on-demand requested system messages in the DU in advance.

[0105] This embodiment describes a method 1 for supporting on-demand system messages between CU and DU provided by the present invention. In this method, the CU sends all on-demand system messages and PRACH configuration information related to the on-demand system messages to the DU via a message on the F1 interface (such as a message on the control plane of the F1 interface, i.e., an F1-C message). When the DU receives a random access preamble (PRACH preamble) related to the requested system message, it sends the requested system message to the user (the sending method may be broadcast, unicast, or multicast). The flowchart of this method is shown in FIG. Figure 2 As shown, the following steps are included:

[0106] Step 201: The CU sends configuration information about supporting on-demand system messages to the DU through a message on the F1 interface (such as an F1-C message). The configuration information includes one or more of the following information:

[0107] 1) Each system message that supports user on-demand requests may contain one SIB (such as SIB4 in LTE), multiple SIBs (such as SIB4, SIB5, SIB6, etc. in LTE), or one or more SIBs;

[0108] 2) Scheduling information of each system message supporting user on-demand requests, such as the time position, and / or frequency position, and / or spatial information, and / or period, etc., of sending the system message;

[0109] 3) PRACH configuration information for requesting system messages, and the correspondence between the PRACH configuration information and each system message that supports on-demand requests by users, the PRACH configuration information includes PRACH preamble information and / or PRACH resource information (e.g., time-frequency resources for sending PRACH preamble, spatial resources for sending PRACH preamble). For example, PRACH configuration 1 is used to request system message 1, PRACH configuration 2 is used to request system message 2, etc. In addition, one PRACH configuration may also be used to request multiple system messages, such as PRACH configuration 3 is used to request system message 1 and system message 2. Table 1 shows an example of the correspondence between PRACH configurations and on-demand system messages.

[0110] PRACH Configuration 1 System Message 1 PRACH Configuration 2 System Message 2 PRACH Configuration 3 System message 1 and system message 2 PRACH Configuration 4 System message 2 and system message 3 PRACH Configuration 5 System message 4 and system message 5

[0111] Table 1

[0112] The configuration information in this step can be sent to the DU via the same F1 interface message, or can be sent to the DU via different F1 interface messages. In addition, if the configuration information is updated, the CU will also send an update message to the DU to update the configuration information.

[0113] Before or after this step, or in this step, it is assumed that the CU or DU has sent the PRACH configuration information for requesting the system message, and the correspondence between the PRACH configuration information and each system message supporting the user's on-demand request, to the user.

[0114] Step 202: The user sends a random access preamble to the DU to request a system message.

[0115] In this step, the user sends a corresponding random access preamble according to the received configuration information (PRACH configuration information for requesting system messages, and the corresponding relationship between the PRACH configuration information and each system message supporting user on-demand request) and the system message it wants to request.

[0116] Step 203: The DU determines one or more system messages requested by the user according to the received random access preamble, and then sends a confirmation message to the user. The confirmation message represents at least one of the following meanings:

[0117] 1) Confirm that the network side (CU and / or DU and / or base station) will send the system message requested by the user;

[0118] 2) confirming that the random access preamble sent by the user in step 202 has been received;

[0119] 3) confirming that the random access preamble sent by the user in step 202 has been received, and knowing that the user is requesting a system message;

[0120] 4) confirming that the random access preamble sent by the user in step 202 has been received, and knowing which one or several system messages the user is requesting (i.e. knowing the system messages requested by the user);

[0121] 5) Confirm that the random access preamble sent by the user in step 202 has been received, and learn which one or several system messages the user is requesting, and the DU stores the system message requested by the user (ie, the DU stores the system message requested by the user).

[0122] Step 204: The DU sends the system message requested by the user to the user.

[0123] Before step 204, if the system message and / or scheduling information stored at the DU is changed, the CU will send the updated system message and / or scheduling information to the DU in step 203a.

[0124] Embodiment 2

[0125] In this embodiment, the CU notifies the DU of the PRACH configuration for requesting system messages.

[0126] This embodiment describes the second method for supporting on-demand system message request between CU and DU provided by the present invention. In this method, CU sends the PRACH configuration for requesting system message to DU. When DU receives a random access preamble for requesting system message, it notifies CU of the configuration information corresponding to the received random access preamble. CU learns the system message requested by the user and sends the system message to the user through DU. The flowchart of this method is shown in FIG. Figure 3 As shown, the following steps are included:

[0127] Step 301: CU sends an F1 interface message to DU, which includes PRACH configuration information for requesting system messages, and the configuration information includes PRACH preamble information and / or PRACH resource information (e.g., the time-frequency resource position for sending PRACH preamble, the spatial resource for sending PRACH preamble). For example, the message includes PRACH configuration 1 for requesting system messages, PRACH configuration 2 for requesting system messages, etc. Based on this information, DU cannot learn the correspondence between PRACH configurations and system messages, and can only learn that if a random access preamble matching these configurations is received, it means that the user is requesting a system message.

[0128] Before or after this step, or in this step, it is assumed that the CU or DU has sent the PRACH configuration information for requesting the system message, and the correspondence between the PRACH configuration information and each system message supporting the user's on-demand request, to the user.

[0129] Step 302: The user sends a random access preamble to the DU to request a system message.

[0130] In this step, the user sends a corresponding random access preamble according to the received configuration information (PRACH configuration information for requesting system messages, and the corresponding relationship between the PRACH configuration information and each system message supporting user on-demand request) and the system message it wants to request.

[0131] Step 303: The DU sends an F1AP message (such as a system message request) to the CU, which includes the PRACH configuration information (PRACH preamble information and / or PRACH resource information) corresponding to the random access preamble received by the DU. Optionally, the DU can limit the time when the DU receives the response message in one of the following ways:

[0132] Mode 1: The message sent in step 303 includes clock information (such as time length information, time point information), which indicates the latest time point when the CU sends the response message;

[0133] Mode 2: After sending the message in step 303, the DU may start a timer. The DU expects to receive a response message before the timer times out. If not, it indicates that the message sent in step 303 is not successfully received by the CU.

[0134] Step 304: The CU replies a response message (such as a system message request response) to the DU, which is used to indicate that the CU confirms receipt of the message sent by the DU in step 303. This step is optional. In addition, the response message may also include one or more of the following information:

[0135] 1) One or more system messages requested by the user;

[0136] 2) Scheduling information of one or more system messages requested by the user.

[0137] Step 305: The DU sends a confirmation message to the user. The confirmation message represents at least one of the following meanings:

[0138] 1) Confirm that the network side (CU and / or DU and / or base station) will send the system message requested by the user;

[0139] 2) confirming that the random access preamble sent by the user in step 302 has been received;

[0140] 3) confirming that the random access preamble sent by the user in step 302 has been received, and knowing that the user is requesting a system message;

[0141] 4) confirming that the random access preamble sent by the user in step 302 has been received, and knowing that the user is requesting a system message, and sending a corresponding request message to the CU;

[0142] 5) Confirm that the random access preamble sent by the user in step 302 has been received, and that the user is requesting a system message, and has sent a corresponding request message to the CU, and the CU has confirmed the user's request.

[0143] Step 306: The DU sends the system message requested by the user to the user.

[0144] If there is no step 304, or step 304 does not include the system message requested by the user, or the system message requested by the user and / or the scheduling information stored at the DU is updated, there may be a step 305a before step 306. In step 305a, the CU sends the system message requested by the user and / or the scheduling information of the system message to the DU, and then through step 306, the DU sends the system message requested by the user to the user.

[0145] If the CU does not send the response message to the DU in time in the above step 304, steps 305 and 306 do not need to be performed.

[0146] Embodiment 3

[0147] In this embodiment, the CU notifies the DU of the PRACH configuration for requesting system messages and index information of each configuration.

[0148] This embodiment describes the third method for supporting on-demand system message requests between CU and DU provided by the present invention. In this method, CU sends the PRACH configuration for requesting system messages and the index information (index) corresponding to each PRACH configuration to DU. When DU receives a random access preamble requesting a system message, it notifies CU of the index information corresponding to the configuration information of the received random access preamble. CU learns the system message requested by the user and sends the system message to the user through DU. The flowchart of this method is shown in FIG. Figure 4 As shown, the following steps are included:

[0149] Step 401: CU sends an F1 interface message to DU, which includes PRACH configuration information for requesting system messages, and the configuration information includes PRACH preamble information and / or PRACH resource information (e.g., the time-frequency resource position for sending PRACH preamble, the spatial resource for sending PRACH preamble) and index information corresponding to each PRACH configuration information. For example, the message includes PRACH configuration 1 and index value 1 for requesting system messages, PRACH configuration 2 and index value 2 for requesting system messages, etc. Based on this information, DU cannot know the correspondence between PRACH configuration and system messages, but can only know that if a random access preamble matching these configurations is received, it means that the user is requesting a system message.

[0150] Before or after this step, or in this step, it is assumed that the CU or DU has sent the PRACH configuration information for requesting the system message, and the correspondence between the PRACH configuration information and each system message supporting the user's on-demand request, to the user.

[0151] Step 402: The user sends a random access preamble to the DU to request a system message.

[0152] In this step, the user sends a corresponding random access preamble according to the received configuration information (PRACH configuration information for requesting system messages, and the corresponding relationship between the PRACH configuration information and each system message supporting user on-demand request) and the system message it wants to request.

[0153] Step 403: The DU sends an F1AP message (such as a system message request) to the CU, which includes the index information of the PRACH configuration information (PRACH preamble information and / or PRACH resource information) corresponding to the random access preamble received by the DU. Optionally, the DU can limit the time when the DU receives the response message in one of the following ways:

[0154] Mode 1: The message sent in step 403 includes clock information (such as time length information, time point information), which indicates the latest time point when the CU sends the response message;

[0155] Mode 2: After sending the message in step 403, the DU may start a timer. The DU expects to receive a response message before the timer times out. If not, it indicates that the message sent in step 403 is not successfully received by the CU.

[0156] Step 404: The CU replies a response message (such as a system message request response) to the DU, which is used to indicate that the CU confirms receipt of the message sent by the DU in step 403. This step is optional. In addition, the response message may also include one or more of the following information:

[0157] 1) One or more system messages requested by the user;

[0158] 2) Scheduling information of one or more system messages requested by the user.

[0159] Step 405: The DU sends a confirmation message to the user. The confirmation message represents at least one of the following meanings:

[0160] 1) Confirm that the network side (CU and / or DU and / or base station) will send the system message requested by the user;

[0161] 2) confirming that the random access preamble sent by the user in step 402 has been received;

[0162] 3) confirming that the random access preamble sent by the user in step 402 has been received, and knowing that the user is requesting a system message;

[0163] 4) confirming that the random access preamble sent by the user in step 402 has been received, and knowing that the user is requesting a system message, and sending a corresponding request message to the CU;

[0164] 5) Confirm that the random access preamble sent by the user in step 402 has been received, and that the user is requesting a system message, and has sent a corresponding request message to the CU, and the CU has confirmed the user's request.

[0165] Step 406: The DU sends the system message requested by the user to the user.

[0166] If there is no step 404, or the system message requested by the user is not included in step 404, or the system message requested by the user and / or the scheduling information stored in the DU is updated, there may be step 405a before step 406. In step 405a, the CU sends the system message requested by the user and / or the scheduling information of the system message to the DU, and then in step 406, the DU sends the system message requested by the user to the user.

[0167] If the CU does not send the response message to the DU in time in the above step 404, steps 405 and 406 do not need to be performed.

[0168] Embodiment 4

[0169] In this embodiment, the CU notifies the DU of the PRACH configuration for requesting the system message and the corresponding indication information of the system message.

[0170] This embodiment describes a fourth method for supporting on-demand system message requests between CU and DU provided by the present invention. In this method, the CU sends the PRACH configuration for requesting system messages and the indication information of the system message corresponding to each PRACH configuration to the DU. When the DU receives a random access preamble requesting a system message, the DU will learn the system message requested by the user based on the PRACH configuration and the indication information of the system message corresponding to the previous system message sent by the CU, so that the indication information of the system message requested by the user can be notified to the CU. The CU learns the system message requested by the user and sends the system message to the user through the DU. The flowchart of this method is shown in FIG. Figure 5 As shown, the following steps are included:

[0171] Step 501: CU sends an F1 interface message to DU, which includes PRACH configuration information for requesting system messages, and the configuration information includes PRACH preamble information and / or PRACH resource information (for example: the time-frequency resource position for sending PRACH preamble, the spatial resource for sending PRACH preamble) and the indication information of the system message corresponding to each PRACH configuration information (the indication information may be the index information of the system message). For example: the message includes PRACH configuration 1 for requesting system messages and indication information that the configuration is for requesting system message 1, PRACH configuration 2 for requesting system messages and indication information that the configuration is for requesting system message 2, etc. Based on this information, DU can learn the system message that the user wants to request.

[0172] Before or after this step, or in this step, it is assumed that the CU or DU has sent the PRACH configuration information for requesting the system message, and the correspondence between the PRACH configuration information and each system message supporting the user's on-demand request, to the user.

[0173] Step 502: The user sends a random access preamble to the DU to request a system message.

[0174] In this step, the user sends a corresponding random access preamble according to the received configuration information (PRACH configuration information for requesting system messages, and the corresponding relationship between the PRACH configuration information and each system message supporting user on-demand request) and the system message it wants to request.

[0175] Step 503: The DU sends an F1AP message (such as a system message request) to the CU, which includes the indication information of the system message requested by the user. Optionally, the DU can limit the time when the DU receives the response message in one of the following ways:

[0176] Mode 1: The message sent in step 503 includes clock information (such as time length information, time point information), which indicates the latest time point when the CU sends the response message;

[0177] Mode 2: After sending the message in step 503, the DU may start a timer. The DU expects to receive a response message before the timer times out. If not, it indicates that the message sent in step 503 is not successfully received by the CU.

[0178] Step 504: The CU replies a response message (such as a system message request response) to the DU, which is used to indicate that the CU confirms receipt of the message sent in step 503. This step is optional. In addition, the response message may also include one or more of the following information:

[0179] 1) One or more system messages requested by the user;

[0180] 2) Scheduling information of one or more system messages requested by the user.

[0181] Step 505: The DU sends a confirmation message to the user. The confirmation message represents at least one of the following meanings:

[0182] 1) Confirm that the network side (CU and / or DU and / or base station) will send the system message requested by the user;

[0183] 2) confirming that the random access preamble sent by the user in step 502 has been received;

[0184] 3) confirming that the random access preamble sent by the user in step 502 has been received, and knowing that the user is requesting a system message;

[0185] 4) confirming that the random access preamble sent by the user in step 502 has been received, and knowing which one or more system messages the user is requesting;

[0186] 5) Confirm that the random access preamble sent by the user in step 502 has been received, and learn which one or more system messages the user is requesting, and send a request message to the CU

[0187] 6) Confirm that the preamble sent by the user in step 502 has been received, and that one or more system messages requested by the user have been learned, and a request message has been sent to the CU, and the CU has confirmed the user's request.

[0188] Step 506: The DU sends the system message requested by the user to the user.

[0189] If there is no step 504, or the system message requested by the user is not included in step 504, or the system message requested by the user and / or the scheduling information stored at the DU is updated, there may be step 505a before step 506. In step 505a, the CU sends the system message requested by the user and / or the scheduling information of the system message to the DU, and then in step 506, the DU sends the system message requested by the user to the user.

[0190] If the CU does not send the response message to the DU in time in the above step 504, steps 505 and 506 do not need to be performed.

[0191] Corresponding to the above method, the present application also provides corresponding equipment.

[0192] Figure 6This is a schematic diagram of the composition structure of a preferred base station distribution unit device of the present invention, the device includes: a CU interaction module, a UE interaction module and a storage module, wherein:

[0193] The CU interaction module is used to receive PRACH configuration information for requesting system messages from the CU;

[0194] The storage module is used to store the configuration information of the PRACH used to request the system message;

[0195] The UE interaction module is used to receive a random access preamble for requesting a system message from the UE, determine the system message requested by the UE according to the random access preamble and the configuration information of the PRACH for requesting the system message, and send the system message requested by the UE to the UE.

[0196] Preferably, the CU interaction module is further used to receive at least one of the following information from the CU:

[0197] Configuration information for system messages requested on demand;

[0198] Index information corresponding to each PRACH configuration;

[0199] Index information of the system message corresponding to each PRACH configuration information for requesting the system message.

[0200] Figure 7 The present invention is a schematic diagram of the composition structure of a preferred base station centralized unit device, the device includes: DU interaction module, wherein:

[0201] The DU interaction module is used to send the configuration information of the PRACH used to request the system message to the DU.

[0202] Preferably, the DU interaction module is further used to send at least one of the following information to the DU:

[0203] Configuration information for system messages requested on demand;

[0204] Index information corresponding to each PRACH configuration;

[0205] Index information of the system message corresponding to each PRACH configuration information for requesting the system message.

[0206] The method and device for supporting on-demand request of system messages between gNB-CU and gNB-DU provided by the present invention can solve the problem of how to support the transmission of on-demand request of system messages when the gNB is divided into DU and CU. The user requests the system message through the random access preamble, but the generation of the system message is completed in the CU. The present invention provides how to complete the transmission of the on-demand request of system messages through the information interaction of the F1 interface.

[0207] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

[0208] Example 5

[0209] When a user requests a system message through an RRC message (that is, requests a system message through Message 3 in the random access process), after receiving the RRC message, the base station will send a contention resolution message to the user to inform the user that the RRC message sent by the user to request a system message has been correctly received by the base station, so that the user can prepare to receive the system message it requested. The contention resolution message is generated by the MAC layer (such as a message containing a contention resolution identifier MAC CE (ContentionResolution Identity MAC Control Element)), not an RRC message. Under the CU-DU separation structure, the DU will send the received RRC message for requesting a system message to the CU. However, under the existing mechanism, the DU cannot know whether the CU has correctly received the RRC message. Therefore, the DU cannot send a contention resolution message to the user to inform the user whether the RRC message sent by the user to request a system message has been correctly received. In order to solve this problem, this embodiment proposes the following mechanism:

[0210] The CU sends a confirmation message to the DU that it has correctly received the system information request message sent by the user, such as Figure 8 As shown, this message is used to confirm to the DU that the system information request message sent by it has been correctly received by the CU. The possible implementation of the confirmation message is a message containing at least one of the following information (the following information is for one user. If the confirmation message contains confirmations for multiple users, the message will contain at least one of the following information for each user):

[0211] →User identification information, such as the user's identification information on the DU side (gNB-DU UE F1AP ID), the user's identification information in the cell (C-RNTI)

[0212] →The identifier of the cell where the user is located, such as NR CGI (NR-RAN Cell Global Identifier)

[0213] →Indication information of system information sent by DU to the user, which indicates the system information that DU needs to send to the user

[0214] According to the above "CU sends a confirmation message to DU that the system information request message sent by the user is correctly received", the process of the user requesting system information through the RRC message (i.e., method 5 for supporting on-demand system information requests between CU and DU) is as follows, Fig. 9 As shown:

[0215] Step 601: The user sends a system information request (SystemInfoRequest) message to the DU. The message is an RRC message indicating the system information requested by the user.

[0216] ■Step 602: The DU sends the system information request message received in step 601 to the CU via message 2. The message 2 (the message 2 may be an Initial UL RRC Message Transfer message) may include at least one of the following information: user identification information, such as user identification information on the DU side (gNB-DU UE F1AP ID), user identification information in the cell (C-RNTI)

[0217] ■The identifier of the cell where the user is located, such as NR CGI (NR-RAN Cell Global Identifier)

[0218] ■ The RRC message sent by the user, in this embodiment, is the system information request message sent in step 601

[0219] Step 603: The CU sends a confirmation message to the DU for correctly receiving the system information request message sent by the user. The message is used to confirm to the DU that the system information request message sent by the DU has been correctly received by the CU. The confirmation message may be implemented as a message containing at least one of the following information (the following information is for one user. If the confirmation message contains confirmations for multiple users, the message will contain at least one of the following information for each user):

[0220] →User identification information, such as the user's identification information on the DU side (gNB-DU UE F1AP ID), the user's identification information in the cell (C-RNTI)

[0221] →The identifier of the cell where the user is located, such as NR CGI (NR-RAN Cell Global Identifier)

[0222] →Indication information of system information sent by DU to the user, which indicates the system information that DU needs to send to the user

[0223] Step 604: The DU sends a message 3 to the user, where the message 3 is used to inform the user that the system information request sent by the user has been correctly received by the base station. The message 3 may be a contention resolution message (such as a message including a contention resolution identity MAC Control Element (MAC CE)).

[0224] Step 605: The DU sends the system message requested by the user to the user, which may be sent by broadcast or unicast.

[0225] In the above steps, the order of step 604 and step 605 can be exchanged, or they can occur simultaneously.

[0226] In the above steps, if step 603 does not include "indication information of system information sent by DU to the user", step 604 may further include step 604a as follows: Fig.10 As shown (i.e., method 6 of supporting on-demand system messages between CU and DU):

[0227] Step 604a: The CU sends a system information sending instruction message to the DU, where the message indicates the system information that the DU needs to send to the user.

[0228] In the above steps, the order of step 604, step 604a and step 605 can be exchanged arbitrarily, or can occur simultaneously.

[0229] Before step 601, step 600 may also be included, that is, the CU sends a message 1 to the DU, where the message includes system information and / or information related to scheduling of the system information.

Claims

1. A method performed by a base station distribution unit DU in a wireless communication system, characterized in that: include: receiving a system information request from a user equipment UE via a radio resource control RRC message; Sending a message including the system information request from the UE to a base station central unit CU; receiving a message sent by the CU for confirming receipt of the system information request from the UE, wherein the message for confirming receipt of the system information request from the UE includes: identification information of the UE in the distribution unit, and indication information of the system information that needs to be broadcast by the DU; Sending a message 3 of a random access process to the UE, where the message 3 of the random access process is used to indicate reception of the system information request from the UE; and Broadcasting system information according to the indication information of the system information included in the message for confirming receipt of the system information request from the UE.

2. The method according to claim 1, characterized in that The message for confirming receipt of the system information request from the UE further includes at least the following information: The identifier of the cell where the UE is located.

3. The method according to claim 1, characterized in that The identification information of the UE in the distribution unit includes: the base station distribution unit UE forward interface application protocol identifier gNB-DU UE F1AP ID.

4. The method according to claim 1, characterized in that Message 3 of the random access process includes a contention resolution identifier medium access control MAC control element CE.

5. A method performed by a base station centralized unit CU in a wireless communication system, characterized in that: include: receiving, from a base station distribution unit DU, a message including a system information request from a user equipment UE, wherein the system information request from the UE is received by the DU via a radio resource control RRC message; and sending a message for confirming receipt of the system information request from the UE to the DU, wherein the message for confirming receipt of the system information request from the UE includes: identification information of the UE in the distribution unit, and indication information of the system information to be broadcasted by the DU, The message Message 3 of the random access process sent by the DU to the UE is used to indicate the reception of the system information request from the UE, and The system information is broadcast by the DU according to the indication information of the system information included in the message for confirming receipt of the system information request from the UE.

6. The method according to claim 5, characterized in that The message for confirming receipt of the system information request from the UE further includes at least the following information: The identifier of the cell where the UE is located.

7. The method according to claim 5, characterized in that The identification information of the UE in the distribution unit includes: the base station distribution unit UE forward interface application protocol identifier gNB-DU UE F1AP ID.

8. The method according to claim 5, characterized in that Message 3 of the random access process includes a contention resolution identifier medium access control MAC control element CE.

9. A base station distribution unit DU, characterized in that: include: A first receiving module receives a system information request from a user equipment UE via a radio resource control RRC message; A first sending module, configured to send a message including the system information request from the UE to a base station centralized unit CU; A second receiving module is configured to receive a message sent by the CU for confirming receipt of the system information request from the UE, wherein the message for confirming receipt of the system information request from the UE includes: identification information of the UE in the distribution unit, and indication information that needs to be broadcast by the DU; A second sending module, used to send a message 3 of a random access process to the UE, where the message 3 of the random access process is used to indicate the reception of the system information request from the UE; The third sending module is used to broadcast the system information according to the indication information of the system information included in the message for confirming receipt of the system information request from the UE.

10. The DU according to claim 9, characterized in that: The message for confirming receipt of the system information request from the UE further includes at least the following information: The identifier of the cell where the UE is located.

11. The DU according to claim 9, characterized in that: The identification information of the UE in the distribution unit includes: the base station distribution unit UE forward interface application protocol identifier gNB-DU UE F1AP ID.

12. The DU according to claim 9, characterized in that Message 3 of the random access process includes a message of a contention resolution identifier medium access control MAC control element CE.

13. A base station centralized unit CU, characterized in that: include: A third receiving module is configured to receive a message including a system information request from a user equipment UE from a base station distribution unit DU, wherein the system information request from the UE is received by the DU via a radio resource control RRC message; a fourth sending module, configured to send a message to the DU for confirming receipt of the system information request from the UE, wherein the message for confirming receipt of the system information request from the UE includes: identification information of the UE in the distribution unit, and indication information of the system information to be broadcast by the DU, The message Message 3 of the random access process sent by the DU to the UE is used to indicate the reception of the system information request from the UE, and The system information is broadcast by the DU according to the indication information of the system information included in the message for confirming receipt of the system information request from the UE.

14. The CU according to claim 13, characterized in that: The message for confirming receipt of the system information request from the UE further includes at least the following information: The identifier of the cell where the UE is located.

15. The CU according to claim 13, characterized in that: The identification information of the UE in the distribution unit includes: the base station distribution unit UE forward interface application protocol identifier gNB-DU UE F1AP ID.

16. The CU according to claim 13, characterized in that: Message 3 of the random access process includes a contention resolution identifier medium access control MAC control element CE.

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