Mobility management node, user equipment and method

Abstract

To provide a solution for solving the problems concerning multi-USIM UE.SOLUTION: This disclosure relates to the procedure to handle the services provided by UE (100) supporting multiple USIM cards (105). More specifically it provides a method for paging co-ordination when the UE (100) is registered with a PLMN individually for two or more USIM cards (105).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to procedures for handling services provided by a UE that supports multiple USIM cards. [Background technology]

[0002] A multi-USIM UE supports multiple registrations to a PLMN for multiple USIMs (SUPIs) simultaneously and serves users with multiple USIM subscriptions. The UE mode in which a UE simultaneously registers to a PLMN for multiple USIMs (SUPIs) simultaneously and serves users with multiple USIM subscriptions is also called "multimode." Most common multi-USIM (i.e., multimode) UEs support either dual receivers and a single transmitter, or a single receiver and a dual transmitter. When a multimode UE supporting a single transceiver (single transmitter and single receiver) establishes a connection to the network to use services for one UICC (SUPI-1), the UE cannot send or receive signaling to receive services for another UICC (SUPI-2). For a multiple USIM UE supporting a single transmitter and multiple receiver configuration, while the UE is in connected mode for the first UICC, it can receive paging for the second UICC, but the UE cannot establish a signaling connection to the network for the second UICC, cannot send or receive dedicated signaling for the second UICC, and cannot use services for the dual UICC. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP TR 21.905, “Vocabulary for 3GPP Specifications”, V15.0.0(2018-03) [Non-patent document 2] 3GPP TS 23.501, “System Architecture for the 5G System;Stage 2”, V15.2.0(2018-06) [Non-patent document 3] 3GPP TS 23.502, “Procedures for the 5G System;Stage 2”, V15.2.0(2018-06) [Non-patent document 4] 3GPP TS 24.501, “Non-Access-Stratum (NAS) protocol for 5G System (5GS) Stage 3”, V15.0.0(2018-06) Summary of the Invention [Problem to be solved by the invention]

[0004] Problem statement 1: When a multi-USIM UE supports a single transmitter and receiver and is in connected mode, i.e., has a NAS signaling connection for the first UICC card, the UE cannot receive MT paging for the second UICC. This causes a significant service impact to the user when a high-priority MT service associated with the second UICC is triggered for the user. The user in this scenario will miss the high-priority service. For example, if a user is accessing the Internet using the first UICC and an MT IMS call is terminating for the second UICC, the user will not be able to receive the MT IMS call.

[0005] Problem statement 2: If a multi-USIM UE supports a single transmitter and receiver and is in connected mode for one UICC, the UE cannot send any signaling or data messages to the network of any other UICC. This creates two problems: i) In this scenario, if the UE cannot be updated periodically, the UE has presence in the network for another UICC. ii) If an event triggers a deregistration procedure for the second UIM (e.g., 5G services are disabled for the second UICC or the second UICC is deleted), the UE cannot send a deregistration message for the second USIM, and the network retains the UE context for the second UICC. Therefore, when an MT service is performed for the second UICC, the network may send paging or reserve network resources (buffer packets for services related to the second USIM). In this scenario, it is unclear whether the UE will perform the deregistration procedure when it enters idle mode.

[0006] In view of the above problems, the present disclosure aims to provide a solution for solving at least one of the various problems. [Means for solving the problem]

[0007] A method for a network device according to the present disclosure includes receiving a message including a registration request for a second SUPI (Subscription Permanent Identifier) ​​from a UE (User Equipment) including a first USIM (Universal Subscriber Identity Module) having a first SUPI (Subscription Permanent Identifier) ​​registered in an AMF (Access and Mobility Management Function) and a second USIM having a second SUPI, determining a target AMF based on the registration request for the second SUPI, and sending a message including the registration request for the second SUPI to the target AMF.

[0008] A method for a network device according to the present disclosure includes registering a first SUPI (Subscription Permanent Identifier) ​​for a first USIM (Universal Subscriber Identity Module) included in a UE (User Equipment) and a second SUPI for a second USIM included in the UE, receiving a message from an NF (Network Function) for transmitting signaling or data to the UE for the second SUPI, and paging the UE to transmit the signaling or data for the second SUPI.

[0009] A method for a UE (User Equipment) according to the present disclosure includes registering a first SUPI (Subscription Permanent Identifier) ​​for a first USIM (Universal Subscriber Identity Module) included in the UE and a second SUPI for a second USIM included in the UE with an AMF (Access and Mobility Management Function), initiating a UE initiation procedure with the second SUPI, sending a first message for the second SUPI to the AMF, performing the UE initiation procedure, and receiving a second message for the second SUPI from the AMF. [Brief explanation of the drawings]

[0010] [Figure 1] Figure 1 shows a multi-USIM UE configuration. [Figure 2] FIG. 2 illustrates a registration procedure using NG-RAN with steering to a target AMF according to the first aspect. [Figure 3] Figure 3 shows a registration procedure using an AMF that performs steering to a target AMF according to the second aspect. [Figure 4] FIG. 4 illustrates another variation of rerouting through the NG-RAN according to the second embodiment. [Figure 5] FIG. 5 illustrates a paging procedure in connected mode according to a third embodiment. [Figure 6] FIG. 6 shows a paging procedure in idle mode according to a fourth embodiment. [Figure 7] FIG. 7 illustrates a UE initiated procedure in connected mode with another SUPI according to a fifth aspect. [Figure 8] FIG. 8 shows a schematic block diagram of a UE. [Figure 9] FIG. 9 shows a schematic block diagram of an (R)AN. [Figure 10]FIG. 10 shows a schematic block diagram of an AMF. DETAILED DESCRIPTION OF THE INVENTION

[0011] Multi-USIM UE configuration Figure 1 illustrates a multi-USIM UE configuration. As shown, the UE 100 includes a Mobile Equipment (ME) 102 that includes one or more antennas 101, one or more transmitters 103, and one or more receivers 104, and multiple USIMs 105 (USIM-1, USIM-2, USIM-n).

[0012] Abbreviation For purposes of this specification, the abbreviations set forth in Non-Patent Document 1 and below apply. Where an abbreviation is defined herein, it takes precedence over the definition of the same abbreviation in Non-Patent Document 1. 5GC 5G Core Network 5GS 5G System 5G-AN 5G Access Network 5G-GUTI 5G Globally Unique Temporary Identifier 5G S-TMSI 5G S-Temporary Mobile Subscription Identifier 5QI 5G QoS Identifier AF Application Function AMF Access and Mobility Management Function AN Access Node AS Access Stratum AUSF Authentication Server Function CM Connection Management CP Control Plane CSFB Circuit Switched (CS) Fallback DL Downlink DN Data Network DNAI DN Access Identifier DNN Data Network Name EDT Early Data Transmission EPS Evolved Packet System EPC Evolved Packet Core FQDN Fully Qualified Domain Name GFBR Guaranteed Flow Bit Rate GMLC Gateway Mobile Location Centre GPSI Generic Public Subscription Identifier GUAMI Globally Unique AMF Identifier HR Home Routed (roaming) I-RNTI I-Radio Network Temporary Identifier LADN Local Area Data Network LBO Local Break Out (roaming) LMF Location Management Function LRF Location Retrieval Function MAC Medium Access Control MFBR Maximum Flow Bit Rate MICO Mobile Initiated Connection Only MME Mobility Management Entity N3IWF Non-3GPP Inter Working Function NAI Network Access Identifier NAS Non-Access Stratum NEF Network Exposure Function NF Network Function NG-RAN Next Generation Radio Access Network NR New Radio NRF Network Repository Function NSI ID Network Slice Instance Identifier NSSAI Network Slice Selection Assistance Information NSSF Network Slice Selection Function NSSP Network Slice Selection Policy PCF Policy Control Function PEI Permanent Equipment Identifier PER Packet Error Rate PFD Packet Flow Description PLMN Public Land Mobile Network PPD Paging Policy Differentiation PPI Paging Policy Indicator PSA PDU Session Anchor QFI QoS Flow Identifier QoE Quality of Experience (R)AN (Radio) Access Network RLC Radio Link Control RM Registration Management RQA Reflective QoS Attribute RQI Reflective QoS Indication RRC Radio Resource Control SA NR Standalone New Radio SBA Service Based Architecture SBI Service Based Interface SD Slice Differentiator SDAP Service Data Adaptation Protocol SEAF Security Anchor Functionality SEPP Security Edge Protection Proxy SMF Session Management Function S-NSSAI Single Network Slice Selection Assistance Information SSC Session and Service Continuity SST Slice / Service Type SUCI Subscription Concealed Identifier SUPI Subscription Permanent Identifier UDSF Unstructured Data Storage Function UICC Universal Integrated Circuit Card UL Uplink UL CL Uplink Classifier USIM Universal Subscriber Identity Module UPF User Plane Function UDR Unified Data Repository URSP UE Route Selection Policy SMS Short Message Service SMSF SMS Function MT Mobile Terminated UAC Unified Access Control ODACD Operator Defined Access Category Definitions Operating System

[0013] definition For purposes of this specification, the terms and definitions set forth in Non-Patent Document 1 and below apply. Where a term is defined herein, it takes precedence over the definition of the same term in Non-Patent Document 1.

[0014] Aspects Exemplary embodiments will now be described with reference to the accompanying drawings. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. The terminology used in the detailed description of specific exemplary embodiments shown in the accompanying drawings is not intended to be limiting. In the drawings, like numbers refer to like elements.

[0015] It should be noted, however, that the reference signs in the claims indicate only exemplary aspects of the present subject matter and therefore should not be considered to limit its scope, as the subject matter may admit of other equally effective aspects.

[0016] This specification may, in several places, refer to "an," "one," or "some" embodiments. This does not necessarily mean that each such reference is referring to the same embodiment or that the feature applies only to a single embodiment. Single features of different embodiments may be combined to provide other embodiments.

[0017] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless otherwise stated. As used herein, the terms "includes," "comprises," "including," and / or "comprising" indicate the presence of stated features, integers, steps, operations, elements, and / or components, but are further understood to not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. When an element is referred to as "connected" or "coupled" to another element, it is understood that it may be directly connected or coupled to the other element, or that intervening elements may be present. Furthermore, as used herein, "connected" or "coupled" may include operatively connected or coupled. As used herein, the term "and / or" includes any and all combinations and arrangements of one or more associated listed items.

[0018] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this disclosure pertains. Furthermore, terms as defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant art, and unless explicitly defined herein, they should not be interpreted in an idealized or overly formal sense.

[0019] These figures show simplified structures showing only some elements and functional entities, which are all logical units, and their implementation may differ from those shown. The connections shown are logical connections and may differ from actual physical connections. It is clear to those skilled in the art that the structures may also include other functions and structures.

[0020] Additionally, all logical units described and illustrated in the figures include software and / or hardware components necessary for the functioning of that unit. Furthermore, each unit may include one or more implicitly understood components within itself. These components may be operatively coupled to each other and configured to communicate with each other to perform the functions of that unit.

[0021] First aspect (Solution 1 for solving problem statements 1 and 2): The procedure according to the first aspect involves registering all SUPIs of the UE with a single AMF, with steering performed by the NG-RAN. Figure 2 shows the detailed steps of the procedure. The detailed steps of Figure 2 are described below.

[0022] 1. The UE is registered with the AMF of the PLMN for SUPI-1. The UE is assigned 5G-GUTI-1 for SUPI-1.

[0023] In one example, the UE assigns a unique integer (n1) to SUPI-1 (e.g., assigns the USIM slot number of UICC1 to SUPI-1). The UE sends the unique integer assigned to SUPI-1 in a registration request message or other NAS procedure. Upon receiving the unique integer assigned to SUPI-1, the AMF associates the unique integer (n1) with SUPI-1 and stores it in the UE context for SUPI-1.

[0024] 2. The UE is in idle mode, i.e. does not have any NAS signaling connection with the AMF for USIM-1 with SUPI-1. The UE initiates the registration procedure for the second UICC (USIM-2 with SUPI-2).

[0025] 3. The UE sends an RRC (Connection) Setup request message to the NG-RAN to establish an RRC connection.

[0026] 4. The NG-RAN sends an RRC (Connection) Setup message to the UE.

[0027] 5. The UE sends an RRC (Connection) Setup Complete message to the NG-RAN. This message contains the following parameters: i) Registration Request message for SUPI-2. ii) At least one of the SUCI (SUCI-1) of the first UICC1 or the 5G-GUTI (5G-GUTI-1) of the first UICC allocated in step 1.

[0028] In one example, the UE assigns a unique integer (n2) to SUPI-2 (e.g., assigns the USIM slot number of UICC2 to SUPI-2). The UE sends the unique integer n2 assigned to SUPI-2 in a registration request message or other NAS procedure.

[0029] 6. The NG-RAN determines the target AMF for the registration request based on 5G-GUTI-1 or SUCI as follows: i) If SUCI-1 is included in the RRC setup complete message, NG-RAN uses SUCI-1 to detect the AMF to which the UE is currently registered for SUPI-1. In one example, the NG-RAN sends SUCI-1 to a UDM or O&M entity to obtain the identity (GUAMI) of the AMF to which the UE is registered for SUPI-1. ii) If 5G-GUTI-1 is included in the RRC setup complete message, the NG-RAN selects an AMF based on the GUAMI part of 5G-GUTI-1. iii) If both SUCI-1 and 5G-GUTI-1 are included, the NG-RAN selects the AMF based on SUCI-1 or 5G-GUTI as described in points i) and ii) of step 6 above.

[0030] 7. After selecting the target AMF, the NG-RAN sends an Initial UE message with a registration request message including SUCI-2 to the selected AMF.

[0031] 8. Upon receiving the registration request message and the initial UE message with 5G-GUTI-1 or SUCI-1, the AMF processes the registration request message for SUPI-2 and generates a context for SUPI-2. The AMF uses 5G-GUTI-1 or SUCI-1 to find the 5GMM context associated with SUPI-1. The AMF associates the 5GMM context of SUPI-1 with the 5GMM context of SUPI-2, i.e., the 5GMM contexts of SUPI-1 and SUPI-2 are linked to each other. In other words, the 5GMM context of SUPI-1 contains a pointer to the 5GMM context of SUPI-2, and vice versa. The 5GMM context of SUPI-1 is used to fetch the 5GMM context of SUPI-2, and vice versa.

[0032] The AMF may also perform association between the 5GMM context of SUCI-1 and the 5GMM context of SUCI-2.

[0033] When one ME is shared by multiple USIMs, the AMF may maintain associations between multiple 5GMM contexts.

[0034] The AMF associates a unique integer (n2) with SUPI-2 and stores it in the UE context for SUPI-2.

[0035] 9. AMF completes the registration procedure for SUPI-2.

[0036] In one example, the AMF allocates a single temporary identity for both SUPI-1 and SUPI-2, where a unique integer (e.g., n1, n2) is used to distinguish between SUPI-1 or SUPI-2.

[0037] This procedure also applies if the UE has an established NAS signaling connection for SUPI-1 and the UE initiates the registration procedure for SUPI-2. In this scenario, neither steps 3 nor 4 are performed, but in step 5 the UE sends an RRC message containing a registration request message, 5G-GUTI-1 or SUPI-1.

[0038] Second aspect (Solution 2 to solve problem statements 1 and 2):

[0039] The procedure according to the second aspect involves registering all SUPIs of the UE to a single AMF with steering performed by the AMF. Figure 3 shows the detailed steps of the procedure. The detailed steps of Figure 3 are described below.

[0040] 1. The UE registers with the AMF of the PLMN for the first UICC (UUSIM-1 with SUPI-1). The UE is assigned 5G-GUTI-1 for the first UICC.

[0041] In one example, the UE assigns a unique integer (n1) to SUPI-1 (e.g., assigns the USIM slot number of UICC1 to SUPI-1). The UE sends the unique integer assigned to SUPI-1 in a registration request message or other NAS procedure. AMF1 associates the unique integer (n1) with SUPI-1 and stores it in the UE context for SUPI-1.

[0042] 2. The UE is in idle mode, i.e. does not have any NAS signaling connection with the AMF. The UE initiates the registration procedure for the second UICC (USIM-2 with SUPI-2).

[0043] 3. The UE sends an RRC (Connection) Setup request message to the NG-RAN to establish an RRC connection.

[0044] 4. The NG-RAN sends an RRC (Connection) Setup message to the UE.

[0045] 5. The UE sends an RRC (Connection) Setup Complete message to the NG-RAN containing the following parameters: i) Registration Request message for SUPI-2. ii) At least one of the SUCI (SUCI-1) of the first UICC1 or the 5G-GUTI (5G-GUTI-1) of the first UICC allocated in step 1.

[0046] In one example, the UE assigns a unique integer (n2) to SUPI-2 (e.g., assigns the USIM slot number of UICC2 to SUPI-2). The UE sends the unique integer n2 assigned to SUPI-2 in a registration request message or other NAS procedure.

[0047] 6. NG-RAN selects an AMF based on its internal logic. In this flow, AMF2 is selected.

[0048] 7. After selecting the target AMF, the NG-RAN sends an Initial UE message with a registration request message including SUCI-2 to the selected AMF.

[0049] 8. Upon receiving the registration request message and the initial UE message with 5G-GUTI-1 or SUCI-1, AMF2 determines the target AMF for SUCI-2 as follows: i) If SUPI-1 is included in the NG-AP message, the NG-RAN uses SUCI-1 to discover the AMF to which the UE is currently registered in SUPI-1. In one example, the NG-RAN sends SUCI-1 to a UDM or O&M entity to obtain the identity (GUAMI) of the AMF to which the UE is registered for SUPI-1. ii) If 5G-GUTI1 is included in the NG-AP message, the NG-RAN selects an AMF based on the GUAMI of 5G-GUTI-1. iii) If both SUCI-1 and 5G-GUTI-1 are included in the NG-AP message, the NG-RAN selects the AMF based on SUCI-1 or 5G-GUTI as described in points i) and ii) of step 8 above.

[0050] If the AMF internal process determines that 5G-GUTI-1 is accommodated in AMF2 as described above, steps 9 and 10 are skipped because rerouting is not required.

[0051] Please note that either steps 9 and 10 in Figure 3 or steps 9a and 10a in Figure 4 are performed, depending on the network configuration according to Non-Patent Document 3.

[0052] 9. After AMF2 selects the target AMF1, AMF2 sends a Namf_Communication N1MessageNotify message together with SUCI-2 and SUCI-1 or SUPI-1 or 5G-GUTI-1 to AMF1 to reroute the registration request message to AMF1.

[0053] 10. AMF1 sends a Namf_Communication N1MessageNotify response message to AMF2.

[0054] 9a. This is another variation for rerouting to AMF1. After AMF2 selects the target AMF1 in step 8, AMF2 sends a Reroute NAS message to NG-RAN together with SUCI-2 and SUCI-1 or 5G-GUTI-1 to reroute the Registration Request message to AMF1.

[0055] 10a. After the NG-RAN receives the Reroute NAS message in step 9a, the NG-RAN sends an Initial UE message with a Registration Request message containing SUCI-2 to the selected AMF1.

[0056] 11. When AMF1 receives a Namf_Communication N1MessageNotify message with SUCI-2, 5G-GUTI-1, SUCI-1, or SUPI-1, AMF1 processes a registration request message for SUPI-2 and creates a context for SUPI-2. After linking the 5GMM context of SUPI-2 with the 5GMM context of SUPI-1 in the context creation, AMF1 associates the 5GMM context of SUPI-1 with the 5GMM context of SUPI-2, i.e., the 5GMM contexts of SUPI-1 and SUPI-2 are linked to each other. In other words, the 5GMM context of SUPI-1 contains a pointer to the 5GMM context of SUPI-2, and vice versa. The 5GMM context of SUPI-1 is used to fetch the 5GMM context of SUPI-2, and vice versa. AMF1 may also associate the 5GMM context of SUCI-1 with the 5GMM context of SUPI-2. If one ME is shared by multiple USIMs, the AMF1 may maintain associations between multiple 5GMM contexts.

[0057] AMF1 associates a unique integer (n2) with SUPI-2 and stores it in the UE context of SUPI-2.

[0058] 12. AMF1 completes the registration procedure for SUPI-2.

[0059] In one example, AMF1 assigns a single temporary identity to both SUPI-1 and SUPI-2, where a unique integer (e.g., n1, n2) is used to distinguish between SUPI-1 or SUPI-2.

[0060] This procedure also applies if the UE has an established NAS signaling connection for SUPI-1 and the UE initiates the registration procedure for SUPI-2. In this scenario, neither steps 3 nor 4 are performed, but in step 5 the UE sends an RRC message containing a registration request message, 5G-GUTI-1 or SUPI-1.

[0061] In one example, 5G-GUTI-1 or SUPI-1 is sent within the registration request message of steps 5 and 7.

[0062] Third aspect (Solution 3 for solving problem statements 1 and 2): The procedure according to the third aspect involves paging coordination for a SUPI using the establishment of a NAS signaling connection for another SUPI. Figure 5 shows the detailed steps of the procedure. The detailed steps of Figure 5 are described below.

[0063] 1. The UE is registered with the AMF of the PLMN for SUPI-1 and SUPI-2 using either the first aspect or the second aspect.

[0064] 2. The UE establishes a NAS signaling connection for SUPI-1, i.e., is in 5GMM CONNECTED mode for SUPI-1 and 5GMM IDLE mode for SUPI-2.

[0065] 3. The AMF receives a message from the NF (Network Function) and sends signaling or data to the UE for SUPI-2. In one example, the message for sending signaling or data to the UE for SUPI-2 may be a Namf_Communication_N1N2MessageTransfer message or a Namf_MT_EnableUEReachability message. Next, the AMF checks whether the UE with USIM-1 (SUPI-1) is CM CONNECTED.

[0066] Either one of steps 4a, 4b, or 4c is performed.

[0067] 4a. The AMF sends a NAS message to inform the UE about pending Mobile Terminated signaling or date for SUPI-2. The NAS message includes a first IE containing SUPI-2 and a second IE containing the reason for notifying the UE (e.g., paging cause configured for MT data or MT signaling characteristics).

[0068] 4b. If the UE and the AMF associate unique integers n1 and n2 with SUPI-1 and SUPI-2, respectively, during the registration procedure according to the procedures of the first and second aspects, the network includes n2 and the paging cause in the NAS message. If the UE receives n2 in the NAS message, the UE associates the NAS message with SUPI-2 based on the received parameter n2.

[0069] 4c. In one example, the UE supports only two SUPIs, and the AMF sends only the paging cause in the NAS message. The UE associates the NAS message with the SUPI (e.g., SUPI-2) for which the UE is in idle state in the current scenario.

[0070] 5. When the UE receives the NAS message, the UE may suspend or release the NAS signaling connection of SUPI-1. In this step 5, the RRC connection may be released or maintained (including suspended).

[0071] Based on the paging cause and the services active for the UE with SUPI-1, the UE may not accept the requested service for SUPI-2. For example, when the UE is on an IMS Voice call with SUPI-1, the paging cause indicates an MT packet service for SUPI-2. In this case, a second NAS message is sent from the UE to the AMF, indicating that the indicated service is not accepted by the UE. When the AMF receives the second NAS message, the AMF may further inform the requesting NF that the downlink packet cannot be delivered to the UE because the UE is busy, so that the NF can take appropriate action.

[0072] 6. After the NAS signaling connection of USIM-1 is successfully suspended or released, the UE initiates a service request procedure for SUPI-2. If the UE's 5GMM state is 5GMM-IDLE Normal service for SUPI-2, the UE performs the procedure if an NAS message is received or a registration procedure is pending for SUPI-2. The service request procedure for SUPI-2 may be performed using the RRC connection maintained in step 5.

[0073] In one example, when the UE is in idle state for both SUPI-1 and SUPI-2, the UE performs PUT (Periodic Update Timers) for both SUPI-1 and SUPI-2, and the AMF performs MRT (Mobile Reachable Timers) for SUPI-1 and SUPI-2. If a NAS signaling connection is established for one SUPI, the UE and AMF stop PUT and MRT for both SUPI-1 and SUPI-2. Both the UE and AMF retain the 5GMM context for SUPI-2, which is in 5GMM IDLE state. If the UE state changes to idle state for both SUPI-1 and SUPI-2 at the UE and AMF, the UE and AMF start MRT and PUT for both SUPI-1 and SUPI-2.

[0074] In one example, when the UE is in idle state for both SUPI1 and SUPI2, the UE performs PUT (Periodic Update Timers) for both SUPI-1 and SUPI-2, and the AMF performs MRT (Mobile Reachable Timers) for SUPI-1 and SUPI-2. If the NAS signaling connection for SUPI-1 is established, the UE and the AMF continue to perform PUT and MRT for the second SUPI-2, which is in idle state. If the PUT for SUPI-2 expires, the UE performs a periodic update procedure using the NAS signaling connection for SUPI-1 by sending a NAS message indicating a periodic update for SUPI-2 (e.g., a registration request message with a registration type of periodic, or the NAS message is an existing NAS message or a new NAS message).

[0075] In one example, if the UE and AMF run a single PUT and MRT timer for both SUPI-1 and SUPI-2, when that periodic timer expires, the UE sends a single periodic registration request message to the AMF for both SUPI-1 and SUPI-2. When the AMF receives the registration request message, the AMF stops the MRT and updates both SUPI-1 and SUPI-2 to be registered with the AMF. When the MRT expires, the AMF marks the UE as unreachable for paging. The AMF may de-register both SUPI-1 and SUPI-2 after the MRT expires.

[0076] In one example, the NAS message may be a NOTIFICATION message or a DL NAS TRANSPORT message.

[0077] In one example, the second NAS message may be a NOTIFICATION RESPONSE message or a UL NAS TRANSPORT message.

[0078] Fourth aspect (Solution 4 for solving Problem Statements 1 and 2): The procedure according to the fourth aspect involves paging coordination in idle mode using the same temporary identity assigned to both SUPI-1 and SUPI-2. Figure 6 shows the detailed steps of the procedure. The detailed steps of Figure 6 are described below.

[0079] 1. The UE and the AMF perform a registration procedure according to the first or second aspect, and the network assigns the same temporary identity (e.g., 5G-GUTI) to both SUPI-1 and SUPI-2.

[0080] 2. The UE and AMF are in idle mode for both SUPI-1 and SUPI-2.

[0081] 3. The AMF receives a message from the NF (Network Function) and sends signaling or data to the UE for SUPI-2. In one example, the message for sending signaling or data to the UE for SUPI-2 may be a Namf_Communication_N1N2MessageTransfer message or a Namf_MT_EnableUEReachability message. Next, the AMF checks whether the UE with USIM-1 (SUPI-1) is CM CONNECTED.

[0082] 4. The AMF initiates the paging procedure to SUPI-2 by sending an NGAP paging message containing a paging cause, a temporary identity (such as 5G-GUTI), and n2. The NG-RAN performs the paging including the paging cause, the temporary identity, and n2.

[0083] In Figure 6, steps 4a, 4b, and 4c are shown as one line each from the AMF to the UE for simplicity, but each line may be divided into two parts: one over the N2 interface between the AMF and the NG-RAN, and the other over the air interface between the NG-RAN and the UE.

[0084] 5. When the UE receives the paging message, the UE determines that the paging is for the UE based on the temporary identity and for SUPI-1 based on n2.

[0085] 6. The UE initiates a service request using 5G-GUTI with n2 if the UE is idle and successfully camped on a cell or a registration procedure if the UE requests a registration procedure.

[0086] Fifth aspect (Solution 5 for solving problem statements 1 and 2): The procedure according to the fifth aspect includes a UE initiated procedure for a SUPI using a NAS signaling connection establishment of another SUPI, the detailed steps of which are shown in Figure 7, and the detailed steps of Figure 7 are described below.

[0087] 1. The UE is registered with the AMF of the PLMN for SUPI-1 and SUPI-2 using either the first aspect or the second aspect.

[0088] 2. The UE establishes a NAS signaling connection for SUPI-1, i.e., is in 5GMM CONNECTED mode for SUPI-1 and 5GMM IDLE mode for SUPI-2.

[0089] 3. The UE starts the UE initiated procedure with SUPI-2.

[0090] 4. The UE transmits a first (1st) NAS message for SUPI-2. The first NAS message includes SUPI-2.

[0091] In one example, the first NAS message for SUPI-2 is NAS-secured (encrypted or integrity protected) in the NAS security context of SUPI-2.

[0092] In one example, the first NAS message for SUPI-2 is NAS secured (encrypted or integrity guaranteed) in the NAS security context of SUPI-1.

[0093] In one example, the UE uses the AS layer security context of SUPI-1 at the AS layer.

[0094] 5. A UE initiated procedure is performed.

[0095] 6. The AMF sends a second (2nd) NAS message to the UE. The second NAS message includes SUPI-2.

[0096] In one example, the first NAS message may be a Registration request message, a Registration Complete message, a Deregistration request message, or a UL NAS TRANSPORT.

[0097] In one example, the second NAS message may be a Reregistration response message, a Deregistration response message, or a DL NAS TRANSPORT message.

[0098] In one example, the UE-initiated procedure may be a Registration procedure, a UE-initiated de-registration procedure, a MO SMS over NAS procedure, or a UE-initiated NAS transport procedure.

[0099] In one example, the second NAS message for SUPI-2 is NAS secured (encrypted or integrity guaranteed) in the NAS security context of SUPI-2.

[0100] In one example, the second NAS message for SUPI-2 is NAS secured (encrypted or integrity guaranteed) in the NAS security context of SUPI-1.

[0101] In one example, the UE uses the AS layer security context of SUPI-1 at the AS layer.

[0102] In one example, the first NAS message or the second NAS message is sent standalone, i.e., without being encapsulated in any NAS message of SUPI-1.

[0103] In one example, the first NAS message is encapsulated in a UL NAS TRANSPORT message.

[0104] In one example, the second NAS message is encapsulated in a DL NAS TRANSPORT message of SUPI-1.

[0105] Other Aspects User Equipment (or "UE," "mobile station," "mobile device," or "wireless device") in this disclosure is an entity that connects to a network via a wireless interface.

[0106] As explained in the following paragraphs, it should be noted that the UE in this specification is not limited to a dedicated communication device, but is applicable to any device having communication capabilities as a UE as described in this specification.

[0107] The terms “User Equipment” or “UE” (as the term is used in 3GPP®), “mobile station,” “mobile device,” and “wireless device” are generally intended to be synonymous with each other and include standalone mobile stations such as terminals, mobile phones, smartphones, tablets, cellular IoT devices, IoT devices, and machinery.

[0108] It is understood that the terms "UE" and "wireless device" also include devices that remain stationary for extended periods of time.

[0109] The UE may be, for example, an item of production or manufacturing equipment and / or an item of energy-related machinery (such as equipment or machinery such as: boilers, engines, turbines, solar panels, wind turbines, hydroelectric generators, thermal generators, nuclear generators, batteries, nuclear systems and / or related equipment, heavy electrical machinery, pumps including vacuum pumps, compressors, fans, blowers, oil hydraulic equipment, pneumatic equipment, metalworking machinery, manipulators, robots and / or their application systems, tools, moulds or dies, rolls, conveying equipment, lifting equipment, material handling equipment, textile equipment, sewing equipment, printing and / or related machinery, paper converting machinery, chemical machinery, mining and / or construction machinery and / or related equipment, machinery and / or implements for agriculture, forestry and / or fishing, safety and / or environmental protection equipment, tractors, precision bearings, chains, gears, power transmission equipment, lubrication equipment, valves, plumbing fixtures, and / or application systems of the aforementioned equipment or machinery, etc.).

[0110] A UE may be, for example, an item of transportation equipment (e.g., transportation equipment such as: vehicles, automobiles, motorcycles, bicycles, trains, buses, carts, rickshaws, ships and other watercraft, aircraft, rockets, satellites, drones, balloons, etc.).

[0111] The UE may be, for example, an item of information and communication equipment (eg, information and communication equipment such as: electronic computers and related equipment, communications and related equipment, electronic components, etc.).

[0112] The UE may be, for example, a refrigerator, a refrigerator application product, an item of trade and / or service industry equipment, a vending machine, an automated service machine, an office machine or equipment, a household appliance or electronic device (e.g., a home appliance such as: audio equipment, video equipment, loudspeakers, radios, televisions, microwave ovens, rice cookers, coffee machines, dishwashers, washing machines, dryers, electronic fans or related equipment, vacuum cleaners, etc.).

[0113] The UE may be, for example, an electrical application system or device (eg, an electrical application system or device such as an x-ray system, a particle accelerator, a radioisotope device, a sonic device, an electromagnetic application device, a motorized application device, etc.).

[0114] The UE may be, for example, an electronic lamp, lighting fixture, measuring instrument, analyzer, tester, or surveying or sensing equipment (e.g., surveying or sensing equipment such as a smoke detector, human alarm sensor, motion sensor, wireless tag, etc.), a watch or clock, laboratory equipment, optical equipment, medical equipment and / or systems, a weapon, an item of blade, a hand tool, etc.

[0115] A UE may be, for example, a wirelessly implemented personal digital assistant or related equipment (such as a wireless card or module designed for attachment or insertion into another electronic device (e.g., a personal computer, an electrical measuring instrument)).

[0116] The UE may be a device or part of a system that uses various wired and / or wireless communication technologies to provide the applications, services, and solutions described below in relation to the "Internet of things" (IoT).

[0117] Internet of Thing devices (or "things") may be equipped with appropriate electronics, software, sensors, network connectivity, etc., allowing these devices to collect and exchange data with each other and other communicating devices. IoT devices may consist of automated machines that follow software instructions stored in their internal memory. IoT devices may operate without requiring human supervision or interaction. IoT devices may remain stationary and / or inactive for long periods of time. IoT devices may be implemented as part of (typically) fixed equipment. IoT devices may be integrated into non-fixed equipment (such as vehicles) or attached to the animals or people they monitor / track.

[0118] It is understood that IoT technology can be implemented in any communication device that can connect to a communication network to send and receive data, regardless of whether such communication device is controlled by human input or by software instructions stored in memory.

[0119] An IoT device may also be referred to as a Machine-Type Communication (MTC) device, a Machine-to-Machine (M2M) communication device, or a Narrow Band-IoT UE (NB-IoT UE). It is understood that a UE may support one or more IoT or MTC applications. Some examples of MTC applications are shown in Table 1 (Source: 3GPP TS 22.368 V14.0.1 (2017-08), Annex B, the contents of which are incorporated herein by reference). This list is not exhaustive and is intended to illustrate some examples of machine-type communication applications.

[0120] [Table 1]

[0121] The applications, services, and solutions may be MVNO (Mobile Virtual Network Operator) services, emergency wireless communication systems, PBX (Private Branch eXchange) systems, PHS / digital cordless telecommunications systems, POS (Point of sale) systems, advertising call systems, MBMS (Multimedia Broadcast and Multicast Service), V2X (Vehicle to Everything) systems, train radio systems, location-related services, disaster / emergency wireless communication services, community services, video streaming services, femtocell application services, VoLTE (Voice over LTE) services, charging services, radio on-demand services, roaming services, activity monitoring services, carrier / communication network selection services, function restriction services, PoC (Proof of Concept) services, personal information management services, ad hoc networks / DTN (Delay Tolerant Networking) services, and the like.

[0122] Furthermore, the above UE categories are merely examples of applications of the technical ideas and exemplary aspects described herein. Needless to say, these technical ideas and aspects are not limited to the above UEs and may be modified in various ways.

[0123] User Equipment (UE) In all the above aspects, the UE is configured with multiple UICCs, USIMs, or embedded USIMs (eUSIMs) as MEs. In addition to FIG. 1, a schematic block diagram of the UE is described below.

[0124] Figure 8 is a block diagram illustrating the main components of a UE 300. As shown, the UE 300 includes transceiver circuitry 304 operable to transmit signals to and receive signals from connected nodes via one or more antennas 305. Although not necessarily shown in Figure 8, the UE 300 of course has all the usual functionality of a traditional mobile device (such as a user interface 303), which may be provided by any one or any combination of hardware, software, and firmware, as appropriate. Software may be pre-installed in memory 302 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD).

[0125] The controller 301 controls the operation of the UE 300 according to software stored in the memory 302. For example, the controller 301 may be realized by a CPU (Central Processing Unit). The software includes, among other things, an operating system 308 and a communication control module 306 having at least a transceiver control module 307. The communication control module 306 (using its transceiver control sub-module) is capable of processing (generating / sending / receiving) signaling and uplink / downlink data packets between the UE 300 and other nodes, such as base stations / (R)AN nodes, MMEs, AMFs (and other core network nodes), etc. Such signaling may include, for example, appropriately formatted signaling messages related to connection establishment and maintenance (e.g., RRC messages), periodic location update-related messages (e.g., tracking area updates, paging area updates, location area updates), and other NAS messages.

[0126] (R)AN Node FIG. 9 is a block diagram illustrating the main components of an exemplary (R)AN node 400, e.g., a base station ("eNB" in LTE, "gNB" in 5G). As shown, (R)AN node 400 includes transceiver circuitry 404 operable to transmit and receive signals to and from connected UEs via one or more antennas 405, and to transmit and receive signals to and from other network nodes (either directly or indirectly) via network interface 403. Controller 401 controls operation of the (R)AN node according to software stored in memory 402. For example, controller 401 may be implemented by a central processing unit (CPU). The software may be pre-installed in memory 402 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The software includes, among other things, an operating system 408 and a communications control module 406 having at least a transceiver control module 407.

[0127] The communications control module 406 (using its transceiver control sub-module) is capable of processing (generating / sending / receiving) signaling between the (R)AN node 400 and other nodes (such as UEs, MMEs, AMFs (direct or indirect), etc.). The signaling may include, for example, appropriately formatted signaling messages related to radio connection and location procedures (for a particular UE), in particular connection establishment and maintenance (e.g., RRC connection establishment and other RRC messages), periodic location update related messages (e.g., tracking area updates, paging area updates, location area updates), S1 AP messages and NG AP messages (i.e., messages over the N2 reference point), etc. Such signaling may also include, for example, broadcast information (e.g., master information and system information) in the transmission case.

[0128] When implemented, the controller 401 is also configured (by software or hardware) to handle related tasks such as UE mobility estimation and / or moving trajectory estimation.

[0129] AMF FIG. 10 is a block diagram illustrating the main components of the AMF 500. The AMF 500 is included in the 5GC. As shown, the AMF 500 includes a transceiver circuit 504 operable to transmit signals to and receive signals from other nodes (including UEs) via a network interface 503. A controller 501 controls the operation of the AMF 500 according to software stored in a memory 502. For example, the controller 501 may be implemented by a central processing unit (CPU). The software may be pre-installed in the memory 502 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The software includes, among other things, an operating system 507 and a communication control module 505 having at least a transceiver control module 506.

[0130] The communications control module 505 (using its transceiver control sub-module) is capable of processing (generating / sending / receiving) signals between the AMF 500 and other nodes (e.g., UEs, base stations / (R)AN nodes (e.g., "gNBs" or "eNBs") (directly or indirectly), etc.). Such signaling may include, for example, appropriately formatted signaling messages related to the procedures described herein, such as NG AP messages (i.e., messages over the N2 reference point) for conveying NAS messages to and from the UE.

[0131] As will be appreciated by those skilled in the art, the present disclosure may be embodied as a method and a system, and thus may take the form of an entirely hardware embodiment, a software embodiment, or an embodiment combining software and hardware embodiments.

[0132] It will be understood that each block of the block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to generate an apparatus, and such instructions, when executed by the processor of the computer or other programmable data processing apparatus, can generate means for implementing the function / acts identified in the block or blocks of the flowcharts and / or block diagrams. A general-purpose processor may be a microprocessor; alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a computing device, e.g., multiple microprocessors, one or more microprocessors, or any other such combination of configurations.

[0133] The methods or algorithms described in connection with the examples disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. The storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integrated into the processor. The processor and the storage medium may reside in an ASIC.

[0134] The above description of the disclosed examples is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these examples will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other examples without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the examples set forth herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0135] This application is based on and claims the benefit of priority to Indian Patent Application No. 201841049571 filed on December 28, 2018, the disclosure of which is incorporated herein by reference in its entirety. [Explanation of symbols]

[0136] 100 UE 101 Antenna 102 ME 103 Transmitter 104 Receiver 105 USIM 300 UE 301 Controller 302 memory 303 User Interface 304 Transceiver Circuit 305 Antenna 306 Communication Control Module 307 Transceiver Control Module 308 Operating Systems 400 (R)AN nodes 401 Controller 402 memory 403 Network Interface 404 Transceiver Circuit 405 Antenna 406 Communication Control Module 407 Transceiver Control Module 408 Operating System 500 AMF 501 Controller 502 memory 503 Network Interface 504 Transceiver Circuit 505 Communication Control Module 506 Transceiver Control Module 507 Operating Systems

Claims

1. A method executed by a mobility management node, comprising: Perform a registration process corresponding to a first Universal Subscriber Identity Module (USIM) and a second Universal Subscriber Identity Module (USIM) of the user equipment; sending paging cause information for the second USIM to the user equipment in an RRC state corresponding to the first USIM that is RRC_CONNECTED and an RRC state corresponding to the second USIM that is RRC_IDLE, the paging cause information indicating a service corresponding to paging; receiving a rejection message from the user equipment, the rejection indicating that the user equipment does not accept the paging.

2. A mobility management node, Perform a registration process corresponding to a first Universal Subscriber Identity Module (USIM) and a second Universal Subscriber Identity Module (USIM) of the user equipment; means for transmitting paging cause information for the second USIM to the user equipment in an RRC state corresponding to the first USIM that is RRC_CONNECTED and an RRC state corresponding to the second USIM that is RRC_IDLE; the paging cause information indicating a service corresponding to paging; means for receiving a rejection message from the user equipment, the rejection indicating that the user equipment does not accept the paging; Mobile management node.

3. A method for a user equipment, comprising: receiving paging cause information for a first Universal Subscriber Identity Module (USIM) from a mobility management node that has performed registration processing corresponding to the first USIM and the second USIM, when an RRC state corresponding to a first USIM in the user equipment is RRC_CONNECTED and an RRC state corresponding to the second USIM is RRC_IDLE, the paging cause information indicating a service corresponding to paging; sending a rejection message to the mobility management node, the rejection indicating that the user equipment does not accept the paging.

4. A user device, comprising: means for receiving paging cause information for a second Universal Subscriber Identity Module (USIM) from a mobility management node that has executed registration processes corresponding to the first USIM and the second USIM when an RRC state corresponding to the first USIM in the user equipment is RRC_CONNECTED and an RRC state corresponding to the second USIM is RRC_IDLE; the paging cause information indicates a service corresponding to paging; means for transmitting a rejection message to the mobility management node, the rejection indicating that the user equipment does not accept the paging; User equipment.

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