WO2021232852A1

WO2021232852A1 - Method and apparatus for terminal to access network

Info

Publication number: WO2021232852A1
Application number: PCT/CN2021/074698
Authority: WO
Inventors: 杨晨晨; 晋英豪; 谭巍; 韩锋
Original assignee: 华为技术有限公司
Priority date: 2020-05-18
Filing date: 2021-02-01
Publication date: 2021-11-25
Also published as: CN113692063A

Abstract

Provided in the embodiments of the present application are a method and apparatus for a terminal to access a network, used for saving air interface signaling overhead and reducing time delay for the terminal to access the network. A first DU sends a first request message to a selected first CU to access the terminal to the first CU; if the first CU does not support the terminal access, the first DU receives a first response message from the first CU, wherein the first response message carries auxiliary information for assisting the first DU to reselect a CU, and the first DU selects a second CU according to the auxiliary information, so as to access the terminal to the network by means of the second CU.

Description

Method and device for terminal to access network

Cross-references to related applications

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 202010421420.2, and the application name is "a method and device for terminal access to the network" on May 18, 2020, the entire content of which is incorporated by reference In this application.

Technical field

This application relates to the field of communication technology, and in particular to a method and device for a terminal to access a network.

Background technique

The 3rd generation partnership project (3GPP) version 16 (release16, R16) standard introduced non-public networks (NPN). Different from traditional cellular networks, NPN networks only allow certain users with specific permissions to access.

3GPP defines two NPN deployment modes: stand-alone non-public networks (SNPN) with independent networking, and public network integrated NPN (INPN) with non-independent networking. Among them, the non-independent networking NPN is also called PNI-NPN. For ease of description, the independent networking NPN is marked as SNPN, and the non-independent networking NPN is marked as PNI-NPN.

The public network integrated NPN (PNI-NPN) is generally identified by the public land mobile network (PLMN) identity (ID) and the closed access group (CAG) ID. Logo. When the terminal accesses the PNI-NPN network, it will report the PLMN ID corresponding to the network that the terminal has selected in the initial radio resource control (radio resource control, RRC) setup complete (RRC setup complete) message, which is selected PLMN ID, but does not report the CAG ID that the terminal selects to access. Therefore, under the architecture that the access network equipment is a centralized unit (CU) and a distributed unit (DU), DU and CU They cannot perceive the CAG ID that the terminal selects to access, that is, they cannot perceive the PNI-NPN that the terminal accesses.

The CU-DU separation architecture can support DU sharing: a DU is connected to a physical CU, and a physical CU can be logically divided into multiple logical CUs, one of which corresponds to a physical cell, and each logical CU corresponds to a logical Cell, so the same physical cell can correspond to multiple logical cells, that is, multiple logical CUs share one DU.

Among multiple logical cells corresponding to the same physical cell, different logical cells can be configured with different networks, but these different networks can be configured with the same PLMN ID. This will cause a problem: Although the PLMN ID of the logical cell that the DU accesses for the terminal is the same as the PLMN ID that the terminal selects to access, the network where the DU is the logical cell that the terminal accesses may not support terminal access. For example, the network that the terminal selects to access is based on the non-public network identified by PLMN ID#1 and CAG ID#1, and the logical cell that DU is the terminal access is based on the public network identified by PLMN ID#1; another example is the terminal selection The accessed network is based on the non-public network 1 identified by PLMN ID#1 and CAG ID#1, and the logical cell that DU is the terminal access is based on the non-public network 2 identified by PLMN ID#1 and CAG ID#2.

In this case, when the access and mobility management function (AMF) is performing admission control on the terminal, if it is determined that the network of the logical cell selected by the DU does not support terminal access, The terminal's access request will be directly rejected, and then the connection between the terminal and the DU will be disconnected, which will cause the terminal to perform cell selection and random access procedures again, which increases the overhead of air interface signaling and the delay of terminal access to the network.

Summary of the invention

The embodiments of the present application provide a method and device for a terminal to access a network, which are used to save air interface signaling overhead and reduce the time delay for the terminal to access the network.

In a first aspect, an embodiment of the present application provides a method for a terminal to access a network, including: a first distributed unit DU sends a first request message to a selected first centralized unit CU, wherein the first request message is used Requesting the terminal to access the first CU; the first DU receives a first response message from the first CU, where the first response message is used to instruct the first DU to reselect a CU, so The first response message carries auxiliary information, and the auxiliary information is used to assist the first DU to reselect a CU; the first DU reselects a second CU according to the auxiliary information to pass the terminal through the The second CU is connected to the network.

In the embodiment of this application, when the first CU selected by the first DU does not support terminal access, the network side may not directly reject the terminal access, but may use the first CU to return auxiliary information to assist the first DU to reselect the second CU to continue. The access process can avoid the problem that the network side directly denies the terminal access and the terminal needs to perform cell selection and random access procedures again, which can save air interface signaling overhead and reduce the time delay for the terminal to access the network.

Optionally, the first DU sends a second request message to the second CU, where the second request message is used to request the terminal to access the second CU.

Optionally, the auxiliary information includes one or more of the following information: a public land mobile network identity PLMN ID; a closed access group identity CAG ID; a closed access group CAG list of the terminal that is allowed to access; Indication information of whether the terminal can only access the CAG cell.

Through this implementation manner, the first DU can help the first DU to quickly determine the second CU, reduce the probability that the first DU selects the CU by mistake, and further reduce the delay of the terminal accessing the network.

Optionally, the second request message includes one or more of the following information: CU reselection information of the first DU; the CAG ID; the PLMN ID; the CAG list; the Indication of whether the terminal can only access the CAG cell.

Through this implementation manner, the first CU can learn that the first DU has performed CU reselection, which improves the efficiency of the network to perform admission control on the terminal, and further reduces the time delay for the terminal to access the network.

In a second aspect, an embodiment of the present application provides a method for a terminal to access a network, including: the access and mobility management function AMF receives a third request message from a first CU, where the third request message is used to request that the terminal Access the AMF; the AMF judges that the first CU does not support the terminal access according to the subscription information of the terminal, the AMF sends a third response message to the first CU, the third response A message is used to instruct the first DU to reselect a CU, the third response message carries auxiliary information, and the auxiliary information is used to assist the first DU in selecting a CU.

In the embodiment of this application, when the first CU selected by the first DU does not support terminal access, the AMF may not directly reject the terminal access, but may use the first CU to return auxiliary information to assist the first DU to reselect the CU such as the second CU. Continuing the access process can avoid the problem that the AMF directly rejects the terminal access and the terminal needs to perform cell selection and random access procedures again, which can save air interface signaling overhead and reduce the time delay for the terminal to access the network.

Optionally, the third request message includes indication information for indicating whether the access network RAN has a CU-DU separated architecture; the AMF sending a third response message to the first CU includes: After determining that the RAN is a CU-DU separated architecture according to the indication information, the AMF sends a third response message to the first CU.

Through this implementation manner, the AMF instructs the first DU to reselect a CU after determining that the RAN is a CU-DU separated architecture (that is, the first DU has the possibility of selecting other CUs), which improves the reliability of the solution.

Optionally, the third request message includes CU reselection information of the first DU; the AMF sending a third response message to the first CU includes: the AMF according to the CU reselection information After determining that the first DU has not performed CU reselection, or the number of CU reselections performed by the first DU does not exceed a preset value, or there are unselected CUs among the CUs connected to the first DU, Send a third response message to the first CU.

Through this embodiment, the AMF determines that the first DU has not performed CU reselection, or the number of CU reselections performed by the first DU does not exceed the preset value, or there are unselected CUs among the CUs connected to the first DU. , The first DU is instructed to reselect the CU to ensure that the first DU can select other CUs, which further improves the reliability of the solution.

Optionally, the third response message includes one or more of the following information: public land mobile network identification PLMN ID; closed access group identification CAG ID; closed access group CAG that the terminal is allowed to access List; information indicating whether the terminal can only access the CAG cell.

In a third aspect, an embodiment of the present application provides a method for a terminal to access a network, including: a first CU receives a first request message from a first DU, where the first request message is used to request the terminal to access the The first CU; the first CU sends a third request message to the AMF, where the third request message is used to request the terminal to access the AMF; the first CU receives the third response message from the AMF , Wherein the third response message is used to instruct the first DU to reselect a CU, the third response message carries auxiliary information, and the auxiliary information is used to assist the first DU in reselecting a CU; A CU sends a first response message to the first DU, where the first response message is used to instruct the first DU to reselect a CU, and the first response message carries the auxiliary information.

Optionally, the third request message includes indication information used to indicate whether the access network RAN has a CU-DU separated architecture.

Optionally, the third request message includes CU reselection information of the first DU.

For the beneficial effects of the embodiments in the third aspect described above, please refer to the beneficial effects of the corresponding embodiments in the first and second aspects, which will not be repeated here.

In a fourth aspect, an embodiment of the present application provides a method for a terminal to access a network, including:

The second CU receives a second request message from the first DU, where the second request message is used to request the terminal to access the second CU; the second CU sends a fourth request message to the AMF, where The fourth request message is used to request the terminal to access the AMF; the second CU receives an initial context establishment request message from the AMF; the second CU according to the initial context establishment request message is The terminal establishes a context.

Optionally, the second request message and/or the fourth request message include: CU reselection information of the first DU.

For the beneficial effects of the embodiments in the fourth aspect described above, please refer to the beneficial effects of the corresponding embodiments in the first and second aspects, which will not be repeated here.

In a fifth aspect, an embodiment of the present application provides a method for a terminal to access a network, including:

The first DU determines that the public-network-converged non-public network PNI-NPN network configured on the selected first CU does not support the network that the terminal requests to access;

The first DU sends a sixth request message to the first CU, which is used to instruct the first CU to release the context configured for the terminal, and the first DU selects a second CU, and sends a message to the first CU. The second CU sends a seventh request message, where the seventh request message is used to request the terminal to access the second CU.

In the embodiment of this application, when the first DU senses that the selected first CU does not support terminal access, it may not directly reject the terminal access, but inform the first CU to release the context of the terminal to support the reselection of the CU and continue to connect the terminal. Access to the network can prevent the AMF from directly denying the terminal access, which causes the terminal to retry (cell selection and random access process issues, which can save air interface signaling overhead and reduce the time delay for the terminal to access the network.

Optionally, the sixth request message includes a cause value, and the cause value is used to indicate that the first CU needs to release the context configured for the terminal because it does not support the PNI-NPN network requested by the terminal.

Through this embodiment, the reliability of the solution can be improved.

Optionally, the cause value includes one or more of the following information: the first CU does not support the closed access group identification CAG ID requested by the terminal; the first CU does not support the non-public information requested by the terminal Network NPN; the first CU does not support the public network convergence non-public network PNI-NPN requested by the terminal; the CAG ID requested by the terminal is invalid; the NPN requested by the terminal is invalid; the PNI requested by the terminal NPN is invalid.

Through this embodiment, multiple implementation methods of the cause value are provided, and the flexibility of the solution can be improved.

Optionally, the seventh request message includes CU reselection information of the first DU.

Through this implementation manner, after the subsequent AMF determines that the second CU does not support the network that the terminal requests to access, it can determine whether it is necessary to instruct the first DU to continue reselecting the CU.

In a sixth aspect, an embodiment of the present application provides a method for a terminal to access a network, including: a second CU receives a seventh request message from a first DU, where the seventh request message is used to request that the terminal access The second CU; the second CU sends a ninth request message to the AMF, where the ninth request message is used to request the terminal to access the AMF; the second CU receives the AMF The initial context establishment request message is used to establish a context for the terminal according to the initial context establishment request message.

For the beneficial effects of the above-mentioned sixth aspect, please refer to the beneficial effects of the fifth aspect, which will not be repeated here.

In a seventh aspect, an embodiment of the present application provides a method for a terminal to access a network, including: an AMF receives a ninth request message from a second CU, where the ninth request message is used to request that the terminal access the AMF; the AMF determines that the second CU supports the terminal access, and sends an initial context establishment request message to the second CU.

For the beneficial effects of the seventh aspect mentioned above, please refer to the beneficial effects of the fifth aspect, which will not be repeated here.

In an eighth aspect, an embodiment of the present application provides a method for a terminal to access a network, including:

The first CU receives a sixth request message from the first DU, where the sixth request message is used to instruct the first CU to release the context configured for the terminal;

The first CU releases the context of the terminal in response to the sixth request message.

For the beneficial effects of the above-mentioned eighth aspect, please refer to the beneficial effects of the above-mentioned fifth aspect, which will not be repeated here.

In a ninth aspect, an embodiment of the present application provides a method for a terminal to access a network, including:

The first DU determines that the public-network-converged non-public network PNI-NPN network on the selected first CU configuration does not support the network that the terminal requests to access;

Sending, by the first DU, a fifth request message to the first CU, where the fifth request message is used to request the first CU to send an access request message to the AMF;

The first DU receives a fifth response message from the first CU, where the fifth response message is used to instruct the terminal to access the first DU or another network configured on the first CU.

In the embodiment of this application, when the first DU senses that the selected first CU does not support terminal access, it may not directly reject the terminal access, but instruct the CU to continue sending requests to the AMF, as long as the first CU or the first DU Any one of the supported networks is supported by the terminal, and the AMF can allow the terminal's access. It can avoid the problem that the AMF directly refuses the terminal access and the terminal needs to perform cell selection and random access procedures again, which can save air interface signaling overhead and reduce the time delay for the terminal to access the network.

Optionally, the fifth request message includes indication information, and the indication information is used to indicate that although the first CU does not support the network that the terminal requests to access, the first CU still needs to notify the AMF Send a request for access message.

Through this embodiment, after the AMF determines that the first CU does not support the network that the terminal requests to access, it can connect the terminal or make the terminal online contract or make the terminal access the first DU or the first DU through third-party authentication. Other networks configured on the CU improve the efficiency of the terminal's access to the network.

Optionally, the fifth request message includes CU reselection information of the first DU.

Through this embodiment, the first CU can pass the CU reselection information of the first DU to the AMF, so that after the AMF determines that the first CU does not support the network that the terminal requests to access, it is based on the CU reselection of the first DU. The selection information determines whether the first DU needs to be instructed to reselect the CU, which further improves the reliability of the solution.

For the beneficial effects of the aforementioned ninth aspect, please refer to the beneficial effects of the aforementioned fifth aspect, which will not be repeated here.

In a tenth aspect, an embodiment of the present application provides a method for a terminal to access a network, including: a first CU receives a fifth request message from a first DU, where the fifth request message is that the first DU determines the Generated when the public-network-converged non-public network PNI-NPN network configured on the first CU does not support the network that the terminal requests to access, the fifth request message is used to request the first CU to send access to the AMF Request message; the first CU sends an eighth request message to the AMF, where the eighth request message is used to request the terminal to access the AMF.

For the beneficial effects of the embodiments in the tenth aspect described above, please refer to the beneficial effects of the embodiments in the ninth aspect, which will not be repeated here.

In an eleventh aspect, an embodiment of the present application provides a method for a terminal to access a network, including: an AMF receives an eighth request message from a first CU, where the eighth request message is used to request that the terminal access the network. The AMF, wherein the eighth request message is generated by the first CU when the PNI-NPN network configured on the first CU does not support the network that the terminal requests to access; the AMF determines that the first DU or Whether other networks configured on the first CU support terminal access, and if so, the terminal is connected to the other networks.

For the beneficial effects of the above-mentioned eleventh aspect, please refer to the beneficial effects of the ninth aspect, which will not be repeated here.

In a twelfth aspect, an embodiment of the present application provides a device for wireless access to a network. The device may be a DU or a device on the DU. The device includes a device for performing the first aspect or any one of the first aspects. The module of the method described in the design.

Exemplarily, the device includes:

A sending module, configured to send a first request message to the selected first CU, where the first request message is used to request the terminal to access the first CU;

The receiving module is configured to receive a first response message from the first CU, where the first response message is used to instruct the device to reselect a CU, and the first response message carries auxiliary information, the auxiliary information Used to assist the device to reselect CU;

The processing module is configured to select a second CU according to the auxiliary information, so as to connect the terminal to the network through the second CU.

Optionally, the sending module is further configured to send a second request message to the second CU, where the second request message is used to request the terminal to access the second CU.

Optionally, the auxiliary information includes one or more of the following information:

Public land mobile network identification PLMN ID;

CAG ID of the closed access group;

The CAG list of the closed access group that the terminal is allowed to access;

Indication information of whether the terminal can only access the CAG cell.

Optionally, the second request message includes one or more of the following information:

CU reselection information of the device;

The CAG ID;

The PLMN ID;

The CAG list;

Indication information of whether the terminal can only access the CAG cell.

In a thirteenth aspect, an embodiment of the present application provides a core network device. The device may be an AMF or a device on the AMF. The device includes a possible design for implementing the second aspect or any of the second aspects. Module of the method described in.

Exemplarily, the device includes:

A receiving module, configured to receive a third request message from the first CU, where the third request message is used to request the terminal to access the device;

A processing module, configured to determine, according to the subscription information of the terminal, that the first CU does not support the terminal access;

The sending module is configured to send a third response message to the first CU, where the third response message is used to instruct the first DU to reselect a CU, and the third response message carries auxiliary information, the auxiliary information Used to assist the first DU to reselect a CU.

Optionally, the third request message includes indication information used to indicate whether the access network RAN has a CU-DU separated architecture;

The processing module is further configured to determine whether the RAN is a CU-DU separated architecture according to the indication information;

The sending module is configured to send a third response message to the first CU after the processing module determines that the RAN is a CU-DU separated architecture.

Optionally, the third request message includes CU reselection information of the first DU;

The processing module is further configured to determine, according to the CU reselection information, whether the first DU has performed CU reselection, or whether the first DU has performed CU reselection times and does not exceed a preset value, or Whether there is an unselected CU among the CUs connected to the first DU;

The sending module is configured to: the processing module determines that the first DU has not performed CU reselection, or the number of CU reselections performed by the first DU does not exceed a preset value, or the first DU After there is an unselected CU among the connected CUs, a third response message is sent to the first CU.

Optionally, the third response message includes one or more of the following information:

Public land mobile network identification PLMN ID;

CAG ID of the closed access group;

The CAG list of the closed access group that the terminal is allowed to access;

Indication information of whether the terminal can only access the CAG cell.

In a fourteenth aspect, an embodiment of the present application provides a device for wireless access to a network. The device may be a CU or a device on the CU. The device includes a device for executing the third aspect or any one of the third aspects. The module of the method described in the design.

Exemplarily, the device includes:

A receiving module, configured to receive a first request message from a first DU, where the first request message is used to request a terminal to access the device;

A sending module, configured to send a third request message to the AMF, where the third request message is used to request the terminal to access the AMF;

The receiving module is further configured to receive a third response message from the AMF, where the third response message is used to instruct the first DU to reselect a CU, and the third response message carries auxiliary information, so The auxiliary information is used to assist the first DU to reselect a CU;

The sending module is further configured to send a first response message to the first DU, where the first response message is used to instruct the first DU to reselect a CU, and the first response message carries the auxiliary information.

In a fifteenth aspect, an embodiment of the present application provides a device for wireless access to a network. The device may be a CU or a device on the CU. The device includes a device for performing any of the foregoing fourth aspect or the fourth aspect. The module of the method described in the design.

Exemplarily, the device includes:

A receiving module, configured to receive a second request message from the first DU, where the second request message is used to request the terminal to access the device;

A sending module, configured to send a fourth request message to the AMF, where the fourth request message is used to request the terminal to access the AMF;

The receiving module is further configured to receive an initial context establishment request message from the AMF;

The processing module is configured to establish a context for the terminal according to the initial context establishment request message.

In a sixteenth aspect, an embodiment of the present application provides a device for wireless access to a network. The device may be a DU or a device on the DU. The device includes a device for performing any one of the fifth aspect or the fifth aspect above. The module of the method described in the design.

Exemplarily, the device includes:

A processing module, configured to determine that the public-network-converged non-public network PNI-NPN network on the selected first CU configuration does not support the network that the terminal requests to access;

A sending module, configured to send a sixth request message to the first CU, used to instruct the first CU to release the context configured for the terminal;

The processing module is also used to select a second CU;

The sending module is further configured to send a seventh request message to the second CU, where the seventh request message is used to request the terminal to access the second CU.

Optionally, the seventh request message includes CU reselection information of the device.

In a seventeenth aspect, an embodiment of the present application provides a device for wireless access to a network. The device may be a CU or a device on the CU. The device includes a module for executing the method described in the sixth aspect.

Exemplarily, the device includes:

A receiving module, configured to receive a seventh request message from the first DU, where the seventh request message is used to request the terminal to access the device;

A sending module, configured to send a ninth request message to the AMF, where the ninth request message is used to request the terminal to access the AMF;

In an eighteenth aspect, an embodiment of the present application provides a core network device. The device may be an AMF or a device on the AMF. The device includes a module for executing the method in the seventh aspect.

Exemplarily, the device includes:

A receiving module, configured to receive a ninth request message from a second CU, where the ninth request message is used to request the terminal to access the device;

The sending module is configured to send an initial context establishment request message to the second CU when the second CU supports the terminal access.

In a nineteenth aspect, an embodiment of the present application provides a device for wireless access to a network. The device may be a CU or a device on the CU. The device includes a module for executing the method in the eighth aspect.

Exemplarily, the device includes:

A receiving module, configured to receive a sixth request message from the first DU, where the sixth request message is used to instruct the first CU to release the context configured for the terminal;

The processing module is configured to release the context of the terminal in response to the sixth request message.

In a twentieth aspect, an embodiment of the present application provides a device for wireless access to a network. The device may be a first DU, or a device on the first DU, and the device includes methods for performing the method described in the ninth aspect. Module.

Exemplarily, the device includes:

A processing module, configured to determine that the public-network-converged non-public network PNI-NPN network configured on the selected first CU does not support the network that the terminal requests to access;

A sending module, configured to send a fifth request message to the first CU, where the fifth request message is used to request the first CU to send an access request message to the AMF;

The receiving module is configured to receive a fifth response message from the first CU, where the fifth response message is used to instruct the terminal to access the device or another network configured on the first CU.

In the twenty-first aspect, an embodiment of the present application provides a device for wireless access to a network. The device may be a first CU or a device on the first CU. The device includes a device for performing the tenth aspect or the tenth aspect. Any one of the possible designs of the method described in the aspect.

The receiving module is configured to receive a fifth request message from the first DU, where the fifth request message is that the first DU determines that the public network converged non-public network PNI-NPN network configured on the first CU is not Generated when supporting the network that the terminal requests to access, the fifth request message is used to request the device to send an access request message to the AMF;

The sending module is configured to send an eighth request message to the AMF, where the eighth request message is used to request the terminal to access the AMF.

Optionally, the fifth request message includes indication information, and the indication information is used to indicate that although the device does not support the network that the terminal requests to access, the device still needs to send a request for access to the AMF information.

In the twenty-second aspect, an embodiment of the present application provides a core network device. The device may be an AMF or a device on the AMF. The device includes a module for executing the method described in the eleventh aspect.

Exemplarily, the device includes:

The receiving module is configured to receive an eighth request message from the first CU, where the eighth request message is used to request the terminal to access the device, and the eighth request message is for the first CU Generated by the first CU when the configured PNI-NPN network does not support the network that the terminal requests to access;

The processing module is used to determine whether the first DU or other network configured on the first CU supports terminal access, and if it does, connect the terminal to the other network.

In a twenty-third aspect, an embodiment of the present application provides a communication device, and the device includes:

At least one processor; and,

A memory and a communication interface communicatively connected with the at least one processor;

Wherein, the memory stores instructions that can be executed by the at least one processor, and the at least one processor executes any one of the first aspect to the eleventh aspect, by executing the instructions stored in the memory, Or the method described in any one of the optional implementation manners of the first aspect to the eleventh aspect.

In a twenty-fourth aspect, an embodiment of the present application provides a computer-readable storage medium, including a program or instruction, when the program or instruction runs on a computer, any aspect of the first aspect to the eleventh aspect , Or the method described in any one of the optional implementation manners of the first aspect to the eleventh aspect is executed.

In the twenty-fifth aspect, the embodiments of the present application provide a computer program product, which when running on a computer, makes any one of the first aspect to the eleventh aspect, or the first aspect to the eleventh aspect The method described in any one of the optional implementations is executed.

In a twenty-sixth aspect, an embodiment of the present application provides a chip, which is coupled with a memory, and is configured to read and execute program instructions stored in the memory to implement any one of the first aspect to the eleventh aspect Aspect, or the method described in an optional implementation of any one of the first aspect to the eleventh aspect.

In a twenty-seventh aspect, an embodiment of the present application provides a communication system, including:

The device of the twelfth aspect, the device of the thirteenth aspect, the device of the fourteenth aspect, and the device of the fifteenth aspect; or,

The device of the sixteenth aspect, the device of the seventeenth aspect, the device of the eighteenth aspect, and the device of the nineteenth aspect; or,

The device described in the twentieth aspect, the device described in the twenty-first aspect, and the device described in the twenty-second aspect.

For the beneficial effects of the above-mentioned eleventh aspect to the twenty-seventh aspect, please refer to the beneficial effects of the corresponding implementation manners in the first aspect to the eleventh aspect, which will not be repeated here.

Description of the drawings

Figure 1A is a schematic diagram of independent networking NPN and non-independent networking NPN;

Figure 1B is a schematic diagram of different logical CUs configured with different networks;

FIG. 1C is a schematic diagram of the format of the network identification NID;

Figure 2 is a schematic diagram of the initial access process when the UE accesses the PNI-NPN network;

FIG. 3A is a schematic structural diagram of a possible communication system to which an embodiment of this application is applicable;

Figure 3B is a schematic diagram of the first DU being shared by a physical entity;

Figure 3C is a schematic diagram of the first DU being shared by logical entities;

4A is a flowchart of a method for a terminal to access a network according to an embodiment of the application;

4B is a flowchart of a method for a terminal to access a network according to an embodiment of the application;

FIG. 5 is a flowchart of another method for a terminal to access a network according to an embodiment of the application;

FIG. 6 is a flowchart of another method for a terminal to access a network according to an embodiment of the application;

FIG. 7 is a schematic structural diagram of a wireless access network device 700 provided by an embodiment of this application;

FIG. 8 is a schematic structural diagram of a core network device 800 provided by an embodiment of this application;

FIG. 9 is a schematic structural diagram of a wireless access network device 900 provided by an embodiment of this application;

FIG. 10 is a schematic structural diagram of an apparatus 1000 for wireless access to a network provided by an embodiment of this application;

FIG. 11 is a schematic structural diagram of a wireless access network device 1100 provided by an embodiment of this application;

FIG. 12 is a schematic structural diagram of an apparatus 1200 for wireless access to a network provided by an embodiment of this application;

FIG. 13 is a schematic structural diagram of a core network device 1300 provided by an embodiment of this application;

FIG. 14 is a schematic structural diagram of a wireless access network device 1400 provided by an embodiment of this application;

FIG. 15 is a schematic structural diagram of an apparatus 1500 for wireless access to a network provided by an embodiment of this application;

FIG. 16 is a schematic structural diagram of an apparatus 1600 for wireless access to a network provided by an embodiment of this application;

FIG. 17 is a schematic structural diagram of a core network device 1700 provided by an embodiment of this application;

FIG. 18 is a schematic structural diagram of a communication device 1800 provided by an embodiment of this application.

Detailed ways

Figure 1A is a schematic diagram of an independent networking NPN and a non-independent networking NPN provided by an embodiment of the present application.

As shown in Figure 1A, in an independent networking NPN, SNPN and PLMN have independent core networks, and SNPN can have independent radio access networks (RAN), or can share RAN with PLMN. In the independent networking NPN, a SNPN network is identified by the PLMN ID and the network identifier (NID), where the mobile country code (MCC) part of the PLMN ID is a specific value or the mobile operator deploying the SNPN PLMN ID; NID can be allocated globally or locally. The cell of an SNPN next generation radio access network (NG-RAN) node can broadcast one or more of the following parameters: one or more PLMN IDs and a list of NIDs corresponding to each PLMN ID , Human-readable network name (HRMN) to support the user's manual network selection and instructions to prohibit other terminals that do not support SNPN from accessing.

As shown in Figure 1A, in a non-independent networking NPN, the NPN and the PLMN share the core network and/or access network. The NPN depends on the PLMN for deployment, and the PLMN ID can be used to identify the PNI-NPN network. The NPN may be a specific slice in the PLMN, and the terminal has subscription data of the PLMN. According to the agreement between the mobile operator and the NPN service provider, the NPN may only be deployed in certain tracking areas (TAs). When the terminal moves out of this range, the network may indicate that the terminal cannot continue to use the current slice resources in the new registration area.

In order to prevent unauthorized terminals from accessing PNI-NPN cells, 3GPP proposed the concept of closed access group (CG). A CAG represents a group of people that can access a CAG cell (PNI-NPN cell). user. It can be represented by a CAG ID, which is unique in a PLMN. In the non-independent networking NPN, the PNI-NPN network can be deployed with the support of the public network. The PNI-NPN cell must not only broadcast the cell identifier, but also broadcast the closed access group identifier (CAG ID) The CAG ID is used to identify a group of users who are allowed to access one or more cells associated with the CAG, and prevent terminals that are not allowed to access the PNI-NPN through the cell associated with the CAG to automatically select and access the cell. A PNI-NPN cell can broadcast one or more CAG identifiers; it can also broadcast the HRNN corresponding to the CAG identifier for the user to manually select. For ease of description, the embodiment of this application regards both the PLMN ID and the CAG ID as the network identification information of the PNI-NPN network.

In FIG. 1A, four user equipment (UE) that respectively support different network types are shown, namely UE1, UE2, UE3, and UE4. Among them, UE1 supports both public network PLMN A and non-public network CAG X deployed based on public network PLMN A; UE2 only supports non-public network CAG X deployed based on public network PLMN A; UE3 only supports public network PLMN A; UE4 only Support independent deployment of non-public network SNPN.

As mentioned above, for the PNI-NPN network, the PNI-NPN cell will broadcast in the system information the network identification information of the PNI-NPN it supports (such as PLMN ID(s) and CAG ID(s), which may also include HRNN(s)), the terminal locally stores the network information of the PNI-NPN it subscribes to (such as PLMN ID(s) and CAG ID(s), and may also include HRNN(s)), and the terminal receives the cell broadcast In the system information, the network identification information of the PNI-NPN broadcast by the cell is compared with the network information of the PNI-NPN subscribed to by the local storage. If there is a PNI-NPN that is allowed to be accessed, the terminal can access the corresponding cell. The AMF will also store the terminal's subscription information (for example, it will store the terminal's allowed CAG List (allowed CAG List)), and the AMF performs processes such as user admission control based on the stored terminal's subscription information.

In the DU sharing scenario, one DU can be connected to multiple CUs. It should be understood that the multiple CUs connected to one DU are multiple logically divided CUs. In fact, the multiple CUs may correspond to the same physical CU (or entity CU). There are many ways to divide logical CUs. For example, the network configures different calculation parameters (instances) for different logical CUs, the network configures different network resources for different logical CUs, or the network configures different networks for different logical CUs. Wait, there is no restriction here.

The following is an example of how the network configures different networks for different logical CUs.

Referring to Fig. 1B, the CU connected to the DU includes two logical CUs, namely CU#A and CU#B, where CU#A and CU#B are configured with different networks.

For example, CU#A supports the public network identified by PLMN ID#1, and CU#B supports PNI-NPN#1 identified by PLMN ID#1 and CAG ID#1. For example, CU#B supports PNI-NPN#1 identified by PLMN ID#1 and CAG ID#1; CU#B supports PNI-NPN#2 identified by PLMN ID#1 and CAG ID#2. For example, CU#A supports the public network identified by PLMN ID#1, and CU#B supports PNI-NPN#3 identified by PLMN ID#2 and CAG ID#1. For example, CU#B supports PNI-NPN#1 identified by PLMN ID#1 and CAG ID#1; CU#B supports PNI-NPN#4 identified by PLMN ID#2 and CAG ID#2. For example, CU#B supports PNI-NPN#1 identified by PLMN ID#1 and CAG ID#1; CU#B supports PNI-NPN#3 identified by PLMN ID#2 and CAG ID#1.

Of course, the network type on which the logical CU is configured is not limited to PNI-NPN and public network, for example, it can also be SNPN. For the logical CU configured with SNPN, it needs to be identified by PLMN ID and NID.

For example, CU#A supports the public network identified by PLMN ID#1, and CU#B supports SNPN#1 identified by PLMN ID#1 and NID#1. For example, CU#B supports SNPN#1 identified by PLMN ID#1 and NID#1; CU#B supports SNPN#2 identified by PLMN ID#1 and NID#2. For example, CU#A supports the public network identified by PLMN ID#1, and CU#B supports SNPN#3 identified by PLMN ID#2 and NID#1. For example, CU#B supports SNPN#1 identified by PLMN ID#1 and NID#1; CU#B supports SNPN#4 identified by PLMN ID#2 and NID#2. For example, CU#B supports SNPN#1 identified by PLMN ID#1 and NID#1; CU#B supports SNPN#3 identified by PLMN ID#2 and NID#1.

In short, the public network is identified by PLMN ID, PNI-NPN is jointly identified by PLMN ID and CAG ID, and SNPN is jointly identified by PLMN and NID. Different types of networks must belong to different networks. Networks of the same type only need the ID of the network identification. Inconsistent values are different networks.

Among them, the CAG ID is generally a fixed-length 32-bit value. PLMN ID is composed of mobile country code (MCC) and mobile network code (MNC), that is, PLMN ID=MCC||MNC. NID includes an assignment mode (assignment mode) and a NID value (NID value), as shown in Figure 1C.

Further, in the DU sharing scenario, the DU can broadcast the system information block (SIB) 1, and the physical cell identifier (PCI) can be used in the SIB1 to identify a physical cell corresponding to the DU. A cell can correspond to several logical cells, one logical cell corresponds to one logical CU connected to the DU, and each logical cell is identified by a cell identity (cell identity). As shown in Figure 2, the logical CU#A and logical CU#B connected to the DU correspond to logical cells identified by different cell identities.

3GPP R16 stipulates that each logical cell only supports one of the public network, PNI-NPN or SNPN network type, but in 3GPP R17, a shared logical cell will be introduced, that is, a logical cell can support the public network and PNI-NPN at the same time And multiple network types in SNPN.

Figure 2 is a schematic diagram of the initial access process when the UE accesses the PNI-NPN network, as shown in Figure 2, including:

S201. The UE sends an RRC setup request (RRC setup request) message to the DU to request access to the physical cell corresponding to the DU.

S202. The DU selects a CU, such as CU#A, and sends an initial uplink (UL) RRC message to CU#A.

Among them, there are many ways for DU to select CU, and there are no restrictions here. For example: DU randomly selects a CU; or, DU selects a CU with a smaller load based on the load information of the CU; or, DU selects a frequently accessed CU based on the historical access information of the CU; or, the DU is configured with a default CU (default CU), select the default CU.

S203, CU#A and DU configure signaling radio bearer (SRB) 1 resources for the UE on the F1 interface, the context of the UE on the F1 interface, etc., and then return a downlink (DL) RRC information forwarding message, and Information such as the configured SRB1 resources and the context of the UE on the F1 interface is notified to the DU.

Among them, the context of the UE on the F1 interface, such as gNB-DU UE F1 application protocol (F1AP) ID, gNB-CU UE F1AP ID, or supplementary uplink (SUL) access indication (access indication), etc.

It should be understood that in steps S202-S203, since the UE has not yet reported to the network the network information it has selected to access, such as PLMN ID, CAG ID, etc., the DU and CU do not know the PLMN ID and CAG that the UE has selected to access. ID.

S204. The DU sends configuration parameters to the UE and enables the UE to configure resources such as SRB1 on the terminal side.

S205. The terminal reports the ID of the PLMN selected by the UE to access, that is, the selected PLMN ID, in the RRC setup complete (RRC setup complete) message of the initial access, but does not report the CAG ID that the UE selects to access.

Among them, the non-access stratum (NAS) layer information contained in the RRC establishment complete message may or may not carry the CAG ID, and there is no restriction here. Because neither the DU nor the CU parses the NAS layer information, no matter whether the NAS layer information carries or does not carry the CAG ID, the DU and CU#A cannot perceive the CAG ID that the UE selects to access.

S206. The DU sends the information in step S205 to CU#A.

It should be understood that DU and CU#A cannot perceive the CAG ID that the UE selects to access.

S207. CU#A sends an initial UE message (Initial UE message) to AMF, which carries a list of CAG IDs supported by the logical cell (CU#A) that the UE selects to access, where CU#A supports terminal selection The PLMN corresponding to the accessed network.

Among them, the CAG ID list supported by the logical cell (CU#A) refers to a list in which one or more CAG IDs supported by CU#A are recorded. In this article, a logical cell (such as CU#A) supports a CAG ID list, which means that the logical cell (such as CU#A) supports each CAG ID recorded in the CAG ID list.

S208. After receiving the Initial UE message, the AMF judges whether CU#A supports UE access.

Specifically, compare the locally stored PLMN ID list that the UE is allowed to access and the CAG ID list supported by each PLMN ID with the PLMN ID of the logical cell (CU#A) carried in the message and the CAG supported by it. If there is an overlap in the ID list, it is determined that CU#A supports UE access, and step S209A is executed; otherwise, it is determined that CU#A does not support UE access, and S209B is executed.

S209A. Send an initial context setup request (initial context setup request) message to CU#A. For the specific process of granting UE access, refer to related prior art, which will not be repeated here.

S209B. Send an error indication (error indication) message to CU#A. For the specific process of denying UE access, reference may be made to related prior art, which will not be repeated here.

R16 specifies that a logical cell (cell identity in SIB1 identifies a logical cell, and a PCI identifies a physical cell) only supports one of the public network, PNI-NPN, and SNPN. In 3GPP R17, a shared logical cell was introduced, that is, a logical cell can support multiple network types in the public network, PNI-NPN and SNPN at the same time. Regardless of R16 or R17 (or other scenarios, here is not limited to R16 and R17), when the terminal access is controlled based on the method shown in Figure 2, there may be the following problems: DU has selected the logical cell (CU #A) If the network does not support terminal access, AMF will directly reject the terminal's access request, and the connection between the terminal and the DU will be disconnected, causing the terminal to perform cell selection and random access procedures again, adding air interface signaling The cost of the terminal and the delay of the terminal accessing the network.

Here is an example to illustrate:

Logical cell supported by CU#A (assumed to be identified by cell identity#1): support the public network identified by PLMN ID#1, and also support PNI-NPN#2 identified by PLMN ID#1+CAG ID#2; or, only support One of the above public networks or PNI-NPN#2.

Logical cell supported by CU#B (assumed to be identified by cell identity#2): Support PNI-NPN#1 identified by PLMN ID#1+CAGID#1.

UE signs: PNI-NPN#1 identified by PLMN ID#1+CAG#1.

If the DU selects CU#A (that is, selects the logical cell supported by CU#A), then when the AMF performs admission control on the UE, because the UE has not signed the PNI-NPN#2 supported by CU#A, the AMF will refuse The access request of the UE causes both CU#A and DU to reject the access of the UE. If the UE continues to access the network, it needs to re-select cells (including physical cells) and re-initiate the random access process. Not only is the air interface signaling overhead large, but the UE access delay is also large.

In view of this, the embodiments of the present application provide a method and device for a terminal to access the network. When the CU selected by the DU for the terminal to access does not support terminal access, the DU may not reject the terminal’s access, but select a new CU. In order to connect the terminal to the network, it is possible to avoid the problem that the terminal needs to perform the (physical) cell selection and random access procedures again due to the direct rejection of the terminal, which can save air interface signaling overhead and reduce the delay of the terminal accessing the network.

Hereinafter, the embodiments of the present application will be described in further detail with reference to FIGS. 3A to 17.

The embodiments of this application can be applied to fifth generation (5G) communication systems, such as 5G new radio (NR), or to various future communication systems, as long as the radio access network equipment of the communication system It suffices that there is a CU-DU separation architecture or an architecture equivalent to the functions of the CU-DU separation architecture.

For example, FIG. 3A is a schematic structural diagram of a possible communication system to which an embodiment of this application is applicable. The communication system includes a 5G core network (the 5 ^th generation core, 5GC), a radio access network (radio access network, RAN), and a terminal.

Among them, the terminal can also be referred to as terminal equipment, user equipment (UE), mobile station (MS), mobile terminal (MT), etc. It is a kind of voice or data connectivity that provides users with voice or data connectivity. The device can also be an Internet of Things device. For example, the terminal includes a handheld device with a wireless connection function, a vehicle-mounted device, and so on. At present, the terminal can be: mobile phone (mobile phone), tablet computer, notebook computer, palm computer, mobile internet device (MID), wearable device (such as smart watch, smart bracelet, pedometer, etc.), In-vehicle equipment (for example, cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed rail, etc.), virtual reality (VR) equipment, augmented reality (AR) equipment, industrial control (industrial control) Wireless terminals, smart home equipment (for example, refrigerators, TVs, air conditioners, electric meters, etc.), smart robots, workshop equipment, wireless terminals in self-driving, wireless terminals in remote medical surgery, and smart Wireless terminals in a smart grid, wireless terminals in transportation safety, wireless terminals in a smart city, or wireless terminals in a smart home, and flying equipment (e.g., smart Robots, hot air balloons, drones, airplanes), etc. In the embodiments of this application, a UE or a terminal is used to describe the solution.

The 5GC includes one or more functions or devices, such as a session management function (SMF). These functions or devices may be network elements in hardware devices, software functions running on dedicated hardware, or virtualization functions instantiated on a platform (for example, a cloud platform). It is understandable that the names of various core network devices are the names in the 5G communication system, and as the communication system evolves, they can be replaced with other names with the same functions.

The RAN may also be called an access network device or a base station, and may also be called a RAN node (or RAN device). At present, some examples of access network equipment are: gNB/NR-NB, transmission reception point (TRP), evolved Node B (evolved Node B, eNB), next generation eNodeB (next generation eNodeB) , Ng-eNB) radio network controller (RNC), node B (Node B, NB), base station controller (BSC), base transceiver station (BTS), home base station (For example, home evolved NodeB, or home Node B, HNB), baseband unit (BBU), or wireless fidelity (Wifi) access point (AP), or possible future communications Access network equipment in the system. It can also be 5G, such as NR, gNB in the system, or transmission point (TRP or TP), one or a group of (including multiple antenna panels) antenna panels of the base station in the 5G system, or it can also be composed A network node of a gNB or transmission point, such as a baseband unit (BBU), or DU, etc. In some deployments, gNB may include CU and DU.

As shown in Figure 3A, for the base station gNB of NR, the gNB can be divided into two parts according to the function of the protocol stack: CU and DU, that is, the protocol stack of the base station is divided. CU and DU have different parts of the base station. Protocol stack. Generally, the service data adaptation protocol (SDAP) layer, radio resource control (RRC) layer, and packet data convergence protocol (PDCP) layer (where the PDCP layer includes the control plane) The PDCP-C layer and the user plane PDCP-U layer) are configured in the CU, and the radio link control (radio link control, RLC) layer (where the RLC layer includes the control plane RLC-C layer and the user plane RLC-U layer), The medium access control (MAC) layer and the physical layer (PHY) are configured in the DU. It should be understood that the division of the protocol stack described above is only an example and not a limitation, and the embodiment of the present application does not limit the division of the protocol stack.

A gNB can contain one CU and multiple DUs. CU and DU are connected through the F1 interface. One CU can be connected to multiple DUs at the same time, and one DU can only be connected to one CU. The CU is connected with other gNBs using the Xn interface, and the CU is connected with the 5GC using the NG interface. In addition, in the specific implementation process, considering the fault tolerance and stability of the system, one DU can also be connected to multiple CUs (this is only an implementation, not standardization).

As mentioned above, under the CU-DU separation architecture of the radio access network equipment, it can support shared DU. One DU corresponds to one physical cell, and a physical cell can be configured with multiple logical cells. Correspondingly, the CU can be configured from Logically divided into multiple logical CUs. As shown in FIG. 3A, assuming that two logical cells are configured in the physical cell of the DU, the CU can be considered to be divided into two logical CUs, that is, a first logical CU and a second logical CU. The first DU can choose to connect to the first logical CU or the second logical CU (that is, the first logical CU and the second logical CU share the first DU). Similarly, the second DU can choose to connect to the second logical CU. A logical CU may also choose to access a second logical CU (that is, the first logical CU and the second logical CU share the second DU).

It should be understood that the DU sharing in this document can be the sharing of physical entities or the sharing of logical entities. In the physical shared DU scenario, one DU can only be connected to one CU at a time.

Take the sharing of the first DU in FIG. 3A as an example, that is, take the sharing of the first DU by the first logical CU and the second logical CU as an example.

Referring to FIG. 3B, it is an example that the sharing of the first DU is physical entity sharing. The first DU of the physical entity can be further divided into logical entities DU#A and DU#B, and both DU#A and DU#B are deployed in the first DU of the physical entity. The first logical CU and the logical DU#A in the first DU constitute RAN1, and the second logical CU and the logical DU#B in the first DU constitute RAN2. In the scenario shown in Figure 3B, the first logical CU and the second logical CU are connected to the same physical entity DU, that is, the first DU, but the first logical CU and the second logical CU are respectively connected to two of the first DU Different logical DUs, so the first logical CU and the second logical CU share the physical resource instance of the first DU.

Referring to FIG. 3C, it is an example that the sharing of the first DU is the sharing of logical entities. The first DU of the physical entity can be further divided into logical entities DU#A and DU#B, and both DU#A and DU#B are deployed in the first DU of the physical entity. The first logical CU and the logical DU#A in the first DU constitute RAN1, and the second logical CU and the logical DU#A in the first DU constitute RAN2. In the scenario shown in FIG. 3C, the first logical CU and the second logical CU are not only connected to the same physical entity DU, that is, the first DU, but also the first logical CU and the second logical CU are connected to the same logical DU in the first DU. , So the first logical CU and the second logical CU share the logical resource instance of the first DU (ie DU#A).

It should be understood that the technical solutions provided in the embodiments of the present application are applicable to both physical DU sharing and logical DU sharing deployment scenarios. For ease of description, for the deployment scenario of physical DU sharing, the communication between the first logical CU and DU#A is uniformly described as the communication between the first logical CU and the first DU, and the communication between the second logical CU and DU#B The communication is described as the communication between the second logical CU and the first DU; for the deployment scenario where the logical DU is shared, the communication between the first logical CU and DU#A is uniformly described as the communication between the first logical CU and the first DU , The communication between the second logical CU and DU#A is described as the communication between the second logical CU and the first DU. That is, the DU involved in the following text does not distinguish whether it is a logical DU or a physical DU.

It should be understood that under the CU-DU separation architecture of the radio access network equipment, there is an intersection between the network supported by the DU and the network supported by each logical CU connected to the DU. Among them, the intersection of the network supported by any logical CU connected to the DU and the network supported by the DU may be exactly the same as the network supported by any logical CU (in this case, the network supported by the first DU may be The union of the networks supported by all logical CUs), or just a part of the networks supported by any logical CU, there is no restriction here.

Still take the first DU in FIG. 3B or FIG. 3C as an example. For example, the network supported by the first logical CU is {1, 2}, the network supported by the second logical CU is {3, 4}, and the network supported by the first DU is {1, 2, 3, 4}. For another example, the network supported by the first logical CU is {1, 2}, the network supported by the second logical CU is {3, 4}, and the network supported by the first DU is {1, 4, 5}.

In the following embodiments of the text, it is mainly taken as an example that the network supported by the first DU is the union of the networks supported by all logical CUs, that is, the first DU supports the networks supported by each logical CU to which it is connected.

For ease of description, the first logical CU is referred to as "first CU" in the following description, and the second logical CU is referred to as "second CU" in the following.

It should be understood that FIGS. 3A to 3C only illustrate a few functions or devices involved in the embodiments of the present application, and the communication system architecture may also include more or fewer functions or devices. For example, the 5GC in FIG. 3A may also include unified data management (UDM) or data network (DN), and the DU may also be configured with more logical cells.

The communication system architecture applicable to the embodiments of the present application is not limited to those shown in FIGS. 3A to 3C, and communication system architectures that can implement the functions of the devices shown in FIGS. 3A to 3C are all applicable to the present application.

The terms "system" and "network" in the embodiments of this application can be used interchangeably. "At least one" means one or more, and "plurality" means two or more. "And/or" describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and/or B, which can mean: A alone exists, A and B exist at the same time, and B exists alone, where A, B can be singular or plural. The character "/" generally indicates that the associated objects before and after are in an "or" relationship. "The following at least one item (a)" or similar expressions refers to any combination of these items, including any combination of a single item (a) or a plurality of items (a). For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a and b and c.

And, unless otherwise stated, the ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects, and are not used to limit the order, timing, priority, or order of multiple objects. Importance. For example, the first priority criterion and the second priority criterion are only for distinguishing different criteria, but do not indicate the difference in content, priority, or importance of the two criteria.

In addition, the terms "including" and "having" in the embodiments of the present application, claims and drawings are not exclusive. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the listed steps or modules, and may also include unlisted steps or modules.

As shown in FIG. 4A, an embodiment of the present application provides a method for a terminal to access a network. The method can be applied to the network architecture shown in FIG. 3A, but is not limited to the network architecture shown in FIG. 3A. In this embodiment, the first DU, the first CU, and the second CU cannot perceive the CAG ID that the terminal selects to access. When the PNI-NPN network configured on the first CU currently selected by the first DU does not support the terminal requesting access When entering the network, the AMF can instruct the first DU to reselect a CU (such as the second CU) to connect the terminal to the network. For details, see S401A to S407A.

It should be understood that both the first CU and the second CU in this embodiment refer to logical CUs. For example, the first CU and the second CU are the first logical CU and the second logical CU in FIG. 3A or FIG. 3B or FIG. 3C, respectively.

The first DU in this embodiment may refer to a logical DU or a physical DU. For example, in the physical DU sharing scenario shown in FIG. 3B, the first DU in this embodiment is the first DU shown in FIG. 3B, which is a physical DU, including logical DU#A and logical DU#B. For example, in the logical DU sharing scenario shown in FIG. 3C, the first DU in this embodiment is equivalent to CU#A in the first DU shown in FIG. 3C, and is a logical DU.

S401A. The first DU sends a first request message to the selected first CU, and the first CU receives the first request message from the first DU, where the first request message is used to request the terminal to access the first CU.

Wherein, the first DU is in communication connection with the terminal. The scenario in which the first DU selects the first CU may be the CU selection scenario performed by the first DU when the terminal initially accesses, or it may be the CU selection scenario performed by the first DU when the UE performs RRC re-establishment or RRC recovery. Do restrictions. For ease of presentation, the embodiments of the present application mainly take a terminal initial access scenario as an example.

It should be understood that the selected first CU here can be understood as: the first DU has selected the first CU, or that the first DU and the first CU have established an F1 connection, or that the first DU and the first CU are already terminals The transmission resource is configured.

The first request message carries the PLMN ID of the network that the terminal selects to access, that is, the Selected PLMN ID. In addition, for ease of description, the "PLMN ID of the network that the terminal selects to access" in this article can also be said to be the "PLMN ID of the PLMN that the terminal selects to access", and "the CAG ID of the network that the terminal selects to access" in this article. It can also be said as "the CAG ID that the terminal chooses to access".

It should be understood that the PLMN ID corresponding to the network selected by the terminal and the PLMN ID of the network configured by the first CU should be the same, but the network selected by the terminal to access and the network configured by the first CU are not necessarily the same. For example, the first CU is configured with the public network identified by PLMN ID#1, and the network requested by the terminal is PNI-NPN#1 identified by PLMN ID#1 and CAG ID#1, or the first CU is The configuration is PNI-NPN#1 identified by PLMN ID#1 and CAG ID#1, and the network that the terminal requests to access is PNI-NPN#2 identified by PLMN ID#1 and CAG ID#2.

Before step S401A, the terminal also needs to perform cell selection and random access procedures. Exemplarily, the cell selection and random access process specifically includes the following steps:

1) The terminal sends an RRC setup request (RRC setup request) message to the first DU to request access to the cell under the first DU;

2) The first DU configures logical entity resources such as RLC, MAC, and PHY of SRB1 for the terminal, selects the first CU, and sends an initial UL RRC message (initial UL RRC message) to the first CU, and transmits the related parameters of the configuration;

3) The first CU configures the SDAP and PDCP layer logical entities based on the received configuration parameters, and sends the SDAP, PDCP, and parameters to the DU.

It should be understood that when the first DU and the first CU configure SRB1 for the UE in steps 2) and 3), the DU and CU do not know the PLMN ID and CAG ID selected by the terminal.

4) The DU sends an RRC setup (RRC setup) message to the terminal, which carries parameters such as SDAP, PDCP, RLC, MAC, and PHY, so that the terminal configures the response logic entity for SRB1 on the terminal side;

5) The terminal reports the PLMN ID corresponding to the network that the terminal selects to access in the RRC setup complete message of the initial access, but does not report the CAG ID that the terminal selects to access.

After performing the foregoing steps 1) to 5), the first DU sends the foregoing first request message to the selected first CU.

In the embodiment of the present application, the first CU may be the CU selected by the first DU for the first time, or the CU reselected by the first DU (that is, the first DU reselects the CU after trying to connect the terminal to the network through other CUs and fails. One CU).

If the first CU is the CU reselected by the first DU, in addition to the selected PLMN ID, the first request message may also carry one or more of the following information: 1) CU reselection information of the first DU, To indicate whether the first DU has undergone CU reselection, or the number of CU reselections performed by the first DU, or information such as unselected CUs in the CU to which the first DU is connected; for ease of description, the first The CU reselection information of the DU is called indication information #4; 2) PLMN ID, where the PLMN ID is another PLMN ID or PLMN ID list that is different from the selected PLMN ID; 3) CAG ID; 4) Whether the terminal can only be accessed CAG cell indication information (CAG-only access); 5) The closed access group CAG list (allowed CAG) of the terminal that is allowed to access.

Of course, if the first CU is the CU selected by the first DU for the first time, the first request message may also carry the CU reselection information of the first DU. In this case, the CU reselection information of the first DU is used to indicate: A DU has not undergone CU reselection, or the number of times of CU reselection performed by the first DU is 0, or there are unselected CUs among the CUs connected to the first DU, etc.

Optionally, the first request message is an uplink RRC message (UL RRC message) sent by the first DU to the first CU when the terminal device initially accesses. The UL RRC message carries the Selected PLMN ID and the RRC container (container), where the RRC container contains the relevant information reported by the air interface UE.

S402A. The first CU sends a third request message to the AMF, and the AMF receives the third request message from the first CU, where the third request message is used to request the terminal to access the AMF.

Wherein, the third request message carries a list of PLMN IDs and CAG IDs supported by the first CU, so that in the subsequent step S403A, the AMF determines whether the first CU supports the terminal access. It should be understood that the PLMN ID supported by the first CU includes the selected PLMN ID.

The third request message also carries indication information for indicating whether the RAN is a CU-DU separated architecture, so that after the AMF determines that the first CU does not support terminal access in the subsequent step S403A, it determines whether it is necessary to instruct the first DU to reconnect. Choose CU. For ease of description, the indication information used to indicate whether the RAN is a CU-DU separated architecture is referred to as indication information #1 in the embodiment of the present application.

Optionally, the first CU is the CU selected by the first DU for the first time, and the third request message is the initial UE message.

Optionally, the first CU is a reselected CU, and the third request message is an initial UE message or a path switch request (path switch request) message.

Optionally, the third request message contains the CU reselection information of the first DU, where the first CU obtains the CU reselection information by reporting the first DU to the first CU, or other network elements (such as core Net) notify the first CU, there is no restriction here.

S403A. The AMF determines whether the first CU supports terminal access according to the subscription information of the terminal.

Whether the first CU supports the terminal access can be understood as: whether the network configured by the first CU supports terminal access, or whether the network configured by the first CU is a network that the terminal has subscribed to, or the first CU Whether the type of the configured network matches the type of the network that the terminal has subscribed to.

The AMF compares the PLMN ID carried in the third request message with the supported CAG ID list (that is, the PLMN ID and CAG ID list supported by the first CU), and the terminal subscription information stored locally in the AMF that the terminal is allowed to access If there is no overlapping PLMN ID+CAG ID list, and the CAG ID list supported by each PLMN ID, it is determined that the first CU does not support terminal access.

S404A. If the first CU supports terminal access, the AMF performs an admission control process on the terminal, for example, sending an initial context setup request message to the first CU. For the specific admission control process, please refer to relevant existing Technology, I won’t go into details here.

S405A: If the first CU does not support terminal access, the AMF sends a third response message to the first CU, and the first CU receives the third response message from the AMF.

Specifically, the third request message includes indication information for indicating whether the RAN has a CU-DU separated architecture (that is, the above-mentioned indication information #1). After the AMF learns whether the RAN has a CU-DU separated architecture according to the third request message, Send a third response message to the first CU. If the RAN is not in the CU-DU separated architecture, the terminal is directly denied access, for example, sending an error indication message to the first CU; if the RAN is in the CU-DU separated architecture, the third response message is sent to the first CU. The third response message is used to instruct the first DU to select a CU again, the third response message carries auxiliary information, and the auxiliary information is used to assist the first DU to select the second CU.

Exemplarily, suppose that the first CU supports the public network identified by PLMN ID#1, and also supports PNI-NPN#1 identified by PLMN ID#1+CAG ID#1; the second CU supports PLMN ID#1+CAG ID#2 Identified PNI-NPN#2. Suppose that the UE has subscribed to the PNI-NPN#2 identified by the PLMN ID#1+CAG#2. Although the AMF determines that the first CU does not support terminal access, it finds that the terminal has subscribed to other PNI-NPNs supported by the same PLMN ID (i.e. PNI-NPN#2), so the AMF does not directly deny terminal access, but instructs the first DU to perform CU reselection.

Among them, the auxiliary information includes one or more of the following information:

1) Instruction information for instructing to reselect CU. For ease of description, the instruction information for instructing to reselect CU is referred to as instruction information #2;

2) PLMN ID;

The PLMN ID here can be a selected PLMN ID, or it can be another PLMN ID or a list of PLMN IDs.

3) Closed access group identification CAG ID;

A PLMN ID and a CAG ID can identify a PNI-NPN. The combination of the selected PLMN ID and the PNI-NPN identified by the CAG ID in item 3) is used to indicate the PNI-NPN of the second CU to be reselected; or, the PLMN ID in item 2) and item 3) above The combination of PNI-NPN identified by the CAG ID is used to indicate the PNI-NPN of the second CU to be reselected.

4) The closed access group CAG list (allowed CAG list) of the terminal that is allowed to access is used to assist the first DU to renew the CAG ID of the CU included in the allowed CAG list. ；

5) The indication information (CAG-only access) of whether the terminal can only access the CAG cell is used to assist the first DU in reselecting the CU configured with CAG. For ease of description, CAG-only access is referred to as indication information #3 here.

The above-mentioned information in item 1) can be used to explicitly instruct the first DU to perform CU reselection, that is, if the first DU receives instruction information for instructing to reselect a CU, it directly learns that the CU reselection operation needs to be performed.

Items 2) to 5) above can also be used to implicitly instruct the first DU to perform CU reselection, that is, if item 1) above is not received, but items 2) to 5) above are received At least any of the items, the first DU can learn that it needs to perform the operation of reselecting the CU.

For example, it may include information such as whether the first DU has performed CU reselection, the number of times the first DU has performed CU reselection, or the CU to which the first DU is connected, and there are still unselected CUs. Correspondingly, the AMF can only determine according to the third request message that the first DU has not performed CU reselection, or the number of CU reselections performed by the first DU does not exceed the preset value, or there are still unselected CUs in the CU connected to the first DU. After the selected CU, a third response message is sent to the first CU; otherwise, the terminal can be directly denied access, for example, an error indication (error indication) message is sent to the first CU. For example, if there is no unselected CU among the CUs connected to the first DU, it indicates that the first DU has tried to connect to all possible CUs for the terminal but failed to connect the terminal to the network. In this case, the AMF directly refuses the terminal to connect to the network. enter.

Optionally, the third response message is specifically an error indication (error indication) message or an initial context setup request (initial context setup request) message. Of course, it can also be other messages, and there is no restriction here. It should be understood that if the third response message reuses an existing message, for example, the third response message is an error indication message or an initial context setup request message, then the third response message here is the same as the error indication message or initial in the prior art. The context setup request message is different: the third response message contains auxiliary information, so the third response message instructs the first DU to reselect the CU, while the error indication message in the prior art does not contain auxiliary information and is used to deny terminal access The initial context setup request message in the prior art does not include auxiliary information, and is used to request the first CU to establish a context for the terminal.

S406A. The first CU sends a first response message to the first DU, and the first DU receives the first response message from the first CU, where the first response message is used to instruct the first DU to reselect a CU.

Specifically, the first CU determines whether the first DU needs to perform CU reselection according to the third response message information, and if reselection is required, the first CU sends a first response message to the first DU.

The first response message contains one or more of the following information: 1) Indication information #2; 2) PLMN ID; 3) CAG ID; 4) Indication information #3; 5) Allowed access of the terminal CAG list.

Optionally, the first response message is a downlink RRC message transfer (DL RRC message transfer) message.

S407A: The first DU reselects a CU according to the first response message.

For example, if the first response message only carries indication information #2, then the first DU randomly selects a CU from CUs that have never been selected. For example, if the first response message carries the PLMN ID and CAG ID subscribed by the terminal, the first DU can select a CU that supports the PLMN ID and CAG ID from all CUs (it should be understood that when the first DU and CU perform F1 interface establishment, , The first DU and CU will inform each other of the network conditions they support, such as PLMN ID, CAG ID, etc.). Of course, the actual selection method is not limited to the above two, and the specific selection method can be determined according to the information carried in the first response message.

After the first DU reselects the CU, it initiates the access procedure to the reselected CU again (the reselected CU is different from the first CU, for example, the second CU), that is, returns to S401A, and re-executes the above figure based on the reselected CU 4A method flow.

According to the above, when the AMF finds that the CU selected by the first DU does not support terminal access in the embodiment of the application, it may not directly reject the terminal access, but return auxiliary information to assist the first DU to reselect the CU to continue the access process. It avoids the problem that the AMF directly refuses the terminal access and causes the terminal to re-execute the (physical) cell selection and random access process, which can save air interface signaling overhead and reduce the time delay for the terminal to access the network. In order to better understand the above method flow, let's enumerate a complete example.

Referring to Figure 4B, assuming that the first CU is the CU initially selected by the first DU, and the second CU is the CU that is selected again according to the auxiliary information sent by the AMF after the terminal fails to access the network through the first CU, the following procedures are as follows: S401B-S411B :

S401B. The first DU sends a first request message to the selected first CU, and the first CU receives the first request message from the first DU, where the first request message is used to request the terminal to access the first CU.

For specific implementation, refer to S401A above. Note that the first CU is the CU initially selected by the first DU, so the first request message is the UL RRC message, which specifically carries the Selected PLMN ID and RRC container, where the RRC container contains the relevant information reported by the air interface UE.

S402B. The first CU sends a third request message to the AMF, and the AMF receives the third request message from the first CU, where the third request message is used to request the terminal to access the AMF.

See S402A above for specific implementation. Note that the first CU here is the CU initially selected by the first DU, so the third request message is the initial UE message.

Optionally, the third request message includes CU reselection information of the first DU (used to indicate whether the first DU has undergone CU reselection or the number of CU reselections performed by the first DU or the CU to which the first DU is connected There are also unselected CUs and other information in). For ease of description, the CU reselection information of the first DU here is referred to as indication information #4.

S403B. The AMF determines whether the first CU supports terminal access according to the subscription information of the terminal.

See S403A above for specific implementation.

S405B. If the first CU does not support terminal access, the AMF sends a third response message to the first CU, and the first CU receives the third response message from the AMF.

For specific implementation, refer to S405A above.

S406B. The first CU sends a first response message to the first DU, and the first DU receives the first response message from the first CU, where the first response message is used to instruct the first DU to reselect a CU.

See S406A above for specific implementation.

S407B. The first DU reselects a CU according to the auxiliary information in the first response message. In this example, the reselected CU is the second CU.

For example, the first response message carries PLMN ID and CAG ID, and the first response message carries PLMN ID and CAG ID to identify the non-public network configured in the second CU. The first DU can directly Determine the second CU.

S408B. The first DU sends a second request message to the second CU, where the second request message is used to request the terminal to access the second CU.

It should be understood that, in addition to the selected PLMN ID, the second request message may also carry one or more of the following information:

1) CU reselection information of the first DU (used to indicate whether the first DU has undergone CU reselection or the number of CU reselections performed by the first DU or there are unselected CUs in the CU connected to the first DU, etc. Information). For ease of description, the CU reselection information of the first DU here is referred to as indication information #4';

2) PLMN ID, where the PLMN ID is another PLMN ID or a PLMN ID list that is different from the selected PLMN ID;

3) CAG ID;

4) Instruction information #3;

5) The closed access group CAG list (allowed CAG) of the terminal that is allowed to access.

It should be understood that the above items 2) to 5) here are used to implicitly indicate the CU reselection information of the first DU. That is, if the second CU does not receive the above item 1), but receives at least any one of the above items 2) to 5), the second CU can also learn that the first DU has performed the reselection CU Operation.

It should be understood that the content of the CU reselection information of the first DU carried in the request messages sent by the first DU at different stages may be different. For example, the third request message may also carry the CU reselection information of the first DU (such as indication information #4). Although the indication information #4' and indication information #4 have similar functions (for example, indication information #4, indication information #4) Information #4' can both be used to indicate whether the first DU has undergone CU reselection, the number of CU reselections that have been performed, etc.), but the content of the two can be different. For example, indication information #4 indicates that the first DU has not undergone CU reselection, and indication information #4' indicates that the first DU has undergone CU reselection. For another example, the indication information #4 may indicate that the first DU has performed CU reselection 0 times, and the indication information #4' indicates that the first DU has performed CU reselection 1 times.

Of course, it is not ruled out that the content of the CU reselection information of the first DU carried in the request messages sent by the first DU at different stages is the same. The second reselection of the CU, assuming that the selection result is the third CU, the request message sent by the first DU to the third CU after the second reselection can carry indication information #4", and indication information #4" and the second request The indication information #4' in the message is used to indicate that the first DU has undergone CU reselection.

Optionally, the second request message is specifically an initial UL RRC message.

S409B. The second CU sends a fourth request message to the AMF, and the AMF receives the fourth request message from the second CU, where the fourth request message is used to request the terminal to access the AMF.

It should be understood that the second CU here is the CU re-selected by the first DU, so the fourth request message is an initial UE message or a path switch request message (path switch request), which is not limited here.

The fourth request message carries a list of CAG IDs supported by the PLMN ID in the logical cell currently selected for access by the first DU (ie, the second CU), so that the AMF can determine whether the second CU supports the terminal access.

Optionally, the fourth request message also carries the above-mentioned indication information #4', so that the subsequent AMF can determine whether the first DU has performed CU reselection according to the indication information #4' in the fourth request message, or the first DU Whether the number of performed CU reselections does not exceed a preset value, or whether there is an unselected CU among the CUs connected to the first DU.

Of course, the fourth request message may also implicitly indicate the CU reselection information of the first DU by carrying the aforementioned PLMN ID, CAG ID, indication information #3, or the allowed CAG list of the terminal.

S410B. The AMF determines whether the second CU supports terminal access according to the subscription information of the terminal.

The judgment method here can refer to the specific implementation of S403A above, which will not be repeated here.

When the AMF determines that the second CU supports terminal access, S411B is executed.

In S411B, the AMF performs an admission control procedure on the terminal. For example, the AMF sends an initial context setup request message to the second CU. For the specific admission control procedure, please refer to the related prior art, which will not be repeated here.

Optionally, if the AMF determines that the second CU still does not support terminal access, the AMF determines that the first DU has performed CU reselection according to indication information #4', or the number of CU reselections performed by the first DU has exceeded the preset number of CU reselections. If the value is set, or there is no unselected CU in the CU connected to the first DU, an error indication message is sent to the second CU to deny the terminal access to the network; or, the AMF determines that the first DU is After CU reselection has been performed but the number of CU reselections performed by the first DU has not exceeded the preset value, or the CU connected to the first DU has other unselected CUs besides the first CU and the second CU. , Through the second CU to the first DU to return the instruction information indicating the reselection of the CU again, that is, instruction information #2, and repeat the above-mentioned process after S405B until the terminal successfully accesses or there is no CU that can be reselected.

Referring to FIG. 5, another embodiment of the present application provides a method for a terminal to access a network. The method can be applied to the network architecture shown in FIG. 3A, but is not limited to the network architecture shown in FIG. 3A. Different from the embodiment shown in Figure 4A and Figure 4B, the first DU in this embodiment can sense the CAG ID that the terminal selects to access. When the PNI-NPN network configured on the first CU does not support the terminal requesting access In the case of a network, the first DU can directly decide to reselect network access. For details, please refer to S501 to S506.

S501. The first DU determines that the PNI-NPN network configured on the selected first CU does not support the network that the terminal requests to access.

Similarly, the selected first CU here can be understood as: the first DU has selected the first CU, or the first DU and the first CU have established an F1 connection, or the first DU and the first CU have been terminals The transmission resource is configured.

Similarly, the scenario where the first DU selects the first CU can be the CU selection scenario performed by the first DU when the terminal initially accesses, or the CU selection performed by the first DU when the UE performs RRC re-establishment or RRC recovery. Scene, there is no restriction here. For ease of presentation, the embodiments of the present application mainly take a terminal initial access scenario as an example.

Similarly, before performing step S501, the terminal also needs to perform cell selection and random access procedures. For specific implementation procedures, please refer to the introduction of the relevant part above, which will not be repeated here.

It should be understood that when the first DU selects the first CU, it has not yet sensed the CAG ID that the terminal selects to access, so the first CU does not necessarily support terminal access. For example, the first CU that has been selected here is selected for access in the stages S202-S203 shown in FIG. 2, and the terminal has not yet reported the selected CAG ID at this time.

In the embodiment of this application, the first DU can know whether the network that the terminal selects to access is the public network or PNI-NPN. When the terminal requests access to the PNI-NPN, and the logic corresponding to the first CU selected by the first DU When the cell only supports the public network or does not support the PNI-NPN that the terminal requests to access, it is determined that the selected first CU does not support the network that the terminal requests to access.

Among them, the first DU learns the manner in which the terminal selects to access the network, which is not limited in the embodiment of the present application. For example, the terminal can simultaneously report the PLMN ID and CAG ID corresponding to the network that the terminal selects to access in the RRC setup complete message, so that the first DU can compare the PLMN ID and CAG ID supported by the first CU with the terminal’s Whether the PLMN ID and CAG ID corresponding to the selected network to be accessed match is determined to determine whether the PNI-NPN network configured on the first CU supports the PNI-NPN network that the terminal requests to access. For another example, the terminal can report the network index (network index) or PLMN ID index (PLMN Index) that the terminal selects to access at the same time in the RRC setup complete message, and the first DU can learn that the terminal requests access based on the above index value information PLMN ID and CAG ID corresponding to the network, so that the first DU can compare the PLMN ID and CAG ID supported by the first CU to determine whether the PLMN ID and CAG ID corresponding to the network that the terminal selects to access match. It is determined whether the PNI-NPN network configured on the first CU supports the PNI-NPN network that the terminal requests to access.

S502: The first DU sends a sixth request message to the first CU, which is used to instruct the first CU to release the context of the terminal.

Specifically, the sixth request message is a UE context release request (UE context release request) message, or an error indication message (error indication), etc.

S503: The first CU releases the context of the terminal.

Optionally, the sixth request message includes a cause value, which is used to indicate that the first CU needs to release the context of the terminal because it does not support the PNI-NPN network requested by the terminal.

Further optionally, the reason value includes one or more of the following information:

The first CU does not support the closed access group requested by the terminal (CAG ID(s) not served by the CU);

The first CU does not support the non-public network requested by the terminal (NPN(s) not served by the CU);

The first CU does not support the PNI-NPN requested by the terminal (PNI-NPN(s) not served by the CU);

The CAG ID requested by the terminal is invalid (invalid CAG ID(s));

The NPN requested by the terminal is invalid (invalid NPN);

The PNI-NPN requested by the terminal is invalid (invalid PNI-NPN);

CAG access denied (CAG access denied);

NPN access denied (NPN access denied);

PNI-NPN access denied (PNI-NPN access denied).

S504: The first DU reselects a CU, and the selection result is the second CU.

It should be understood that the sequence of steps S502 and S504 is not limited.

S505: The first DU sends a seventh request message to the reselected second CU, and the second CU receives the seventh request message, where the seventh request message is used to request the terminal to access the second CU.

It should be understood that step S505 is similar to step S408B in the foregoing embodiment.

The method steps performed after step S505 are similar to the method steps after step S408B in the foregoing embodiment.

For example, after step S505, it also executes:

S506: The second CU sends a ninth request message to the AMF to request the terminal to access the second CU. The ninth request message here is similar to the fourth request message in step S409B in the foregoing embodiment.

S507. The AMF sends a ninth response message to the second CU. The ninth response message here is similar to the initial context establishment request message in step S4011B in the foregoing embodiment.

For the specific implementation manner of the method steps performed after step S505, please refer to the specific implementation manner of the method steps after S408B above, which will not be repeated here.

According to the above, when the first DU can perceive the network type of the logical cell that the terminal selects to access in the embodiment of this application, if the first DU finds that the selected first CU does not support terminal access, it may not directly reject the terminal Instead, it notifies the first CU to release the context of the terminal and reselect the CU to perform access, which can avoid the problem that the AMF directly rejects the terminal access and causes the terminal to re-select (physical) cell selection and random access procedures, which can save air interfaces The signaling overhead reduces the time delay for the terminal to access the network.

Referring to FIG. 6, another embodiment of the present application provides a method for a terminal to access a network. The method can be applied to the network architecture shown in FIG. 3A, but is not limited to the network architecture shown in FIG. 3A. The difference from the embodiment shown in FIG. 4A is that the first DU in this embodiment can sense the CAG ID that the terminal selects to access. The difference from the embodiment in FIG. 5 is that when the first CU is configured on the PNI-NPN network When the network that the terminal requests to access is not supported, the first DU instructs the first CU to continue sending requests to the AMF. As long as the first CU or any network supported by the first DU is supported by the terminal, the AMF can allow the terminal to access . For details, please refer to S601 to S606.

S601. The first DU determines that the PNI-NPN network configured on the selected first CU does not support the network that the terminal requests to access.

For the specific implementation of this step, please refer to the specific implementation of S501 above, which will not be repeated here.

S602: The first DU sends a fifth request message to the first CU, and the first CU receives the fifth request message from the first sub-DU.

The fifth request message is used to request the first CU to send an access request message to the AMF. The fifth request message carries indication information #5, which is used to indicate that although the first CU does not support the network that the terminal requests to access, the first CU still needs to send an access request message to the AMF to allow the terminal to access Or make the terminal online contract or through a third-party authentication method to make the terminal access the first DU or other network configured on the first CU.

It should be understood that the other network configured on the first CU refers to the first network that supports terminal access among the multiple networks configured on the first CU, and the first network is different from the network that the terminal requests to access. Exemplarily, the public network identified by PLMN ID#1 and the PNI-NPN#1 identified by PLMN ID#1+CAG ID#1 are configured on the first CU, and the UE subscribes to the PNI identified by PLMN ID#1+CAG#2 -NPN#2, PNI-NPN#1 identified by PLMN ID#1+CAG ID#1, the first DU supports the public network identified by PLMN ID#1, PNI-NPN#1, PNI-NPN#2, UE requests to connect The entered network is PNI-NPN#2, then the other network refers to PNI-NPN#1. Although PNI-NPN#1 is not the network that the UE requests to access, it supports UE access. The other network configured on the first DU refers to the second network that supports terminal access among multiple networks configured on the first DU. The second network is the same as or different from the network that the terminal requests to access, and the first CU does not support this The second network. Exemplarily, the public network identified by PLMN ID#1 and PNI-NPN#1 identified by PLMN ID#1+CAG ID#1 are configured on the first CU, and the public network identified by PLMN ID#1 is configured on the second CU. , PLMN ID#1+CAG ID#2 identifies PNI-NPN#2, UE signs PNI-NPN#2 identified by PLMN ID#1+CAG#2, the first DU supports the public network identified by PLMN ID#1, PNI-NPN#1, PNI-NPN#2, the network that the UE requests to access is PNI-NPN#2, then the other network refers to PNI-NPN#2.

Optionally, the fifth request message is specifically an uplink RRC message transfer (UL RRC message transfer) message.

S603. The first CU sends an eighth request message to the AMF, and the AMF receives the eighth request message, which is used to request the terminal to access the AMF.

Among them, the eighth request message contains indication information #5.

Optionally, the eighth request message also includes indication information #1 for indicating whether the access network RAN has a CU-DU separated architecture, so that after the AMF determines that the RAN has a CU-DU separated architecture according to the eighth request message , Connect the terminal or make the terminal online contract or through the third-party authentication to make the terminal access other networks configured on the first DU, for example, instruct the first DU to re-select the network access of the second CU.

Optionally, the eighth request message is an initial UE message.

S604. The AMF judges whether the first DU or other network configured on the first CU supports terminal access, and if it does, the terminal is connected to the other network.

For example, after the AMF receives the eighth request message of the first CU, it determines that although the first CU does not support the network requested by the terminal, but the first CU supports other networks that the terminal signs up, the terminal will be connected to the first CU. Support other networks that the terminal has contracted.

For example, after the AMF receives the eighth request message of the first CU, it determines that although the first CU of the terminal does not support the network requested by the terminal, the following possibility is not ruled out: Since the RAN is a CU-DU separation architecture, the first The first DU connected to the CU may also be configured with other networks. For example, the first DU may also be connected to the second CU, and the second CU supports the network requested by the terminal. One DU performs CU reselection based on the auxiliary information, thereby connecting the terminal to the second CU.

Optionally, the fifth request message and/or the eighth request message contains the CU reselection information of the first DU, so that after the AMF determines that the first CU does not support the network that the terminal requests to access, it determines whether the first DU needs to be instructed. DU reselects CU. For example, the AMF only determines, according to the eighth request message, that the first DU has not performed CU reselection, the number of CU reselections performed by the first DU does not exceed a preset value, or there are unselected CUs among the CUs connected to the first DU. , Instruct the first DU to reselect CU to access.

Optionally, if other networks (such as the second CU) configured on the first DU support terminal access, the method further includes the following steps: the first CU receives the eighth response message from the AMF, where the eighth response message is used for Instruct the first DU to reselect the CU; the first CU sends a fifth response message to the first DU, the fifth response message is used to instruct the first DU to reselect the CU; after the first DU receives the fifth response message, it reselects the second CU Initiate the access process.

Further optionally, the eighth response message and the fifth response message include one or more of the following information: instruction information for reselecting the CU; public land mobile network identification PLMN ID; closed access group identification CAG ID; the CAG list of the closed access group that the terminal is allowed to access; the indication information of whether the terminal can only access the CAG cell.

Similarly, the method steps performed after the second CU reselected by the first DU may refer to the method steps performed after the second CU reselected by the first DU in the embodiment shown in FIG. 4A, which will not be repeated here. .

According to the above, when the first DU can perceive the network type of the logical cell that the terminal selects to access in the embodiment of this application, if the first DU finds that the selected first CU does not support terminal access, it may not directly reject the terminal Access, but instructs the first CU to continue sending a request to the AMF. As long as any network supported by the first CU or the first DU is supported by the terminal, the AMF can allow the terminal to access. It can avoid the problem that the AMF directly refuses the terminal access and the terminal needs to re-select (physical) cell selection and random access procedures, which can save air interface signaling overhead and reduce the time delay for the terminal to access the network.

In another embodiment of the present application, it may be defined that the public network or NPN network corresponding to the same PLMN ID needs to be configured with the same cell identity, so that the same cell identity points to the same CU. In this way, different cell identities (that is, different CUs) configured with the same PLMN ID can be avoided, which causes the first DU to select a CU that the terminal does not support to access, thereby saving air interface signaling overhead and reducing terminal access to the network. Time delay.

The method for terminal access to the network provided by the embodiment of the present application is described in detail above with reference to FIGS. 4A to 6, and the device used to implement the foregoing method in the embodiment of the present application is described in detail below with reference to FIGS. 7-17. Therefore, all the above content can be used in the subsequent embodiments, and the repeated content will not be repeated.

Based on the same technical concept, referring to FIG. 7, an embodiment of the present application provides an apparatus 700 for wireless access to a network. The apparatus 700 may be a DU or a device on the DU. Module of method steps performed by the first DU in 4B.

Exemplarily, the apparatus 700 may include:

The sending module 701 is configured to send a first request message to the selected first centralized unit CU, where the first request message is used to request the terminal to access the first CU;

The receiving module 702 is configured to receive a first response message from the first CU, where the first response message is used to instruct the device 700 to reselect a CU, the first response message carries auxiliary information, and the The auxiliary information is used to assist the device 700 to reselect a CU;

The processing module 703 is configured to select the second CU according to the auxiliary information, so as to connect the terminal to the network through the second CU.

Optionally, the sending module 701 is further configured to send a second request message to the second CU, where the second request message is used to request the terminal to access the second CU.

Public land mobile network identification PLMN ID;

CAG ID of the closed access group;

The CAG list of the closed access group that the terminal is allowed to access;

Indication information of whether the terminal can only access the CAG cell.

CU reselection information of the device 700;

The CAG ID;

The PLMN ID;

The CAG list;

Indication information of whether the terminal can only access the CAG cell.

Based on the same technical concept, referring to FIG. 8, an embodiment of the present application provides an apparatus 800 for a core network. The apparatus 800 may be an AMF or an apparatus on the AMF. A module of method steps performed by AMF.

Exemplarily, the apparatus 800 may include:

The receiving module 801 is configured to receive a third request message from the first centralized unit CU, where the third request message is used to request the terminal to access the device 800;

The processing module 802 is configured to determine, according to the subscription information of the terminal, that the first CU does not support the terminal access;

The sending module 803 is configured to send a third response message to the first CU, where the third response message is used to instruct the first DU to reselect a CU, and the third response message carries auxiliary information, and the auxiliary The information is used to assist the first DU to reselect a CU.

The processing module 802 is further configured to determine whether the RAN is a CU-DU separated architecture according to the indication information;

The sending module 803 is configured to send a third response message to the first CU after the processing module 802 determines that the RAN is a CU-DU separated architecture.

The processing module 802 is further configured to determine, according to the CU reselection information, whether the first DU has performed CU reselection, or whether the first DU has performed CU reselection times and does not exceed a preset value, or Whether there is an unselected CU among the CUs connected to the first DU;

The sending module 803 is configured to: the processing module 802 determines that the first DU has not performed CU reselection, or the number of CU reselections performed by the first DU does not exceed a preset value, or the first DU After an unselected CU still exists among CUs connected to a DU, a third response message is sent to the first CU.

Public land mobile network identification PLMN ID;

CAG ID of the closed access group;

The CAG list of the closed access group that the terminal is allowed to access;

Indication information of whether the terminal can only access the CAG cell.

Based on the same technical concept, referring to FIG. 9, an embodiment of the present application provides a device 900 for wireless access to a network. The device 900 may be a CU or a device on the CU. Module of method steps executed by the first CU in 4B.

Exemplarily, the device 900 includes:

The receiving module 901 is configured to receive a first request message from a first DU, where the first request message is used to request a terminal to access the device;

The sending module 902 is configured to send a third request message to the AMF, where the third request message is used to request the terminal to access the AMF;

The receiving module 901 is further configured to receive a third response message from the AMF, where the third response message is used to instruct the first DU to reselect a CU, and the third response message carries auxiliary information, The auxiliary information is used to assist the first DU to reselect a CU;

The sending module 902 is further configured to send a first response message to the first DU, where the first response message is used to instruct the first DU to reselect a CU, and the first response message carries the Supplementary information.

Based on the same technical concept, referring to FIG. 10, an embodiment of the present application provides an apparatus 1000 for wireless access to a network. The apparatus 1000 may be a CU or a device on the CU. Module of method steps executed by the second CU in 4B.

Exemplarily, the device 1000 includes:

The receiving module 1001 is configured to receive a second request message from a first DU, where the second request message is used to request the terminal to access the device;

The sending module 1002 is configured to send a fourth request message to the AMF, where the fourth request message is used to request the terminal to access the AMF;

The receiving module 1001 is further configured to receive an initial context establishment request message from the AMF;

The processing module 1003 is configured to establish a context for the terminal according to the initial context establishment request message.

Based on the same technical concept, referring to FIG. 11, an embodiment of the present application provides an apparatus 1100 for wireless access to a network. The apparatus 1100 may be a DU or a device on the DU. The module of the method steps performed by the first DU.

Exemplarily, the device 1100 includes:

The processing module 1101 is configured to determine that the public-network-converged non-public network PNI-NPN network configured on the selected first centralized unit CU does not support the network that the terminal requests to access;

The sending module 1102 is configured to send a sixth request message to the first CU, which is used to instruct the first CU to release the context configured for the terminal;

The processing module 1101 is also used to select a second CU;

The sending module 1102 is further configured to send a seventh request message to the second CU, where the seventh request message is used to request the terminal to access the second CU.

Based on the same technical concept, referring to FIG. 12, an embodiment of the present application provides an apparatus 1200 for wireless access to a network. The apparatus 1200 may be a second CU or an apparatus on the second CU. The apparatus 1200 includes a device for performing the foregoing Figure 5 shows the module of the method.

Exemplarily, the device 1200 includes:

The receiving module 1201 is configured to receive a seventh request message from the first DU, where the seventh request message is used to request the terminal to access the device;

The sending module 1202 is configured to send a ninth request message to the AMF, where the ninth request message is used to request the terminal to access the AMF;

The receiving module 1201 is further configured to receive an initial context establishment request message from the AMF;

The processing module 1203 is configured to establish a context for the terminal according to the initial context establishment request message.

Based on the same technical concept, referring to FIG. 13, an embodiment of the present application provides a core network device 1300. The device 1300 may be an AMF or a device on the AMF. Module of method steps to be executed.

Exemplarily, the device 1300 includes:

The receiving module 1301 is configured to receive a ninth request message from the second CU, where the ninth request message is used to request the terminal to access the device;

The sending module 1302 is configured to send an initial context establishment request message to the second CU when the second CU supports the terminal access.

Based on the same technical concept, referring to FIG. 14, an embodiment of the present application provides an apparatus 1400 for wireless access to a network. The apparatus 1400 may be a CU or a device on the CU. Module of method steps executed by the first CU.

Exemplarily, the device 1400 includes:

The receiving module 1401 is configured to receive a sixth request message from a first DU, where the sixth request message is used to instruct the first CU to release the context configured for the terminal;

The processing module 1402 is configured to release the context of the terminal in response to the sixth request message.

Based on the same technical concept, referring to FIG. 15, an embodiment of the present application provides an apparatus 1500 for wireless access to a network. The apparatus 1500 may be a DU or a device on the DU. The module of the method steps performed by the first DU.

Exemplarily, the device 1500 includes:

The processing module 1501 is configured to determine that the public-network-converged non-public network PNI-NPN network configured on the selected first centralized unit CU does not support the network that the terminal requests to access;

The sending module 1502 is configured to send a fifth request message to the first CU, where the fifth request message is used to request the first CU to send an access request message to the AMF;

The receiving module 1503 is configured to receive a fifth response message from the first CU, where the fifth response message is used to instruct the terminal to access the device or another network configured on the first CU.

Based on the same technical concept, referring to FIG. 16, an embodiment of the present application provides an apparatus 1600 for wireless access to a network. The apparatus 1600 may be a CU or an apparatus on the CU. Module of method steps executed by the first CU.

Exemplarily, the device 1600 includes:

The receiving module 1601 is configured to receive a fifth request message from a first DU, where the fifth request message is a PNI-NPN network that is a public network converged non-public network configured on the first CU as determined by the first DU Generated when the network that the terminal requests to access is not supported, the fifth request message is used to request the device to send an access request message to the AMF;

The sending module 1602 is configured to send an eighth request message to the AMF, where the eighth request message is used to request the terminal to access the AMF.

Based on the same technical concept, referring to FIG. 17, an embodiment of the present application provides a core network device 1700. The device 1700 may be an AMF or a device on the AMF. Module of method steps to be executed.

Exemplarily, the device 1700 includes:

The receiving module 1701 is configured to receive an eighth request message from a first CU, where the eighth request message is used to request the terminal to access the device 1700, and the eighth request message is the first Generated by the first CU when the PNI-NPN network configured on the CU does not support the network that the terminal requests to access;

The processing module 1702 is configured to determine whether the first DU or another network configured on the first CU supports terminal access, and if it does, connect the terminal to the other network.

Based on the same technical concept, referring to FIG. 18, an embodiment of the present application provides a communication device 1800, and the device 1800 includes:

At least one processor 1801; and,

A memory 1802 and a communication interface 1803 that are communicatively connected with the at least one processor 1801;

Wherein, the memory 1802 stores instructions that can be executed by the at least one processor 1801, and the at least one processor 1801 executes the instructions stored in the memory 1802 to execute the instructions shown in FIG. 4A or FIG. 4B or FIG. 5 or FIG. The method shown in 6.

Optionally, the memory 1802 is located outside the device 1800.

Optionally, the device 1800 includes the memory 1802, the memory 1802 is connected to the at least one processor 1801, and the memory 1802 stores instructions that can be executed by the at least one processor 1801. FIG. 18 uses a dashed line to indicate that the memory 1802 is optional for the device 1800.

Wherein, the processor 1801 and the memory 1802 may be coupled through an interface circuit, or may be integrated together, which is not limited here.

The specific connection medium between the aforementioned processor 1801, memory 1802, and communication interface 1803 is not limited in the embodiment of the present application. In the embodiment of the present application in FIG. 18, the processor 1801, the memory 1802, and the communication interface 1803 are connected by a bus 1804. The bus is represented by a thick line in FIG. 18. The connection mode between other components is only for schematic illustration. , Is not limited. The bus can be divided into an address bus, a data bus, a control bus, and so on. For ease of presentation, only one thick line is used in FIG. 18 to represent it, but it does not mean that there is only one bus or one type of bus.

It should be understood that the processor mentioned in the embodiments of the present application may be implemented by hardware or software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, or the like. When implemented by software, the processor may be a general-purpose processor, which is implemented by reading software codes stored in the memory.

Exemplarily, the processor may be a central processing unit (Central Processing Unit, CPU), or other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), and Application Specific Integrated Circuit (ASIC) , Ready-made programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like.

It should be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Among them, the non-volatile memory can be read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable programmable read-only memory (Erasable PROM, EPROM), and electrically available Erase programmable read-only memory (Electrically EPROM, EEPROM) or flash memory. The volatile memory may be a random access memory (Random Access Memory, RAM), which is used as an external cache. By way of exemplary but not restrictive description, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), double data rate synchronous dynamic random access memory (Double Data Eate SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (Enhanced SDRAM, ESDRAM), synchronous connection dynamic random access memory (Synchlink DRAM, SLDRAM) ) And Direct Rambus RAM (DR RAM).

It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated in the processor.

It should be noted that the memories described herein are intended to include, but are not limited to, these and any other suitable types of memories.

Based on the same technical concept, the embodiments of the present application also provide a computer-readable storage medium, including a program or instruction. When the program or instruction is run on a computer, it will be shown in FIG. 4A or FIG. 4B or FIG. 5 or FIG. The method shown is executed.

Based on the same technical concept, the embodiments of the present application also provide a computer program product, which when running on a computer, enables the method shown in FIG. 4A or FIG. 4B or FIG. 5 or FIG. 6 to be executed.

Based on the same technical concept, an embodiment of the present application also provides a chip, which is coupled with a memory, and is used to read and execute the program instructions stored in the memory, so as to realize the implementation shown in FIG. 4A or FIG. 4B or FIG. 5 or FIG. 6 The method shown.

Based on the same technical concept, an embodiment of the present application also provides a communication system, including:

The above-mentioned device 700, device 800, device 900, and device 1000; or,

The above-mentioned device 1100, device 1200, device 1300, and device 1400; or,

The above-mentioned device 1500, device 1600, and device 1700.

Among them, all relevant content of each step involved in the above method embodiment can be cited in the functional description of the corresponding functional module of each device in the device embodiment, and will not be repeated here.

The embodiments of the present application are described with reference to the flowcharts and/or block diagrams of the methods, equipment (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and/or block in the flowchart and/or block diagram, and the combination of processes and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing equipment are used to generate It is a device that realizes the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, it can be implemented in the form of a computer program product in whole or in part. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another readable storage medium. For example, the computer instructions may be passed from a website, a computer, a server, or a data center. Wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) to transmit to another website, computer, server, or data center. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrated with one or more available media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a digital versatile disc (DVD)), or a semiconductor medium (for example, a solid state disk (SSD)). ))Wait.

Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. In this way, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

A method for a terminal to access a network, characterized in that it includes:

The first distributed unit DU sends a first request message to the selected first centralized unit CU, where the first request message is used to request the terminal to access the first CU;

The first DU receives a first response message from the first CU, the first response message is used to instruct the first DU to reselect a CU, the first response message carries auxiliary information, and the auxiliary The information is used to assist the first DU to reselect a CU;

The first DU selects a second CU according to the auxiliary information, so as to connect the terminal to the network through the second CU.
The method according to claim 1, wherein after the first DU selects the second CU according to the auxiliary information, the method further comprises:

The first DU sends a second request message to the second CU, where the second request message is used to request the terminal to access the second CU.
The method according to claim 2, wherein the auxiliary information contains one or more of the following information:

Public land mobile network identification PLMN ID;

CAG ID of the closed access group;

The CAG list of the closed access group that the terminal is allowed to access;

Indication information of whether the terminal can only access the CAG cell.
The method according to claim 3, wherein the second request message contains one or more of the following information:

CU reselection information of the first DU;

The CAG ID;

The PLMN ID;

The CAG list;

Indication information of whether the terminal can only access the CAG cell.
A method for a terminal to access a network, characterized in that it includes:

The access and mobility management function AMF receives a third request message from the first centralized unit CU, where the third request message is used to request the terminal to access the AMF;

The AMF judges that the first CU does not support the terminal access according to the subscription information of the terminal, the AMF sends a third response message to the first CU, and the third response message is used to indicate the The first DU reselects a CU, and the third response message carries auxiliary information, and the auxiliary information is used to assist the first DU in reselecting a CU.
The method according to claim 5, wherein the third request message contains indication information for indicating whether the radio access network RAN is a CU-DU separated architecture;

The sending of the third response message by the AMF to the first CU includes:

After determining that the RAN is a CU-DU separated architecture according to the indication information, the AMF sends a third response message to the first CU.
The method according to claim 5 or 6, wherein the third request message contains CU reselection information of the first DU;

The sending of the third response message by the AMF to the first CU includes:

The AMF determines, according to the CU reselection information, that the first DU has not performed CU reselection, or the number of CU reselections performed by the first DU does not exceed a preset value, or the first DU is connected After an unselected CU still exists in the CU, the third response message is sent to the first CU.
The method according to any one of claims 5-7, wherein the auxiliary information contains one or more of the following information:

Public land mobile network identification PLMN ID;

CAG ID of the closed access group;

The CAG list of the closed access group that the terminal is allowed to access;

Indication information of whether the terminal can only access the CAG cell.
A device for wirelessly accessing a network, characterized in that it comprises:

A sending module, configured to send a first request message to the selected first centralized unit CU, where the first request message is used to request the terminal to access the first CU;

The receiving module is configured to receive a first response message from the first CU, where the first response message is used to instruct the device to reselect a CU, and the first response message carries auxiliary information, the auxiliary information Used to assist the device to reselect CU;

The processing module is configured to select a second CU according to the auxiliary information, so as to connect the terminal to the network through the second CU.
The apparatus according to claim 9, wherein the sending module is further configured to send a second request message to the second CU, wherein the second request message is used to request the terminal to access the station. The second CU.
The device of claim 10, wherein the auxiliary information includes one or more of the following items:

Public land mobile network identification PLMN ID;

CAG ID of the closed access group;

The CAG list of the closed access group that the terminal is allowed to access;

Indication information of whether the terminal can only access the CAG cell.
The device according to claim 11, wherein the second request message contains one or more of the following information:

CU reselection information of the device;

The CAG ID;

The PLMN ID;

The CAG list;

Indication information of whether the terminal can only access the CAG cell.
A core network device, characterized in that it comprises:

A receiving module, configured to receive a third request message from the first centralized unit CU, where the third request message is used to request the terminal to access the device;

A processing module, configured to determine, according to the subscription information of the terminal, that the first CU does not support the terminal access;

The sending module is configured to send a third response message to the first CU, where the third response message is used to instruct the first DU to reselect a CU, and the third response message carries auxiliary information, the auxiliary information Used to assist the first DU to reselect a CU.
The apparatus according to claim 13, wherein the third request message contains indication information used to indicate whether the access network RAN is a CU-DU separated architecture;

The processing module is further configured to determine whether the RAN is a CU-DU separated architecture according to the indication information;

The sending module is configured to send a third response message to the first CU after the processing module determines that the RAN is a CU-DU separated architecture.
The apparatus according to claim 13 or 14, wherein the third request message contains CU reselection information of the first DU;

The processing module is further configured to determine, according to the CU reselection information, whether the first DU has performed CU reselection, or whether the first DU has performed CU reselection times and does not exceed a preset value, or Whether there is an unselected CU among the CUs connected to the first DU;

The sending module is configured to: the processing module determines that the first DU has not performed CU reselection, or the number of CU reselections performed by the first DU does not exceed a preset value, or the first DU After there is an unselected CU among the connected CUs, a third response message is sent to the first CU.
The device according to any one of claims 13-15, wherein the third response message contains one or more of the following information:

Public land mobile network identification PLMN ID;

CAG ID of the closed access group;

The CAG list of the closed access group that the terminal is allowed to access;

Indication information of whether the terminal can only access the CAG cell.
A communication device, characterized in that the device comprises:

At least one processor; and,

A memory and a communication interface communicatively connected with the at least one processor;

Wherein, the memory stores instructions that can be executed by the at least one processor, and the at least one processor executes the instructions as described in any one of claims 1-4 or 5-8 by executing the instructions stored in the memory. The method described.
A computer-readable storage medium, characterized by comprising a program or instruction, when the program or instruction runs on a computer, the method according to any one of claims 1-4 or 5-8 is executed .
A computer program product, characterized in that when it runs on a computer, the method according to any one of claims 1-4 or 5-8 is executed.
A chip, characterized in that the chip is coupled with a memory, and is used to read and execute program instructions stored in the memory to implement the method according to any one of claims 1-4 or 5-8.