Method and system for providing paging reasons to MUSIM user equipment

Abstract

The present invention relates to a 5G communication system or a 6G communication system for supporting higher data rates beyond a 4G communication system such as Long Term Evolution (LTE). An embodiment of the present invention provides a method for an access and mobility management function (AMF) controller in a wireless communication network. The method includes receiving a NAS request message including an AI request from a multi-universal SIM user equipment (MUSIM UE), the AI ​​request indicating a request for a paging cause in a paging message. In addition, the method includes storing the AI ​​request received in the NAS request message. In addition, the method includes providing a NAS response message including an AI to the MUSIM UE, wherein the AI ​​indicates whether the paging cause is provided to the MUSIM UE as part of one of a paging procedure and a NAS notification procedure.

Description

Technical Field

[0001] The present disclosure relates to cellular systems, and more particularly to methods and systems for providing paging causes to a Multiple Universal Subscriber Identity Module (MUSIM) User Equipment (UE) in a wireless communication network. Background Art

[0002] Considering the development of wireless communications from generation to generation, these technologies have been developed mainly for services targeting people, such as voice calls, multimedia services, and data services. With the commercialization of 5G (fifth generation) communication systems, the number of connected devices is expected to grow exponentially. They will be connected to communication networks more and more. Examples of connected things may include vehicles, robots, drones, home appliances, displays, smart sensors connected to various infrastructures, construction machinery, and factory equipment. Mobile devices are expected to develop in various forms, such as augmented reality glasses, virtual reality headsets, and holographic devices. In order to provide various services by connecting hundreds of billions of devices and things in the 6G (sixth generation) era, efforts have been made to develop improved 6G communication systems. For these reasons, 6G communication systems are called super 5G systems.

[0003] The 6G communication system, which is expected to be commercialized around 2030, will have a peak data rate of terabit (1000 gigabits) bps and a radio latency of less than 100 μsec, so it will be 50 times faster than the 5G communication system and have a radio latency of 1 / 10 of that of the 5G communication system.

[0004] In order to achieve such high data rates and ultra-low latency, the implementation of 6G communication systems in the terahertz band (e.g., 95GHz to 3Thz band) has been considered. Since the path loss and atmospheric absorption in the terahertz band are more serious than those in the millimeter wave band introduced in 5G, it is expected that technologies that can ensure the signal transmission distance (i.e., coverage) will become more critical. As the main technology to ensure coverage, it is necessary to develop radio frequency (RF) elements, antennas, and new waveforms with better coverage than orthogonal frequency division multiplexing (OFDM), beamforming and massive multiple input multiple output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, and multi-antenna transmission technologies such as massive antennas. In addition, new technologies to improve the coverage of terahertz band signals have been discussed, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS).

[0005] In addition, in order to improve spectrum efficiency and overall network performance, the following technologies have been developed for 6G communication systems: full-duplex technology for enabling uplink transmission and downlink transmission to use the same frequency resources at the same time; network technology that utilizes satellites, high altitude platform stations (HAPS), etc. in an integrated manner; an improved network structure for supporting mobile base stations, etc., and enabling network operation optimization and automation, etc.; dynamic spectrum sharing technology based on spectrum usage prediction through conflict avoidance; use of artificial intelligence (AI) in wireless communications, which improves overall network operations by utilizing AI from the design stage of developing 6G and internalizing end-to-end AI support functions; and next-generation distributed computing technology that overcomes UE computing power limitations through ultra-high performance communication and computing resources accessible on the network (such as mobile edge computing (MEC), cloud, etc.). In addition, attempts are continuing to strengthen connectivity between devices, optimize networks, promote softwareization of network entities, and increase openness of wireless communications by designing new protocols to be used in 6G communication systems, developing mechanisms for implementing hardware-based security environments and secure use of data, and developing technologies for maintaining privacy.

[0006] It is expected that the research and development of 6G communication systems in hyperconnectivity, including human-to-machine (P2M) and machine-to-machine (M2M), will bring about the next hyperconnectivity experience. In particular, services such as truly immersive extended reality (XR), high-fidelity mobile holograms, and digital replicas are expected to be provided through 6G communication systems. In addition, services such as remote surgery, industrial automation, and emergency response for enhanced safety and reliability will be provided through 6G communication systems, making it possible for the technology to be applied to various fields such as industry, healthcare, automobiles, and home appliances.

[0007] The cellular network provides Assistance Information (AI) to the MUSIM UE as part of a paging message, which is considered an expensive resource. Whenever a MUSIM UE needs to be paged, the cellular network consumes resources to derive the value of AI. Therefore, unless the cellular network receives a request for AI from the MUSIM UE, providing AI to the MUSIM UE is an unnecessary operation and a waste of resources.

[0008] The cellular network delivers control plane messages over signaling radio bearers, where control plane messages take precedence over Internet Packet Switched (PS) data by default. Control plane messages, such as manipulation of roaming information, routing ID update, network slice configuration, UE policy delivery, non-access stratum (NAS) control plane (CP) messages, etc. are important for the smooth operation of MUSIM UEs. As part of the paging procedure or notification procedure, control plane messages and Internet PS data need to be distinguished and indicated to the MUSIM UE through one USIM. Therefore, when accessing ongoing services through other USIMs, the MUSIM UE can make the right decision about whether to respond to the paging message.

[0009] Consider an example scenario where the MUSIM UE is in idle mode on the first USIM and in connected mode on the second USIM. The cellular network of the first USIM initiates a deregistration procedure with a "re-registration required" flag. When the deregistration request (e.g., CP message) is not distinguished by the cellular network of the first USIM, the AI ​​will be "other data". In addition, in response to receiving a paging message from the cellular network of the first USIM, the MUSIM UE can ignore the paging message by assuming that PS data is pending. In addition, the cellular network of the first USIM will have to be locally detached, and the MUSIM UE assumes that the MUSIM UE is registered with the cellular network of the first USIM. In addition, from the perspective of the MT, the MUSIM UE will be permanently out of service. When the MUSIM UE initiates MO operation, then the MUSIM UE receives an "implicit detach" AI, which causes the UE to perform a registration procedure and ultimately the MO service will be delayed. In addition, there are also some sets of information elements, such as SOR information, routing ID, any changes in network slice information, etc., which need to be provided to the MUSIM UE in real time. The information elements are very important for the normal operation of the MUSIM UE. Therefore, it is better to distinguish control plane messages compared to Internet PS data, which is also called user plane data, which allows the MUSIM UE to make the correct decision whether to respond to the paging message.

[0010] Consider another example scenario, wherein a MUSIM UE is conducting a Packet Data Unit (PDU) session related to a Mission Critical Service (MCS) and an Internet PDU session (i.e., user plane data) on a first USIM. A second USIM is for personal use on which only calls are allowed as per user configuration. Consider that the second USIM is busy due to a call or PLMN search operation. When downlink data is triggered for MCS, then the MUSIM UE may assume that the trigger for the downlink data is for the Internet PDU session and ignore the paging message, which impacts the access to the MCS. Furthermore, when downlink data is triggered for the Internet PDU session on the first USIM, and if the MUSIM UE assumes that the trigger is for the MCS PDU session, then the MUSIM UE responds to the paging message, which impacts the call or PLMN search operation performed using the second USIM.

[0011] Figure 1 A signaling diagram between the MUSIM UE 100 and the cellular networks 300A-300B for providing a paging message to the MUSIM UE 100 when the MUSIM UE 100 is using services is shown. Consider that service-1 is ongoing (101) between the MUSIM UE 100 and the first network 300A corresponding to the first USIM of the MUSIM UE 100. The second network 300B corresponding to the second USIM of the MUSIM UE 100 initiates service-2 (102) for the MUSIM UE 100. The AMF controller sends (103) a first paging message with an AI value of AI-1 to the MUSIM UE 100 via the second RAN 300B to trigger a first paging procedure. Consider that the MUSIM UE 100 decides (104) not to respond to the first paging message due to the AI ​​value of AI-1, while the MUSIM UE 100 may have responded to the second paging message with an AI value of AI-2. At the same time, the second network 300B initiates (105) service-3 with an AI value of AI-2 for the MUSIM UE 100. When the second paging message is a low priority message compared to the first paging message, the second network 300B discards the second paging message or delays sending the second paging message until a response to the first paging message is received from the MUSIM UE 100, which affects the user experience.

[0012] Optionally, the second network 300B waits for the time for the first paging process to be completed to send the second paging request, which time is called a paging duration (PD). The second network 300B sends a second paging message to the MUSIM UE 100 after the PD by upgrading the first paging process. After the PD is terminated, the second network 300B sends (107) a second paging request with an AI value of AI-2 to the MUSIM UE 100. In addition, the MUSIM UE 100 responds to the second paging message with an AI value of AI-2. However, sending the second paging request with an AI value of AI-2 to the MUSIM UE 100 after the PD affects the user experience. Therefore, it is desired to solve the above-mentioned shortcomings or at least provide a useful alternative. Summary of the invention

[0013] Technical issues

[0014] The main purpose of the embodiments of the present invention is to provide a method and system for providing a paging cause to a MUSIM UE in a wireless communication network. Therefore, in response to learning about the triggering of a service through the paging cause, the MUSIM UE can make an appropriate decision.

[0015] Solution to the problem

[0016] Another object of an embodiment of the present invention is to indicate a request for a paging cause to an Access and Mobility Management Function (AMF) controller in a paging message.

[0017] Another object of an embodiment of the present invention is to send an AI request received from a MUSIM UE to a RAN to decide whether to provide a paging cause to the MUSIM UE.

[0018] Another object of an embodiment of the present invention is that the MUSIM UE determines whether to respond to a paging message or not to respond to a paging message based on an identification that the wireless communication network supports a paging cause. Therefore, the method allows the MUSIM UE to make an appropriate decision based on an identification that the wireless communication network supports a paging cause.

[0019] Another object of an embodiment of the present invention is to send a second paging message including at least one paging cause for services to be delivered to the MUSIM UE even if the MUSIM UE does not respond to the first paging message. Thus, the method allows the MUSIM UE to be aware of all services to be received even if the MUSIM UE does not respond to the first paging message. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present method and apparatus are illustrated in the following drawings, in which the same reference numerals represent corresponding parts in the various figures. Embodiments of the present invention will be better understood from the following description with reference to the accompanying drawings, in which:

[0021] Figure 1 shows a signaling diagram between a MUSIM UE and a cellular network for providing a paging message to the MUSIM UE when the MUSIM UE is using a service according to the prior art;

[0022] Figure 2A is a block diagram of a MUSIM UE for managing paging causes in a wireless communication network according to an embodiment of the present invention;

[0023] Figure 2B A system for providing a paging cause to a MUSIM UE in a wireless communication network according to an embodiment of the present invention is shown;

[0024] Figure 3 is a flow chart illustrating a method for providing a paging cause to a MUSIM UE in a wireless communication network according to an embodiment of the present invention;

[0025] Figure 4 is a flow chart illustrating a method for managing paging causes in a wireless communication network according to an embodiment of the present invention;

[0026] Figure 5 is a signaling diagram illustrating a registration process in a wireless communication network according to an embodiment of the present invention;

[0027] Figure 6 is a signaling diagram illustrating a process for providing AI in a CM_IDLE state in a wireless communication network according to an embodiment of the present invention;

[0028] Figure 7 is a signaling diagram illustrating a process for providing AI in an RRC inactive state in a wireless communication network according to an embodiment of the present invention;

[0029] Figure 8 is a signaling diagram illustrating that the AMF controller or the gNodeB initiates a second paging procedure even when the first paging procedure is not completed according to an embodiment of the present invention;

[0030] Fig. 9 is a signaling diagram illustrating transmission of a second paging message with a multiplexed AI value by an AMF controller or a gNodeB according to an embodiment of the present invention; and

[0031] Fig.10is a signaling diagram illustrating a scenario in which a NAS or AS procedure is triggered by a MUSIM UE to notify a second RAN of a deactivated state of a service according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] Therefore, an embodiment of the present invention provides a method for providing a paging cause to a MUSIM UE in a wireless communication network. The method includes sending, by the MUSIM UE, a non-access stratum (NAS) request message including an AI request to an AMF controller, the AI ​​request indicating a request for a paging cause in a paging message. In addition, the method includes receiving, by the AMF controller, a NAS request message with an AI request from the MUSIM UE. In addition, the method includes storing, by the AMF controller, the AI ​​request received in the NAS request message. In addition, the method includes providing, by the AMF controller, a NAS response message including an AI to the MUSIM UE, wherein the AI ​​indicates whether the paging cause will be provided to the MUSIM UE as part of one of a paging procedure and a NAS notification procedure.

[0033] In an embodiment, wherein providing, by the AMF controller, a NAS response message including an AI to the MUSIM UE comprises sending, by the AMF controller, an AI request received from the MUSIM UE to the RAN for making a decision whether to provide a paging cause to the MUSIM UE, receiving, by the RAN, the MUSIM AI from the AMF controller, and in response to determining that the AMF AI indicates that a paging cause is provided to the MUSIM UE, providing, by the RAN, a paging message including a paging cause to the MUSIM UE in an RRC inactive state as part of a RAN paging procedure.

[0034] In an embodiment, the paging reasons include mission critical service, multimedia priority service, emergency service (also referred to as critical service).

[0035] In an embodiment, the paging cause also includes voice services based on instant messaging service (IMS) and non-IMS, short message service (SMS) / unstructured supplementary service data (USSD) based on IMS and non-IMS, IMS services other than voice / SMS, CP signaling and other data / other services / default.

[0036] In an embodiment, the method further includes receiving a paging message from an AMF controller by the MUSIM UE terminal. In addition, the method includes determining, by the MUSIM UE, that the paging message includes an indication that the wireless communication network supports a paging cause, wherein the indication may include a new paging cause value or a new dedicated indication. In addition, the method includes determining, by the MUSIM UE, whether to respond to the paging message or not to respond to the paging message based on an indication that the wireless communication network supports a paging cause.

[0037] In an embodiment, responding to the paging message includes sending a service request or registration request message by the MUSIM UE to the AMF controller to establish a NAS signaling connection, and when the MUSIM UE is in an idle state, receiving an input service by the MUSIM UE from the AMF controller, or when the MUSIM UE is in an inactive state, sending an RRC message to the gNodeB and entering a connected mode, that is, typically, the MUSIM UE responds to the network with a NAS or AS message, and causes the MUSIM UE to enter a connected mode.

[0038] In an embodiment, not responding to the paging message includes performing, by the MUSIM UE, one of: ignoring the paging message, and sending a NAS message or an AS message with a busy indication to the network.

[0039] In an embodiment, the method further comprises detecting, by the AMF controller, a triggering of a second paging message having a second paging cause. In addition, the method comprises sending, by the AMF controller, a second paging message to the MUSIM UE, wherein the second paging message comprises at least one paging cause different from the paging cause of the first paging message to the MUSIM UE.

[0040] Therefore, an embodiment of the present invention provides a MUSIM UE for managing paging causes in a wireless communication network. The MUSIM UE includes an AI controller, a memory, and a processor, wherein the AI ​​controller is coupled to the memory and the processor. The AI ​​controller is configured to send a NAS request message including an AI request to an AMF controller, the AI ​​request indicating a request for a paging cause in a paging message. In addition, the AI ​​controller is configured to receive a NAS response message including an AI, wherein the AI ​​indicates whether the paging cause is provided to the MUSIM UE as part of one of a paging procedure and a NAS notification procedure.

[0041] Accordingly, an embodiment of the present invention provides a system for providing a paging cause to a MUSIM UE in a wireless communication network. The system includes a RAN and an AMF controller. The AMF controller is configured to receive a NAS request message with an AI request from the MUSIM UE, wherein the AI ​​request indicates a request for a paging cause in a paging message. The AMF controller is configured to store the AI ​​request received in the NAS request message. The AMF controller is configured to provide a NAS response message including an AI to the MUSIM UE, wherein the AI ​​indicates whether the paging cause is provided to the MUSIM UE as part of one of a paging procedure and a NAS notification procedure.

[0042] When considered in conjunction with the following description and accompanying drawings, these and other aspects of embodiments of the present invention will be better understood and appreciated. However, it should be understood that although the following description points out preferred embodiments and many specific details therein, these descriptions are given in an illustrative manner, rather than restrictive. Without departing from the spirit of the present invention, many changes and modifications may be made within the scope of embodiments of the present invention, and embodiments of the present invention include all such modifications.

[0043] The embodiments herein and their various features and advantageous details are explained more fully with reference to the non-limiting embodiments shown in the accompanying drawings and described in detail in the following description. Descriptions of well-known components and processing techniques are omitted so as not to unnecessarily obscure the embodiments of the present invention. In addition, the various embodiments described in the present invention are not necessarily mutually exclusive, because some embodiments can be combined with one or more other embodiments to form new embodiments. Unless otherwise stated, the term "or" used herein refers to non-exclusive or. The examples used without the invention are merely to facilitate understanding of the ways in which the embodiments herein can be practiced, and further enable those skilled in the art to practice the embodiments herein. Therefore, these examples should not be interpreted as limiting the scope of the embodiments herein.

[0044] According to the tradition of the art, embodiments can be described and illustrated according to blocks that perform one or more functions described. These blocks may be referred to herein as managers, units, modules, hardware components, etc., which are physically implemented by analog and / or digital circuits, such as logic gates, integrated circuits, microprocessors, microcontrollers, storage circuits, passive electronic components, active electronic components, optical components, hard-wired circuits, etc., and are optionally driven by firmware. For example, the circuit may be contained in one or more semiconductor chips, or on a substrate support such as a printed circuit board. The circuits constituting the blocks may be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuits), or by a combination of dedicated hardware that performs some functions of the block and a processor that performs other functions of the block. Without departing from the scope of the present disclosure, each block of the embodiment may be physically divided into two or more interacting and discrete blocks. Similarly, without departing from the scope of the present disclosure, the blocks of the embodiment may be physically combined into more complex blocks.

[0045] Therefore, an embodiment of the present invention provides a method for providing a paging cause to a multi-universal SIM user equipment (MUSIM UE) in a wireless communication network. The method includes sending, by the MUSIM UE, a non-access stratum (NAS) request message including an auxiliary information (AI) request to an access and mobility management function (AMF) controller, the auxiliary information (AI) request indicating a request for a paging cause in a paging message. In addition, the method includes receiving, by the AMF controller, a NAS request message with an AI request from the MUSIM UE. In addition, the method includes storing, by the AMF controller, the AI ​​request received in the NAS request message. In addition, the method includes providing, by the AMF controller, a NAS response message including an AI to the MUSIM UE, wherein the AI ​​indicates whether the paging cause is provided to the MUSIM UE as part of one of a paging procedure and a NAS notification procedure.

[0046] Referring now to the drawings and more particularly to the Figures 2A to 10 The preferred embodiment is shown.

[0047] Figure 2A 1 is a block diagram of a MUSIM UE 100 for managing paging causes in a wireless communication network according to an embodiment of the present invention. Examples of the MUSIM UE 100 are, but are not limited to, smart phones, tablet computers, personal digital assistants (PDAs), Internet of Things (IoT), etc. In an embodiment, the MUSIM UE 100 includes an AI controller 110, a memory 120, a processor 130, and a communicator 140. The AI ​​controller 110 is coupled to the memory 120 and the processor 130. In an embodiment, the AI ​​controller 110 includes a NAS message controller 111 and an action controller 112. An example of a wireless communication network is a wireless communication network including an AMF controller 200 (e.g., Figure 2B ) and at least one radio access network (RAN) 300 (as shown Figure 2B The cellular network of FIG. 1 is a cellular network of FIG. 10 (shown in FIG. 10 ). A gNodeB is an example of a RAN. In an embodiment, the paging reasons include mission-critical services, multimedia priority services, emergency services (also referred to as critical services), voice services based on Instant Messaging Service (IMS) and non-IMS, short message service (SMS) / unstructured supplementary service data (USSD) based on IMS and non-IMS, IMS services other than voice / SMS, CP signaling, and other data.

[0048] The AI ​​controller 110 is configured to send a NAS or AS request message including an AI request to the AMF controller 200, the AI ​​request indicating a request for a paging cause in a paging message. In addition, the AI ​​controller 110 is configured to receive a NAS or AS response message including an AI, wherein the AI ​​indicates whether the paging cause is provided to the MUSIM UE 100 as part of one of a paging procedure and a NAS notification procedure. The AI ​​controller 110 is configured to receive a paging message from the AMF controller 200. In addition, the AI ​​controller 110 is configured to determine that the paging message includes an indication that the wireless communication network supports the paging cause, wherein the indication may include a new paging cause value or a new dedicated indication. In addition, the AI ​​controller 110 is configured to determine whether to respond to the paging message or not to respond to the paging message based on an indication that the wireless communication network supports the paging cause.

[0049] In an embodiment, the NAS message controller 111 sends a NAS request message to the AMF controller 200. The NAS message controller 111 receives a NAS response message including an AI. The NAS message controller 111 receives a paging message from the AMF controller 200. The NAS message controller 111 determines that the paging message includes an indication that the wireless communication network supports the paging cause. The NAS message controller 111 identifies that the paging cause in the paging message indicates that the paging cause is supported by the wireless communication network. The action controller 112 determines whether to respond to the paging message or not to respond to the paging message based on the indication that the wireless communication network supports the paging cause.

[0050] In an embodiment, responding to the paging message includes sending a service request or registration request message by the action controller 112 to the AMF controller 200 to establish a NAS signaling connection, and when the MUSIM UE 100 is in an idle state, receiving an input service from the AMF controller 200 by the action controller 112, or when the MUSIM UE 100 is in an inactive state, sending an RRC message to the gNodeB and entering a connected mode, that is, typically, the MUSIM UE 100 responds to the network with a NAS or AS message and causes the MUSIM UE 100 to enter a connected mode.

[0051] In an embodiment, not responding to the paging message includes ignoring the paging message by the action controller 112, or sending a NAS message or an AS message with a busy indication to the network by the action controller 112.

[0052] The memory 120 may include a non-volatile memory element. Examples of such non-volatile memory elements may include a magnetic hard disk, an optical disk, a floppy disk, a flash memory, or an electrically programmable memory (EPROM) or an electrically erasable programmable memory (EEPROM).

[0053] In addition, in some examples, memory 120 can be considered a non-transitory storage medium. The term "non-transitory" can mean that the storage medium is not implemented in a carrier wave or a propagating signal. However, the term "non-transitory" should not be interpreted as memory 120 being non-removable. In some examples, memory 120 can be configured to store a larger amount of information than memory 120, respectively. In some examples, a non-transitory storage medium can store data that can change over time (e.g., in a random access memory (RAM) or a cache).

[0054] Processor 130 is configured to execute instructions stored in memory 120. Communicator 140 is configured to conduct internal communications between hardware components in MUSIM UE 100. In addition, communicator 140 is configured to facilitate communications between MUSIM UE 100 and a wireless communication network.

[0055] although Figure 2A The hardware components of MUSIM UE 100 are shown, but it should be understood that other embodiments are not limited thereto. In other embodiments, MUSIM UE 100 may include fewer or more components. In addition, the labels or names of the components are for illustrative purposes only and do not limit the scope of the present invention. One or more components may be combined to perform the same or substantially similar functions to manage paging causes.

[0056] Figure 2B A system 1000 for providing a paging cause to a MUSIM UE 100 in a wireless communication network according to an embodiment of the present invention is shown. In an embodiment, the system 1000 includes an AMF controller 200 and a RAN 300, wherein the AMF controller 200 is coupled to the RAN 300. In an embodiment, the AMF controller 200 includes an AI controller 210, a memory 220, a processor 230, and a communicator 240. In an embodiment, the RAN 300 includes an AI controller 310, a memory 320, a processor 330, and a communicator 340.

[0057] The AMF controller 200 is configured to receive a NAS request message with an AI request from the MUSIM UE 100. In addition, the AMF controller 200 is configured to store the AI ​​request received in the NAS request message. In addition, the AMF controller 200 is configured to provide a NAS response message including the AI ​​to the MUSIM UE 100.

[0058] In an embodiment, the AI ​​controller 210 receives a NAS request message having an AI request from the MUSIM UE 100. In addition, the AI ​​controller 210 stores the AI ​​request received in the NAS request message to the memory 220. In addition, the AI ​​controller 210 provides a NAS response message including the AI ​​to the MUSIM UE 100.

[0059] In an embodiment, the AMF controller 200 is configured to send the AI ​​request received from the MUSIM UE 100 to the RAN 300 to decide whether to provide a paging cause to the MUSIM UE 100. In addition, the RAN is configured to receive the MUSIM AI from the AMF controller 200. In addition, the RAN is configured to provide a paging cause to the MUSIM UE 100 in response to determining that the AMF AI indicates that the paging cause is provided to the MUSIM UE 100, and provide a paging message including the paging cause to the MUSIM UE 100 in the RRC inactive state as part of the RAN 300 paging procedure.

[0060] In an embodiment, the AI ​​controller 210 sends the AI ​​request received from the MUSIM UE 100 to the RAN 300 to decide whether to provide a paging cause to the MUSIM UE 100. In addition, the AI ​​controller 310 receives the MUSIM AI from the AMF controller 200. In addition, the AI ​​controller 310 indicates to the MUSIM UE 100 in the RRC inactive state whether the paging message should include a paging cause as part of the RAN 300 paging procedure.

[0061] In another embodiment, the AMF controller 200 is configured to detect a trigger of a second paging message having a second paging cause. In addition, the AMF controller 200 is configured to send a second paging message to the MUSIM UE 100, wherein the second paging message includes at least one paging cause that is different from the paging cause of the first paging message to the MUSIM UE (100).

[0062] In an embodiment, the AI ​​controller 210 detects a triggering of a second paging message with a second paging cause. In addition, the AI ​​controller 210 sends a second paging message to the MUSIM UE 100, wherein the second paging message includes at least one paging cause to be used to deliver a second service to the MUSIM UE 100.

[0063] The memory 220 and the memory 320 may be the same kind of memory 120. The processor 230 is configured to execute instructions stored in the memory 220. The communicator 240 is configured to perform internal communication between hardware components in the AMF controller 200. In addition, the communicator 240 is configured to facilitate communication between the AMF controller 200 and other devices (e.g., MUSIM UE 100, RAN 300, etc.).

[0064] The processor 330 is configured to execute instructions stored in the memory 320. The communicator 340 is configured to perform internal communication between hardware components in the RAN 300. In addition, the communicator 340 is configured to facilitate communication between the RAN 300 and other devices (e.g., MUSIM UE 100, AMF controller 200, etc.).

[0065] although Figure 2B The hardware components of the system 1000 are shown, but it should be understood that other embodiments are not limited thereto. In other embodiments, the system 1000 may include fewer or more components. In addition, the labels or names of the components are for illustration purposes only and do not limit the scope of the present invention. One or more components may be combined together to perform the same or substantially similar functions for providing a paging cause to the MUSIM UE 100.

[0066] Figure 3 300 is a flow chart illustrating a method for providing a paging cause to a MUSIM UE 100 in a wireless communication network according to an embodiment of the present invention. In step 301, the method includes sending a NAS request message including an AI request to the AMF controller 200, the AI ​​request indicating a request for a paging cause in a paging message. In an embodiment, the method allows the NAS message controller 111 to send a NAS request message including an AI request to the AMF controller 200, the AI ​​request indicating a request for a “paging cause in a paging message”. In step 302, the method includes receiving a NAS request message with an AI request from the MUSIM UE 100. In an embodiment, the method allows the AI ​​controller 210 to receive a NAS request message with an AI request from the MUSIM UE 100.

[0067] In step 303, the method includes storing the AI ​​request received in the NAS request message. In an embodiment, the method allows the AI ​​controller 210 to store the AI ​​request received in the NAS request message. In step 304, the method includes providing a NAS response message including the AI ​​to the MUSIM UE, wherein the AI ​​indicates whether the paging cause is provided to the MUSIM UE as part of one of the paging procedure and the NAS notification procedure. In an embodiment, the method allows the AI ​​controller 210 to provide a NAS response message including the AI ​​to the MUSIM UE, wherein the AI ​​indicates whether the paging cause is provided to the MUSIM UE as part of one of the paging procedure and the NAS notification procedure.

[0068] The various activities, actions, blocks, steps, etc. in the flowchart 300 can be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, some activities, actions, blocks, steps, etc. can be omitted, added, modified, skipped, without departing from the scope of the present invention.

[0069] Figure 4 4 is a flowchart 400 showing a method for managing paging causes in a wireless communication network according to an embodiment of the present invention. In step 401, the method includes sending a NAS request message including an AI request to the AMF controller 200, the AI ​​request indicating a request for a paging cause in a paging message. In an embodiment, the method allows the NAS message controller 111 to send a NAS request message including an AI request to the AMF controller 200, the AI ​​request indicating a request for a paging cause in a paging message. In step 402, the method includes receiving a NAS response message including an AI, wherein the AI ​​indicates whether the paging cause is provided to the MUSIM UE 100 as part of one of a paging procedure and a NAS notification procedure. In an embodiment, the method allows the NAS message controller 111 to receive a NAS response message including an AI, wherein the AI ​​indicates whether the paging cause is provided to the MUSIM UE 100 as part of one of a paging procedure and a NAS notification procedure.

[0070] In step 403, the method includes receiving a paging message from the AMF controller 200. In an embodiment, the method allows the NAS message controller 111 to receive a paging message from the AMF controller 200. In step 404, the method includes determining that the paging message includes an indication that the wireless communication network supports the paging cause. In an embodiment, the method allows the NAS message controller 111 to determine that the paging message includes an indication that the wireless communication network supports the paging cause. In step 405, the method includes determining whether to respond to the paging message or not to respond to the paging message based on an indication that the wireless communication network supports the paging cause. In an embodiment, the method allows the action controller 112 to determine whether to respond to the paging message or not to respond to the paging message based on an indication that the wireless communication network supports the paging cause.

[0071] The practical problem of identifying whether the wireless communication network supports the paging cause is that all RAN nodes 300 (i.e. gNBs) in the network cannot be upgraded at the same time. It is very likely that gNB-1 is upgraded while gNB-2 is not upgraded to support the paging function (or general MUSIM function). However, both gNBs can be connected to the same AMF controller 200. The AMF controller 200 supports the paging cause feature. Considering the example of a voice call, when the AMF controller 200 sends a paging message through gNB-1, gNB-1 will page with the paging cause "Voice" and if the paging cause is not any standard feature, such as Internet User Plane Data, the AMF controller 200 will send a paging message again and then gNB-1 will page the MUSIM UE 100 without including the paging cause. Similarly, if the MUSIM UE 100 is in the gNB-2 area, for "Voice" and "Internet Data", the MUSIM UE 100 will not receive the paging cause in the paging message. Therefore, when a paging cause is not included, the MUSIM UE 100 cannot identify whether the paging message is from gNB-1 or gNB-2. Therefore, the MUSIM UE 100 cannot identify whether the incoming paging message that does not include a paging cause is for "voice" or "Internet data". Therefore, the MUSIM UE 100 cannot decide whether to respond to the paging or not to respond to the paging message because the MUSIM UE 100 cannot identify the incoming service, i.e., the downlink service. Therefore, it is necessary to define a mechanism in which the MUSIM UE 100 will be able to identify whether the current wireless communication network supports the paging cause. The following method is proposed to identify whether the current wireless communication network supports the paging cause (or a general MUSIM feature).

[0072] The paging message itself provides information on whether the current serving network node (such as gNB and AMF controller 200) supports the paging cause. For example, the paging message may have a dedicated indication that the network node supports the paging cause. Using this indication (or information), the MUSIM UE 100 identifies whether the paging cause is supported, and the MUSIM UE 100 can make an appropriate decision.

[0073] In another embodiment, the network node always provides the paging cause to the MUSIM UE 100 (optionally upon UE request), even when paging services other than standard services, i.e., there may also be paging causes for non-standard services like Internet data, such as "other services" or "other data", "default" or "other", etc. A set of standard services, such as voice, SMS, CP signaling, IMS signaling, are uniquely identified by the paging cause. With this dedicated paging cause for non-standard services, the MUSIM UE 100 can identify that the current serving network node supports the paging cause, and if the paging cause is not included in the paging message, the MUSIM UE 100 can identify that the network node does not support the paging cause.

[0074] In another embodiment, the gNB may broadcast whether the network node supports the paging cause. Therefore, whenever a paging message without a paging cause is received, the MUSIM UE 100 may check the broadcast information to identify whether the network node supports the paging cause. The broadcast information may also be on-demand system information, which may be requested on-demand by the MUSIM UE 100. In this case, when the broadcast information indicates that the paging cause is supported by the network, but if the paging cause is not included in the paging message, the MUSIM UE 100 recognizes that paging is occurring for a service that is not described in the paging cause list because the service is not a standard service.

[0075] In another embodiment, the network node (gNB or AMF controller 200) provides a paging cause support indication to the MUSIM UE 100, for example, in an AS message or a NAS message, which may be provided for each cell, each TAI, each registration area (i.e., a TAI list), or for a given geographical area, such as a TAI list, a cell ID list, etc. Therefore, whenever the MUSIM UE 100 is in that particular geographical area, the MUSIM UE 100 knows that the current serving network node supports the paging cause. In this case, when the MUSIM UE 100 is in the geographical area indicated by the network node (RAN 200 or AMF controller 200), if the paging cause is not provided to the MUSIM UE 100, the MUSIM UE 100 recognizes that paging is occurring for a service that is not described in the paging cause list because the service is not a standard service.

[0076] If the MUSIM UE 100 identifies that the paging cause is not supported by one or all serving network nodes (RAN 300 or AMF controller 200), that is, it is a legacy node, then if a paging message without a paging cause value is received by the MUSIM UE 100, the MUSIM UE 100 will respond to the paging message. Since the MUSIM UE 100 is not aware of the incoming service, only after the MUSIM UE 100 accepts the incoming service after responding to the paging message, the MUSIM UE 100 can identify whether the incoming service is a priority service or a non-priority service.

[0077] The various activities, actions, blocks, steps, etc. in the flowchart 400 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, some activities, actions, blocks, steps, etc. may be omitted, added, modified, or skipped without departing from the scope of the present invention.

[0078] Figure 5 is a signaling diagram illustrating a registration process in a wireless communication network according to an embodiment of the present invention. In an embodiment, only a MUSIM UE 100 that has more than one currently active USIM and wants to optimize USIM operation should request the network (i.e., the AMF controller 200 or the RAN 300) to provide the MUSIM UE 100 with an AI. Please note that this does not mean that a MUSIM UE 100 with MUSIM capabilities can request an AI. For example, a MUSIM UE 100 may have DSDS capabilities, but if a second USIM is not inserted, the AI ​​is of no use to the MUSIM UE 100. In an embodiment, the MUSIM UE 100 may request an AI as part of the registration process, or as part of an access layer process, during the initial registration process and the mobility registration update process or any other NAS process. The mobility registration update process may be used to dynamically change the negotiated value. For example, if the UE conditions change and the second USIM is removed from the MUSIM UE 100, and no more than one USIM is active on the MUSIM UE 100, or the user configuration is such that only one SIM is active and all other SIMs are passive.

[0079] In an embodiment, if the AMF controller 200 wants to activate the RRC inactive state for the MUSIM UE 100, the "Request AI" flag is provided by the AMF controller 200 to the NG-RAN 300 (g-Node B), for example, together with the RRC inactive AI. The term AI indicates the type of service to be delivered to the MUSIM UE 100 over the 3GPP access, such as IMS voice call, IMS SMS, video call, etc.

[0080] Provide AI request flags to the network such as Figure 5 As shown, the proposed method is used to let the network know whether the network has to provide AI to the MUSIM UE 100. It is recommended that the MUSIM UE 100 indicate to the AMF controller 200 that the MUSIM UE 100 requires AI as part of the registration process. When the RRC inactive state is activated, the AMF controller 200 can indicate "UE requires AI" along with the RRC inactive AI to the RAN 300. The RAN node 300 will use this information to determine whether the RAN paging should contain AI. The proposed method can also be used for EPS, but with the following changes:

[0081] The AMF controller 200 in the above description is replaced by the MME. No information is provided to the RAN.

[0082] Procedure: The proposed method has an impact on the registration procedure in 3GPP TS 23.502 subclause 4.2.2.2. The changes related to the existing procedure are shown below. Figure 5 Only the affected steps are shown in (Registration Procedure (Affected Steps in TS 23.502)).

[0083] At step 501 , a MUSIM UE 100 with more than one USIM active initiates a registration procedure as described in 3GPP TS 23.502 subclause 4.2.2.2.2.

[0084] At step 502, the MUSIM UE 100 sends a NAS message, such as a Registration Request message including the requested AI, to the AMF controller 200. The MUSIM UE 100 sending the requested AI to the AMF controller 200 is not only based on UE capabilities. The MUSIM UE 100 will only request the AI ​​when more than one USIM is active and the constraints of the MUSIM UE 100 require the AI ​​for effective MUSIM operation. For example, a single Rx / Tx UE that cannot operate two networks at the same time.

[0085] At step 503, if the AMF controller 200 wants to activate the RRC Inactive state for the MUSIM UE 100, the AMF controller 200 sends the value received in the AI ​​requested from the MUSIM UE 100 (optionally together with the RRC Inactive AI) to the RAN, so that the RAN 300 can provide the AI ​​to the MUSIM UE 100 in the RRC Inactive state as part of the RAN paging procedure.

[0086] At step 504, as part of a NAS message (e.g., Registration Accept), the network decides and indicates to the MUSIM UE 100 that the network will provide AI to the MUSIM UE 100 as part of a paging message or a notification message. The network indicates that AI will be provided to the MUSIM UE 100 based on local policy or subscription information (e.g., received from the UDM).

[0087] In yet another embodiment, the AMF controller 200 or the RAN node 300 provides AI to the MUSIM UE 100 only when the MUSIM UE 100 requests AI in a NAS procedure or an AS procedure and the network decides to provide AI. Otherwise, the network will not provide AI to the MUSIM UE 100. When the AMF controller 200 knows that the MUSIM UE 100 has MUSIM capabilities based on negotiation with the MUSIM UE 100, the AMF controller 200 will increase the mobile reachable timer or the implicit deregistration timer, because the MUSIM UE 100 may be busy performing a higher priority operation on another SIM and may not perform a periodic update procedure with the network exactly when the periodic timer expires. The increase in the mobile reachable timer or the implicit deregistration timer may be based on simply increasing the time of the timer when compared to other users, or simply restarting the timer without taking any action, restarting x times each time the timer expires. After x restarts, the AMF controller 200 may decide to perform an implicit deregistration.

[0088] When a paging message is received by the MUSIM UE 100, and if no AI is included, the MUSIM UE 100 will respond to the paging procedure by performing an appropriate NAS procedure, such as a service request procedure in a normal service state, or a registration procedure in an attempt to update the state.

[0089] When a paging message is received by the MUSIM UE 100, and if the AI ​​is not included, the MUSIM UE 100 will respond to the paging procedure by performing appropriate NAS or AS procedures. For example, by performing a recovery procedure and entering connected mode. Optionally, when no AI is received, the MUSIM UE 100 will be forced to respond to the paging, which can be based on a negotiation between the MUSIM UE 100 and the network, that is, the AI ​​will be shared with the MUSIM UE 100 as part of the paging message, that is, the MUSIM UE 100 requests the provision of the AI, and the network indicates to the MUSIM UE 100 in the registration acceptance that it will be provided.

[0090] Figure 6is a signaling diagram illustrating a process for providing AI in a CM_IDLE state in a wireless communication network according to an embodiment of the present invention. In an embodiment, the method may be used to indicate pending CP signaling for the MUSIM UE 100 with the AI ​​"CP signaling" so that in the MUSIM UE 100 implementation, the CP signaling can be distinguished on the Internet PS data. Here, CP signaling is a name used to indicate a control plane downlink message from the AMF controller 200, and this is just an example. There may be further granularity, for example, each NAS or SM message may have a different AI value, which can be used to identify it, such as a network-initiated detachment, a DLNAS transmission, or a UE configuration update message may have a different AI value for the MUSIM UE 100. In an embodiment, the method may be used to avoid possible ambiguity in the MUSIM UE 100 implementation. It is recommended that the 3GPP system provide mission critical services (MCS) and emergency services as AI to the MUSIM UE 100.

[0091] Based on the above observations, the following AI table is proposed.

[0092] Service Type ID Downlink service type 0 MCS, MPS, emergency services (critical services) 1 CP signaling 2 Other data

[0093] The steps to provide AI in CM_IDLE state are as follows:

[0094] At step 601, conditions are met to initiate a network triggered service request procedure for downlink data or signaling on a 3GPP access as specified in 3GPP TS 23.502 subclause 4.2.3.3.

[0095] At step 602a, if the AMF controller 200 decides to send a paging message without setting up access to "non-3GPP" as specified in 3GPP TS 23.502 subclause 4.2.3.3, the AMF controller 200 may include an AI indicating the type of traffic pending for the MUSIM UE 100 on the 3GPP access.

[0096] At step 602b, if the AMF controller 200 decides to send a NAS notification message including a 3GPP access type to the MUSIM UE 100 via a non-3GPP access as specified in 3GPP TS 23.502 subclause 4.2.3.3, the AMF controller 200 may include an AI indicating the pending traffic type of the MUSIM UE 100 via the 3GPP access. In an embodiment, the decision of the AMF controller 200 to provide the AI ​​to the MUSIM UE 100 is based on a request from the MUSIM UE 100 to provide the AI ​​as part of a NAS procedure.

[0097] At step 603, the MUSIM UE 100 may choose to respond to the paging message or the NAS notification message based on the AI ​​received in the corresponding message by performing a NAS procedure, for example, the Service Request procedure (if in the Normal Service state) or the Mobility and Registration Update procedure (Attempting to Update state) described in 3GPP TS 23.502.

[0098] In step 603, if the MUSIM UE 100 is registered in the same PLMN through 3GPP and non-3GPP access at the same time, and if the MUSIM UE 100 decides not to respond to the NAS notification message or paging message of step 602a or step 602. For example, when the MUSIM UE 100 is busy with a higher priority operation on another USIM of the same device, the MUSIM UE 100 will respond with a NAS notification response message through non-3GPP access to indicate the same to the network. The NAS notification message may include a timer value before which the network should not send a paging message or NAS notification message with the same AI for downlink data or signaling to the MUSIM UE 100 through 3GPP access, wherein the timer value is determined based on the UE implementation. Upon receiving the NAS notification response message, the network will restart the mobile reachable timer, as well as the implicit detach timer. At the same time, the MUSIM UE 100 will restart the periodic registration timer. In yet another embodiment, the notification response message from the MUSIM UE 100 may clearly indicate the reason why the MUSIM UE 100 is busy, for example, with some other operations on another USIM, and therefore does not respond to the message, the network will restart the mobile reachable timer and implicitly detach the timer. At the same time, the MUSIM UE 100 will restart the periodic registration timer.

[0099] Figure 7 1 is a signaling diagram illustrating a process for providing AI in an RRC inactive state in a wireless communication network according to an embodiment of the present invention. The steps in the process of providing AI in an RRC inactive state are given below:

[0100] At step 701, the MUSIM UE 100 is in an RRC inactive state.

[0101] In step 702, the triggering for performing RAN paging (e.g., entering the DL user plane, DL signaling from 5GC, etc.) is met as described in 3GPP TS38.300 subclause 9.2.2.4.2.

[0102] In step 703, if the AMF controller 200 notifies the RAN 300 that the MUSIM UE 100 requests AI as part of the N2 message, the RAN 300 may include the AI ​​in the paging message. In addition, as described in 3GPP TS 38.300, the MUSIM UE 100 may choose to respond to the paging message based on the received AI and enter the connected mode.

[0103] The dual registration process is as follows:

[0104] According to the current specification, dual registration is limited to the case where the PLMN that the MUSIM UE 100 attempts to register should be the same or equivalent PLMN. However, due to the deployment requirements of the operator, there are specific use cases where the PLMNs do not need to be the same or equivalent.

[0105] Here is an example of such a scenario:

[0106] 1) The operator deploys PLMN A in NGRAN / 5GS.

[0107] 2) PLMN A and PLMN B are deployed in EUTRAN.

[0108] 3) PLMN A and PLMN B are equivalent PLMNs and support "interworking without N26".

[0109] 4) The operator wants the dual-registered UE to register on PLMN A in 5GS and on PLMN B in EPS.

[0110] 5) The operator also wants to restrict the IRAT mobility of these UEs between PLMNs deployed in EUTRAN (ie, PLMN A and PLMN B).

[0111] According to the current mandate in the specification, only the same or equivalent PLMN is allowed to be selected in dual registration mode, supporting the above configuration is not possible in the current implementation. In addition, there may be use cases where an operator wants to support dual registration across different VPLMNs to enable access to different services without session transfer. The current definition of this feature does not allow for same. The following proposal looks at the way in which the network can enable the UE to operate in dual registration mode between different and non-equivalent PLMNs.

[0112] Solution 1: Provide a set of PLMNs that the MUSIM UE 100 is allowed to register on simultaneously for dual registration. The above list can be provided when the MUSIM UE 100 is registered on one RAT. In the case where the network wants to restrict certain PLMNs to certain RATs, the list can be made more specific by providing PLMN+RAT combinations. The list can also include paired PLMN+RAT sets, thereby informing the MUSIM UE 100 of possible operating combinations. These details can also be pre-configured in the MUSIM UE 100.

[0113] Solution 2: Allow the MUSIM UE 100 to follow the priorities defined in the UPLMN / OPLMN list. The UPLMN / OPLMN list defines the most likely PLMNs where the MUSIM UE 100 can obtain services and their priorities. Consider the following use case: the MUSIM UE 100 has PLMN A, PLMN B, PLMN C in order of priority from high to low. The MUSIM UE 100 is registered on PLMN A in N1 mode and receives PLMN C as an equivalent PLMN. Although coverage of PLMN B is available in the area in EUTRAN, the MUSIM UE 100 is registered on PLMN C in S1 mode. Since the equivalent PLMN is determined by the VPLMN, the preference list of the HPLMN may not be consistent with the preference of the VPLMN in certain use cases. In such use cases, the MUSIM UE 100 may be restricted from moving to a more preferred VPLMN based on the HPLMN preference. To avoid such conflicts and follow the preference of the HPLMN list, dual registration can be performed for each RAT based on existing PLMN selection principles and by selecting the most preferred PLMN in each RAT. The MUSIM UE 100 can restrict this behavior to situations where session handover across RATs is not desired.

[0114] Solution 3: A method where the network decides the EPLMN based on the MUSIM UE 100 sending a "UE Status Information Element". The UE Status Information Element (IE) is used to derive whether the MUSIM UE 100 is operating in single registration mode or dual registration mode based on the value sent in the UE Status Information Element (IE). A network that wants to selectively assign the EPLMN only to UEs operating in single registration mode can use the IE to distinguish the UE registration mode (i.e., single or dual) and can decide to send the EPLMN accordingly. Therefore, a network that wants to restrict a dual registered MUSIM UE 100 from reselecting across PLMNs in EUTRAN can use the IE to not send the EPLMN in EUTRAN.

[0115] Since during dual registration, the EPLMN is maintained based on the RAT, the same network can send the PLMNs in the EPLMN list for the UE's registration in N1 mode. Therefore, the network can use the MUSIM UE 100 status IE to selectively control the EPLMN list based on the RAT. If the network has received a request to provide an AI to the MUSIM UE 100, the network will not filter the paging.

[0116] In this embodiment, AI is also referred to as paging cause, which means the type of service to be delivered to MUSIM UE 100 via 3GPP access. Using AI, MUSIM UE 100 can decide whether to respond to paging based on current activities in MUSIM UE 100, for example, if there is a higher priority service ongoing on another USIM.

[0117] If the incoming service is for a priority service (also called a critical service), such as an emergency service / MCS service / MPS service, etc., the network (i.e., the AMF controller 200 or the gNodeB) will not provide a paging cause. If there is no AI, it means that the network has paged the MUSIM UE 100 for the priority service, and therefore requires the MUSIM UE 100 to respond to the paging message. Optionally, this behavior in the network and the MUSIM UE 100 is implemented only when the MUSIM UE 100 and the network successfully negotiate that the AI ​​will be provided to the MUSIM UE 100 in the NAS or AS process.

[0118] If the MUSIM UE 100 and the network successfully negotiate that the AI ​​will be provided to the MUSIM UE 100 in the NAS or AS procedure, the RAN 300 will increase the value of the RNA update timer on the gNodeB side and whenever the timer expires, the RAN layer 300 will restart the timer without affecting the inactive context for an implementation-dependent number of times, because the MUSIM UE 100 may be in dual SIM operation and may not be able to perform the periodic RAN area update procedure when the RNA timer expires (i.e., the periodic timer is inactive).

[0119] Consider an example where the AMF controller 200 has already triggered a paging procedure with an AI value of AI1, and now after the existing procedure, the AMF controller 200 determines that another paging must be triggered (optionally, it may have a lower priority depending on the local configuration when compared to the first paging message sent), however it has a different AI value of AI2. The AMF controller 200 will trigger the second paging procedure without waiting for the MUSIM UE 100 to respond to the first paging, because for the first paging request, the MUSIM UE 100 may not respond based on the AI ​​value. In other words, if the second request turns out to be for the same AI value, the AMF controller 200 does not need to page the MUSIM UE 100. The gNodeB (i.e., the RAN node 300) must also apply the same procedure for RAN paging in the RRC inactive state. This means that there can be multiple paging messages with different auxiliary values ​​sent to the same MUSIM UE 100. In addition, the MUSIM UE 100 is expected to read all paging messages, and the lower layers in the MUSIM UE 100 should report all received paging messages with auxiliary values ​​to the NAS layer. Optionally, this behavior of the AMF controller 200 or the RAN node 300 can be completed if the MUSIM UE 100 and the network successfully negotiate that the AI ​​will be provided to the MUSIM UE 100 in the NAS or AS process.

[0120] Figure 8 is a signaling diagram showing that the AMF controller 200 or gNodeB initiates a second paging procedure even if the first paging procedure is not completed according to an embodiment of the present invention. The AMF controller 200 may know that the UE is a MUSIM UE 100, so it may decide not to respond to the paging based on the paging cause. Considering that service-1 is in progress between the MUSIM UE 100 and the first network 300A corresponding to the first USIM of the MUSIM UE 100 (801). The second network 300B corresponding to the second USIM of the MUSIM UE 100 initiates service-2 for the MUSIM UE 100 (802). For downlink (DL) data or signaling, the AMF controller 200 sends (803) a first paging message with an AI value AI-1 to the MUSIM UE 100. Now, DL data or signaling (805) is initiated again in the core network for the same USIM stack (i.e., MUSIM UE 100), and the AMF controller 200 will immediately send (806, 807) a second paging request to the MUSIM UE 100 with a different AI value (i.e., AI-2), so that the MUSIM UE 100 can be aware of its new pending downlink service and can decide (808) whether to respond to the second paging message.

[0121] Fig. 9 is a signaling diagram showing transmission of a second paging message by multiplexing an AI value by the AMF controller 200 or a gNodeB according to an embodiment of the present invention. Considering that service-1 is being carried out between the MUSIM UE 100 and the first network 300A corresponding to the first USIM of the MUSIM UE 100 (901). The second network 300B corresponds to the second USIM of the MUSIM UE 100 and initiates service-2 (902) for the MUSIM UE 100. The AMF controller 200 has triggered (903) a paging procedure with an AI value of AI-1. When the MUSIM UE 100 receives the paging, it may decide (904) not to respond to the paging. One reason may be that a particular service MUSIM UE 100 has been terminated, so it becomes a lower priority. For example, the related PDU session has been locally deactivated by the MUSIM UE 100. However, since the network has no information about the local deactivation of the service. It continuously pages the MUSIM UE 100. In a general implementation, this may cause the paging procedure to escalate in a larger area.

[0122] The second network 300B may send (906, 907) a second paging request to the MUSIM UE 100, or multiplex all AI values ​​into the same paging request message to the MUSIM UE 100, i.e., the second paging message will have all AI values ​​corresponding to the various multiplexed services to be delivered to the MUSIM UE 100. According to the proposed method, the multiplexing of AI values ​​may be done by the AMF controller 200 or the gNode B. It is expected that the MUSIM UE 100 reads all paging messages or all values ​​of AI values ​​to identify the type of traffic entering the MUSIM UE 100 in the DL direction. This allows the MUSIM UE 100 to make an informed decision to respond or not respond to the paging message (908).

[0123] The second paging message with or without multiplexing of the AI ​​value as described in the proposed method can only be performed when the MUSIM UE 100 and the AMF controller 200 negotiate that the MUSIM UE 100 has communication constraints due to its need for AI. The AI ​​in the present invention is a value together with the paging or notification message sent by the second network 300B, which indicates to the MUSIM UE 100 the type of data service or signaling service (or in other words, service) to be transmitted to the MUSIM UE 100. In addition, the second network decides to send the second paging message to the MUSIM UE 100 only when the AI ​​value is different from the first paging message AI value or different from the last multiplexed AI value. The proposed method is described for the AMF controller 200 or the CN entity. The same invention applies to RAN paging when the MUSIM UE 100 is in an inactive state. Paging cause and AI value are terms that can be used interchangeably.

[0124] Fig.10 1 is a signaling diagram illustrating a scenario in which a NAS or AS procedure is triggered by the MUSIM UE 100 to notify the second network 300B of the deactivated state of a service according to an embodiment disclosed in the present invention. Consider that service-1 is being performed between the MUSIM UE 100 and the first network 300A corresponding to the first USIM of the MUSIM UE 100 (1001). The second network 300B, corresponding to the second USIM of the MUSIM UE 100, initiates (1002) service-2 for the MUSIM UE 100. In a conventional method and system, consider that the AMF controller 200 has triggered a paging procedure with an AI value of AI-1. When the MUSIM UE 100 receives a paging cause, it may decide not to respond to the paging. One reason may be that the MUSIM UE 100 has terminated a particular service, so it becomes a lower priority. For example, the related PDU session has been locally deactivated by the MUSIM UE 100. However, since the second network 300B has no information about the local deactivation of the service. It continuously pages the MUSIM UE 100. In a typical implementation, this may result in the paging process being escalated over a larger area.

[0125] refer to Fig.10, when the MUSIM UE 100 receives (1003) a paging with a paging cause (in other words AI), for which the MUSIM UE 100 has deactivated (1004) a service (e.g. a PDU session), the MUSIM UE 100 will trigger a NAS or AS procedure to inform the network of the deactivated state of the service. For example: by triggering a registration procedure or a service request procedure (using the PDU Session Status IE). The PDU Session Status IE will indicate that the corresponding PDU session has been released on the MUSIM UE 100 side. By triggering a registration procedure, it is indicated that SMS or LCS is no longer supported by the MUSIM UE 100. By triggering (1005) a paging rejection message or a busy indication message to the second network 300B, including the PDU Session Status IE or indicating the deregistration of SMS (generally, any service). With this information, the second network 300B will also deactivate the corresponding service, for example by releasing the PDU session or SMS service deregistration, and this will avoid the second network 300B from paging to the MUSIM UE 100.

[0126] In general, when the AMF controller 200 has sent a paging message with a paging cause (AI-1) to the MUSIM UE 100 and a new trigger is generated at the core network, the AMF controller 200 will consider what the paging cause of the second paging message is. If the paging cause of the second paging message is different from the first already sent paging cause of the first paging message, the AMF controller 200 may perform one of the following mechanisms.

[0127] 1. The AMF controller 200 will immediately send the second paging message by multiplexing the paging causes of the first paging message and the second paging message.

[0128] 2. The AMF Controller 200 shall immediately send the second paging message. The AMF Controller 200 and the gNB shall perform both paging procedures simultaneously and in parallel with their own implementation-dependent retry counts. The first paging procedure shall not affect the execution of the second paging procedure and vice versa.

[0129] 3. The AMF controller 200 may inform the SMF that the paging procedure should be retried after a specific duration, where the SMF will send the paging message again after the expiration of the specific duration (an example maintained by a timer).

[0130] 4. The AMF Controller 200 will remember that the second paging procedure is pending and will force the second paging procedure to be performed if the MUSIM UE 100 does not respond to the first paging procedure (optionally after expiration of the paging protection timer).

[0131] 5. Because the first paging procedure is ongoing. The second paging procedure can be initiated by the AMF Controller 200 or the SMF, or after an interaction between the AMF Controller 200 and the SMF after the retry duration. Basically, the core network (AMF Controller 200, SMF and UPF) should remember that they have to send the second paging message even if the first paging procedure expires and the MUSIM UE 100 does not respond to the first paging message, i.e. the SMF and UPF can indicate to the AMF Controller 200 that the downlink data of the second paging message is pending after the retry duration. The retry duration timer can be started at the AMF Controller 200, SMF or UPF or any other core network entity.

[0132] When the MUSIM UE 100 decides not to respond to the paging message based on the paging cause, the MUSIM UE 100 will provide a busy indication to the network as part of a NAS or AS message. The MUSIM UE 100 will also include the paging cause based on which the MUSIM UE 100 decides not to respond to the paging message as part of a NAS message with a busy indication or an AS message with a busy indication. This allows the network to accurately identify whether the busy indication is for the first paging message or the second paging message or the nth paging message. If the paging cause is not included, the MUSIM UE 100 will make a clear indication that the MUSIM UE 100 does not respond to the paging without the paging cause as part of the busy indication, for example by not including the paging cause in the NAS or AS message with a busy indication or a dedicated information element. The explanation in this embodiment is about the first and second paging messages, but this can be extended to n paging procedures.

[0133] As an example, this embodiment is discussed from the core network element of 5GS, but the same invention is also applicable to 4GS, where MME plays the role of AMF controller 200, eNodeB plays the role of RAN node 300 (similar to gNB), etc.

[0134] The foregoing description of specific embodiments will fully reveal the general nature of the embodiments of the present invention, so that others can easily modify and / or adjust the specific embodiments for various applications by applying current knowledge without departing from the general concepts, and therefore, such adjustments and modifications should and are intended to be understood within the meaning and scope of equivalents of the disclosed embodiments. It should be understood that the words or terms used herein are for descriptive purposes and not for limitation. Therefore, although embodiments of the present invention have been described according to preferred embodiments, those skilled in the art will recognize that embodiments of the present invention can be modified to be implemented within the scope of the embodiments described in the present invention.

Claims

1. A method for receiving a paging message by a user equipment (UE) in a wireless communication system supporting multiple universal subscriber identity modules (USIM), the method comprising: transmitting, via a radio access network RAN, a registration request message to an access and mobility management function AMF, the registration request message comprising information indicating that the UE has a capability of using the multiple USIMs; receiving, via the RAN, a registration accept message from the AMF, the registration accept message indicating that a paging cause indication for a voice service is supported in the RAN; In a case where the UE receives the paging message from the RAN supporting a paging cause indicating the voice service, identifying whether the paging message includes a paging cause indication for the voice service; In a case where the paging message includes a paging cause indication for the voice service, determining whether to respond to the paging message based on the paging cause indication; as well as In a case where the UE determines not to respond to the paging message including the paging cause indication for the voice service, a message for rejecting the paging message is transmitted to the RAN.

2. The method according to claim 1, wherein: The UE in a radio resource control (RRC) inactive state receives the paging message as a RAN paging message, and Wherein, at least one of the multiple USIMs is active on the UE.

3. The method according to claim 1, wherein: In case that the paging message includes the paging cause indication, the UE determines that the paging message is received for the voice service. 4 . The method according to claim 1 , further comprising performing a service request procedure if the UE determines to respond to the paging message.

5. The method of claim 1 , further comprising, if one of the multiple USIMs is active on the UE during a registration process, indicating to the AMF via the RAN that the UE does not support use of the multiple USIMs.

6. A user equipment UE in a wireless communication system supporting multiple universal subscriber identity modules USIM, the UE comprising: a communicator; and A processor is coupled to the communicator and is configured to: transmitting, via a radio access network RAN, a registration request message to an access and mobility management function AMF, the registration request message comprising information indicating that the UE has a capability of using the multiple USIMs, receiving a registration accept message from the AMF via the RAN, the registration accept message indicating that a paging cause indication for a voice service is supported in the RAN, in a case where the processor receives a paging message from the RAN supporting a paging cause indicating the voice service, identifying whether the paging message includes a paging cause indication for the voice service, In a case where the paging message includes a paging cause indication for the voice service, determining whether to respond to the paging message based on the paging cause indication, and In a case where the UE determines not to respond to the paging message including the paging cause indication for the voice service, a message for rejecting the paging message is transmitted to the RAN.

7. The UE according to claim 6, wherein: The UE in a radio resource control (RRC) inactive state receives the paging message as a RAN paging message, and Wherein, at least one of the multiple USIMs is active on the UE.

8. The UE according to claim 6, wherein: The processor is configured to determine that the paging message is received for the voice service if the paging message includes the paging cause indication.

9. The UE according to claim 6, wherein: The processor is further configured to perform a service request procedure if the UE determines to respond to the paging message.

10. The UE of claim 6, wherein the processor is further configured to transmit, through the communicator, information indicating that the UE does not support use of the multiple USIMs to the AMF via the RAN when one of the multiple USIMs is active on the UE during a registration process.

11. A method performed by an access and mobility management function (AMF) in a wireless communication system supporting multiple universal subscriber identity modules (USIM) in a user equipment (UE), the method comprising: receiving a registration request message from the UE via a radio access network RAN, the registration request message including information indicating that the UE has a capability of using the multiple USIMs; A registration accept message is transmitted to the UE via the RAN, the registration accept message indicating that a paging cause indication for a voice service is supported by the RAN, and the RAN transmits a RAN paging message including the paging cause indication for the voice service to the UE.

12. The method according to claim 11, wherein: At least one of the multiple USIMs is active on the UE which is in a Radio Resource Control, RRC, inactive state.

13. An access and mobility management function (AMF) in a wireless communication system supporting multiple universal subscriber identity modules (USIM) in a user equipment (UE), the AMF comprising: a communicator; and The processor is configured as: receiving, by the communicator, a registration request message from the UE via a radio access network RAN, the registration request message indicating that the UE has a capability of using the multiple USIMs, A registration accept message is transmitted to the UE via the RAN by the communicator, the registration accept message indicating that a paging cause indication for a voice service is supported by the RAN, and the RAN transmits a RAN paging message including the paging cause indication for the voice service to the UE.

14. The AMF according to claim 13, wherein: At least one of the multiple USIMs is active on the UE which is in a Radio Resource Control, RRC, inactive state.

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