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US-12628068-B2 - Communication method, system, base station, and terminal

US12628068B2US 12628068 B2US12628068 B2US 12628068B2US-12628068-B2

Abstract

The present disclosure relates to a communication method, system, base station, and terminal. The method includes: sending, by a first BS, a broadcast message, wherein the broadcast message comprising: one or more CAG IDs and one or more PLMN IDs supported by the first BS; receiving, by the first BS, a connection request sent from a terminal; establishing, by the first BS, a RRC connection with the terminal according to the connection request; receiving, by the first BS, a RRC connection setup complete message sent from the terminal, wherein the RRC connection setup complete message carries a CAG ID and a PLMN ID, which correspond to a CAG cell that the terminal selects to access; and allowing, by the first BS, the terminal to access the CAG cell that the terminal selects to access, according to the RRC connection setup complete message.

Inventors

  • Shengnan LIU
  • Zheng Jiang
  • Peng Chen
  • Xiaoming She

Assignees

  • CHINA TELECOM CORPORATION LIMITED

Dates

Publication Date
20260512
Application Date
20200713
Priority Date
20191030

Claims (19)

  1. 1 . A communication method, comprising: sending, by a first Base Station (BS), a broadcast message, wherein the broadcast message comprising: one or more Closed Access Group identities (CAG IDs) and one or more Public Land Mobile Network Identities (PLMN IDs) supported by the first BS; receiving, by the first BS, a connection request sent from a terminal, wherein the connection request represents that the first BS supports at least one of one or more CAGs subscribed by the terminal; establishing, by the first BS, a Radio Resource Control (RRC) connection with the terminal according to the connection request; receiving, by the first BS, a RRC connection setup complete message sent from the terminal, wherein the RRC connection setup complete message carries a CAG ID and a PLMN ID, which correspond to a CAG cell that the terminal selects to access; and allowing, by the first BS, the terminal to access the CAG cell that the terminal selects to access, according to the RRC connection setup complete message; receiving, by the first BS, a measurement report sent from the terminal, wherein the measurement report comprises a CAG ID, a PLMN ID, and signal quality information, which correspond to each of one or more neighborhood cells measured by the terminal; making a handover judgment and determining a cell corresponding to a third BS as a target cell according to the measurement report by the first BS; sending, by the first BS, a handover required message to a core network element, to initiate a handover request to the third BS through the core network element, wherein the handover required message comprises an identifier of the target cell, in a case where the first BS judges that a handover condition is met, the handover request comprises a mobility restriction list, which comprises an Allowed CAG list of the terminal and an access mode indication of the terminal, wherein the Allowed CAG list comprises the one or more CAG IDs and one or more PLMN IDs subscribed by the terminal, the access mode indication comprises a CAG-only indication; determining, by the third BS, that the terminal can only access a CAG cell, according to the access mode indication; determining, by the third BS, whether to allow a handover of the terminal according to a comparison result between one or more CAG IDs and one or more PLMN IDs supported by the third BS and the Allowed CAG list of the terminal or a comparison result between a CAG ID and a PLMN ID supported by the target cell and the Allowed CAG list of the terminal; sending, by the third BS, a handover request acknowledge message to the core network element in a case where the handover of the terminal is allowed; and receiving, by the first BS, a handover command returned by the core network element, and executing a handover process, wherein the handover command represents that the target cell supports a CAG of the one or more CAGs subscribed by the terminal.
  2. 2 . The communication method according to claim 1 , wherein allowing, by the first BS, the terminal to access the CAG cell that the terminal selects to access comprises: sending, by the first BS, an initial user equipment (UE) message to a core network element, wherein the initial UE message comprises the CAG ID and the PLMN ID, which correspond to the CAG cell that the terminal selects to access, which are used for verifying whether a current access of the terminal is legal; and receiving, by the first BS, a downlink non-access stratum transport message sent from the core network element, and allowing the terminal to access the CAG cell that the terminal selects to access according to the downlink non-access stratum transport message, wherein the downlink non-access stratum transport message represents that the current access of the terminal is legal.
  3. 3 . The communication method according to claim 1 , further comprising: receiving, by the first BS, a measurement report sent from the terminal, wherein the measurement report comprises: a CAG ID, a PLMN ID, and signal quality information, which correspond to each of one or more neighborhood cells measured by the terminal; making a handover judgment and determining a cell corresponding to a second BS as a target cell according to the measurement report by the first BS; sending, by the first BS, a handover request to the second BS, in a case of judging that a handover condition is met, wherein the handover request comprises an Allowed CAG list of the terminal, the Allowed CAG list of the terminal comprising one or more CAG IDs and one or more PLMN IDs subscribed by the terminal; receiving, by the first BS, a handover request acknowledge message returned from the second BS; and handing over the terminal to the target cell by the first BS, according to the handover request acknowledge message, wherein the handover request acknowledge message represents that the target cell supports a CAG ID and a PLMN ID subscribed by the terminal.
  4. 4 . The communication method according to claim 3 , wherein the handover request further comprises an access mode indication of the terminal, the access mode indication comprising a CAG-only indication, and the method further comprising: determining, by the second BS, that the terminal can only access a CAG cell according to the access mode indication; determining, by the second BS, whether to allow a handover of the terminal according to a comparison result between one or more CAG IDs and one or more PLMN IDs supported by the second BS and the Allowed CAG list of the terminal, or a comparison result between a CAG ID and a PLMN ID supported by the target cell and the Allowed CAG list of the terminal; and sending, by the second BS, the handover request acknowledge message to the first BS, in a case that the handover of the terminal is allowed.
  5. 5 . The communication method according to claim 3 , wherein making a handover judgment and determining a cell corresponding to a second BS as a target cell according to the measurement report by the first BS, and sending, by the first BS, a handover request to the second BS, in a case of judging that a handover condition is met comprises: making a handover judgment according to a matching result between the CAG ID and the PLMN ID, which correspond to the each of the one or more neighborhood cells measured by the terminal and the Allowed CAG list of the terminal, as well as the signal quality information corresponding to the each of the one or more neighborhood cells measured by the terminal, selecting the cell corresponding to the second BS as the target cell, in a case of judging that the handover condition is met, and sending the handover request to the second BS by the first BS, wherein the Allowed CAG list of the terminal is obtained by the first BS through an initial context setup request sent from the core network element.
  6. 6 . The communication method according to claim 1 , further comprising: determining, by the core network element, whether a current handover of the terminal is legal according to a comparison result between one or more CAG IDs and one or more PLMN IDs supported by the third BS and an Allowed CAG list of the terminal or a comparison result between a CAG ID and a PLMN ID supported by the target cell and the Allowed CAG list of the terminal; and sending, by the core network element, the handover request to the third BS, in a case that the current handover of the terminal is legal, wherein the Allowed CAG list comprises the one or more CAG IDs and the one or more PLMN IDs subscribed by the terminal; optionally, wherein the third BS sends the one or more CAG IDs supported by the third BS to the core network element through a Next Generation (NG) setup request or a Radio Access Network (RAN) configuration update message.
  7. 7 . A base station (BS), comprising: a processor; and a memory coupled to the processor and storing instructions that when executed by the processor, cause the processor to execute the communication method according to claim 1 .
  8. 8 . The communication method according to claim 2 , wherein an Allowed CAG list of the terminal and an access mode indication of the terminal are added to a mobility restriction list of the downlink non-access stratum transport message, wherein the Allowed CAG list comprises one or more CAG IDs and one or more PLMN IDs subscribed by the terminal, and the access mode indication comprises a CAG-only indication.
  9. 9 . The communication method according to claim 8 , wherein whether the current access of the terminal is legal is determined according to a comparison result between the CAG ID and the PLMN ID, which correspond to the CAG cell that the terminal selects to access and the Allowed CAG list of the terminal.
  10. 10 . A communication method, comprising: receiving, by a terminal, a broadcast message sent from a first Base Station (BS), wherein the broadcast message comprising: one or more Closed Access Group identities (CAG IDs) and one or more Public Land Mobile Network Identities (PLMN IDs) supported by the first BS; determining, by the terminal, whether the first BS supports at least one of one or more CAGs subscribed by the terminal according to the broadcast message; if the first BS supports at least one of the one or more CAGs subscribed by the terminal, selecting, by the terminal, a CAG from the least one of the one or more CAGs subscribed by the terminal and supported by the first BS; sending, by the terminal, a connection request to the first BS, and establishing a Radio Resource Control (RRC) connection with the first BS; and sending, by the terminal, a RRC setup complete message to the first BS, wherein the RRC setup complete message carries a CAG ID and a PLMN ID, which correspond to a CAG cell that the terminal selects to access, to instruct the first BS to connect the terminal to the CAG cell that the terminal selects to access; sending, by the first BS, an initial user equipment (UE) message to a core network element, wherein the initial UE message comprises the CAG ID and the PLMN ID, which correspond to the CAG cell that the terminal selects to access, which are used for verifying whether a current access of the terminal is legal; and receiving, by the first BS, a downlink non-access stratum transport message sent from the core network element, and allowing the terminal to access the CAG cell that the terminal selects to access according to the downlink non-access stratum transport message, wherein the downlink non-access stratum transport message represents that the current access of the terminal is legal.
  11. 11 . The communication method according to claim 10 , wherein determining, by the terminal, whether the first BS supports least one of one or more CAGs subscribed by the terminal according to the broadcast message comprises: determining, by the terminal, whether the first BS supports least one of the one or more CAGs subscribed by the terminal according to a comparison result between the one or more CAG IDs and the one or more PLMN IDs supported by the first BS and an Allowed CAG list of the terminal, wherein the Allowed CAG list comprises: one or more CAG IDs and one or more PLMN IDs subscribed by the terminal.
  12. 12 . The communication method according to claim 10 , further comprising: sending, by the terminal, a measurement report to the first BS, wherein the measurement report comprises: a CAG ID, a PLMN ID, and signal quality information, which correspond to each of one or more neighborhood cells measured by the terminal, which is used for handing over the terminal by the first BS.
  13. 13 . A communication system, comprising: a Base Station (BS) according to claim 7 , and a terminal, wherein the terminal comprise: a processor; and a memory coupled to the processor and storing instructions that when executed by the processor, cause the processor to execute the communication method according to claim 10 .
  14. 14 . The communication system according to claim 13 , wherein the BS is a first BS, and the system further comprises: a core network element configured to receive an initial user equipment (UE) message sent from the first BS, determine whether a current access of the terminal is legal according to the initial UE message, send a downlink non-access stratum transport message to the first BS, in a case where the current access of the terminal is legal, wherein the initial UE message comprises a CAG ID and a PLMN ID, which correspond to the CAG cell that the terminal selects to access.
  15. 15 . The communication system according to claim 14 , wherein: the core network element is configured to determine whether the current access of the terminal is legal according to a comparison result between the CAG ID and the PLMN ID, which correspond to the CAG cell that the terminal selects to access and an Allowed CAG list of the terminal, wherein the Allowed CAG list comprises one or more CAG IDs and one or more PLMN IDs subscribed by the terminal; or the core network element is further configured to receive a handover required message sent from the first BS, send a handover request to a third BS according to the handover required message, receive a handover request acknowledge message sent from the third BS, and return a handover command to the first BS according to the handover request acknowledge message.
  16. 16 . The communication system according to claim 14 , further comprising: a second BS configured to receive a handover request sent from the first BS, determine whether to allow a handover of the terminal according to the handover request, return a handover request acknowledge message to the first BS, in a case that the second BS allows the handover of the terminal, wherein the handover request comprises an Allowed CAG list of the terminal, and the Allowed CAG list comprises one or more CAG IDs and one or more PLMN IDs subscribed by the terminal.
  17. 17 . The communication system according to claim 15 , further comprising: the third BS, wherein: the core network element is configured to determine whether a current handover of the terminal is legal according to between one or more CAG IDs and one or more PLMN IDs supported by the third BS and an Allowed CAG list of the terminal or a comparison result between a CAG ID and a PLMN ID supported by the target cell and the Allowed CAG list of the terminal, and send a handover request to the third BS, in a case that the current handover of the terminal is legal; or the third BS is configured to receive the handover request from the core network element, wherein the handover request comprises an Allowed CAG list of the terminal and an access mode indication of the terminal, and the access mode indication comprising a CAG-only indication, determine that the terminal can only access a CAG cell according to the access mode indication, determine whether to allow a handover of the terminal according to a comparison result between one or more CAG IDs and one or more PLMN IDs supported by the third BS and the Allowed CAG list of the terminal or a comparison result between a CAG ID and a PLMN ID supported by the target cell and the Allowed CAG list of the terminal, and send a handover request acknowledge message to the core network element, in a case that the handover of the terminal is allowed.
  18. 18 . A terminal, comprising: a processor; and a memory coupled to the processor and storing instructions that when executed by the processor, cause the processor to execute the communication method according to claim 10 .
  19. 19 . The communication system according to claim 16 , wherein the handover request further comprises an access mode indication of the terminal, and the access mode indication comprising a CAG-only indication; and the second BS is configured to determine that the terminal can only access a CAG cell according to the access mode indication, determine whether to allow the handover of the terminal according to a comparison result between one or more CAG IDs and one or more PLMN IDs supported by the second BS and the Allowed CAG list of the terminal, or a comparison result between a CAG ID and a PLMN ID supported by the target cell and the Allowed CAG list of the terminal, and send the handover request acknowledge message to the first BS, in a case that the handover of the terminal is allowed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present disclosure is a U.S. National Stage Application under 35 U.S.C. § 371 of International Patent Application No. PCT/CN2020/101569, filed on Jul. 13, 2020, which is based on and claims priority of Chinese application for invention No. 201911042165.4 filed on Oct. 30, 2019, the disclosures of both of which are hereby incorporated into this disclosure by reference in its entirety. TECHNICAL FIELD The present disclosure relates to the field of communication technologies, and in particular, to a communication method and system, a base station, and a terminal. BACKGROUND The research goal of 5G technology is to provide communication with higher reliability and lower delay, so as to meet requirements of different users in different industries. For example, according to requirements of some specific users in a coverage of a public network, non-public networks dedicated to the specific users can be designed for communication services. Non-standalone (NSA) non-public networks can meet requirements of some specific users in a coverage of a network, a concept of which can be described by Closed Access Group (CAG). A user belonging to a CAG cell can select to access the network via a public network or access the network via the CAG cell according to their own registration information. Through building CAG cells, operators can provide non-public network access for special building scenarios covered by a public network (such as large shopping malls, SOHO, etc.). At present, a research point of considering that the 5G network will support the function of the NSA non-public networks in the future has been found in the research of NR (New Radio) high-level core network technology. However, there is no solution for CAG service proposed in the current research of wireless side. In order to support the NSA non-public networks in the 5G stage, it is necessary to design a corresponding system process. SUMMARY According to some embodiments of the present disclosure, a communication method is provided, comprising: sending, by a first Base Station (BS), a broadcast message, wherein the broadcast message comprising: one or more Closed Access Group identities (CAG IDs) and one or more Public Land Mobile Network Identities (PLMN IDs) supported by the first BS; receiving, by the first BS, a connection request sent from a terminal, wherein the connection request represents that the first BS supports at least one of one or more CAGs subscribed by the terminal; establishing, by the first BS, a Radio Resource Control (RRC) connection with the terminal according to the connection request; receiving, by the first BS, a RRC connection setup complete message sent from the terminal, wherein the RRC connection setup complete message carries a CAG ID and a PLMN ID, which correspond to a CAG cell that the terminal selects to access; and allowing, by the first BS, the terminal to access the CAG cell that the terminal selects to access, according to the RRC connection setup complete message. In some embodiments, allowing, by the first BS, the terminal to access the CAG cell that the terminal selects to access comprises: sending, by the first BS, an initial user equipment (UE) message to a core network element, wherein the initial UE message comprises the CAG ID and the PLMN ID, which correspond to the CAG cell that the terminal selects to access, which are used for verifying whether a current access of the terminal is legal; and receiving, by the first BS, a downlink non-access stratum transport message sent from the core network element, and allowing the terminal to access the CAG cell that the terminal selects to access according to the downlink non-access stratum transport message, wherein the downlink non-access stratum transport message represents that the current access of the terminal is legal; optionally, wherein an Allowed CAG list of the terminal and an access mode indication of the terminal are added to a mobility restriction list of the downlink non-access stratum transport message, wherein the Allowed CAG list comprises one or more CAG IDs and one or more PLMN IDs subscribed by the terminal, and the access mode indication comprises a CAG-only indication; optionally, wherein whether the current access of the terminal is legal is determined according to a comparison result between the CAG ID and the PLMN ID, which correspond to the CAG cell that the terminal selects to access and the Allowed CAG list of the terminal. In some embodiments, the method further comprises: receiving, by the first BS, a measurement report sent from the terminal, wherein the measurement report comprises: a CAG ID, a PLMN ID, and signal quality information, which correspond to each of one or more neighborhood cells measured by the terminal; making a handover judgment and determining a cell corresponding to a second BS as a target cell according to the measurement report by the first BS; sending, by the first BS, a h