Service recovery during registration with new air interface network

Abstract

A user equipment (UE) is configured to: configure transceiver circuitry to transmit a packet data network (PDN) connection request to a first network; decoding an activation default evolved packet system (EPS) bearer context request message comprising an extended protocol configuration option (ePCO) indicating that the UE can access a network slice on a public land mobile network (PLMN) or a separate non-public network (SNPN) according to signaling received from the first network; configuring a transceiver circuit to send a registration request comprising the network slice and a default list of configured network slices to a second network of the PLMN or SNPN; and decoding a registration acceptance message according to signaling received from the second network, the registration acceptance message including an indication that the registration request for the network slice has been accepted by the second network and a list of configured network slices for the second network.

Description

[0001] Inventors: V. Mysore Viswanath and V. G. Gupta

[0002] Priority / Incorporated by Reference

[0003] This application claims priority to U.S. Provisional Application Serial No. 63 / 371,017, filed on August 10, 2022, entitled “Service Recovery During Registration with New Radio Network,” the entire contents of which are incorporated herein by reference. Background Art

[0004] User equipment (UE) can be connected to a network where multiple network slices are deployed. Generally speaking, a network slice refers to an end-to-end logical network that is configured to provide specific services and / or have specific network characteristics. Each network slice can be isolated from each other but run on a shared network infrastructure. Therefore, each network slice can share network resources but facilitate different functions.

[0005] A UE camping on a Long Term Evolution (LTE) network may receive a configuration list of network slices for a current Public Land Mobile Network (PLMN) or Standalone Non-Public Network (SNPN). The UE may then register with a New Radio (NR) network for the same PLMN or SNPN. However, the UE will recognize that the configuration list of network slices for the LTE network is invalid for the NR network. Therefore, the UE will not be able to connect to the network slices on the configuration list on the NR network. Summary of the invention

[0006] Some exemplary embodiments relate to a user equipment (UE) device having a processing circuit configured to: configure a transceiver circuit to send a packet data network (PDN) connection request to a first network; decode an activate default evolved packet system (EPS) bearer context request message including an extended protocol configuration option (ePCO) based on signaling received from the first network, the extended protocol configuration option indicating that the UE is able to access a network slice on a public land mobile network (PLMN) or a standalone non-public network (SNPN); configure the transceiver circuit to send a registration request including the network slice and a default list of configured network slices to a second network of the PLMN or SNPN; and decode a registration acceptance message based on signaling received from the second network, the registration acceptance message including an indication that the registration request for the network slice has been accepted by the second network and a list of configured network slices for the second network.

[0007] Other exemplary embodiments relate to a processor of a user equipment (UE), the processor being configured to: configure a transceiver circuit to send a packet data network (PDN) connection request to a first network; decode, based on signaling received from the first network, an activate default evolved packet system (EPS) bearer context request message including an extended protocol configuration option (ePCO), the extended protocol configuration option indicating that the UE is capable of accessing a network slice on a public land mobile network (PLMN) or a standalone non-public network (SNPN); configure the transceiver circuit to send a registration request including the network slice and a default list of configured network slices to a second network of the PLMN or SNPN; and decode a registration acceptance message based on signaling received from the second network, the registration acceptance message including an indication that the registration request for the network slice has been accepted by the second network and a list of configured network slices for the second network. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Exemplary network arrangements are shown according to various exemplary embodiments.

[0009] Figure 2 An exemplary user equipment (UE) is shown in accordance with various exemplary embodiments.

[0010] Figure 3 An exemplary base station according to various exemplary embodiments is shown.

[0011] Figure 4 An exemplary call flow for initial registration of NR services enabled by registering to a slice from a configured NSSAI is shown according to various exemplary embodiments.

[0012] Figure 5 An exemplary call flow for enabling mobility registration of NR services by registering to slices from a configured NSSAI is shown according to various exemplary embodiments. DETAILED DESCRIPTION

[0013] The exemplary embodiments may be further understood with reference to the following description and related drawings, in which like elements are provided with like reference numerals. The exemplary embodiments introduce enhancements that enable registration to a configured slice list during initial registration or mobility registration to an NR network.

[0014] The exemplary embodiments are described with reference to UE. However, the use of the term "UE" is for illustrative purposes only. The exemplary embodiments may be utilized with any electronic component that can establish a connection with a network and is configured with hardware, software and / or firmware for exchanging information and data with the network. Therefore, the UE described herein is used to represent any suitable electronic component.

[0015] Exemplary embodiments are also described with reference to fifth generation (5G) networks and LTE networks that support network slicing. In general, network slicing refers to a network architecture in which multiple end-to-end logical networks run on a shared physical network infrastructure. Each network slice can be configured to provide a specific set of capabilities and / or features. Therefore, the physical infrastructure of a 5G network or an LTE network can be sliced ​​into multiple virtual networks, each of which is configured for a different purpose. Throughout the specification, references to network slicing may represent any type of end-to-end logical network that is configured for a specific purpose and implemented on a 5G or LTE physical infrastructure.

[0016] In addition, throughout the specification, it should be understood that different radio access networks (RANs) may be connected to the same core network. For example, a 5G RAN may be connected to a 5G core network (5GC), and an LTE-RAN may also be connected to the same 5GC. In another example, a 5G RAN may be connected to a 5GC, and an LTE-RAN may be connected to an LTE core network (evolved packet core (EPC)). It should be understood that the exemplary embodiments may be implemented in any of these core network connection scenarios, and the scenarios described below are exemplary only.

[0017] Throughout the specification, specific messages with specific message names are referenced as being exchanged between the UE and the network. For example, when the UE receives a REGISTER ACCEPT message, the UE is connected to the 5G network, and when the UE receives an ACTIVATE BEARER CONTEXT REQUEST message or an ACTIVATE DEFAULT EPS BEARER CONTEXT REQUEST message, the UE is connected to the LTE network. However, it should be understood that these messages and message names are merely exemplary, and messages carrying the described information may be referred to by different names.

[0018] A network slice may be identified by a single network slice selection assistance information (S-NSSAI). Each instance of S-NSSAI may be associated with a public land mobile network (PLMN). Throughout the specification, S-NSSAI refers to a single network slice, and the terms "NSSAI" or "S-NSSAI" may be used to refer to one or more network slices interchangeably.

[0019] The UE may be configured to perform any of a variety of different tasks. Thus, the UE may be configured to utilize one or more network slices. To provide an example, the UE may utilize a first network slice for one or more operator services (e.g., voice, multimedia messaging service (MMS), Internet, etc.) and a different second network slice for third-party services. However, the configuration purpose of network slices is beyond the scope of the exemplary embodiments. The exemplary embodiments are not limited to any particular type of network slice.

[0020] Examples described herein may refer to the terms “allowed NSSAI,” “configured NSSAI,” “requested NSSAI,” and “denied NSSAI.” Before discussing example enhancements, a brief description of each of these terms and how they relate to each other is provided below.

[0021] Those skilled in the art will appreciate that the term "allowed NSSAI" refers to the S-NSSAI provided by the network that the UE can use in the serving PLMN for a particular registration area. As will be described in more detail below, the allowed NSSAI may be provided by the network to the UE during the registration process. Due to the relationship between the registered NSSAI and the allowed NSSAI, in some embodiments, the term "registered network slice" may be used interchangeably with the allowed NSSAI to refer to the same concept.

[0022] In order to track the allowed NSSAI, the UE may operate a list of allowed NSSAI stored locally at the UE, or any other appropriate mechanism may be adopted. The number of network slices that can be considered as allowed NSSAI for the UE may be limited to a predetermined maximum number of allowed NSSAI. For example, some 3GPP specifications may limit the maximum number of allowed NSSAI to a length of 8 S-NSSAIs. In some cases, when the S-NSSAI is stored locally as an allowed NSSAI, the UE may attempt to establish a packet data unit (PDU) session on the S-NSSAI. However, when the S-NSSAI is not considered to be part of the allowed NSSAI, the UE may ignore the upper layer request for the S-NSSAI and the UE may not initiate PDU session establishment on the network slice.

[0023] Those skilled in the art will understand that the term "configured NSSAI" refers to the S-NSSAI that is provided in the UE and is applicable to one or more PLMNs. In order to track the configured NSSAI, the UE may operate a list of configured NSSAIs stored locally at the UE, or any other appropriate mechanism may be adopted. When the network slice is stored locally as the configured NSSAI, the value of the S-NSSAI is known to the UE. When the network slice is not stored locally as the configured NSSAI, the UE may not know the value of the S-NSSAI. The number of configured NSSAIs may be limited to a predetermined maximum number of configured NSSAIs. For example, some 3GPP specifications may limit the maximum number of configured NSSAIs to a length of 16 S-NSSAIs. In some embodiments, the term "subscribed network slice" may be used interchangeably with configured NSSAI to refer to the same concept.

[0024] During operation, the number of configured NSSAIs stored locally at the UE may be greater than the number of allowed NSSAIs stored locally at the UE. Therefore, there may be one or more S-NSSAIs that are considered by the UE as configured NSSAIs rather than part of the allowed NSSAIs. For example, S-NSSAI-A may be part of a configured NSSAI list stored locally at the UE rather than a part of an allowed NSSAI list stored locally at the UE. In such a configuration, the UE may not initiate PDU session establishment on S-NSSAI-A because S-NSSAI-A is not part of the allowed NSSAI list. Throughout this specification, any reference to "S-NSSAI-A" is provided solely to distinguish one network slice from other network slices and is not intended to limit the exemplary embodiments in any way.

[0025] Those skilled in the art will appreciate that the term "requested NSSAI" refers to the NSSAI provided by the UE to the network during the registration process. The network may then determine whether to allow the UE to register to each requested S-NSSAI. For example, the UE may store the S-NSSAI-A as part of the configured NSSAI. The UE may then send a registration request to the network indicating that the UE wishes to register to one or more network slices, such as S-NSSAI-A, etc. In response, the network may indicate that the requested S-NSSAI is an allowed NSSAI. The UE may then store the S-NSSAI-A in the allowed NSSAI list.

[0026] Alternatively, in response to the requested NSSAI, the network may indicate that the request for the S-NSSAI-A is rejected. The UE may then treat the S-NSSAI-A as a "rejected NSSAI". To track rejected NSSAIs, the UE may operate a list of rejected NSSAIs stored locally at the UE, or any other appropriate mechanism may be employed. In some cases, the UE may be configured to omit or ignore rejected NSSAIs during other operations and / or processes. For example, under certain conditions, the UE may not attempt to register on a locally stored network slice that is part of a rejected NSSAI.

[0027] The above examples provide a general overview of the relationship between the terms “allowed NSSAI,” “configured NSSAI,” “requested NSSAI,” and “denied NSSAI.” These examples are not intended to limit the scope of these terms or the exemplary embodiments in any way.

[0028] Some exemplary embodiments relate to enabling registration to a default configured NSSAI list under certain conditions. These exemplary embodiments allow the UE to transmit a default configured NSSAI list during initial registration or mobility registration with the NR network, and allow the NR network to transmit a configured slice list to the UE.

[0029] Figure 1 An exemplary network arrangement 100 according to various exemplary embodiments is shown. The exemplary network arrangement 100 includes a UE 110. Those skilled in the art will appreciate that the UE 110 may be any type of electronic component configured to communicate via a network, such as a mobile phone, a tablet computer, a desktop computer, a smart phone, a phablet, an embedded device, a wearable device, an Internet of Things (IoT) device, etc. It should also be appreciated that an actual network arrangement may include any number of UEs used by any number of users. Therefore, the example of a single UE 110 is provided for illustrative purposes only.

[0030] UE 110 may be configured to communicate with one or more networks. In the example of network configuration 100, the networks with which UE 110 may wirelessly communicate are 5G NR radio access network (RAN) 120 and LTE-RAN 122. However, UE 110 may also communicate with other types of networks (e.g., 5G cloud RAN, next generation RAN (NG-RAN), traditional cellular network, wireless local area network (WLAN), etc.), and UE 110 may also communicate with the network via a wired connection. Referring to the exemplary embodiment, UE 110 may establish a connection with 5G NR RAN 120 or LTE-RAN 122. Therefore, UE 110 may have a 5G NR chipset for communicating with 5G NR RAN 120 and an LTE chipset for communicating with LTE-RAN 122.

[0031] The 5G NR RAN 120 and the LTE-RAN 122 may be part of a cellular network that may be deployed by a network operator, such as Verizon, AT&T, T-Mobile, etc. The 5G NR RAN 120 and the LTE-RAN 122 may, for example, include nodes, cells, or base stations (e.g., Node B, eNodeB, HeNB, eNBS, gNB, gNodeB, macro cell, micro cell, small cell, femto cell, etc.) configured to transmit and receive traffic from a UE equipped with an appropriate cellular chipset.

[0032] The network arrangement 100 also includes a corresponding cellular core network for each of the 5G NR RAN 120 and the LTE-RAN 122. This may include a fifth generation core (5GC) 130 and an evolved packet core (EPC) 135. The cellular core networks 130, 135 may refer to an interconnected collection of components that manage the operation and traffic of a cellular network. The cellular core networks 130, 135 also manage traffic flowing between the cellular network and the Internet 140.

[0033] Those skilled in the art will appreciate that any relevant process may be performed to connect the UE 110 to the 5G NR-RAN 120 and / or the LTE-RAN 122. For example, as discussed above, the 5G NR-RAN 120 and / or the LTE-RAN 122 may be associated with a particular cellular provider at which the UE 110 and / or its user has a contract and credential information (e.g., stored on a SIM card). Upon detecting the presence of the 5G NR-RAN 120 and / or the LTE-RAN 122, the UE 110 may send corresponding credential information to associate with the 5G NR-RAN 120 and / or the LTE-RAN 122. More specifically, the UE 110 may be associated with a particular base station (e.g., a next generation Node B (gNB) 120A of the 5G NR RAN 120 or an evolved Node B (eNB) 122A of the LTE-RAN 122).

[0034] The network arrangement 100 also includes the Internet 140, an IP Multimedia Subsystem (IMS) 150, and a network service backbone 160. The IMS 150 can be generally described as an architecture for delivering multimedia services to the UE 110 using IP protocols. The IMS 150 can communicate with the cellular core networks 130, 135 and the Internet 140 to provide multimedia services to the UE 110. The network service backbone 160 communicates directly or indirectly with the Internet 140 and the cellular core networks 130, 135. The network service backbone 160 can be generally described as a collection of components (e.g., servers, network storage arrangements, etc.) that implement a set of services that can be used to extend the functionality of the UE 110 to communicate with various networks.

[0035] Figure 2 An exemplary UE 110 is shown according to various exemplary embodiments. The UE 110 will refer to Figure 1 100. UE 110 may include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. Other components 230 may include, for example, an audio input device, an audio output device, a power supply, a data acquisition device, a port for electrically connecting UE 110 to other electronic devices, etc.

[0036] The processor 205 may be configured to execute multiple engines of the UE 110. For example, the engine may include a registration request engine 235. The registration request engine 235 may perform operations related to the UE 110 performing a registration operation (initial registration or mobility registration) with the 5G NRRAN 120 so that the configured slice list can be used by the UE 110. The exemplary operations are described in more detail below.

[0037] The engine 235 referenced above is provided as an application (e.g., program) executed by the processor 205 for illustrative purposes only. The functionality associated with the engine 235 may also be represented as a separate combined component of the UE 110, or may be a modular component coupled to the UE 110, for example, an integrated circuit with or without firmware. For example, the integrated circuit may include an input circuit for receiving a signal and a processing circuit for processing the signal and other information. The engine may also be embodied as one application or multiple separate applications. In addition, in some UEs, the functionality described for the processor 205 is split between two or more processors (such as a baseband processor and an application processor). The exemplary embodiments may be implemented in any of these or other configurations of the UE.

[0038] The memory arrangement 210 may be a hardware component configured to store data related to operations performed by the UE 110. The display device 215 may be a hardware component configured to display data to a user, and the I / O device 220 may be a hardware component that enables a user to enter input. The display device 215 and the I / O device 220 may be separate components or may be integrated together (such as a touch screen). The transceiver 225 may be a hardware component configured to establish a connection with the 5G NR-RAN 120, LTE-RAN (not shown in the figure), traditional RAN (not shown in the figure), WLAN (not shown in the figure), etc. Therefore, the transceiver 225 can operate on a variety of different frequencies or channels (e.g., a set of continuous frequencies).

[0039] The transceiver 225 includes circuits configured to send and / or receive signals (e.g., control signals, data signals). Such signals may be encoded with information for implementing any of the methods described herein. The processor 205 may be operably coupled to the transceiver 225 and configured to receive signals from and / or send signals to the transceiver 225. The processor 205 may be configured to encode and / or decode signals (e.g., signaling from a base station of a network) for implementing any of the methods described herein.

[0040] Figure 3An exemplary base station 300 is shown in accordance with various exemplary embodiments. Base station 300 may represent a gNB 120A or any other access node that a UE 110 may use to establish a connection and manage network operations.

[0041] The base station 300 may include a processor 305, a memory arrangement 310, an input / output (I / O) device 315, a transceiver 320, and other components 325. These other components 325 may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, ports for electrically connecting the base station 300 to other electronic devices and / or a power source, and the like.

[0042] The processor 305 may be configured to execute multiple engines of the base station 300. The engine as an application (e.g., a program) executed by the processor 305 is merely exemplary. The functionality associated with the engine may also be represented as a separate combined component of the base station 300, or may be a modular component coupled to the base station 300, such as an integrated circuit with or without firmware. For example, the integrated circuit may include input circuits for receiving signals and processing circuits for processing signals and other information. In addition, in some base stations, the functionality described for the processor 305 is split between multiple processors (e.g., baseband processors, application processors, etc.). The exemplary embodiments may be implemented in any of these or other configurations of the base station.

[0043] The memory 310 may be a hardware component configured to store data related to operations performed by the base station 300. The I / O device 315 may be a hardware component or port that enables a user to interact with the base station 300. The transceiver 320 may be a hardware component configured to exchange data with the UE 110 and any other UE in the network arrangement 100. The transceiver 320 may operate on a variety of different frequencies or channels (e.g., a continuous set of frequencies). Thus, the transceiver 320 may include one or more components (e.g., radio components) that enable data exchange with various networks and UEs.

[0044] The transceiver 320 includes circuits configured to send and / or receive signals (e.g., control signals, data signals). Such signals may be encoded with information that implements any of the methods described herein. The processor 305 may be operably coupled to the transceiver 320 and configured to receive signals from and / or send signals to the transceiver 320. The processor 305 may be configured to encode and / or decode signals (e.g., signaling from a UE) for implementing any of the methods described herein.

[0045] As described above, some exemplary embodiments relate to enabling NR services by registering to slices from a configured NSSAI. Before describing enabling NR services by registering to slices from a configured NSSAI, an exemplary scenario will be described to illustrate the problem solved by the exemplary embodiments.

[0046] In an exemplary scenario, UE 110 is powered on and attached to a Home PLMN (HPLMN) on EPC 130 without any stored configured NSSAI. UE 110 receives S-NSSAI_1 associated with the HPLMN during a PDN connection establishment procedure in an Evolved Packet System (EPS) and adds S-NSSAI_1 to a configured NSSAI list for the HPLMN. UE 110 then performs an inter-system transition from S1 mode (LTE) to N1 mode (NR) and transmits a mobility registration request with only S-NSSAI_1 as part of the requested NSSAI. UE 110 then receives a Registration Accept message with S-NSSAI_1 as part of the allowed NSSAI, but does not receive the configured NSSAI from 5GC 130. Since UE 110 does not receive the configured NSSAI from 5GC 130, UE 110 will not be able to register slices using the configured NSSAI of the HPLMN and will therefore not be able to use the slices.

[0047] If the NSSAI configured in UE 110 includes only the S-NSSAI received in EPC 135 via ePCO, the exemplary embodiment provides a solution to this problem by allowing UE 110 to transmit the default configured NSSAI to the network (e.g., 5GC 130) in the requested NSSAI of the registration request.

[0048] For the initiation of the initial registration attempt of the 5GC 130, the solution can be expressed as follows. If the UE does not have an allowed NSSAI for the current PLMN or SNPN and / or does not have a configured NSSAI for the current PLMN or SNPN, or the configured NSSAI only contains the S-NSSAI received from the network during the PDN connection establishment procedure in the EPS or via the Evolved Packet Data Gateway (ePDG), and has a default configured NSSAI, then the UE shall a) include the S-NSSAI in the Requested NSSAI IE of the Registration Request message using the default configured NSSAI; and b) include the Network Slice Indication IE with the default configured NSSAI indication bit set to "Requested NSSAI created from default configured NSSAI" in the Registration Request message.

[0049] For the initiation of mobility and periodic registration updates for the 5GC 130, the solution can be expressed as follows. If the UE has no allowed NSSAI for the current PLMN or SNPN, no configured NSSAI for the current PLMN or SNPN, or the configured NSSAI is contained only in the S-NSSAI received from the network during the PDN connection establishment procedure in the EPS or via the ePDG, and neither the active PDU sessions or PDN connections to be transferred associated with the applicable S-NSSAI in the current PLMN or SNPN, nor the active PDU sessions or PDN connections to be transferred associated with the mapped S-NSSAI have a default configured NSSAI, then the UE shall a) include the S-NSSAI in the Requested NSSAI IE of the Registration Request message using the default configured NSSAI, and b) include the Network Slice Indication IE with the default configured NSSAI indication bit set to "Requested NSSAI created from default configured NSSAI" in the Registration Request message.

[0050] An exemplary flow chart is provided below, illustrating enabling NR services by registering to slices from the configured NSSAI.

[0051] Figure 4 An exemplary call flow 400 for initial registration of NR services enabled by registering to a slice from a configured NSSAI is shown according to various exemplary embodiments. The exemplary call flow is performed between UE 110, 5GC 130, and EPC 135.

[0052] In 405, UE 110 may be considered registered in PLMN_1 on EPC 135 without a stored configured NSSAI. In 410, UE 110 transmits a PDN connection request to EPC 135. In 615, LTE-RAN 122 activates an EPS bearer context request including an ePCO with S-NSSAI_1 for PLMN_1.

[0053] In 420, UE 110 detaches from EPC 135 and camps on 5GC 130. In 425, UE 110 transmits an initial registration request with a requested NSSAI including S-NSSAI_1 and a default configured NSSAI to 5GC 130, e.g., the above conditions are satisfied so that UE 110 is allowed to transmit the default configured NSSAI to 5GC 130. In 430, UE 110 receives an initial registration accept message with an allowed NSSAI including S-NSSAI_1 and a configured NSSAI from 5GC 130. Therefore, in 435, UE 110 may trigger mobility registration to register to a slice included on the configured NSSAI.

[0054] Figure 5 An exemplary call flow 500 for enabling mobility registration of NR services by registering to slices from a configured NSSAI according to various exemplary embodiments is shown. The exemplary call flow is performed between UE 110, 5GC 130, and EPC 135.

[0055] In 505, UE 110 may be considered to be registered in PLMN_1 on EPC 135 without a stored configured NSSAI. In 510, UE 110 transmits a PDN connection request to EPC 135. In 515, EPC 135 activates an EPS bearer context request (e.g., activate default EPS bearer context request) including an ePCO with S-NSSAI_1 for PLMN_1.

[0056] In 520, UE 110 camps on 5GC 130. In 525, UE 110 transmits a mobility registration request with a requested NSSAI including S-NSSAI_1 and a default configured NSSAI to 5GC 130, e.g., the above conditions are satisfied, so that UE 110 is allowed to transmit the default configured NSSAI to 5GC 130. In 530, UE 110 receives a mobility registration accept message with an allowed NSSAI including S-NSSAI_1 and a configured NSSAI from 5GC 130. Therefore, in 535, UE 110 may trigger mobility registration to register to a slice included on the configured NSSAI.

[0057] Example

[0058] In a first embodiment, a method performed by a user equipment (UE), the method comprising: sending a packet data network (PDN) connection request to a first network; receiving an activate default evolved packet system (EPS) bearer context request message including an extended protocol configuration option (ePCO), the extended protocol configuration option indicating that the UE can access a network slice on a public land mobile network (PLMN) or a standalone non-public network (SNPN); sending a registration request including the network slice and a default list of configured network slices to a second network of the PLMN or SNPN; and receiving a registration acceptance request, the registration acceptance request including an indication that the registration request for the network slice has been accepted by the second network and a list of configured network slices for the second network.

[0059] In a second embodiment, according to the method of the first embodiment, the registration request comprises an initial registration request for the second network.

[0060] In a third embodiment, the method according to the second embodiment, wherein the default list of configured network slices sent is based on the UE not having a configured network slice of the second network for the PLMN or SNPN.

[0061] In a fourth embodiment, the method according to the second embodiment, wherein the default list of configured network slices sent is based on the UE having configured network slices that only include the network slices received from the first network in the activate default EPS bearer context request message.

[0062] In a fifth embodiment, according to the method of the first embodiment, the registration request comprises a mobility registration request for the second network.

[0063] In a sixth embodiment, the method according to the fifth embodiment, wherein the default list of configured network slices sent is based on the UE having configured network slices that only include the network slices received from the first network in the activate default EPS bearer context request message.

[0064] In a seventh embodiment, according to the method of the first embodiment, the first network is a Long Term Evolution (LTE) network, and the second network is a Fifth Generation New Radio (5G NR) network.

[0065] In an eighth embodiment, a processor is provided, wherein the processor is configured to execute any one of the methods according to the first to seventh embodiments.

[0066] In a ninth embodiment, a user equipment (UE) includes a transceiver configured to communicate with a network; and a processor communicatively coupled to the transceiver and configured to perform any one of the methods according to the first to seventh embodiments.

[0067] Those skilled in the art will appreciate that the exemplary embodiments described above may be implemented with any suitable software configuration or hardware configuration or combination thereof. Exemplary hardware platforms for implementing the exemplary embodiments may include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, mobile devices with operating systems such as iOS, Android, etc. The exemplary embodiments of the above methods may be embodied as a program comprising lines of code stored on a non-transitory computer-readable storage medium, which, when compiled, may be executed on a processor or microprocessor.

[0068] Although this application describes various embodiments, each having different features in various combinations, those skilled in the art will understand that any feature of one embodiment may be combined with features of other embodiments in any manner that is not expressly negated or that is not functionally or logically inconsistent with the operation of the device or the prescribed function of the disclosed embodiment.

[0069] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of the authorized use should be clearly stated to users.

[0070] It will be apparent to those skilled in the art that various modifications may be made to the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, it is intended that the present disclosure covers modifications and variations of the present disclosure as long as they fall within the scope of the appended claims and their equivalents.

Claims

1. An apparatus of a user equipment (UE), the apparatus comprising a processing circuit, the processing circuit being configured to: configuring the transceiver circuitry to send a packet data network (PDN) connection request to the first network; decoding, according to signaling received from the first network, an activate default evolved packet system (EPS) bearer context request message including an extended protocol configuration option (ePCO), the extended protocol configuration option (ePCO) indicating that the UE can access a network slice on a public land mobile network (PLMN) or a standalone non-public network (SNPN); configuring the transceiver circuitry to send a registration request including the network slice and a configured default list of network slices to a second network of the PLMN or SNPN; as well as A registration accept message is decoded based on signaling received from the second network, the registration accept message including an indication that the registration request for the network slice has been accepted by the second network and a list of configured network slices for the second network.

2. The apparatus of claim 1, wherein the registration request comprises an initial registration request for the second network.

3. An apparatus according to claim 2, wherein the default list of configured network slices sent is based on the UE not having a configured network slice of the second network for the PLMN or SNPN.

4. An apparatus according to claim 2, wherein the default list of configured network slices sent is based on the UE having configured network slices that only include the network slices received from the first network in the activate default EPS bearer context request message.

5. The apparatus of claim 1, wherein the registration request comprises a mobility registration request for the second network.

6. An apparatus according to claim 5, wherein the default list of configured network slices sent is based on the UE having configured network slices that only include the network slices received from the first network in the activate default EPS bearer context request message.

7. The apparatus of claim 1, wherein the first network is a Long Term Evolution (LTE) network and the second network is a Fifth Generation New Radio (5G NR) network.

8. A processor of a user equipment (UE), the processor being configured to: configuring the transceiver circuitry to send a packet data network (PDN) connection request to the first network; decoding, according to signaling received from the first network, an activate default evolved packet system (EPS) bearer context request message including an extended protocol configuration option (ePCO), the extended protocol configuration option (ePCO) indicating that the UE can access a network slice on a public land mobile network (PLMN) or a standalone non-public network (SNPN); configuring the transceiver circuitry to send a registration request including the network slice and a configured default list of network slices to a second network of the PLMN or SNPN; as well as A registration accept message is decoded based on signaling received from the second network, the registration accept message including an indication that the registration request for the network slice has been accepted by the second network and a list of configured network slices for the second network.

9. The processor of claim 8, wherein the registration request comprises an initial registration request for the second network.

10. The processor of claim 9, wherein the default list of configured network slices sent is based on the UE not having a configured network slice for the second network of the PLMN or SNPN.

11. The processor of claim 9, wherein the default list of configured network slices sent is based on the UE having configured network slices that are only included in the network slices received from the first network in the activate default EPS bearer context request message.

12. The processor of claim 8, wherein the registration request comprises a mobility registration request for the second network.

13. The processor of claim 12, wherein the default list of configured network slices sent is based on the UE having configured network slices that are only included in the network slices received from the first network in the activate default EPS bearer context request message.

14. A method performed by a user equipment (UE), the method comprising: Sending a packet data network (PDN) connection request to the first network; receiving an activate default evolved packet system (EPS) bearer context request message including an extended protocol configuration option (ePCO), the extended protocol configuration option (ePCO) indicating that the UE can access a network slice on a public land mobile network (PLMN) or a standalone non-public network (SNPN); sending a registration request including the network slice and a default list of configured network slices to a second network of the PLMN or SNPN; as well as A registration accept message is received, the registration accept message including an indication that the registration request for the network slice has been accepted by the second network and a list of configured network slices for the second network.

15. The method of claim 14, wherein the registration request comprises an initial registration request for the second network.

16. The method of claim 15, wherein sending the default list of configured network slices is based on the UE not having a configured network slice of the second network for the PLMN or SNPN.

17. The method of claim 15, wherein the default list of configured network slices sent is based on the UE having configured network slices that are only included in the network slices received from the first network in the activate default EPS bearer context request message.

18. The method of claim 14, wherein the registration request comprises a mobility registration request for the second network.

19. The method of claim 18, wherein the default list of configured network slices sent is based on the UE having configured network slices that are only included in the network slices received from the first network in the activate default EPS bearer context request message.

20. The method of claim 14, wherein the first network is a Long Term Evolution (LTE) network and the second network is a Fifth Generation New Radio (5G NR) network.

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