Connection pause for multiple sims

Abstract

The invention relates to connection pause for multiple SIMs. Apparatuses, methods, and systems for connection pause for SIM are disclosed. An apparatus 600 includes a processor 605, a first SIM 645 registered with a first mobile communication network, a second SIM 650 registered with a second mobile communication network, and a transceiver 625 in communication with the first and second mobile communication networks. The processor 605 receives 815 a communication trigger associated with the first SIM 645, the communication trigger indicating a service type, and determines 820 whether a short connection pause is applied to the second SIM 650 or a long connection pause is applied to the second SIM 650, the determination based on the service type. The processor 605 additionally applies 825 a selected one of the short connection pause and the long connection pause to the second SIM 650.

Description

[0001] This application is a divisional application of application No. 201980100075.8, filed in the PCT on September 6, 2019, with the international application number PCT / EP2019 / 073833, entered into the Chinese national phase on March 4, 2022, and having the title “Connection Suspension for Multiple SIMs”. TECHNICAL FIELD

[0002] The subject matter disclosed herein relates generally to wireless communication, and more particularly relates to suspending connection of one SIM during multiple SIM operation. BACKGROUND

[0003] The following abbreviations and acronyms, among others, are herewith defined, at least some of which are mentioned hereinbelow.

[0004] Third Generation Partnership Project (“3GPP”), Fifth Generation Core (“5GC”), Fifth Generation QoS Indicator (“5QI”), Access and Mobility Management Function (“AMF”), Access Network Performance (“ANP”), Access Point Name (“APN”), Access Stratum (“AS”), Access Traffic Steering, Switching and Splitting (“ATSSS”), Allocation / Retention Priority (“ARP”), Application Program Interface (“API”), Common Search Space (“CSS”), Data Network Name (“DNN”), Data Radio Bearer (“DRB”), Differentiated Services Code Point (“DSCP”), Downlink (“DL”), Enhanced Mobile Broadband (“eMBB”), Encapsulating Security Payload (“ESP”), Evolved Node B (“eNB”), Evolved Packet Core (“EPC”), Evolved UMTS Terrestrial Radio Access Network (“E-UTRAN”), European Telecommunications Standards Institute (“ETSI”), Echo Acknowledgement Indicator (“EAI”), Request Indicator (“ERI”), ERI-d refers to an ERI associated with a dummy payload, ERI-v refers to an ERI associated with a valid payload), Globally Unique Temporary UE Identity (“GUTI”), General Packet Radio Service (“GPRS”), GPRS Tunnelling Protocol (“GTP”, GTP-C refers to control signalling tunnel, while GTP-U refers to user data tunnel), Home Subscriber Server (“HSS”), Internet of Things (“IoT”), IP Multimedia Subsystem (“IMS”),Also known as the "IP Multimedia Core Network Subsystem"), Internet Protocol ("IP"), Key Performance Indicators ("KPIs"), Licensed Auxiliary Access ("LAA"), Load-Based Equipment ("LBE"), Listen-After-Speak ("LBT"), Long Term Evolution ("LTE"), LTE Advanced ("LTE-A"), Media Access Control ("MAC"), Multiple Access ("MA"), Modulation and Coding Scheme ("MCS"), Machine Type Communication ("MTC"), Massive MTC ("mMTC"), Mobile Network Operator ("MNO"), Mobility Management ("MM"), Mobility Management Entity ("MME") Multiple-Input Multiple-Output (“MIMO”), Multi-Path TCP (“MPTCP”), Multi-User Shared Access (“MUSA”), Non-Access Stratum (“NAS”), Narrowband (“NB”), Network Function (“NF”), Network Access Identifier (“NAI”), Next-Generation (e.g., 5G) Node B (“gNB”), Next-Generation Radio Access Network (“NG-RAN”), New Radio (“NR”), Policy Control and Charging (“PCC”), Policy Control Function (“PCF”), Policy Control and Charging Rule Function (“PCRF”), Packet Data Network (“PDN”), Packet Data Unit (“PDU”) PDN Gateway (“PGW”), Public Land Mobile Network (“PLMN”), Quality of Service (“QoS”), QoS Category Identifier (“QCI”), Registration Area (“RA”), Radio Access Network (“RAN”), Radio Access Technology (“RAT”), Radio Resource Control (“RRC”), Receive (“RX”), Single Network Slice Selection Auxiliary Information (“S-NSSAI”), Scheduling Request (“SR”), Secure User Plane Location (“SUPL”), Serving Gateway (“SGW”), Session Management Function (“SMF”), Flow Control Transmission Protocol (“SCTP”), System Information Block (“SIB”), Tracking Area (“TA”), Transmission Control Protocol (“TCP”), Transport (“TX”), Unified Data Management (“UDM”), User Entity / Equipment (Mobile Terminal) (“UE”), Uplink (“UL”), User Plane (“UP”), Universal Mobile Telecommunications System (“UMTS”), Ultra Reliable and Low Latency Communication (“URLLC”), User Datagram Protocol (“UDP”), UE Routing Policy (“URSP”), Unstructured Supplementary Service Data (USSD), Wireless Local Area Network (“WLAN”), and Global Microwave Access Interoperability (“WiMAX”).

[0005] Some UEs support multiple subscriber identity modules, such as USIM-1 and USIM-2, for the same MNO or different MNOs. The following operating modes for multi / dual USIM devices are defined in the GSMA TS.37 document: passive, dual SIM / dual standby, and dual SIM / dual active.

[0006] In passive mode, the UE contains two SIMs, but only one can be used at any given time. A passive dual-SIM device is effectively a single-SIM device because the SIMs share a single transceiver, and the UE can only logically connect to a single network at any given time. In other words, only a single USIM module / profile is registered at any given time.

[0007] In Dual SIM Dual Standby (DSDS) mode, both SIMs can be used for idle mode network connectivity, but the second connection is disabled when the radio connection is active. Similar to the passive case, the SIMs in a DSDS device share a single transceiver. Through time-division multiplexing, both radio connections are maintained in idle mode. When one SIM has a call on the network, it is no longer possible to maintain a radio connection with the second SIM's network, therefore that connection is unavailable during the call. Registration with the second network is maintained. The UE maintains idle operation on one subscription while maintaining a best-effort data connection on the other.

[0008] Dual SIM Dual Activation (DSDA): Both SIMs can be used in both idle and connected modes. Each SIM has a dedicated transceiver, meaning that at the modem level, idle or connected mode operation is independent of each other. Note that in some DSDA devices, the second transceiver may only be 2G. Summary of the Invention

[0009] Methods for suspending the connection of one SIM during multi-SIM operation are disclosed. Apparatus and systems also perform the functions of these methods.

[0010] A method for a UE to suspend a SIM connection during multi-SIM operation includes registering a first SIM with a first mobile communication network and registering a second SIM with a second mobile communication network. The first method includes receiving a communication trigger associated with the first SIM, the communication trigger indicating a service type, and determining whether to apply a short connection suspension or a long connection suspension to the second SIM. Here, the determination is based on the service type. The first method includes applying one of short connection suspension and long connection suspension to the second SIM.

[0011] A method for suspending a network function (e.g., eNB or gNB) of a SIM connection during multi-SIM operation includes receiving an RRC layer suspension request from the UE. The method includes maintaining the UE's UE AS context. The method includes disabling downlink transmissions to the UE in response to the RRC layer suspension request. The method includes enabling downlink transmissions to the UE in response to receiving an RRC layer connection restoration request from the UE. Attached Figure Description

[0012] A more detailed description of the embodiments briefly described above will be presented with reference to the specific embodiments shown in the accompanying drawings. It should be understood that these drawings depict only a few embodiments and are therefore not intended to limit the scope. These embodiments will be described and explained with additional specificity and detail using the drawings, in which:

[0013] Figure 1 This is a schematic block diagram illustrating one embodiment of a wireless communication system for suspending the connection of one SIM during multi-SIM operation;

[0014] Figure 2A This is a block diagram illustrating one embodiment of a single USIM UE and multiple USIM UEs;

[0015] Figure 2B This is a block diagram illustrating one embodiment of the protocol stack for multiple USIM UEs;

[0016] Figure 3 This is a flowchart illustrating one embodiment of the process of suspending the connection of one SIM during multi-SIM operation;

[0017] Figure 4A This is a signal flow diagram illustrating one embodiment of suspending the connection of a SIM during multi-SIM operation;

[0018] Figure 4B yes Figure 4A The continuation of the process depicted in the text;

[0019] Figure 5A This is a signal flow diagram illustrating one embodiment of restoring a SIM connection during multi-SIM operation;

[0020] Figure 5B yes Figure 5A The continuation of the process depicted in the text;

[0021] Figure 6 This is a block diagram illustrating one embodiment of a UE device apparatus for suspending the connection of one SIM during multi-SIM operation;

[0022] Figure 7This is a block diagram illustrating one embodiment of a network device apparatus for suspending the connection of one SIM during multi-SIM operation;

[0023] Figure 8 This is a flowchart illustrating an embodiment of a first method for suspending the connection of one SIM during multi-SIM operation; and

[0024] Figure 9 This is a flowchart illustrating an embodiment of a second method for suspending the connection of one SIM during multi-SIM operation. Detailed Implementation

[0025] As those skilled in the art will understand, aspects of the embodiments can be embodied as systems, apparatus, methods, or program products. Therefore, embodiments can take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects.

[0026] For example, the disclosed embodiments can be embodied as hardware circuitry, including custom-designed very large-scale integration (“VLSI”) circuitry or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. The disclosed embodiments can also be embodied in programmable hardware devices, such as field-programmable gate arrays, programmable array logic, programmable logic devices, etc. As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code, which may, for example, be organized as objects, processes, or functions.

[0027] Furthermore, embodiments may take the form of a program product embodied in one or more computer-readable storage devices storing machine-readable code, computer-readable code, and / or program code—hereinafter referred to as code. The storage device may be tangible, non-transitory, and / or non-transitive. The storage device may not specifically implement signals. In certain embodiments, the storage device uses only signals to access the code.

[0028] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable storage medium. A computer-readable storage medium may be a storage device for storing code. A storage device may be, for example, but not limited to, electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof.

[0029] More specific examples of storage devices (a non-exhaustive list) will include the following: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (“RAM”), read-only memory (“ROM”), erasable programmable read-only memory (“EPROM” or flash memory), portable optical disc read-only memory (“CD-ROM”), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium can be any tangible medium capable of containing or storing programs used by or in conjunction with an instruction execution system, apparatus, or device.

[0030] Throughout this specification, references to "an embodiment," "embodiment," or similar language mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Therefore, unless expressly stated otherwise, the phrases "in an embodiment," "in one embodiment," and similar language throughout this specification may, but do not necessarily, refer to the same embodiment, but rather mean "one or more, but not all, embodiments." Unless expressly stated otherwise, the terms "comprising," "including," "having," and variations thereof mean "including, but not limited to,". Unless expressly stated otherwise, the list of enumerated items does not imply that any or all items are mutually exclusive. Unless expressly stated otherwise, the terms "an," "a," and "the" also mean "one or more".

[0031] As used herein, a list with the conjunction “and / or” includes any single item in the list or a combination of items in the list. For example, a list of A, B, and / or C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B, and C. As used herein, a list using the term “one or more” includes any single item in the list or a combination of items in the list. For example, one or more of A, B, and C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B, and C. For example, “one of A, B, and C” includes only A, only B, or only C and excludes combinations of A, B, and C. As used herein, “a member selected from the group consisting of A, B, and C” includes one and only one of A, B, or C and excludes combinations of A, B, and C. As used in this article, “members selected from the group consisting of A, B and C and their combinations” includes only A, only B, only C, combinations of A and B, combinations of B and C, combinations of A and C, or combinations of A, B and C.

[0032] Furthermore, the features, structures, or characteristics of the described embodiments can be combined in any suitable manner. Numerous specific details, such as examples of programming, software modules, user selection, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., are provided in the following description to provide a thorough understanding of the embodiments. However, those skilled in the art will recognize that embodiments can be implemented without one or more specific details, or using other methods, components, materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments.

[0033] The following description of aspects of the embodiments is based on schematic flowcharts and / or schematic block diagrams of methods, apparatus, systems, and program products according to the embodiments. It should be understood that each block of the schematic flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. This code can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to generate a machine such that instructions executable via the processor of the computer or other programmable data processing apparatus create means for implementing the functions / actions specified in the schematic flowcharts and / or schematic block diagrams.

[0034] The code can also be stored in a storage device that can instruct a computer, other programmable data processing apparatus or other device to operate in a particular manner, such that the instructions stored in the storage device produce an article of art including instructions that implement the functions / actions specified in the schematic flowchart and / or schematic block diagram.

[0035] The code may also be loaded onto a computer, other programmable data processing apparatus or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device, thereby producing a computer-implemented process, such that the code executing on the computer or other programmable apparatus provides a process for implementing the functions / actions specified in the schematic flowchart and / or schematic block diagram.

[0036] The schematic flowcharts and / or schematic block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, systems, methods, and program products according to various embodiments. In this regard, each block in the schematic flowcharts and / or schematic block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions for implementing a specified logical function.

[0037] It should also be noted that in some alternative implementations, the functions mentioned in the boxes may not occur in the order shown in the figures. For example, depending on the functions involved, two boxes shown consecutively may actually be executed substantially simultaneously, or these boxes may sometimes be executed in reverse order. Other steps and methods can be envisioned that are functionally, logically, or effectively equivalent to one or more boxes or portions thereof in the figures shown.

[0038] The description of each element in the figures may refer to elements in the preceding figures. Throughout all the figures, the same numbers denote the same elements, including alternative embodiments of the same elements.

[0039] Methods, apparatus, and systems for suspending a SIM connection during multi-SIM operation are disclosed. In various embodiments, this disclosure introduces enhancements to the DSDS operation mode of a multi-SIM UE, wherein the UE can dynamically determine which connection to use, e.g., the connection to USIM-A or the connection to USIM-B, regardless of whether any existing connection to any USIM already exists. Note that "existing connection" refers to, for example, an existing NAS connection where the UE is in a CM connection state to a USIM.

[0040] This document discloses mechanisms that allow suspending (e.g., interrupting) and resuming ongoing connections in a network associated with USIM-A, enabling a UE to temporarily leave to reach a network associated with USIM-B and then return to the network associated with USIM-A in a network-controlled manner. Various embodiments describe optimizations for efficiently suspending a connection to a USIM (e.g., USIM-A) by reducing control plane signaling used for suspending and resuming. Various embodiments describe network behavior when an ongoing connection in a network associated with USIM-A is suspended, such as whether the PLMN-A resolving USIM-A (e.g., SMF / UPF) should buffer or store DL packets, how GBR QoS flows are handled, what procedures the UE uses to resume the suspended connection to USIM-A, and what information is exchanged between the UE and the network during connection resumption.

[0041] Figure 1A wireless communication system 100 for suspending the connection of one SIM during multi-SIM operation, according to an embodiment of this disclosure, is described. In one embodiment, the wireless communication system 100 includes at least one remote unit 105, a 5G-RAN 115, and a mobile core network 140. The 5G-RAN 115 and the mobile core network form a mobile communication network. The 5G-RAN 115 may consist of a 3GPP access network 120 including at least one cellular base station unit 121 and / or a non-3GPP access network 130 including at least one access point 131. The remote unit communicates with the 3GPP access network 120 using a 3GPP communication link 123 and with the non-3GPP access network 130 using a non-3GPP communication link 133. Although in Figure 1 The document describes a specific number of remote units 105, 3GPP access network 120, cellular base station unit 121, 3GPP communication link 123, non-3GPP access network 130, access point 131, non-3GPP communication link 133, and mobile core network 140. However, those skilled in the art will recognize that any number of remote units 105, 3GPP access network 120, cellular base station unit 121, 3GPP communication link 123, non-3GPP access network 130, access point 131, non-3GPP communication link, and mobile core network 140 may be included in the wireless communication system 100.

[0042] In one implementation, the wireless communication system 100 conforms to the 5G system specified in the 3GPP specification. However, more generally, the wireless communication system 100 may implement other open or proprietary communication networks, such as LTE / EPC (referred to as 4G) or WiMAX, and other networks. This disclosure is not intended to limit it to any particular wireless communication system architecture or protocol implementation.

[0043] In one embodiment, remote unit 105 may include computing devices such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smartphones, smart TVs (e.g., internet-connected TVs), smart appliances (e.g., internet-connected appliances), set-top boxes, game consoles, security systems (including security cameras), in-vehicle computers, network devices (e.g., routers, switches, modems), etc. In some embodiments, remote unit 105 may include wearable devices such as smartwatches, fitness bands, optical head-mounted displays, etc. Furthermore, remote unit 105 may be referred to as a UE, subscriber unit, mobile device, mobile station, user, terminal, mobile terminal, fixed terminal, subscriber station, user terminal, wireless transmit / receive unit (“WTRU”), device, or other terms used in the art.

[0044] Remote unit 105 can communicate directly with one or more cellular base station units 121 in 3GPP access network 120 via uplink (“UL”) and downlink (“Downlink”) communication signals. Furthermore, UL and DL communication signals can be carried on 3GPP communication link 123. Similarly, remote unit 105 can communicate with one or more access points 131 in non-3GPP access network 130 via UL and DL communication signals carried on non-3GPP communication link 133. Here, access networks 120 and 130 are intermediate networks providing remote unit 105 with access to mobile core network 140.

[0045] In some embodiments, remote unit 105 communicates with application server 151 (or other communication peers) via a network connection to mobile core network 140. For example, an application in remote unit 105 (e.g., a web browser, media client, telephony / VoIP application) can trigger remote unit 105 to establish a PDU session (or other data connection) with mobile core network 140 using 5G-RAN 115 (e.g., 3GPP access network 120 and / or non-3GPP access network 130). Mobile core network 140 then uses the PDU session to relay traffic between remote unit 105 and data network 150 (e.g., application server 151). Note that remote unit 105 may establish one or more PDU sessions (or other data connections) with mobile core network 140. Thus, remote unit 105 may have at least one PDU session for communicating with data network 150. Remote unit 105 may establish additional PDU sessions for communicating with other data networks and / or other communication peers.

[0046] Cellular base station unit 121 may be distributed over a geographical area. In some embodiments, cellular base station unit 121 may also be referred to as an access terminal, base station, base station, Node B, eNB, gNB, home Node B, relay node, device, or any other term used in the art. Cellular base station unit 121 is typically part of a radio access network (“RAN”), such as 3GPP access network 120, which may include one or more controllers communicatively coupled to one or more corresponding cellular base station units 121. These and other elements of the radio access network are not shown but are generally well known to those skilled in the art. Cellular base station unit 121 is connected to mobile core network 140 via 3GPP access network 120.

[0047] Cellular base station unit 121 can serve multiple remote units 105, such as cells or cell sectors, within its service area via 3GPP communication link 123. Cellular base station unit 121 can communicate directly with one or more remote units 105 via communication signals. Typically, cellular base station unit 121 transmits DL communication signals to serve remote units 105 in the time, frequency, and / or spatial domains. Furthermore, DL communication signals can be carried on 3GPP communication link 123. 3GPP communication link 123 can be any suitable carrier in the licensed or unlicensed radio spectrum. 3GPP communication link 123 facilitates communication between one or more remote units 105 and / or one or more cellular base station units 121.

[0048] Non-3GPP access networks 130 can be distributed across a geographical area. Each non-3GPP access network 130 can serve multiple remote units 105 with a service area. Typically, the service area of ​​a non-3GPP access network 130 is smaller than the service area of ​​a cellular base station unit 121. Access points 131 in non-3GPP access networks 130 can communicate directly with one or more remote units 105 by receiving UL communication signals and transmitting DL communication signals to serve remote units 105 in the time, frequency, and / or spatial domains. Both DL and UL communication signals are carried on non-3GPP communication links 133. 3GPP communication links 123 and non-3GPP communication links 133 can employ different frequencies and / or different communication protocols. In various embodiments, access points 131 can communicate using unlicensed radio spectrum. Mobile core network 140 can provide services to remote units 105 via non-3GPP access networks 130, as described in more detail herein.

[0049] In some embodiments, the non-3GPP access network 130 is connected to the mobile core network 140 via an interworking function 135. The interworking function 135 provides interworking between the remote unit 105 and the mobile core network 140. In some embodiments, the interworking function 135 is a non-3GPP interworking function (“N3IWF”), and in other embodiments, it is a trusted non-3GPP gateway function (“TNGF”). The N3IWF supports connecting “untrusted” non-3GPP access networks to the mobile core network (e.g., 5GC), while the TNGF supports connecting “trusted” non-3GPP access networks to the mobile core network. The interworking function 135 supports connections to the mobile core network 140 via “N2” and “N3” interfaces, and it relays “N1” signaling between the remote unit 105 and the AMF 143. As shown, both the 3GPP access network 120 and the interworking function 135 use the “N2” interface to communicate with the AMF 143. Interoperability 135 also uses the “N3” interface to communicate with UPF 141.

[0050] In some embodiments, the non-3GPP access network 130 may be controlled by the MNO of the mobile core network 140 and may have direct access to the mobile core network 140. This non-3GPP AN deployment is referred to as a “trusted non-3GPP access network.” When the non-3GPP access network 130 is operated by an MNO or a trusted partner, it is considered “trusted” and supports certain security features, such as strong air interface encryption. Conversely, a non-3GPP AN deployment that is not controlled by the operator (or trusted partner) of the mobile core network 140, cannot have direct access to the mobile core network 140, or does not support certain security features is referred to as an “untrusted” non-3GPP access network.

[0051] In one embodiment, the mobile core network 140 is a 5G core (“5GC”) or an evolved packet core (“EPC”), which may be coupled to a data network (e.g., data network 150, such as the Internet and private data networks, as well as other data networks). The remote unit 105 may have a subscription or other account to the mobile core network 140. Each mobile core network 140 belongs to a Public Land Mobile Network (“PLMN”). This disclosure is not intended to limit it to any particular wireless communication system architecture or protocol implementation.

[0052] Mobile core network 140 includes several network functions (“NFs”). As shown, mobile core network 140 includes multiple user plane functions (“UPFs”). Here, mobile core network 140 includes at least one UPF 141 serving 3GPP access network 120 and non-3GPP access network 130. Note that in some embodiments, the mobile core network may include one or more intermediate UPFs, such as a first intermediate UPF serving non-3GPP access network 130 and a second intermediate UPF serving 3GPP access network 120. In such an embodiment, UPF 141 will be the anchor UPF receiving UP services from both intermediate UPFs.

[0053] The mobile core network 140 also includes multiple control plane functions, including but not limited to Access and Mobility Management Functions (“AMF”) 143, Session Management Functions (“SMF”) 145, Policy Control Functions (“PCF”) 147, and Unified Data Management Functions (“UDM”) 149 serving the 3GPP access network 120 and the non-3GPP access network 130. In some embodiments, the mobile core network 140 may also include Authentication Server Functions (“AUSF”), Network Repository Functions (“NRF”) (used by various NFs to discover and communicate with each other via APIs), or other NFs defined for 5GC.

[0054] In various embodiments, the mobile core network 140 supports different types of mobile data connections and different types of network slices, wherein each mobile data connection utilizes a specific network slice. Each network slice includes a set of CP and UP network functions, wherein each network slice is optimized for a specific type of service or traffic category. For ease of illustration, in Figure 1 Different network slices are not shown, but their support is assumed. In one example, each network slice includes SMF and UPF, but various network slices share AMF 143, PCF 147, and UDM 149. In another example, each network slice includes AMF, SMF, and UPF.

[0055] although Figure 1 The description specifies a particular number and type of network functions, but those skilled in the art will recognize that the mobile core network 140 may include any number and type of network functions. Furthermore, in the case where the mobile core network 140 is an EPC, the described network functions can be replaced by appropriate EPC entities, such as MME, S-GW, P-GW, HSS, etc.

[0056] As depicted, remote unit 105 includes USIM-A 107 and USIM-B 109. For ease of illustration, USIM-A 107 and USIM-B 109 are depicted as associated with the same PLMN. Furthermore, USIM-A 107 and USIM-B 109 may be associated with the same or different network slices of the same PLMN. In this case, the PLMN can interpret remote unit 105 as two distinct remote units, each with its own network registration. In other embodiments, USIM-A 107 and USIM-B 109 may be associated with different PLMNs.

[0057] In some embodiments, remote unit 105 receives a communication trigger associated with the first SIM, which indicates a service type, and, if a NAS connection to the second SIM exists, determines whether to apply a short connection pause or a long connection pause to the second SIM, the determination being based on the service type. Remote unit 105 additionally selects between applying a short connection pause and a long connection pause to the second SIM.

[0058] In various embodiments, remote unit 105 is able to indicate to the network the following capabilities during the registration process (e.g., in a registration request message to AMF 143): 1) support for multiple USIM enhancements, and 2) whether multiple pause states (e.g., short pause and long pause) are supported. Based on the supported (or preferred) multiple USIM operation mode from the network (e.g., indicated in a registration acceptance message from AMF 143), remote unit 105 is internally configured to apply either a) no multiple USIM enhancements, b) support for a single (e.g., long pause state), or c) multiple pause states.

[0059] In some embodiments, remote unit 105 can determine whether to apply a short connection pause or a long connection pause (e.g., based on an indication of the service type in a paging message, or the MO service type, or other indication of upcoming communications). In the case of a short pause, remote unit 105 indicates to the source USIM RAN node (e.g., in an RRC message) that it is entering a short pause state.

[0060] In some embodiments, remote unit 105 maintains a timer for a short pause state. One or more mechanisms for configuring the timer can be applied: remote unit 105 may receive the timer configuration from the RAN node via a unicast message (e.g., a pause acceptance as part of an RRC signaling procedure for pause), or it may broadcast the timer configuration in the SIB, or it may negotiate the timer configuration during a NAS procedure (e.g., a registration procedure or UE configuration update). Note that the SIB may announce multi-USIM support (i.e., the feature is supported in the network), multi-USIM preferences, timer values, etc. In some embodiments, the timer value may influence remote unit 105's decision to enter a short pause state or a long pause state.

[0061] In some embodiments, if multiple USIM operation enhancements are preferred and configured in remote unit 105, remote unit 105 can change its advertised radio capabilities to the network. For example, remote unit 105 can change its radio interface capabilities to not support dual connectivity or certain carrier aggregation modes, so as to allow remote unit 105 to camp (e.g., be idle) in a different cell (e.g., a macro cell) of another USIM. If remote unit 105 registers with the network of the first USIM and dual radio capabilities are signaled to the network, and remote unit 105 registers with the network of the second USIM while multiple USIM operation enhancements are configured, remote unit 105 can initiate a signaling procedure to change (e.g., reduce) its radio capabilities in the network serving the first USIM.

[0062] In various embodiments, the 5G-RAN 115 implements the following references. Figure 3 andFigures 4A-4B The apparatus for a short pause state is described in detail. The short pause state can share features with the conventional RRC inactivity state, but the difference is that the remote unit 105 is marked as unreachable (i.e., RAN paging for downlink data or signaling is not performed, even if there is ongoing UL / DL data or signaling transmission (even if it is buffered in, for example, the PDCP layer) and / or no RAN notification area is allocated to the UE, and the RRC connection is also suspended).

[0063] In various embodiments, the AMF 143 (or MME) is capable of receiving multi-USIM capability information from the remote unit 105. The AMF 143 (or MME) indicates the supported (or preferred) operating modes, such as not supporting multi-USIM capabilities, supporting only long pause states, or supporting both short pause and long pause states.

[0064] In various embodiments, remote unit 105 may initiate application / service level signaling before executing the connection suspension process to notify application server 151 (or other communication peers) that the device is temporarily unavailable, thereby allowing service or communication exchange to be interrupted (or suspended or terminated) in a controlled manner at the application / service layer. When the suspended USIM is resumed / continued, remote unit 105 may notify application server 151 (or communication peers) of its availability for communication.

[0065] The following discusses additional details on pausing and resuming a SIM connection during multi-SIM operation.

[0066] Figure 2A A single USIM UE 200 and a multiple USIM UE 205 are depicted according to embodiments of this disclosure. UE 200 includes a mobile device (“ME”) 210 having a single USIM 203 registered for use only once, while the multiple USIM UE 205 includes an ME having multiple USIMs registered for use simultaneously (e.g., a first USIM (USIM-1) 207 and a second USIM (USIM-2) 209). USIM-1 207 and USIM-2 209 may be associated with the same PLMN or different PLMNs. Furthermore, USIM-1 207 and USIM-2 209 may be associated with different network slices of the same PLMN. Note that both USIM-1 207 and USIM-2 209 can be used simultaneously for idle mode network connectivity.

[0067] Each ME 210 (e.g., a transceiver or modem) includes (1) one or more mobile terminals (MT) 215 dedicated to managing the PLMN access interface (3GPP or non-3GPP); and (2) one or more terminal equipment (TE) 220 functions required for user operation of the access protocol. Note that the UE 200 and the multi-USIM UE 205 may implement the Universal Subscriber Identity Module (“USIM”, sometimes referred to as the Subscriber Identity Module, “SIM”) as an integrated circuit or card that needs to be inserted into the UE, and / or as an embedded SIM (“eSIM”) or an embedded universal integrated circuit card (“eUICC”) – a programmable SIM directly embedded in the device.

[0068] Figure 2B The protocol stack 225 of the multi-USIM UE 205 is depicted. Protocol stack 225 includes upper layers 227 (e.g., IP layer, transport (UDP, TCP) layer, etc.). Protocol stack 225 includes a 5GS Session Management (“5GSM”) sublayer 229 and a 5GS Mobility Management (“5GMM”) sublayer 231, which include a NAS layer 230. Note that AMF 143 includes a NAS layer and can establish NAS signaling connections with the multi-USIM UE 205. The AS layer 232 (also referred to as the “radio protocol”) of protocol stack 225 includes an RRC layer 233, a Serving Data Adaptation Protocol (“SDAP”) layer 235, a PCDP layer 237, an RLC layer 239, a MAC layer 241, and a PHY layer 243 (baseband). RAN nodes (e.g., base station element 121) include corresponding AS layers and can establish AS signaling connections with the multi-USIM UE 205.

[0069] Note that multi-USIM UE 205 (e.g., the ME 210 portion of multi-USIM UE 205) requires the implementation of at least as many NAS protocol stacks and radio protocol stacks (e.g., abbreviated as NAS / RP stacks) as the number of USIMs capable of simultaneously registering to the same or different PLMNs. Figure 2B The system contains two NAS / RP stacks and two USIM cards / profiles. Note that each NAS / RP stack has its own receiver (e.g., a first receiver (“Rx-1”) 247 for USIM-1 207 and a second receiver (“Rx-2”) 249 for USIM-2 209), but the multi-USIM UE 205 has a single transmitter 245. Transmitted and received signals are transmitted via a duplexer 251 and an antenna 253.

[0070] Different NAS / RP stacks serving different USIMs need to have the ability to exchange the states of other protocol stacks. For example, if the protocol stack of USIM-1 207 wants to initiate a transition from an idle to a connected state, the USIM-1 protocol stack queries the state of USIM-2 209. Various behavioral scenarios are possible.

[0071] For example, if the USIM-2 209 is connected (e.g., ECM / CM connection on 5GMM NAS level 231), and if the USIM-2 209 application is configured with a higher priority (or the user decides to maintain communication via USIM-2 209 and ignore communication triggers from USIM-1 207), the USIM-1 protocol stack does not initiate a connection activation action; that is, the USIM-1 protocol stack remains idle and indicates to the application that connection establishment is currently impossible. For example, the multi-USIM UE 205 can display a prompt to the user asking whether to interrupt (e.g., temporarily pause) the active service or application of USIM-2 209 to accept a new connection from USIM-1 207 (e.g., a service / application). Furthermore, the user can be prompted whether USIM-1 services / applications should always be able to interrupt USIM-2 services / applications. In other configurations, this user-specified priority can be stored in the multi-USIM UE 205, for example, allowing automatic pause of services / applications.

[0072] In another example, if the USIM-2 209 is connected (e.g., ECM / CM connected at 5GMM NAS level 231), and if the USIM-2 209 application is configured to have a lower priority (or the user decides to maintain communication via USIM-2 209 and ignore communication triggers from USIM-1 207), the USIM-1 protocol stack can request the USIM-2 protocol stack to suspend the ongoing connection. After suspending the connection with USIM-2 209, the USIM-2 protocol stack instructs the USIM-1 protocol stack (e.g., using an internal device in the remote unit) to suspend the connection, allowing the USIM-1 protocol stack to initiate connection establishment. Note that if the USIM-2 is idle (e.g., ECM / CM idle at 5GMM NAS level), inter-SIM priority is irrelevant, as the USIM-1 protocol stack can continue establishing the connection.

[0073] As described above, a UE supporting multiple SIMs can operate in passive mode, DSDS mode, or DSDA mode. Passive mode simply means the UE uses a single USIM at any given time; that is, it never registers more than a single USIM in the network. Therefore, from a 3GPP perspective, a UE in passive mode is not considered a multi-USIM UE 205. Furthermore, DSDA mode is a case where each USIM has a dedicated ME 210 (e.g., transceiver or modem) for each USIM. Therefore, according to this disclosure, a UE in DSDA mode does not fall under the scope of a multi-USIM UE 205.

[0074] Therefore, the multi-USIM UE 205 operates in DSDS mode. Two DSDS sub-modes are introduced here: Multi-USIM Single Activity (“MUSA”) mode is the operating mode for the multi-USIM UE 205, where at most one USIM is available for connection mode at any given time; and Multi-USIM Multi-Activity (“MUMA”) mode is the operating mode for the multi-USIM UE 205, where a subset of multiple UEs (e.g., M USIMs) can be used for connection mode (N connection modes) at any given time. The relationship between M and N is M > N.

[0075] Compared to conventional UEs (e.g., UE 200), the multi-SIM UE 205 supports at least two different levels of connection pause states. One possible criterion for distinguishing pause states could be the duration of the pause. For example, depending on the (estimated) duration of activity of the multi-SIM UE 205 in the target system (e.g., using USIM-1 207), another system (USIM-2 209) could pause the currently active connection for a short time (e.g., a short pause state, completed at RRC layer 233) or a long time (e.g., a long pause state, completed at the NAS layer). In contrast, conventional UEs only support a single pause state (e.g., at the NAS level).

[0076] The multi-SIM UE 205 determines which type of paused connection to use when pausing a connection to a USIM (e.g., USIM-1 207) in order to establish a connection to USIM-2 209. In various embodiments, at least two types of paused connections exist: a) a long paused connection, where NAS protocol exchange between the multi-SIM UE 205 and CN 140 is used to pause the active connection; or b) a short paused connection, where the AS context is maintained in the multi-SIM UE 205 and the RAN node without supporting radio transmissions. An example of a long paused connection is described in international patent application PCT / EP2017 / 076410, published in WO 2019 / 076439, which is incorporated herein by reference.

[0077] Regarding the characteristics of the short-suspended connection state, the serving RAN node maintains the UE AS context (security context, bearer context, etc.) and the multi-SIM UE 205 maintains its AS context. In various embodiments, the state of the multi-SIM UE 205 can be 1) RRC connected or 2) RRC inactive, but importantly, it has disabled transmissions (i.e., disabled DL transmissions from the RAN's perspective, or disabled UL transmissions from the UE's perspective). The short-suspended connection state can be entered even if there is ongoing communication and / or buffered packets for transmission at, for example, the PDCP layer. In this case, the transmission may be incomplete, PDCP packets may be interrupted, and packets may be buffered for the duration of the short-suspended connection state. The short-suspended connection state can be entered upon explicit signaling requested by the multi-SIM UE 205. In some embodiments, when implementing the short-suspended connection of USIM-1 207, the multi-SIM UE 205 is in the RRC connected state and does not trigger a radio link failure (“RLF”) to the upper layers (e.g., NAS, PDCP, SDAP).

[0078] In some embodiments, the short pause state is similar to the RRC_INACTIVE state described in 3GPP TS 38.300, but with other differences such as no transmission availability. In the short pause state, the RAN node knows that the multi-SIM UE 205 is unavailable for DL ​​transmission. The RAN node knows that the multi-SIM UE 205 cannot transmit data / signaling, for example, due to active communication with other USIMs. The RAN node does not perform the RAN paging procedure, and the RAN node does not allocate a RAN Notification Area (RNA). The RAN node may or may not notify the core network (e.g., AMF or SMF) of the activation of the short pause state for a given UE. For example, the RAN node may not notify the core network for one or more of the following reasons: 1) because the duration of the short pause state does not affect, for example, a NAS timer running in the AMF or SMF for NAS message retransmission, or 2) because there is no established DRB (e.g., for URLLC, or urgent or priority service) with delay-critical or high-reliability QoS flows. If the UE requests a short pause state transition (e.g., by sending an RRC connection release request), and the RAN node refuses to transition to the short pause state, as a subsequent action, the UE may request a long pause state transition to the core network (e.g., by sending a NAS MM request message). If the AMF has already requested explicit notification during the transition from idle to connected state (e.g., during the UE initial context establishment process from the AMF / MME to the RAN node), the RAN node may notify the core network (e.g., the AMF or SMF) of the short pause state.

[0079] Alternatively, a short pause state can be an RRC_INACTIVE state where radio transmission is disabled. Here, if DL packets arrive at the RAN node, the RAN node will buffer them, for example, at the PDCP layer. If the buffer is full, the RAN node discards the packets. In other words, a short pause state can be described as similar to a radio link failure (RLF) condition, but instead of being implicitly detected by the RAN node and the multi-SIM UE 205, it is detected by an explicit RRC signaling request from the multi-SIM UE 205. From the UE's perspective, the multi-SIM UE 205 also maintains the AS context (security context, DRB context, etc.), but when UL data arrives, the multi-SIM UE 205 does not request resources for UL transmission. The multi-SIM UE 205 can buffer UL packets, for example, at the PDCP layer, and discard packets if the buffer becomes full.

[0080] Although Figure 3 , Figures 4A-4B and Figures 5A-5B The process is described under the assumption that the UE is operating in MUSA mode, but please note that these solutions can also be applied to UEs operating in MUMA mode.

[0081] Figure 3 A flowchart 300 is depicted illustrating the behavior of a multi-SIM UE suspending the connection of one SIM during multi-SIM operation according to embodiments of the present disclosure. In various embodiments, the process described in flowchart 300 may be implemented by multi-SIM remote unit 105 and / or multi-USIM UE 205.

[0082] The process begins in step 1, where the multi-SIM UE 205 registers / attaches to USIM-1 207 and USIM-2 209 (see box 305). Additionally, for USIM-2 209, the multi-SIM UE 205 enters the CM connected state. In various embodiments, the multi-SIM UE 205 exchanges supported M-USIM capabilities with the network. This may include indicating whether only a single pause state (e.g., a long pause state at NAS) is supported or whether multiple pause states (e.g., a long pause state at NAS and a short pause state at AS) are supported. In various embodiments, the network (e.g., a RAN node or MME / AMF) may respond with a configuration (or preference) indicating which pause mode (e.g., a single pause state or multiple pause states) is used. If the network does not send M-USIM capabilities or M-USIM preferences, the UE can determine that the network does not support M-USIM capabilities, and the UE will initiate any procedures for the long pause state (e.g., at NAS) or the short pause state (at RRC). Flowchart 300 assumes that multiple pause states are supported at the multi-SIM UE 205 and network.

[0083] In step 2, the multi-SIM UE 205 detects a trigger event to suspend the active connection with USIM-2 209 (see box 310). Recall that if the trigger event is for a service with a higher priority than the active connection corresponding to USIM-2 209, the service or application of USIM-1 207 can trigger a suspension. Additionally, the multi-SIM UE 205 determines whether to apply a short connection suspension (i.e., enter a short-suspended connection state) or a long connection suspension (i.e., enter a long-suspended connection state) (see box 315).

[0084] For example, if a multi-SIM UE 205 is paged for USIM-1 207, and if the multi-SIM UE 205 determines, based on the paging reason value, that the MT communication for USIM-1 207 will be short (e.g., less than 1 to 2 seconds), then the multi-SIM UE 205 may decide to enter a short-suspended connection state for USIM-2 209. Otherwise, if the paging reason value does not indicate short MT communication, the multi-SIM UE 205 may decide to enter a long-suspended connection state for USIM-2 209. Alternatively, if the MT communication triggering event for USIM-1 207 indicates a service with a lower priority than the ongoing service for USIM-2 209, the UE may decide to continue communication with USIM-2 209, and the UE will not respond to the paging for USIM-1 207.

[0085] During step 3, which determines whether to apply a short or long pause state, the multi-SIM UE 205 may consider whether a Guaranteed Bit Rate (GBR) QoS stream or bearer is used for the USIM-2 209 connection. One possible behavior is that if a GBR stream is available (or if a QoS stream requiring low latency and / or high reliability, such as a URLLC QoS stream, exists), the multi-SIM UE 205 may determine to apply a long pause state (independent of the possible MT communication duration of USIM-1 207). If only non-GBR streams are available, the multi-SIM UE 205 may determine whether to apply a short or long pause state based on the estimated duration of the USIM-1 207 service type. Another possible behavior is that if the active connection to USIM-2 209 corresponds to an emergency service or other (multimedia) priority service (MPS), then interruption (e.g., triggering a pause) of USIM-1 207 to USIM-2 209 is not permitted.

[0086] In some embodiments where the timer value for the short pause state is known at the point in step 3 (e.g., the timer value is broadcast in a system information broadcast or received during the registration / attachment process), the timer value can influence whether the UE decides to enter a short pause state or a long pause state. For example, if the timer value is 1 second and the triggering event for USIM-1 207 in step 2 is an SMS service, the UE can decide to enter a long pause state because the UE can assume that the cascaded SMS transmission may take more than 1 second. However, if the triggering event for USIM-1 207 in step 2 is a tracking area update or registration process (including periodic and mobility-triggered updates), the UE can decide to enter a short pause state because the UE can assume that such signaling process may take less than 1 second.

[0087] In step 4, assuming short connection pause is selected, the multi-SIM UE 205 performs the AS / RRC procedure for short connection pause for USIM-2 209 (see box 320). Reference Figure 4A This AS / RRC process is described in further detail.

[0088] After MT communication with USIM-2 209 concludes, the UE instructs PLMN2 to release a Retrieval Instruction (RAI) to return to the USIM-1 207 network ASAP as quickly as possible. The RAI allows for a faster transition to the USIM-2 209 idle state. The exchange between the USIM-1 207 protocol stack and the USIM-2 209 protocol stack is as follows: Figure 3 As described in [the text].

[0089] The UE performs RRC connection modification for USIM-1 207 (i.e., PLMN1) to restore the suspended connection (e.g., reactivate radio transmissions). After the UE restores the radio connection, for example after the UE performs step (7), the RAN node attempts to transmit any buffered DL packets. Any lost packets can be recovered via application layer transmission. Similarly, the multi-SIM UE 205 can buffer UL packets at, for example, the PDCP layer, and after the radio connection is restored, for example after the UE performs step (7), the UE attempts to transmit the buffered UL packets.

[0090] In step 5, the UE and the network (e.g., the RAN node) are in a short pause state, where the AS context is preserved (see box 325). Additionally, a timer may be running for state transition. This timer value can be negotiated during step 4 of the process to enter the short pause state (e.g., the network / RAN node may send the timer to the multi-SIMUE 205 in a reply message).

[0091] For example, the timer value for the short pause state could be 3 seconds. The timer starts running in both the multi-SIM UE 205 and the RAN node when the short pause state is entered. If the timer expires, the network (e.g., the RAN node) and the multi-SIM UE 205 can transition to a long pause state. On the UE side, if the timer expires before the end of USIM-1 207 communication (see box 330), the multi-SIM UE 205 can transition to a long pause state (see box 340). In some embodiments, this transition is implicitly performed on the multi-SIM UE 205 by deleting the AS context and indicating a pause in the connection to the NAS layer (long pause) (i.e., without sending signaling to the network). On the network side, the RAN node can perform the UE AS context release and access network (AN) connection release procedure (e.g., TS23.502 Clause 4.2.6).

[0092] If USIM-1 207 communication ends before the timer expires, the multi-SIM UE 205 switches out of short connection suspension and resumes the USIM-2 209 connection (see box 335). See below for reference. Figure 4B and Figures 5A-5B The restoration of connection is discussed in further detail. After the connection is restored, the multi-SIM UE 205 is in the normal state of USIM-2 209 (e.g., CM connected state) (see box 360).

[0093] If the multi-SIM UE 205 selects a long connection pause, then in step 9, the UE performs the NAS MM procedure for a long pause for USIM-2 209 (see box 345). As discussed here, a long connection pause includes deleting the AS context at both the UE and the RAN node. In step 10, for USIM-2 209, the multi-SIM UE 205 remains in a long connection pause state until communication with USIM-1 207 ends (see box 350).

[0094] In step 11, at the end of communication on USIM-1 207, the multi-SIM UE 205 performs a NAS MM procedure to restore the connection to USIM-2 (see box 355). See below for reference. Figure 4B and Figures 5A-5B The restoration of connection is discussed in further detail. In step 12, after the connection is restored, for USIM-2 209, the multi-SIM UE 205 is in a normal state (e.g., CM connection state) (see box 360).

[0095] Although Figure 3 Examples of two different pause states (e.g., short pause state and long pause state) are shown, but this disclosure is not limited to two states. In general, there can be multiple pause states, and means for transitioning between states such as short pause state, intermediate pause state, and long pause state.

[0096] Figures 4A-4B Procedure 400 describes a scenario of suspending a connection for a USIM (e.g., USIM-1) according to an embodiment of this disclosure. Procedure 400 introduces an AS protocol (e.g., an RRC procedure) to implement signaling for the suspension of radio transmissions. Procedure 400 involves UE 205, (R)AN-2 / AMF-2 entity 405, (R)AN-1 node 410, AMF-1 415, and SMF-1 / UPF-1 entity 420. Although (R)AN-2 / AMF-2 405 is depicted as a combined entity, in various embodiments, AMF-2 is not located in the same location as (R)AN-2. (R)AN-2 / AMF-2 405 is part of PLMN2 registered with USIM-2, while entities (R)AN-1 node 410, AMF-1 415, and SMF-1 / UPF-1 420 are part of PLMN1 registered with USIM-1. Similarly, although SMF-1 / UPF-1 420 is depicted as a combined entity, in various embodiments, SMF-1 is not located in the same position as UPF-1.

[0097] exist Figure 4AProcess 400 begins at step 0, at which point UE 205 registers (or attaches) to one or more mobile communication networks using multiple SIMs (e.g., USIM-1 and USIM-2, see signaling 421). When registering with more than one USIM (e.g., when UE 205 has already registered with USIM-1 and initiates registration with USIM-2), UE 205 performs a NAS MM procedure (e.g., a registration request or TAU procedure) to indicate its multi-SIM (“MuSIM”) capability to each network (i.e., for each active USIM). This can be indicated, for example, in a NAS MM message destined for a network serving node (e.g., AMF / MME). MuSIM UE capabilities may include: 1) MuSIM support (e.g., yes / no), 2) pause state support (e.g., long pause state, and / or short pause state, etc.), and / or 3) release assist information (“RAI”) support for CP transmissions, SMS transmissions, and / or UP transmissions. This support for RAI can help determine the rapid termination of control plane transmissions within the network, such as in the RAN node or AMF. For example, a RAN node typically has a so-called "inactivity timer" with a value (e.g., 10 seconds) triggered by UL / DL data. Therefore, if the UE's inactivity timer expires because data has not been sent or received via radio bearers (e.g., signaling bearers and / or data bearers), the RAN node can place the inactive UE into an idle state. An Access Layer RAI ("AS-RAI") indication from the UE lets the RAN node know it can immediately place the UE into an idle state (e.g., at the RRC layer) instead of waiting for the inactivity timer to expire. Similarly, a Non-Access Layer RAI ("NAS_RAI") indication from the UE lets the AMF know it can immediately place the UE into an idle state (e.g., at the NAS layer) instead of waiting for the inactivity timer to expire.

[0098] Note that in one embodiment, UE 205 sends MuSIM information only when the second USIM is activated (this can be a manual activity). Also note that in the description above, the MuSIM UE capability indication in the NAS MM message means a) UE 205 supports... Figure 3The MuSIM mechanism, and b) because multiple USIMs are activated in UE 205, UE 205 wishes to use (i.e., request) the MuSIM mechanism (i.e., UE 205 registers with multiple USIMs). In other words, if UE 205 registers to use multiple USIMs, UE 205 can determine to send a MuSIM UE capability indication in the NAS MM request message. Alternatively, UE 205 may also send two different indications to the network, one regarding MuSIM UE capability and the other regarding required MuSIMs. In one example, the latter indication (required MuSIM) would mean to the network that the network should internally reconfigure to begin sending service / service type indications in paging messages for that UE 205. Note that from the network's perspective, MuSIM feature / enhancement support means that the network supports at least the following: 1) sending service / service type indications in paging messages and / or 2) transitioning to long pause states and / or short pause states.

[0099] Similar to UE indications, network functions (such as AMF or MME) can indicate preferred (or supported) operating modes in NAS MM response messages (such as registration accept or attachment accept messages). If A) UE 205 has already indicated MuSIM support capability in the NAS MM request message, and B) based on the network policy / configuration and subscription type associated with UE 205, the network (e.g., AMF or MME) can decide to send an indication regarding the preferred MuSIM mode. If UE 205 has previously indicated MuSIM support capability, and the network has enabled / applied MuSIM enhancements for UE registration, but in subsequent NAS MM processes, UE 205 does not include MuSIM support capability, or UE 205 includes an explicit indication that MuSIM support is no longer needed, this would mean that UE 205 may have deactivated a USIM card and is now operating in single USIM mode. In this case, the network (e.g., AMF or MME) can remove the previously stored MuSIM support from the UE context, and the network will not include the MuSIM preference in the NAS MM response message. During the deregistration or separation process, the network can remove the stored MuSIM support capabilities in the UE context stored in the AMF / MME.

[0100] The network (e.g., AMF or MME) may send a network indication to the UE in a NAS MM response (e.g., a registration acceptance message), which may include, for example, 1) MuSIM preference / support (e.g., yes / no), 2) pause state preference / support (e.g., long pause state and / or short pause state, and / or preferred duration of short pause state, etc.), and / or 3) release assistance information (“RAI”) support for CP transmission, SMS transmission and / or UP transmission. If the network does not send a MuSIM preference or MuSIM support indication to UE 205 (e.g., an indication included in a response message to a NAS MM procedure requested by the UE), UE 205 determines that the network does not prefer or support MuSIM features / enhancements, and the UE determines not to apply MuSIM features / enhancements (i.e., the UE will not initiate any procedures for long or short pause states). In this sense, when using the current registration in that PLMN, the network (e.g., AMF or MME) is able to determine whether the UE applies MuSIM features / enhancements and / or the appropriate configuration of mechanisms for long or short pause connection states and / or other parameters required for MuSIM enhancements (e.g., the duration of short pause connection states).

[0101] It is possible that one network serving USIM-1 (e.g., PLMN-1 including (R)AN-1 node 410, AMF-1 415, and SMF-1 / UPF-1) supports MuSIM capability or wants to apply MuSIM features, while another network serving USIM-2 (e.g., PLMN-2 including (R)AN-2 / AMF-2 405) does not support MuSIM capability (or does not want to apply MuSIM features). In this case, UE 205 can apply a connection suspension and resumption solution to PLMN-1, such as... Figure 3 As described in steps 3 and 6 below, UE 205 will trigger the connection suspension and resumption process for MO services. UE 205 knows that triggering MT services will not include the service / service type in the MT request (e.g., paging) message. Note that the network may decide to apply MuSIM features / enhancements based on the network operator's policies or configuration. For example, the network may decide to enable / apply MuSIM enhancements for non-roaming UEs but not for roaming UEs. In another example, the network may decide to apply MuSIM enhancements to high-configuration subscribers (e.g., Gold or Silver members) but not to low-configuration subscribers (e.g., Bronze members or prepaid users). It is advantageous if both networks PLMN1 and PLMN-2 apply MuSIM enhancements to obtain all the benefits of this solution, but some / partial advantages may still exist if only one of multiple networks applies MuSIM enhancements.

[0102] During the UE initial context establishment or UE context modification process, the network (e.g., AMF or MME) may send a configuration indication to the RAN node (e.g., gNB or eNB) regardless of whether the UE allows a short pause state. If the UE sends such a request according to step 3a-1, the indication will help the RAN node determine whether to apply a short pause state (see signaling 431). For example, if the AMF / MME does not include an indication that allows (or supports) a short pause state, the RAN node should reject the UE's request to transition to a short pause state according to step 3a-1. Procedure 400 assumes (after registration / attachment) that UE 205 is in a connected state (e.g., CM connected state) for USIM-1 and in an idle state (e.g., ECM / CM-idle state) for USIM-2 (see box 423). In step 1a, UE 205 receives a paging message initiated by the core network (CN) for USIM-2 209 (see signaling 425), where the paging message may include additional paging information indicating the type of service (or traffic) that caused the MT communication, i.e., the paging procedure. The granularity of paging information can be distinguished between the following service categories: a) IMS-based and non-IMS-based voice / video services; b) IMS-based and non-IMS-based SMS or USSD; c) IMS services other than voice / video or SMS; and / or d) other services not listed above, such as data services including video.

[0103] In step 1b, alternatively, the trigger for USIM-2 209 communication can be communication of the Mobile Origin (MO) (see box 427). The upper layer in UE 205 needs to indicate additional information about the service / service type to the NAS layer so that the NAS layer can make decisions about service priority and service duration. In the prior art, the NAS layer may only know which PDU session (e.g., IMS PDU session) will be active, but whether the service on IMS is voice, video, or SMS may be invisible to the NAS layer. Therefore, UE enhancements are needed to indicate the service / service type to the NAS layer, similar to the additional paging information used for MT communication in step 1a.

[0104] In step 2, based on the service type in the paging reason in step 1a—or based on the type of MO communication in step 1b—and based on the supported or preferred capabilities from step 0, UE 205 determines whether to apply a short-suspended connection or a long-suspended connection (see box 429). Reference Figure 3 This section discusses how UE 205 determines which type of connection suspension to apply.

[0105] In step 3, UE 205 applies a connection pause mechanism to USIM-1. For example, step 3a shows the UE procedure for applying a short connection pause (also known as “short connection pause”, see group 430), while step 3b shows the UE procedure for applying a long connection pause (also known as “long connection pause”, see group 440).

[0106] In step 3a-1, if UE 205 determines that a short-term paused connection is being applied, UE 205 performs an RRC procedure to request entry into a short-term paused connection state or release an RRC connection with a specific indication requesting a short-term paused connection state (e.g., an "unavailable indication") (see signaling 431). Note that the "unavailable indication" can be used to distinguish whether the RRC request is for a new short-term paused connection state or for a known paused connection for cellular IoT enhancements in 4G and 5G. In some embodiments, UE 205 may send a dedicated RRC message, such as an RRC pause request message or an RRC connection release request message, to request the network (e.g., a RAN node) to pause the RRC connection and transition to a short-term paused connection state. In other embodiments, existing RRC messages may be used, and the UE may include specific indications (e.g., new information elements, IEs), such as "no transmission," "temporarily unavailable," or "connection released due to activity of other USIMs," or some similar indication. In the UE, sending an RRC connection release / pause request is a new trigger, meaning it's triggered because a connection needs to be established for another USIM, unlike other known triggers for connection release in the UE (i.e., due to reduced power consumption or changes in UE radio capabilities). This instructs the PDCP layer in (R)AN-1 node 410 on the network side to stop sending DL PDUs and buffer upper-layer PDUs. See also Figure 3 The description provides a detailed description of the short pause connection state.

[0107] In step 3a-2, (R)AN-1 node 410 responds with an RRC pause response message, which can indicate a positive or negative response (see signaling 433). For example, in step 3a-2, the existing RRC message RRCConnectionRelease can be used with a short connection pause indication (which should teach the UE about the type of short connection pause state). In various embodiments, the RRC pause response message includes at least one of the following indications: 1) a timer value for transitioning to a stable pause state; and / or 2) the type of stable state. Examples of stable states may include a long connection pause, an RRC-inactive state, and / or an ECM / CM-idle state. Note that a short connection pause state (e.g., "temporarily unavailable") is considered an "unstable" state because UE 205 is considered available to the NAS layer but not to the RRC / AS layer. If the RRC pause response indication rejects the short pause state (i.e., a negative response), then according to step 3b, the UE can determine the procedure for initiating a long pause state (see signaling 440).

[0108] In steps 3a-3, (R)AN-1 node 410 maintains the UE context (security, bearer context, N2 and N3 connections); however, (R)AN-1 node 410 stops DL transmission (e.g., disables DL PDU transmission, and instead buffers DL PDUs in the PDCP layer, see box 435). This state can also be described as the RRC_INACTIVE state where radio transmission is disabled. Furthermore, UE 205 maintains the UE context but stops UL transmission (e.g., disables UL PDU transmission, and optionally buffers UL PDUs in the PDCP layer, see box 437). In various embodiments, a short pause is not applied if a GBR bearer is present. In the case of a GBR stream / bearer, UE 205 may determine to apply a long pause state.

[0109] continue Figure 4B In step 3b, if UE 205 determines that the application is to suspend the connection (e.g., based on the service type in a paging message or MO service trigger), UE 205 performs a NAS MM procedure (e.g., a service request procedure) to notify the service node (e.g., AMF-1 415) that the connection needs to be suspended (see signaling 441).

[0110] In step 4, UE 205 performs connection establishment to USIM-2 (see signaling 443). For example, UE 205 performs a service request procedure to the network (e.g., (R)AN-2 / AMF-2 405) to perform control plane transport or user plane connection activation (PDU session or PDN connection activation).

[0111] In step 5, for control plane transmissions, UE 205 may send a release assistance information (“RAI”) for USIM-2, such as an AS-RAI included in a NAS message (e.g., to RAN-2) or a NAS-RAI (see signaling 445). This indication can be determined in UE 205 based on the knowledge that no more UL / DL data is expected in UE 205. The RAI indication facilitates a quick transition to an idle state.

[0112] In step 6, UE 205 restores its connection to USIM-1. For example, in step 6a-1 of applying a short-suspended connection (and before the timer expires), UE 205 performs an RRC connection restoration procedure (see signaling 447). Here, UE 205 can use an existing RRC message, RRCConnectionResumeRequest, and may optionally include an indication that UE 205 is available again, or may indicate whether UL data is incomplete and request UL resources. Alternatively, UE 205 can use an RRC modification procedure, for example, by sending an RRC modification request message to request USIM-1, which may include parameters or indications that UE 205 is available for transmission again. Furthermore, in step 6a-2, the network (e.g., (R)AN-1 node 410) can respond with an RRCConnectionResume message to activate suspended SRBs and DRBs in the UE and RAN (see signaling 449). As another example, in step 6b of applying a long-suspended connection, UE 205 performs a NAS service request procedure for USIM-1 (see signaling 451).

[0113] After the connection to USIM-1 is suspended (e.g., after the UE enters the CM idle state of USIM-1, i.e., after step 3b or after the timer expires in step 3a-2), the NAS layer in UE 205 can indicate "interface closed" to applications that have already used the established data session (PDU session). This is useful for notifying that the IP connection is no longer available. Once the connection is re-established (e.g., after the connection recovery process in step 6), the NAS layer can notify the application that the IP connection is available again.

[0114] As described above, UE 205 is capable of maintaining a timer in a short pause state (as shown in steps 3a-2 and 3a-3). To configure the timer, one or more of the following mechanisms can be applied: 1) the RAN node sends the timer configuration via a unicast message (e.g., an RRC pause accept / acknowledge message), 2) the timer configuration is broadcast in system information (e.g., SIB), and / or 3) the timer configuration is negotiated during a NAS procedure (e.g., a registration procedure or a UE configuration update).

[0115] The known prior art solution for suspending a connection for a USIM (e.g., USIM-1) releases the NAS signaling connection and then releases user plane resources, resulting in additional signaling between the RAN and CN for removing the RAN node and the UE access layer context in UE205, and releasing N2 and N3 associations. When performing a service request procedure with UP activation, the conventional procedure also results in increased signaling when UE205 resumes the connection to USIM-1. However, by introducing a “short-term connection suspension” state (or RRC_Inactive in the case of disabled radio transmission), greater flexibility is provided at the AS layer (by using only AS signaling, such as RRC suspension) for short-term suspension of radio transmissions without the need for additional signaling at the NAS layer.

[0116] Figures 5A-5B A process 500 is described according to embodiments of the present disclosure, in which missed mobile terminal (MT) communication information is generated during a connection suspension and sent to the UE during connection restoration. Process 500 involves a multi-SIM UE 205, (R)AN-1 node 410, AMF-1 415, SMF 1 / UPF 1 420, and UDM 149. During the connection suspension (i.e., the aforementioned long suspension state), the core network 140 does not attempt to deliver DL data and MT signaling; that is, the core network does not page the multi-SIM UE 205. However, conventional processes are unaware of what happens to DL packets in the network during the connection suspension. The problem is that, upon restoration of the suspended connection, the multi-SIM UE 205 is unaware whether it has missed any communication.

[0117] Procedure 500 illustrates a solution for handling packets buffered during a connection suspension, for example, by notifying the UE of missed activity during the connection suspension. Procedure 500 assumes that the connection to USIM 1207 is suspended when multi-SIM UE 205 establishes a connection to USIM 2209. In some embodiments, the network (e.g., SMF or UPF) may store data packets or MT communication identifiers (“MT communication IDs”) during the “connection suspension” state. The broad term “missed MT communication information” is used.

[0118] If the UE has an active connection to USIM-2 209 (e.g., based on the UE's internal service priority), then after the activity to USIM-2 209 ends, the UE triggers the release of the connection to USIM-2 209 to allow a resumption request for a suspended connection to USIM-1 207. This might be necessary, for example, if the UE is in a CM connection and RRC inactive state for USIM-2 209 (which is considered an active connection to USIM-2 209). Such functionality might be needed because a suspended connection to the USIM might never trigger a paging procedure.

[0119] In some embodiments, after the UE executes NAS MM signaling (e.g., a NAS service request procedure for exiting a suspended state in USIM-1 207), the network sends a stored "missed MT communication information" to the UE. The "missed MT communication information" can be sent to the UE via control plane signaling, such as using NAS session management signaling from the SMF to the UE (e.g., NAS N1-SM signaling). As discussed in International Patent Application PCT / EP2017 / 076410, the UE can use a NAS service request procedure and include a "PDU Session Status" indication to indicate which PDU sessions are still valid for suspended connections. In some embodiments, the UE's 5GSM layer 229 can process this information internally and forward it to the appropriate application. If necessary, the application can trigger the establishment of UP resources.

[0120] exist Figure 5A In process 500, starting with step 1, the multi-SIM UE 205 operating in MUSA mode determines the activation of the connection to USIM-2 209 (see box 501). The multi-SIM UE 205 may have already exchanged MuSIM capabilities with the network during the NAS MM process, such as... Figure 4A As described in step 0, the multi-SIM UE 205 determines the procedure for suspending the connection of USIM-1 207 (i.e., all established PDU sessions). For USIM-1 207, the UE transitions to a CM idle / suspended state. In some embodiments, the UE may use new parameters (or information elements, IEs) to inform the network of the reason for the suspension, as well as the duration of the suspension.

[0121] In step 2, the network serving USIM-1 207 (i.e., AMF-1, SMF-1, UPF-1, etc.) performs the procedure of suspending the existing connection (see box 503). Here, the AMF may indicate one or more of the following parameters to the SMF in the signaling used to suspend the PDU session (note that the AMF performs this step for each PDU session active during the connection suspension): 1) the reason for suspending the PDU session or the reason for releasing the UP (e.g., the suspended connection); 2) the unreachable time, indicating the time during which the SMF should not attempt DL communication; 3) suspend paging requests: meaning that if DL data 505 arrives, the SMF should not send paging request signaling; and / or 4) information about whether the SMF should store downlink data activity during the suspended connection. For example, the SMF may collect MT communication information (e.g., DL packets or store the MT communication ID, the source address of the communication initiator).

[0122] In step 3, the multi-SIM UE 205 determines that it is performing a connection restoration for USIM-1 207 (see box 507). For example, the connection with USIM-2 209 has been released. In step 4, the multi-SIM UE 205 performs a service request procedure (see signaling 509). There may be explicit indication that this procedure is to restore the old connection, i.e., that the multi-SIM UE 205 can be used for DL ​​communication again.

[0123] In step 5, AMF-1 415 resumes all previously suspended PDU sessions (considering PDU session state IE, see box 511). In step 6, the network (e.g., SMF-1) can perform one of the following options:

[0124] Step 6a: If the SMF-1 / UPF-1 420 has already buffered DL packets, the SMF-1 can activate the use of plane resources and deliver the buffered packets (see box 513). Note that the buffered DL packets are transmitted via user plane resources, i.e., the N3 connection and DRB.

[0125] Step 6b: If the SMF-1 / UPF-1 420 has already stored the missed MT communication information, the SMF-1 sends an N1-SM message (e.g., a 5GSM status message) that includes the missed MT communication information (e.g., MT communication ID, such as IP address or application initiator ID, or buffered packets; see box 515 and signaling 517). Note that the MT communication information can be transmitted via the control plane signaling connection.

[0126] In step 7, if the multi-SIM UE 205 receives MT communication information, the multi-SIM UE 205 internally triggers the application identified by the MT communication information (see box 519).

[0127] In step 8, the multi-SIM UE 205 may perform a service request procedure to establish user plane resources for the PDU session associated with the application identified by the MT communication information in step 7 (see signaling 521).

[0128] The benefit of the process 500 solution is that when a connection is suspended, the multi-SIM UE 205 is informed of missed mobile termination communications. This solution can be used for applications (or PDU sessions) that do not automatically contact the application server when the IP connection becomes available again (after it was previously unavailable).

[0129] In the alternative solution to procedure 500, after the connection is restored for a specific USIM—that is, the USIM can use the UE's radio transmission capabilities—the protocol stack associated with that USIM can indicate to the UE application that the IP connection is once again available. The UE application can then contact the appropriate application server (AS) and check for any missed activity during the time the UE application was unable to communicate due to the connection suspension.

[0130] Figure 6 An embodiment of a user equipment device 600 according to embodiments of the present disclosure is depicted, which can be used to suspend the connection of one SIM during multi-SIM operation. The user equipment device 600 may be an embodiment of a remote unit 105. Furthermore, the user equipment device 600 may include a processor 605, a memory 610, an input device 615, an output device 620, and a transceiver 625. In some embodiments, the input device 615 and the output device 620 are combined into a single device, such as a touchscreen. In some embodiments, the user equipment device 600 does not include any input device 615 and / or output device 620.

[0131] As shown in the figure, transceiver 625 includes at least one transmitter 630 and at least one receiver 635. Here, transceiver 625 communicates with a mobile core network (e.g., 5GC) via an interoperability function (e.g., TNGF or N3IWF) and a non-3GPP access network. Furthermore, transceiver 625 may support at least one network interface 640. Here, at least one network interface 640 facilitates communication with an eNB or gNB (e.g., using a "Uu" interface). Additionally, at least one network interface 640 may include interfaces for communication with a UPF, SMF, and / or P-CSCF.

[0132] User equipment device 600 includes a plurality of SIMs. In some embodiments, user equipment device 600 includes a first SIM 645 registered to a first mobile communication network and a second SIM 650 registered to a second mobile communication network.

[0133] In one embodiment, processor 605 may include any known controller capable of executing computer-readable instructions and / or performing logical operations. For example, processor 605 may be a microcontroller, microprocessor, central processing unit (“CPU”), graphics processing unit (“GPU”), auxiliary processing unit, field-programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, processor 605 executes instructions stored in memory 610 to perform the methods and routines described herein. Processor 605 is communicatively coupled to memory 610, input device 615, output device 620, and transceiver 625.

[0134] In various embodiments, processor 605 receives a communication trigger associated with first SIM 645, which indicates a service type. Here, the communication trigger is received when second SIM 650 has an active connection (e.g., user equipment device 600 is in a CM connection state with respect to second SIM 650). In one embodiment, the communication trigger is an indication of mobile termination of communication, such as a paging request. In another embodiment, the communication trigger is an indication of mobile-initiated (“MO”) communication, such as an indication from an internal application of data to be transmitted.

[0135] In response to a communication trigger, processor 605 determines whether to pause a short connection or a long connection for the second SIM application, based on the service type. For example, an MT paging message indicating a Short Message Service (“SMS”) service type can trigger a short connection pause. As another example, an MO Tracking Area Update (“TAU”) message can trigger a short connection pause.

[0136] In some embodiments, a communication trigger associated with the first SIM 645 is allowed to interrupt a service (or application) associated with the second SIM 650 only if the application or service type associated with the first SIM 645 is configured to have a higher priority than the application or service currently used with the second SIM 650. In some embodiments, if the second SIM 650 is involved in an emergency communication session (e.g., the first SIM 645 is not allowed to interrupt the emergency communication service of the second SIM 650), the processor 605 determines not to suspend the connection of the second SIM 650.

[0137] In some embodiments, when determining whether to apply a short connection pause or a long connection pause to the second SIM, the processor 605 also considers the bearer type associated with the second SIM 650. In such an embodiment, in response to the second SIM 650 being associated with a Guaranteed Bit Rate (“GBR”) bearer, the processor 605 may determine to apply a long connection pause.

[0138] In some embodiments, processor 605 controls transceiver 625 to exchange supported M-USIM capabilities with a network (e.g., with a RAN node, AMF, or MME). This may include indicating whether only a single pause state (e.g., a long pause state at NAS) is supported or whether multiple pause states (e.g., a long pause state at NAS and a short pause state at AS) are supported. In various embodiments, transceiver 625 receives a response from the network (e.g., a RAN node or MME / AMF) containing a configuration (or preference) for which pause mode to use (e.g., a single pause state or multiple pause states). If the network does not send M-USIM capabilities or M-USIM preferences, processor 605 may determine that the network does not support M-USIM capabilities, as referenced above. Figure 3 As stated above.

[0139] Processor 605 is selected from short connection suspension and long connection suspension for the second SIM. In some embodiments, processor 605 applies short connection suspension to the second SIM 650 by transmitting an RRC layer suspension request and applies long connection suspension to the second SIM 650 by transmitting a NAS layer suspension request. In some embodiments, applying long connection suspension to the second SIM 650 includes transitioning to a NAS idle state in response to receiving a suspension response message from the second network. Here, the suspension response message can be an RRC layer message or a NAS layer message. Note that the suspension response message is sent as a response to the NAS layer suspension request message.

[0140] In some embodiments, applying a short connection pause includes the processor 605 disabling transmissions for the second SIM 650 in response to receiving an RRC layer pause response. In some embodiments, applying a short connection pause includes the processor 605 maintaining the access layer context of the second SIM 650.

[0141] In some embodiments, registering the first SIM 645 and the second SIM 650 includes indicating support for one or more of the following parameters: multi-SIM enhancement, short connection pause, or long connection pause; receiving an indication of a network preference for applying multi-SIM enhancement, short connection pause, or long connection pause; and configuring the processor to apply multi-SIM enhancement, short connection pause, or long connection pause based on the received network preference. In some embodiments, the absence of any received network preference can be interpreted by the UE as an indication that multi-SIM enhancement is not supported in the network (e.g., it is assumed that it is not supported unless a parameter indicating support is received).

[0142] In various embodiments, processor 605 activates a connection associated with first SIM 645 in response to suspending the active connection of second SIM 650. When the active connection of second SIM 650 is suspended, processor 605 performs communication corresponding to communication triggered by first SIM 645. Subsequently, processor 605 controls transceiver 625 to send release assist information (“RAI”) in response to terminating communication triggered by communication, the release assist information including access stratum (“AS”) RAI and / or non-access stratum (“NAS”) RAI.

[0143] The processor 605 also resumes a suspended connection in the second communication network associated with the second SIM 650 in response to terminating the communication triggered by the communication. In some embodiments, resuming a suspended connection includes sending an RRC layer connection resumption request in response to a transmission RRC layer suspension request (e.g., resuming a short connection suspension of the second SIM 650) and / or sending a NAS layer resumption request in response to a transmission NAS layer suspension request (e.g., resuming a long connection suspension of the second SIM 650).

[0144] In some embodiments, transceiver 625 receives a pause timer value associated with a short-connection pause of the second SIM 650. For example, transceiver 625 may receive a pause response message containing the pause timer value. As another example, the pause timer value may be broadcast in a System Information Block (“SIB”) or negotiated during NAS registration. In such an embodiment, processor 605 may initiate a pause timer in response to receiving an RRC layer pause response, and transition from a short-connection pause to a long-connection pause for the second SIM 650 in response to the expiration of the pause timer.

[0145] In one embodiment, user equipment device 600 may initiate application / service level signaling before performing a connection suspension procedure (e.g., for a long or short suspension state). For example, processor 605 may control transceiver 625 to notify application server (or other communication peer) of the temporary unavailability of the device (e.g., due to suspending one USIM to perform communication on another USIM), so that service or communication exchange can be interrupted (or suspended or terminated) in a controlled manner at the application / service layer. This is particularly beneficial in the case of a long suspension state when user equipment device 600 is unavailable for communication for a considerable period of time. Another benefit is that communication peers will stop sending user data packets, and user plane resources will not be consumed (e.g., buffering and discarding data packets). When the suspended USIM resumes / continues, processor 605 may control transceiver 625 to notify application server (or communication peer) that user equipment device 600 is available for communication again.

[0146] In one embodiment, memory 610 is a computer-readable storage medium. In some embodiments, memory 610 includes volatile computer storage media. For example, memory 610 may include RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and / or static RAM (“SRAM”). In some embodiments, memory 610 includes non-volatile computer storage media. For example, memory 610 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 610 includes both volatile and non-volatile computer storage media. In some embodiments, memory 610 stores data related to suspending the connection of a SIM during multi-SIM operation, such as storing AS context, SIM state, etc. In some embodiments, memory 610 also stores program code and related data, such as an operating system (“OS”) or other controller algorithms and one or more software applications operating on user equipment device 600.

[0147] In one embodiment, input device 615 may include any known computer input device, including a touch panel, buttons, keyboard, stylus, microphone, etc. In some embodiments, input device 615 may be integrated with output device 620, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, input device 615 includes a touchscreen, enabling text input using a virtual keyboard displayed on the touchscreen and / or via handwriting on the touchscreen. In some embodiments, input device 615 includes two or more different devices, such as a keyboard and a touch panel.

[0148] In one embodiment, output device 620 may include any known electronically controllable display or display device. Output device 620 may be designed to output visual, auditory, and / or tactile signals. In some embodiments, output device 620 includes an electronic display capable of outputting visual data to a user. For example, output device 620 may include, but is not limited to, LCD displays, LED displays, OLED displays, projectors, or similar display devices capable of outputting images, text, etc., to a user. As another non-limiting example, output device 620 may include wearable displays, such as smartwatches, smart glasses, heads-up displays, etc. Furthermore, output device 620 may be a component of a smartphone, personal digital assistant, television, desktop computer, laptop computer, personal computer, vehicle dashboard, etc.

[0149] In some embodiments, output device 620 includes one or more speakers for generating sound. For example, output device 620 may generate an auditory alarm or notification (e.g., a beeping or buzzing sound). In some embodiments, output device 620 includes one or more haptic devices for generating vibration, motion, or other haptic feedback. In some embodiments, all or part of output device 620 may be integrated with input device 615. For example, input device 615 and output device 620 may form a touchscreen or similar touch-sensitive display. In other embodiments, all or part of output device 620 may be located near input device 615.

[0150] As described above, transceiver 625 communicates with one or more network functions of a mobile communication network via one or more access networks. Transceiver 625 operates under the control of processor 605 to transmit messages, data, and other signals, and also to receive messages, data, and other signals. For example, processor 605 may selectively activate the transceiver (or a portion thereof) at specific times to send and receive messages.

[0151] Transceiver 625 may include one or more transmitters 630 and one or more receivers 635. Although only one transmitter 630 and one receiver 635 are shown, user equipment device 600 may have any suitable number of transmitters 630 and receivers 635. Furthermore, transmitters 630 and receivers 635 may be of any suitable type. In one embodiment, transceiver 625 includes a first transmitter / receiver pair for communicating with a mobile communication network via licensed radio spectrum and a second transmitter / receiver pair for communicating with a mobile communication network via unlicensed radio spectrum.

[0152] In some embodiments, a first transmitter / receiver pair for communicating with a mobile communication network via licensed radio spectrum and a second transmitter / receiver pair for communicating with a mobile communication network via unlicensed radio spectrum may be combined into a single transceiver unit, such as a single chip performing functions for both licensed and unlicensed radio spectrum. In some embodiments, the first transmitter / receiver pair and the second transmitter / receiver pair may share one or more hardware components. For example, certain transceivers 625, transmitters 630, and receivers 635 may be implemented as physically separate components that access shared hardware and / or software resources, such as, for example, a network interface 640.

[0153] In various embodiments, one or more transmitters 630 and / or one or more receivers 635 may be implemented and / or integrated into a single hardware component, such as a multi-transceiver chip, system-on-a-chip, ASIC, or other type of hardware component. In some embodiments, one or more transmitters 630 and / or one or more receivers 635 may be implemented and / or integrated into a multi-chip module. In some embodiments, other components, such as network interface 640 or other hardware components / circuit, may be integrated with any number of transmitters 630 and / or receivers 635 into a single chip. In such embodiments, transmitters 630 and receivers 635 may be logically configured as transceivers 625 using one or more common control signals, or as modular transmitters 630 and receivers 635 implemented in the same hardware chip or multi-chip module.

[0154] Figure 7 One embodiment of a network device apparatus 700 according to embodiments of the present disclosure is depicted, which can be used to suspend the connection of a SIM during multi-SIM operation. In some embodiments, the network device apparatus 700 may be an embodiment of a RAN node, such as base station unit 121 and / or (R)AN-1 node 410. In other embodiments, the network device apparatus 700 may be an embodiment of AMF 143, AMF-1 415, and / or MME. Furthermore, the network device apparatus 700 may include a processor 705, a memory 710, an input device 715, an output device 720, and a transceiver 725. In some embodiments, the input device 715 and the output device 720 are combined into a single device, such as a touchscreen. In some embodiments, the network device apparatus 700 does not include any input device 715 and / or output device 720.

[0155] As shown in the figure, transceiver 725 includes at least one transmitter 730 and at least one receiver 735. Here, transceiver 725 communicates with one or more remote units 105 and one or more interoperability functions 135, which provide access to one or more PLMNs. Furthermore, transceiver 725 may support at least one network interface 740. In some embodiments, transceiver 725 supports a first interface (e.g., N2 interface) for communicating with RAN nodes—e.g., gNB or eNB), a second interface (e.g., N8, N11, N15, etc. interfaces), for communicating with one or more control plane network functions (e.g., UDM, SMF, PCF) in a mobile core network (e.g., 5GC), and a third interface (e.g., N1 interface), for communicating with remote units (e.g., UEs) via the first interface (N2 interface) through a 3GPP access network or via a non-3GPP access network.

[0156] In one embodiment, processor 705 may include any known controller capable of executing computer-readable instructions and / or performing logical operations. For example, processor 705 may be a microcontroller, microprocessor, central processing unit (“CPU”), graphics processing unit (“GPU”), auxiliary processing unit, field-programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, processor 705 executes instructions stored in memory 710 to perform the methods and routines described herein. Processor 705 is communicatively coupled to memory 710, input device 715, output device 720, and first transceiver 725.

[0157] In various embodiments, network device 700 may operate as a RAN node—e.g., a gNB or eNB. In such an embodiment, transceiver 725 receives an RRC layer pause request from a remote unit (e.g., from a UE), and processor 705 maintains the UE AS context of the remote unit. Furthermore, processor 705 may disable downlink transmission to the remote unit in response to the RRC layer pause request. In response to receiving an RRC layer connection restoration request from the remote unit, processor 705 enables downlink transmission to the remote unit (UE).

[0158] In some embodiments, transceiver 725 transmits a pause timer value associated with a short connection pause of the second SIM, and processor 705 releases the UE AS context in response to the expiration of the pause timer. For example, transceiver 725 may receive a pause response message containing the pause timer value. As another example, the pause timer value may be broadcast in a System Information Block (“SIB”) or negotiated during NAS registration. In such embodiments, transceiver 725 may further indicate the type of pause state to a remote unit, wherein the remote unit transitions to the indicated pause state in response to the expiration of the pause timer. Here, the type of pause state may be transmitted to the remote unit along with the pause timer value.

[0159] In some embodiments, processor 705 buffers downlink packets from the remote unit in response to an RRC layer pause request. Here, transceiver 725 may attempt to deliver the buffered downlink packets in response to receiving an RRC layer connection restoration request from the remote unit. In some embodiments, processor 705 suppresses the RAN paging process of the remote unit in response to receiving an RRC layer pause request. In such an embodiment, processor 705 stops suppressing the RAN paging process of the remote unit in response to receiving an RRC layer connection restoration request.

[0160] In some embodiments, network device apparatus 700 may operate as a CN management function such as AMF 143, AMF-1 415, and MME. In such embodiments, processor 705 may control transceiver 725 to exchange preferred (or supported) M-USIM capabilities with the UE. This may include receiving indications as to whether the UE supports M-USIM features / enhancements, or whether it supports only a single pause state (e.g., a long pause state at NAS) or multiple pause states (e.g., a long pause state at NAS and a short pause state at AS). In various embodiments, processor 705 controls transceiver 725 to send a response to the UE containing a configuration (or preference) for applying M-USIM features / enhancements, or which pause mode (e.g., a single pause state or multiple pause states) or short pause duration (e.g., considered by the UE when determining whether to apply a short or long connection pause state). Processor 705 may also control transceiver 725 to send indication (or configuration) messages to RAN nodes—e.g., gNB or eNB—regarding whether the UE allows short pause states.

[0161] In one embodiment, memory 710 is a computer-readable storage medium. In some embodiments, memory 710 includes volatile computer storage media. For example, memory 710 may include RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and / or static RAM (“SRAM”). In some embodiments, memory 710 includes non-volatile computer storage media. For example, memory 710 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 710 includes both volatile and non-volatile computer storage media. In some embodiments, memory 710 stores data related to suspending the connection of a SIM during multi-SIM operation, such as storing UEAS context, UE state, etc. In some embodiments, memory 710 also stores program code and related data, such as an operating system (“OS”) or other controller algorithms and one or more software applications operating on network device device 700.

[0162] In one embodiment, input device 715 may include any known computer input device, including a touch panel, buttons, keyboard, stylus, microphone, etc. In some embodiments, input device 715 may be integrated with output device 720, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, input device 715 includes a touchscreen, enabling text input using a virtual keyboard displayed on the touchscreen and / or via handwriting on the touchscreen. In some embodiments, input device 715 includes two or more different devices, such as a keyboard and a touch panel.

[0163] In one embodiment, output device 720 may include any known electronically controllable display or display device. Output device 720 may be designed to output visual, auditory, and / or tactile signals. In some embodiments, output device 720 includes an electronic display capable of outputting visual data to a user. For example, output device 720 may include, but is not limited to, LCD displays, LED displays, OLED displays, projectors, or similar display devices capable of outputting images, text, etc., to a user. As another non-limiting example, output device 720 may include wearable displays, such as smartwatches, smart glasses, heads-up displays, etc. Furthermore, output device 720 may be a component of a smartphone, personal digital assistant, television, desktop computer, laptop computer, personal computer, vehicle dashboard, etc.

[0164] In some embodiments, output device 720 includes one or more speakers for generating sound. For example, output device 720 may generate an auditory alarm or notification (e.g., a beeping or buzzing sound). In some embodiments, output device 720 includes one or more haptic devices for generating vibration, motion, or other haptic feedback. In some embodiments, all or part of output device 720 may be integrated with input device 715. For example, input device 715 and output device 720 may form a touchscreen or similar touch-sensitive display. In other embodiments, all or part of output device 720 may be located near input device 715.

[0165] As described above, transceiver 725 can communicate with one or more remote units and / or with one or more interoperability functions that provide access to one or more PLMNs. Transceiver 725 can also communicate with one or more network functions (e.g., in mobile core network 140). Transceiver 725 operates under the control of processor 705 to transmit messages, data, and other signals, and also to receive messages, data, and other signals. For example, processor 705 can selectively activate the transceiver (or a portion thereof) at specific times to send and receive messages.

[0166] Transceiver 725 may include one or more transmitters 730 and one or more receivers 735. In some embodiments, one or more transmitters 730 and / or one or more receivers 735 may share transceiver hardware and / or circuitry. For example, one or more transmitters 730 and / or one or more receivers 735 may share antennas, antenna tuners, amplifiers, filters, oscillators, mixers, modulators / demodulators, power supplies, etc. In one embodiment, transceiver 725 uses different communication protocols or protocol stacks to implement multiple logical transceivers while using common physical hardware.

[0167] Figure 8 A method 800 for suspending the connection of a SIM during multi-SIM operation, according to embodiments of the present disclosure, is described. In some embodiments, method 800 is performed by means such as remote unit 105, multi-SIM UE 205, and / or user equipment device 600. In some embodiments, method 800 may be performed by a processor that executes program code, such as a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0168] Method 800 begins by registering a first SIM with a first mobile communication network (805). Method 800 includes registering a second SIM with a second mobile communication network (810). Method 800 includes receiving a communication trigger associated with the first SIM (815), the communication trigger indicating a service type. Method 800 includes determining (820) whether to apply a short connection pause or a long connection pause to the second SIM. Here, the determination is based on the service type. Method 800 includes applying one of short connection pause and long connection pause to the second SIM (825). Method 800 ends.

[0169] Figure 9 A method 900 for suspending the connection of a SIM during multi-SIM operation, according to embodiments of the present disclosure, is described. In some embodiments, method 900 is performed by a network device such as base station unit 121, (R)AN-1 node 410, network device device 700, gNB, eNB, and / or RAN node. In some embodiments, method 900 may be performed by a processor executing program code, such as a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0170] Method 900 begins by receiving an RRC layer pause request (905) from the UE (e.g., remote unit 105). Method 900 includes maintaining the UE AS context (910) of the UE. Method 900 includes disabling downlink transmissions (915) to the UE in response to the RRC layer pause request. Method 900 includes enabling downlink transmissions (920) to the UE in response to receiving an RRC layer connection restoration request from the UE. Method 900 ends.

[0171] According to embodiments of this disclosure, a first apparatus for suspending the connection of a SIM during multi-SIM operation is disclosed herein. The first apparatus may be implemented by a UE such as remote unit 105, multi-SIM UE 205, and / or user equipment apparatus 600. The first apparatus includes a processor, a first SIM registered to a first mobile communication network, a second SIM registered to a second mobile communication network, and a transceiver communicating with the first and second mobile communication networks. The processor receives a communication trigger associated with the first SIM, the communication trigger indicating a service type, and determines whether to apply a short connection suspension or a long connection suspension to the second SIM, the determination being based on the service type. The processor further applies one of the short connection suspension and long connection suspension to the second SIM.

[0172] In some embodiments, the application or service type associated with the first SIM is configured to have a higher priority than the application or service currently used with the second SIM. In some embodiments, if the second SIM is involved in an emergency communication session, the processor determines not to suspend the second SIM's connection.

[0173] In some embodiments, suspending a short connection for the second SIM application includes transmitting an RRC layer pause request, while suspending a long connection for the second SIM application includes transmitting a NAS layer pause request. In some embodiments, suspending a long connection for the second SIM application also includes transitioning to a NAS idle state in response to receiving a pause response message from the second network, wherein the pause response message includes one or more of the following messages: an RRC layer message or a NAS layer message. Here, the pause response message is sent in response to the NAS layer pause request message.

[0174] In some embodiments, applying short connection pause also includes the processor disabling transmissions of the second SIM in response to receiving an RRC layer pause response. In some embodiments, applying short connection pause includes the processor maintaining the access layer context of the second SIM.

[0175] In some embodiments, registering a first SIM and a second SIM includes indicating support for one or more of the following parameters: multi-SIM enhancement, short connection pause, or long connection pause; receiving an indication of a network preference for applying multi-SIM enhancement, short connection pause, or long connection pause; and configuring the processor to apply multi-SIM enhancement, short connection pause, or long connection pause based on the received network preference. In some embodiments, the absence of any received network preference can be interpreted by the UE as an indication that multi-SIM enhancement is not supported in the network.

[0176] In various embodiments, the processor activates a connection associated with the first SIM, performs communication corresponding to a communication trigger, and sends release assistance information in response to termination of the communication trigger, the release assistance information including one or more of access stratum release assistance information and non-access stratum release assistance information. In such embodiments, in response to termination of the communication trigger, the processor further restores a suspended connection in a second communication network associated with the second SIM. In some embodiments, restoring a suspended connection includes one or more of the following: sending an RRC layer connection restore request in response to a transmitted RRC layer pause request; and sending a NAS layer restore request in response to a transmitted NAS layer pause request.

[0177] In some embodiments, the transceiver also receives a pause timer value associated with a short connection pause for the second SIM, wherein the processor initiates a pause timer in response to receiving an RRC layer pause response, and transitions from a short connection pause to a long connection pause in response to the expiration of the pause timer. In some embodiments, determining whether to apply a short connection pause or a long connection pause to the second SIM is also based on the bearer type associated with the second SIM, wherein the processor determines to apply a long connection pause in response to the second SIM being associated with a guaranteed bit rate bearer.

[0178] According to embodiments of this disclosure, a first method for suspending the connection of a SIM during multi-SIM operation is disclosed herein. The first method may be performed by a UE, such as a remote unit 105, a multi-SIM UE 205, and / or a user equipment device 600. The first method includes registering a first SIM with a first mobile communication network and registering a second SIM with a second mobile communication network. The first method includes receiving a communication trigger associated with the first SIM, the communication trigger indicating a service type, and determining whether to apply a short connection suspension or a long connection suspension to the second SIM. Here, the determination is based on the service type. The first method includes applying one of a short connection suspension and a long connection suspension to the second SIM.

[0179] In some embodiments, applying a short connection pause to the second SIM includes transmitting an RRC layer pause request, and applying a long connection pause to the second SIM includes transmitting a NAS layer pause request. In some embodiments, applying a long connection pause to the second SIM further includes: transitioning to a NAS idle state in response to receiving a pause response message from the second network. In such embodiments, the pause response message includes one or more of an RRC layer message or a NAS layer message. Here, the pause response message is a response to a NAS layer pause request message. In some embodiments, applying a short connection pause further includes disabling transmissions of the second SIM in response to receiving an RRC layer pause response. In some embodiments, applying a short connection pause includes maintaining the access stratum context of the second SIM.

[0180] In some embodiments, registering a first SIM and a second SIM includes instructing the device to support one or more of the following parameters: multi-SIM enhancement, short connection pause, or long connection pause. In such embodiments, registering a first SIM and a second SIM also includes receiving network preferences indicating whether to apply multi-SIM enhancement, short connection pause, or long connection pause, and configuring the device to apply multi-SIM enhancement, short connection pause, or long connection pause based on the received network preferences.

[0181] In some embodiments, the first method includes receiving a pause timer value associated with a short connection pause of the second SIM, initiating a pause timer in response to receiving a pause response from the RRC layer, and switching from a short connection pause to a long connection pause in response to the expiration of the pause timer.

[0182] In some embodiments, the first method includes activating a connection associated with a first SIM, performing communication corresponding to a communication trigger, and sending release assistance information in response to terminating the communication trigger, the release assistance information including one or more of access stratum release assistance information and non-access stratum release assistance information. In such embodiments, the first method may further include resuming a suspended connection in a second communication network associated with a second SIM in response to terminating the communication trigger. In some embodiments, resuming a suspended connection includes one or more of the following: sending an RRC layer connection resumption request in response to transmitting an RRC layer suspension request; and sending a NAS layer resumption request in response to transmitting a NAS layer suspension request.

[0183] In some embodiments, the application or service type associated with the first SIM is configured to have a higher priority than the application or service currently used with the second SIM. In some embodiments, the first method includes determining not to suspend the connection of the second SIM if the second SIM is involved in an emergency communication session.

[0184] In some embodiments, determining whether to apply a short connection pause or a long connection pause to the second SIM is also based on the bearer type associated with the second SIM. In such embodiments, applying a short connection pause or a long connection pause to the second SIM includes applying a long connection pause in response to the second SIM being associated with a guaranteed bit rate bearer.

[0185] According to embodiments of this disclosure, a second means for suspending a connection of a SIM during multi-SIM operation is disclosed herein. The second means may be implemented by a RAN node such as base station unit 121, (R)AN-1 node 410, and / or network equipment device 700. The second means includes a processor and a transceiver that receives an RRC layer suspension request from a remote unit. In response to the RRC layer suspension request, the processor maintains the UE AS context of the remote unit. The processor also disables downlink transmission to the remote unit in response to the RRC layer suspension request and enables downlink transmission to the remote unit in response to receiving an RRC layer connection restoration request from the remote unit.

[0186] In some embodiments, the transceiver also transmits a pause timer value associated with a short connection pause of the second SIM, wherein the processor releases the UE AS context in response to the expiration of the pause timer. In such embodiments, the transceiver may also indicate the type of pause state to the remote unit, wherein the remote unit transitions to the indicated pause state in response to the expiration of the pause timer.

[0187] In some embodiments, the processor further buffers downlink packets of the remote unit in response to an RRC layer pause request, wherein the transceiver attempts to deliver the buffered downlink packets in response to receiving an RRC layer connection restoration request from the remote unit. In some embodiments, the processor further suppresses the RAN paging process of the remote unit in response to receiving an RRC layer pause request, and stops suppressing the RAN paging process of the remote unit in response to receiving an RRC layer connection restoration request.

[0188] According to embodiments of this disclosure, a second method for suspending a connection of a SIM during multi-SIM operation is disclosed herein. The second method may be performed by a RAN node such as base station unit 121, (R)AN-1 node 410, and / or network equipment device 700. The second method includes receiving an RRC layer suspension request from a remote unit and maintaining the UE AS context for the remote unit (e.g., in response to receiving the RRC layer suspension request). The second method includes disabling downlink transmission to the remote unit in response to the RRC layer suspension request and enabling downlink transmission to the remote unit in response to receiving an RRC layer connection restoration request from the remote unit.

[0189] In some embodiments, the second method includes transmitting a pause timer value associated with a short connection pause of the second SIM to a remote unit, and releasing the UE AS context in response to the expiration of the pause timer. In some embodiments, the second method further includes indicating to the remote unit the type of pause state, wherein the remote unit transitions to the indicated pause state in response to the expiration of the pause timer.

[0190] In some embodiments, the second method includes buffering downlink packets of a remote unit in response to an RRC layer pause request, and attempting to deliver the buffered downlink packets in response to receiving an RRC layer connection restoration request from the remote unit. In some embodiments, the second method includes suppressing the RAN paging process of the remote unit in response to receiving an RRC layer pause request, and stopping the suppression of the RAN paging process of the remote unit in response to receiving an RRC layer connection restoration request.

[0191] The embodiments may be practiced in other specific forms. The described embodiments are to be considered illustrative rather than restrictive in all respects. Therefore, the scope of the invention is indicated by the appended claims rather than by the foregoing description. All variations within the equivalent meaning and scope of the claims are included within their scope.

Claims

1. A user equipment (UE) for wireless communication, comprising: At least one memory; as well as At least one processor, coupled to the at least one memory, and configured to cause the UE to: Register the first subscriber identity module (SIM) with the first mobile communication network; Register a second SIM with a second mobile communication network; Send one or more multi-SIM (MUSIM) capabilities to the first mobile communication network communication or the second mobile communication network communication or both, wherein the one or more MUSIM capabilities indicate a capability to support a connection release type, or a capability to support a service type indication in a paging message, or both.

2. The UE according to claim 1, wherein, The ability to support connection release types indicates whether the UE supports Radio Resource Control (RRC) connection release, Non-Access Stratum (NAS) connection release, or both.

3. The UE according to claim 1, wherein, The at least one processor is further configured to cause the UE to: receive a configuration message from a corresponding mobile communication network, wherein the configuration message indicates a preferred connection release type of the corresponding mobile communication network, and wherein the corresponding mobile communication network includes either the first mobile communication network communication or the second mobile communication network communication.

4. The UE according to claim 1, wherein, The at least one processor is configured to cause the UE to: Perform a first registration process with the first mobile communication network; In response to the completion of the first registration process, a second registration process is performed on the second mobile communication network; as well as During the second registration process, the one or more MUSIM capabilities are sent to the second mobile communication network.

5. The UE according to claim 4, wherein, In order to send the one or more MUSIM capabilities to the second mobile communication network, the at least one processor is configured to cause the UE to: send a Non-Access Stratum (NAS) Registration Request message including the one or more MUSIM capabilities.

6. The UE according to claim 4, wherein, The at least one processor is configured to cause the UE to send the one or more MUSIM capabilities to the first mobile communication network during or after the second registration process.

7. The UE according to claim 6, wherein, In order to send the one or more MUSIM capabilities to the first mobile communication network, the at least one processor is configured to cause the UE to: send a Non-Access Stratum (NAS) Tracking Area Update (TAU) message including the one or more MUSIM capabilities.

8. A method performed by a user equipment (UE), the method comprising: Register the first subscriber identity module (SIM) with the first mobile communication network; Register a second SIM with a second mobile communication network; Send one or more multi-SIM (MUSIM) capabilities to the first mobile communication network communication or the second mobile communication network communication or both, wherein the one or more MUSIM capabilities indicate a capability to support a connection release type, or a capability to support a service type indication in a paging message, or both.

9. A mobility management entity for wireless communication, comprising: At least one memory; as well as At least one processor, coupled to the at least one memory, and configured to cause the mobility management entity to: Register a subscriber identity module (SIM) with the mobile communication network; Receive one or more multi-SIM (MUSIM) capabilities associated with the SIM, wherein the SIM is associated with a user equipment (UE), and wherein the one or more MUSIM capabilities indicate a capability to support a connection release type, or a capability to support a service type indication in a paging message, or both; and Send a configuration message indicating the preferred connection release type for the mobility management entity.

10. The mobility management entity according to claim 9, wherein, The ability to support connection release types indicates whether the UE supports Radio Resource Control (RRC) connection release, Non-Access Stratum (NAS) connection release, or both.

11. The mobility management entity according to claim 10, wherein, The preferred connection release type indicates RRC connection release, NAS connection release, or both.

12. The mobility management entity according to claim 9, wherein, The ability to support service type indication in paging messages includes voice service type.

13. The mobility management entity according to claim 9, wherein, The at least one processor is configured to cause the mobility management entity to: For the registration of the SIM, a registration process is performed with the UE; as well as The one or more MUSIM capabilities are received during the registration process.

14. The mobility management entity according to claim 9, wherein, To receive the one or more MUSIM capabilities, the at least one processor is configured to cause the mobility management entity to receive a Non-Access Stratum (NAS) registration request message that includes the one or more MUSIM capabilities.

15. A method for wireless communication performed by a mobility management entity, the method comprising: Register a subscriber identity module (SIM) with the mobile communication network; Receive one or more multi-SIM (MUSIM) capabilities associated with the SIM, wherein the SIM is associated with a user equipment (UE), and wherein the one or more MUSIM capabilities indicate a capability to support a connection release type, or a capability to support a service type indication in a paging message, or both; and Send a configuration message indicating the preferred connection release type for the mobility management entity.

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