Method and user equipment for releasing rrc connection

Abstract

The present application provides a method and a user equipment for releasing an RRC connection performed by a user equipment supporting a multi-USIM mode. The method comprises: upon receiving an authorization indication message indicating an authorization request to release a current RRC connection, determining whether a predetermined condition for triggering an RRC connection release request procedure is met; upon the predetermined condition being met, sending a predetermined request message to a current base station corresponding to the current RRC connection for requesting to release the current RRC connection; and performing an RRC connection release procedure based on a response of the current base station to the predetermined request message.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically, to a user equipment executing a method for releasing an RRC connection performed by a user equipment supporting multiple USIM modes. Background Technology

[0002] In recent years, multi-USIM card (MUSIM) devices have become increasingly popular. For example, a user might install two USIM cards in a phone that supports MUSIM cards, one for subscribing to personal services and the other for subscribing to office services. Existing MUSIM-enabled devices are vendor-implemented and not yet standardized by 3GPP. This leads to different implementations from different vendors, resulting in varying UE (User Equipment) behaviors. In existing implementations, if these USIM cards register separately with networks (either the same network or two or more networks), the UE needs to receive paging from these networks. Depending on the UE's transmit / receive capabilities, a possible scenario is that while the UE is receiving a paging from its current network, another network may also initiate paging, or the UE may be communicating with one network while another network initiates paging. If the UE switches between different networks, one possible consequence is that when the UE switches to another network, it can no longer receive data from its current network. This will impair network performance; for example, the network might send a paging message to the UE, but the UE misses it due to switching to another network, or the UE might switch to another network and be unable to receive scheduling from its current network. Some manufacturers have proposed conducting 3GPP standardization research on the behavior of UEs with multiple USIM cards accessing the network and related networks. The advantage of this is that network performance can be improved based on predictable UE behavior.

[0003] For the reasons mentioned above, in December 2019, at the 3rd Generation Partnership Project (3GPP) RAN#86 plenary meeting, vivo proposed a work project for multi-SIM devices in Rel-17 (see non-patent literature: RP-193263: New WID: Support of Multi-SIM devices in Rel-17), which was approved.

[0004] This invention addresses the problem of a UE in an RRC-connected state in network A releasing its RRC connection to network A when it needs to perform data reception and / or transmission operations in network B. Summary of the Invention

[0005] The purpose of this invention is to provide a method for releasing an RRC connection.

[0006] One aspect of the present invention provides a method for releasing an RRC connection performed by a user equipment supporting multiple USIM modes, comprising: upon receiving an authorization indication message indicating an authorization request to release a current RRC connection, determining whether predetermined conditions for triggering an RRC connection release request process are met; if the predetermined conditions are met, sending a predetermined request message to a current base station corresponding to the current RRC connection for requesting the release of the current RRC connection; and performing the RRC connection release process based on the response of the current base station to the predetermined request message.

[0007] Another aspect of the present invention provides a user equipment, including: a processor; and a memory storing instructions, wherein the instructions, when executed by the processor, perform the method described above.

[0008] Invention Effects

[0009] According to the invention, the RRC connection can be released efficiently, smoothly, and at the appropriate time. Attached Figure Description

[0010] The above and other features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0011] Figure 1A and Figure 1B This is a schematic diagram illustrating the RRC connection in this invention.

[0012] Figure 2 This is a flowchart illustrating a method for releasing an RRC connection according to an embodiment of the present invention;

[0013] Figure 3 This is a flowchart illustrating a method for releasing an RRC connection according to an embodiment of the present invention;

[0014] Figure 4 This is a flowchart illustrating a method for releasing an RRC connection according to an embodiment of the present invention;

[0015] Figure 5 This is a flowchart illustrating a method for releasing an RRC connection according to an embodiment of the present invention;

[0016] Figure 6 This is a structural block diagram of a user equipment according to an embodiment of the present invention. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the present invention should not be limited to the specific embodiments described below. Furthermore, for the sake of simplicity, detailed descriptions of well-known technologies not directly related to the present invention have been omitted to prevent confusion in understanding the present invention.

[0018] The following describes some of the terms involved in this invention. For the specific meaning of the terms, please refer to the latest relevant 3GPP documents, such as TS23.501, TS38.300, TS38.331, TS36.300, TS36.331, etc.

[0019] NAS: Non-access stratum.

[0020] AS: access stratum.

[0021] RRC: Radio Resource Control.

[0022] RRC_CONNECTED: RRC connection state.

[0023] RRC_INACTIVE: RRC inactive state.

[0024] RRC_IDLE: RRC idle state.

[0025] RAN: Radio Access Network.

[0026] USIM: Universal Subscriber Identity Module.

[0027] Tx: transmitter.

[0028] Rx: receiver.

[0029] NR: New RAT, New Wireless Access Technology.

[0030] AMF: Access and Mobility Management Function.

[0031] NGAP: Next Generation Application Protocol.

[0032] CM: Connection Management.

[0033] CM-CONNECTED: A UE in CM-CONNECTED state has a NAS signaling connection with the AMF over N1. For 3GPP access, a NAS signaling connection uses an RRC connection between the UE and the NG-RAN and an NGAP UE association between the AN and the AMF.

[0034] In this invention, unless otherwise specified, the base station and RAN are interchangeable. The network can be a base station and / or a core network, and can be a Long Term Evolution (LTE) network, an NR network, an enhanced Long Term Evolution (eLTE) network, or other networks defined in subsequent 3GPP evolution versions.

[0035] In this invention, a User Equipment (UE) can refer to a device that physically supports multiple USIM cards (two or more USIM cards). The device is equipped with two or more USIM cards, each associated with a network. These multiple USIM cards can come from the same operator or different operators. From a network perspective, different USIM cards correspond to different UEs, with each USIM card corresponding to one UE. Unless otherwise specified, those skilled in the art can easily determine from the context whether the UE refers to a UE supporting multiple USIM cards or a UE corresponding to each USIM card within a device supporting multiple USIM cards. A UE configured with multiple USIM cards can receive and / or transmit data from multiple networks using time-division multiplexing or other methods, employing single-receive-single-transmit or dual-receive-single-transmit methods. For a UE with two Rx (Receiving Scale) values, data can be received from two networks simultaneously. Furthermore, the USIM in this invention can be a physical SIM or an eSIM.

[0036] This invention uses a UE configured with two USIM cards as an example, but those skilled in the art can easily extend it to the case of multiple USIM cards. A UE with two USIM cards must have at least Single-Rx / Single-Tx or Dual-Rx / Single-Tx capabilities. Different UEs corresponding to the two USIM cards can share a pair of Tx and Rx cards or share a single Tx card but each has its own Rx card. In this embodiment, the UE connects to network A through USIM card A and to network B through USIM card B. Switching between different networks is achieved through the switching of the USIM card. The priority of the USIM card is the priority of the network.

[0037] In the embodiments described in this invention, the scenario is that a UE in MUSIM mode is in an RRC connected state on network A, and for the activity of another USIM (e.g., USIM card B needs to perform operations to receive and / or send data), the UE decides to request the release of the RRC connection on network A. The entity or layer in the UE that initiates the request to release the RRC connection can be the NAS layer or the RRC layer. The following embodiments provide methods for the NAS layer or the RRC layer in the UE to request the release of the RRC connection (RRC_CONNECTED) and / or CM-CONNECTED on network A.

[0038] Before describing the specific embodiments of the present invention, the term "RRC connection" in this invention will first be explained. In this invention, "RRC connection" refers to the RRC connection established between an RRC entity and the network, that is, the RRC connection between the USIM card and the network. Figure 1A and Figure 1B These are schematic diagrams illustrating the RRC connection in this invention. Figure 1A In the scenario shown, the user equipment has two USIM cards, corresponding to the first RRC entity and the second RRC entity respectively. RRC connection A is the RRC connection between the first RRC entity and the network, and RRC connection B is the RRC connection between the second RRC entity and the network. Figure 1B In the scenario shown, the user equipment has two USIM cards, corresponding to a first RRC entity and a second RRC entity, respectively. RRC connection A is an RRC connection between the first RRC entity and a first network, and RRC connection B is an RRC connection between the second RRC entity and a second network. In this invention, the number of RRC entities supported by the user equipment and the number of networks it can connect to are arbitrary. Figure 1A and Figure 1B This is merely an example; the number of RRC entities can be more than three, and similarly, the number of networks can also be more than three. It should be noted that, although... Figure 1A and Figure 1BRRC connection A and RRC connection B are shown, but this is only for illustrative purposes and does not mean that the user equipment has established multiple RRC connections with the network through multiple USIM RRC entities at the same time.

[0039] In this invention, "releasing an RRC connection" means releasing the RRC connection between an RRC entity in an RRC connection state and the corresponding network. For example, refer to... Figure 1A If the first entity and the first network are currently in an RRC connected state (RRC_CONNECTED), and the UE wants to release the RRC connection A for some reason (such as energy saving or MUSIM purposes described later), the release request process can be performed using the scheme described in this specification.

[0040] The following is for reference Figures 2 to 5 The outline of the method of the present invention will be described below.

[0041] Figure 2 This is a flowchart illustrating a method for releasing an RRC connection according to an embodiment of the present invention. Figure 2 As shown, in step 220, an authorization indication message indicating an authorization request to release the current RRC connection is received. In step 240, upon receiving the authorization indication message indicating an authorization request to release the current RRC connection, it is determined whether predetermined conditions for triggering the RRC connection release request procedure are met. These predetermined conditions may relate to at least one of the following: whether an ongoing RRC connection release request procedure exists, whether the corresponding upper layer allows initiating an RRC connection release request procedure, or whether an indication related to initiating an RRC connection release request procedure has been received from the corresponding current base station. Specific examples of the predetermined conditions will be described below.

[0042] If the predetermined conditions are met, then in step 260, a predetermined request message for requesting the release of the current RRC connection is sent to the current base station corresponding to the current RRC connection.

[0043] Then, in step 280, based on the current base station's response to the predetermined request message, the RRC connection release process is executed. If predetermined conditions are met, an automatic release timer can also be started. If no response to the predetermined request message is received from the base station before the automatic release timer expires, the current RRC connection can be automatically released.

[0044] The RRC connection release request process can be initiated by the current upper layer (current NAS layer) corresponding to the current RRC layer. In this case, the authorization indication message may include a release request indication from the current upper layer of the current RRC layer. The release request indication is used to instruct the current RRC layer to send a release request message to the current base station to request the release of the current RRC connection.

[0045] Figure 3 An exemplary flowchart illustrates the process of initiating an RRC connection release request from the current RRC layer. For example... Figure 3 As shown in step 302, the current upper layer (such as the current NAS layer) sends a release request indication to the current RRC layer, instructing the current RRC layer to initiate an RRC connection release procedure. If the current RRC layer receives the release request indication, then in step 304, it determines whether a predetermined condition is met. In this example, the predetermined condition may include: there is no RRC connection release request procedure triggered by the current RRC layer. The predetermined condition may also include: a timer for preventing the current RRC layer from sending release preference information to the current base station is not running; this timer may be started when the predetermined condition is met. Figure 3 The operations for 306 and 308 are the same as those for 260 and 280 mentioned above, and will not be repeated here.

[0046] The RRC connection release request process can also be initiated by the current RRC layer. In this case, the authorization indication message may include a release preference provision indication from the current base station. The release preference provision indication instructs the current RRC layer to provide release preference information to the base station, indicating the RRC state expected to be entered when transmitting a predetermined request message requesting the release of the current RRC connection. However, this is only the state expected by the current RRC at this point; the final state that the current RRC connection can enter will be determined by the base station.

[0047] Figures 4-5 A flowchart illustrating an example of an RRC release request process triggered by the RRC layer is shown.

[0048] like Figure 4 As shown, in step 402, the current RRC layer receives a release preference provision indication sent by its corresponding current base station. If a release preference provision indication is received, the current RRC layer proceeds to step 404 to determine whether predetermined conditions are met. In this example, predetermined conditions may include the absence of a timer for prohibiting the transmission of release preference information, the user equipment deciding to leave the current RRC connection, and the absence of an RRC connection release request process triggered by the current upper layer.

[0049] If the predetermined conditions are met, the current RRC layer can send a paging restriction information request message to the current NAS layer at 406. The current NAS layer can send paging restriction information to the current RRC layer at 408.

[0050] If a paging restriction request message is received, the current RRC layer at 410 will send the paging restriction information and release preference information to the base station in a pre-defined request message.

[0051] It should be noted that operations 406 and 408 are not mandatory. The current RRC layer may not request a paging restriction message from the current upper layer. Furthermore, even if the current RRC layer requests a paging restriction message from the current upper layer, the current upper layer may not send a paging restriction message back. In both cases, when performing the operation corresponding to 410, the current RRC layer may send a pre-defined request message without carrying paging restriction information.

[0052] After initiating the RRC connection release request procedure, the current RRC layer can also notify the current upper layer in step 412 that it has initiated the RRC connection release request procedure. Then, in step 414, based on the current base station's response, the RRC connection release is executed.

[0053] Figure 5 Another example is shown where the RRC layer initiates an RRC connection release request process.

[0054] like Figure 5 As shown, in step 502, the current RRC layer receives a release preference indication from its corresponding current base station. If a release preference indication is received, in step 504, it determines whether the UE decides to leave the current RRC connection. If the UE does not intend to leave the current RRC connection, it may not initiate an RRC connection request procedure. If the UE decides to leave the current RRC connection, in step 506, it sends an inquiry message to the current upper layer to ask whether permission is allowed to initiate an RRC connection release request procedure, and then in step 508, it receives a response from the current upper layer.

[0055] The current RRC layer can check at step 510 whether predetermined conditions are met. In this example, predetermined conditions may include a message indicating that the timer for prohibiting the sending of release preference information has not run and that a response has been received from the current upper layer, and that the response does not reject the initiation of the RRC connection release request procedure. If the current upper layer does not respond, or its response indicates that the initiation of the RRC connection release request procedure is not allowed, then the initiation of the RRC connection release request procedure is not executed.

[0056] If the aforementioned predetermined conditions are met, then in step 512, a predetermined request message is sent to the current base station. In step 514, a notification message is sent to the current upper layer informing it that an RRC connection release request process has been initiated. Then, in step 516, based on the current base station's response, the RRC connection release is executed.

[0057] Other embodiments are provided below to illustrate the details of the present invention in more detail.

[0058] Examples of RRC layer operations

[0059] The RRC layer may perform one or more of the following operations:

[0060] (1) When the RRC layer of a UE in MUSIM (Multi-USIM) mode receives a first indication message or a second indication message from an upper layer (e.g., the NAS layer), if a first condition is met, it initiates the UL information transfer procedure by sending a ULInformationTransfer message; and / or if the first condition is not met, it does not initiate the uplink information transfer procedure or does not send a ULInformationTransfer message to terminate the uplink information transfer procedure or discards the received service request message from the upper layer. This uplink information transfer procedure is used to transmit a service request message or registration request message carrying a release indication to initiate the RRC connection release procedure (i.e., requesting the network to release the RRC connection).

[0061] In one implementation, the first condition may be that there is no ongoing RRC layer-triggered request to release an RRC connection. In one implementation, this request to release an RRC connection may be, for example, a request to release an RRC connection triggered by the RRC layer for MUSIM purposes (i.e., for switching between multiple USIM cards or for the activity of another USIM). In another implementation, this request to release an RRC connection may be, for example, a request to release an RRC connection triggered for power reduction purposes. In one implementation, whether there is an ongoing RRC layer-triggered request to release an RRC connection can be determined, for example, by whether an auto-release timer is running. In one implementation, if the auto-release timer is not running, it can be determined that there is no ongoing RRC layer-triggered request to release an RRC connection, i.e., the first condition is met. The auto-release timer may be started when or after sending a release request message for requesting to release an RRC connection to the network. If the auto-release timer is running, it indicates that the RRC layer has triggered a request to release an RRC connection and is waiting for a network response. The release request message sent to the network may, for example, be a UEAssistanceInformation message carrying release preference information, described later.

[0062] In one implementation, the first condition may be that a timer is disabled from running. The timer is used to prevent the transmission of release preference information for the RRC connection release process to the network. During the execution of the timer, the RRC layer is prohibited from sending release request messages to the network.

[0063] (2) If the RRC layer of a UE in MUSIM mode is configured by the base station to provide release preference to the base station, and the disable timer is not running, and there is no ongoing process of requesting to release the RRC connection triggered by an upper layer (such as the NAS layer), and the UE decides to leave the RRC_CONNECTED state (e.g., the UE may decide to leave the RRC_CONNECTED state for MUSIM purposes), then the disable timer or the automatic release timer can be started, and the transmission of the UEAssistanceInformation message can be initiated to provide the release preference. Specifically, the UEAssistanceInformation message contains the desired RRC state on transmission of the UEAssistanceInformation message, for example, the desired RRC state could be RRC_IDLE or RRC_INACTIVE. Optionally, in this case, the UE can also send a third indication information to the upper layer, which can be used to notify the upper layer that the RRC layer has initiated a process of requesting to release the RRC connection (i.e., requesting to leave the RRC_CONNECTED state) or to obtain paging restriction information from the upper layer.

[0064] The release preference information is used to notify the base station of the desired RRC state when the UE sends the UEAssistanceInformation message. Examples include RRC idle state (RRC_IDLE) and RRC inactive state (RRC_Inactive).

[0065] Furthermore, regarding the timer prohibition, if the base station has configured a MUSIM-specific release preference prohibition timer (MUSIMReleasePreferenceProhibitTimer) for the UE for MUSIM purposes, the value of the prohibition timer can be set to MUSIMReleasePreferenceProhibitTimer. Otherwise, the value of the prohibition timer can be set to the release preference prohibition timer (releasePreferenceProhibitTimer) configured for energy saving (i.e., reducing power consumption). Optionally, when the UE starts the MUSIM-specific release preference prohibition timer configured for MUSIM purposes, it also needs to start the release preference prohibition timer configured for energy saving purposes. This prevents the UE from sending a UEAssistanceInformation message carrying the preferred RRC state (preferredRRC-State) to the network for the energy saving purpose again after sending the preferred RRC state to the network for the MUSIM purpose. The preferredRRC-State is used to indicate the UE's preferred RRC state.

[0066] In practical applications, the execution order of the above operations is not limited to the order described in this specification. Those skilled in the art can arrange and combine the operations or change the execution order of the operations to obtain different implementation methods.

[0067] It should be noted that in this disclosure, the RRC layer can determine whether there is an ongoing request to release an RRC connection triggered by the upper layer by whether it receives a first indication message or a second indication message. If the first indication message or the second indication message is received, there is an ongoing request to release an RRC connection triggered by the upper layer; if the first indication message or the second indication message is not received, there is no ongoing request to release an RRC connection triggered by the upper layer. Alternatively, a flag bit can be set to indicate whether there is an ongoing request to release an RRC connection triggered by the upper layer. Specifically, when the RRC receives the first indication message or the second indication message, a flag bit is set to indicate that there is an ongoing request to release an RRC connection triggered by the upper layer, for example, set to 0, 1, TRUE, or FALSE. The RRC layer uses the flag bit to determine whether there is an ongoing request to release an RRC connection triggered by the upper layer. Furthermore, if the base station is configured with a different flag bit for MUSIM purposes... T346fIf the timer is T346f, then the timer in this disclosure is the timer configured for MUSIM purposes; otherwise, it is T346f. The value of timer T346f is configured by the base station for the UE through the releasePreferenceProhibitTimer field carried in the RRC message sent to the UE. The releasePreferenceProhibitTimer is a prohibitor timer for releasing preference assistance information reporting, that is, it is used to prevent the UE from frequently sending UEAssistanceInformation messages containing the preferredRRC-State field to the base station. The UE decides to leave the RRC_CONNECTED state for MUSIM purposes because the UE needs to switch to network B (i.e., USIM B activity or connecting to network B through another USIM card, such as establishing an RRC connection with network B or sending data to network B) and wants network A or the base station to release the UE's RRC connection with network A.

[0068] Optionally, before / during initiating a request to leave the RRC_CONNECTED state (i.e., initiating the transmission of a UEAssistanceInformation message to provide release preference), the RRC layer obtains paging restriction information from the upper layer (e.g., by sending a third indication message to the upper layer) and carries this information in the UEAssistanceInformation message (if the upper layer provides paging restriction information). Optionally, the upper layer may also refuse or send a message to the RRC layer to stop transmitting the UEAssistanceInformation message to provide release preference or stop the process of requesting to leave the RRC_CONNECTED state. In this case, the RRC does not perform the operation for requesting the release of the RRC connection.

[0069] Optionally, before / when initiating a request to leave the RRC_CONNECTED state, the RRC layer can send an inquiry message to the upper layer to ask whether the RRC connection release request process is allowed. If the upper layer responds to the inquiry message and the response does not reject the completion of the RRC connection release request process, the RRC connection release request process can be initiated. In this case, it is not necessary to check whether there is an ongoing RRC connection release request process triggered by the upper layer. Optionally, paging restriction information can be obtained from the upper layer, which can be achieved by sending a paging restriction information retrieval request to the upper layer. In this case, the upper layer can regard the received paging restriction information retrieval request as the aforementioned inquiry message.

[0070] Optionally, during or after initiating a request to release the RRC connection, the RRC layer may notify the upper layer that it has initiated a process to request the release of the RRC connection (i.e., a request to leave the RRC_CONNECTED state). For example, the RRC can perform this notification process by sending the aforementioned third indication message to the upper layer. Similarly, in response to an inquiry message, the upper layer may also refuse or send a stop transmission UEAssanceInformation message to the RRC layer to provide the release preference process or stop the request to leave the RRC_CONNECTED state; in this case, the RRC will not perform the operation used to request the release of the RRC connection.

[0071] The presence of an ongoing RRC-triggered request to release an RRC connection can be determined by checking whether the auto-release timer or the release preference disable timer is running. In other words, if the auto-release timer or the release preference disable timer is running, then an ongoing RRC-triggered request to release an RRC connection is in progress; otherwise, no such process is ongoing.

[0072] When the auto-release timer expires, the UE can automatically release the RRC connection, for example, by performing the actions upon going to RRC_IDLE (see section 5.3.11 of TS38.331 for details).

[0073] It should be noted that messages received by RRC from the upper layer (i.e., the NAS layer) can also be collectively referred to as NAS messages. For example, the service request message in this disclosure is a NAS message.

[0074] Furthermore, the paging restriction information described in this disclosure may indicate one of the following 1)-4):

[0075] 1) All paging is restricted. In this case, the UE does not expect to receive any paging messages.

[0076] 2) All paging is restricted, except for paging for voice service (IMS voice). In this case, the UE only expects to receive paging for voice service.

[0077] 3) All paging is restricted, except for paging for a specific PDU session(s). In this case, the UE only expects to receive paging for a specific PDU session.

[0078] 4) All paging is restricted, except for paging for voice service (IMS voice) and certain PDU Session(s). In this case, the UE only expects to receive paging for voice service and specific PDU sessions.

[0079] To reduce operational complexity and improve execution efficiency, it can be stipulated that RRC connection release request configurations for both MUSIM purposes and energy-saving purposes cannot be configured simultaneously. RRC connection release request configurations can include, for example, release preference configurations, timer disable configurations, and other configurations used when executing RRC connection release requests.

[0080] For example, it can be stipulated that the base station cannot simultaneously configure ReleasePreferenceConfig and MUSIMReleasePreferenceConfig for a UE in MUSIM mode. ReleasePreferenceConfig configures the UE to report assistance information to inform the gNB about the UE's preference when leaving the RRC_CONNECTED state.

[0081] For example, it can be stipulated that the base station cannot simultaneously configure releasePreferenceProhibitTimer and a timer disabled for MUSIM purposes for a UE in MUSIM mode.

[0082] In addition, to reduce operational complexity and improve execution efficiency, it can be stipulated that the base station cannot configure both releasePreferenceProhibitTimer and automatic release timer for a UE in MUSIM mode at the same time.

[0083] Implementation examples of NAS layer operation

[0084] In this embodiment, the service request procedure is used when the UE in MUSIM mode meets the following conditions:

[0085] (1) In CM-CONNECTED state, it is necessary to request release of the UE connection, stop data transmission, discard any pending data, and, optionally, store paging restrictions information.

[0086] (2) In CM-IDLE state, request removal of the Paging Restrictions information.

[0087] If a UE in MUSIM mode and CM-CONNECTED state wants to leave CM-CONNECTED state, it may include the Release Request indication and, optionally, Paging Restrictions information in the Service Request message.

[0088] If a UE in MUSIM mode and CM-CONNECTED state includes a release request indication in its service request message, it sends first indication information to the lower layer (e.g., the RRC layer). This first indication information can be used to indicate to the lower layer that the message contains a release request indication or that the message is used to request the release of the RRC connection. The release request indication is used to request release from the RRC_CONNECTED state.

[0089] Alternatively, if a UE in MUSIM mode and CM-CONNECTED state includes a release request indication and paging restriction information in a service request message, it sends a second indication message to the lower layer (e.g., the RRC layer). The second indication message can be used to indicate to the lower layer that this message contains paging restriction information.

[0090] If a UE in MUSIM mode and CM-CONNECTED state receives a third-party instruction from a lower layer, it may perform at least one of the following operations:

[0091] (a) Provide paging restriction information;

[0092] (b) Instructing the lower layer to stop requesting the release of the RRC connection (e.g., instructing the lower layer to stop transmitting UEAssistanceInformation messages to provide release preferences);

[0093] (c) Instruct the lower layer to continue the process of requesting the release of the RRC connection but do not provide paging restriction information;

[0094] (d) Send a rejection indication to cause the lower layer to stop transmitting UEAssistanceInformation messages to provide the release preference;

[0095] (e) Send an consent instruction to cause the lower layer to initiate the transmission of the UEAssistanceInformation message to provide the release preference.

[0096] For the RRC connection release process initiated by the NAS layer, it can be implemented by carrying a release indication (also known as a release request indication) in the service request message, or by carrying a release indication in the registration process (used when the UE needs to perform a registration update with the network). Therefore, replacing the service request message with a registration request message in the embodiments of this disclosure to obtain new embodiments is also within the scope of protection of this disclosure.

[0097] Figure 6 This is a structural block diagram of a user equipment according to an embodiment of the present invention. Figure 6 As shown, the user equipment 60 includes a processor 61 and a memory 62. The processor 61 may include, for example, a microprocessor, a microcontroller, an embedded processor, etc. The memory 62 may include, for example, volatile memory (such as random access memory, RAM), a hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory. Program instructions are stored on the memory 62. When executed by the processor 61, these instructions can perform the methods described in detail herein, executed by the user equipment.

[0098] Furthermore, the computer-executable instructions or program running on the device according to the invention can be a program that enables the computer to perform the functions of the embodiments of the invention by controlling the central processing unit (CPU). The program or the information processed by the program can be temporarily stored in volatile memory (such as random access memory RAM), hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems.

[0099] Computer-executable instructions or programs for implementing the functions of the various embodiments of the present invention can be recorded on a computer-readable storage medium. The corresponding functions can be implemented by causing a computer system to read and execute the programs recorded on the recording medium. The term "computer system" here can refer to a computer system embedded in the device, and may include an operating system or hardware (such as peripheral devices). "Computer-readable storage medium" can be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a short-time dynamic program storage medium, or any other computer-readable recording medium.

[0100] Various features or functional modules of the devices used in the above embodiments can be implemented or executed by circuits (e.g., monolithic or multi-chip integrated circuits). Circuits designed to perform the functions described in this specification may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above devices. A general-purpose processor may be a microprocessor, or any existing processor, controller, microcontroller, or state machine. The above circuits may be digital circuits or analog circuits. In cases where advancements in semiconductor technology have led to new integrated circuit technologies that replace existing integrated circuits, one or more embodiments of the present invention may also be implemented using these new integrated circuit technologies.

[0101] Furthermore, the present invention is not limited to the embodiments described above. Although various examples of the embodiments have been described, the present invention is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors can be used as terminal devices or communication devices, such as AV equipment, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

[0102] As described above, embodiments of the present invention have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and the present invention also includes any design modifications that do not depart from the spirit of the invention. Furthermore, various modifications can be made to the present invention within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of the present invention. In addition, components with the same effects described in the above embodiments can be substituted for each other.

Claims

1. A method for releasing an RRC connection, performed by a user equipment supporting multiple USIM modes, comprising: Upon receiving an authorization instruction message indicating an authorization request to release the current RRC connection, determine whether the predetermined conditions for triggering the RRC connection release request process are met; When the predetermined conditions are met, a predetermined request message for requesting the release of the current RRC connection is sent to the current base station corresponding to the current RRC connection. as well as Based on the current base station's response to the predetermined request message, the RRC connection release process is executed. The authorization indication message includes a release request indication from the current upper layer of the current RRC layer corresponding to the current RRC connection, or a release preference indication from the current base station. The release request indication is used to instruct the current RRC layer to send a release request message to the current base station to request the release of the current RRC connection. The release preference provision indication is used to instruct the current RRC layer to provide release preference information to the base station, wherein the release preference information indicates the RRC state expected to be entered when transmitting a predetermined request message to release the current RRC connection. The authorization instruction message includes the release preference provision instruction, the pre-request message includes release preference information, and the pre-request conditions include: If the timer for preventing the transmission of the release preference information is not running, the user equipment decides to leave the current RRC connection, and there is no RRC connection release request process triggered by the current upper layer, the timer is started when the predetermined condition is met.

2. The method according to claim 1, further comprising: After sending the predetermined request message, a notification message is sent to the current upper layer. The notification message is used to notify the current upper layer that the current RRC layer has initiated an RRC connection release request process. and / or Before sending the predetermined request message, a paging restriction information request message is sent to the current upper layer, and if paging restriction information corresponding to the paging restriction information request message is received from the current upper layer, the paging restriction information is carried in the predetermined request message and sent to the current base station.

3. The method according to claim 2, wherein, The query message includes a paging restriction information request message for obtaining paging restriction information, which is used to request the network to restrict paging.

4. The method according to claim 1, wherein, The authorization instruction message includes the release request instruction, and the predetermined conditions include: There is no RRC connection release request process triggered by the current RRC; and / or The timer for preventing the transmission of the release preference information is not running; the timer is started when the predetermined condition is met.

5. The method according to claim 1, further comprising: When the predetermined conditions are met, the automatic release timer is started. Based on the current base station's response to the predetermined request message, the RRC connection release process includes: The current RRC connection is released when the automatic release timer expires and the base station does not respond to the predetermined request message.

6. The method according to claim 1, wherein, The RRC connection release process includes: The first RRC connection release procedure performed to reduce the power consumption of the user UE; or This is a second RRC connection release procedure performed to switch the current RRC connection to another RRC connection.

7. A method for releasing an RRC connection, performed by a user equipment supporting multiple USIM modes, comprising: Upon receiving an authorization instruction message indicating an authorization request to release the current RRC connection, determine whether the predetermined conditions for triggering the RRC connection release request process are met; When the predetermined conditions are met, a predetermined request message for requesting the release of the current RRC connection is sent to the current base station corresponding to the current RRC connection. as well as Based on the current base station's response to the predetermined request message, the RRC connection release process is executed. The authorization indication message includes a release request indication from the current upper layer of the current RRC layer corresponding to the current RRC connection, or a release preference indication from the current base station. The release request indication is used to instruct the current RRC layer to send a release request message to the current base station to request the release of the current RRC connection. The release preference provision indication is used to instruct the current RRC layer to provide release preference information to the base station, wherein the release preference information indicates the RRC state expected to be entered when transmitting a predetermined request message to release the current RRC connection. The authorization instruction message includes the release preference provision instruction, and the method further includes: If the user equipment decides to leave the current RRC connection, it sends an inquiry message to the current upper layer to ask whether permission is allowed to initiate an RRC connection release request process. The predetermined conditions include: The timer for preventing the transmission of the release preference information is not running, and the upper layer has responded to the query message and the response did not reject the initiation of the RRC connection release request process. The timer is then started when the predetermined conditions are met. The method further includes: After sending the predetermined request message, a notification message is sent to the current upper layer, the notification message being used to notify the current upper layer that the current RRC layer has initiated an RRC connection release request process; and / or If a message is received from the current upper layer in response to the query message, indicating that the RRC connection release request process is not allowed, then in response to this message, the RRC connection release request process is not executed.

8. The method according to claim 7, wherein, The query message includes a paging restriction information request message for obtaining paging restriction information, which is used to request the network to restrict paging.

9. A user equipment, comprising: processor; as well as Memory, which stores instructions The instructions, when executed by the processor, perform the method according to any one of claims 1 to 8.

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