User equipment and network components for managing multiple wireless connections

Abstract

A user equipment (UE) establishes a first type of connection to a first public land mobile network (PLMN), the first type of connection having a first non-access stratum (NAS) count pair corresponding to a first NAS security context associated with the first PLMN; establishes a second type of connection to a second PLMN, wherein a previous second type of connection was established with the first PLMN, wherein the previous second type of connection has a second NAS count pair corresponding to the first NAS security context, wherein the second type of connection has a third NAS count pair corresponding to a second NAS security context associated with the second PLMN; and deregisters the previous second type of connection with the first PLMN to reset the second NAS count pair at the first PLMN.

Description

Technical Field

[0001] The present application relates generally to wireless communications, and more particularly to NAS counting for multiple wireless connections. Background Art

[0002] 5G New Radio (NR) wireless communications support multiple connections from a user equipment (UE) to a public land mobile network (PLMN). For example, a 3GPP connection (e.g., a 5G wireless connection) and a non-3GPP connection (e.g., a WiFi connection) can be established by a single UE. In this case, the same security context in the Packet Data Convergence Protocol (PDCP) layer is used to encrypt communications for the two connections. One of the parameters input into the encryption algorithm is the Non-Access Stratum (NAS) count. On each connection there is a NAS count for downlink (DL) communications and a NAS count for uplink (communication). Therefore, for a UE with two connections (3GPP and non-3GPP), there are four NAS counts, i.e., one pair of NAS counts (DL and UL) for each connection. Summary of the invention

[0003] Some exemplary embodiments relate to a user equipment (UE) having: a transceiver configured to communicate with a plurality of networks; and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include: establishing a first type of connection to a first public land mobile network (PLMN), the first type of connection having a first NAS count pair corresponding to a first non-access stratum (NAS) security context associated with the first PLMN; establishing a second type of connection to a second PLMN, wherein a previous second type of connection was established with the first PLMN, wherein the previous second type of connection had a second NAS count pair corresponding to the first NAS security context, wherein the second type of connection has a third NAS count pair corresponding to a second NAS security context associated with the second PLMN; and deregistering the previous second type of connection with the first PLMN to reset the second NAS count pair at the first PLMN.

[0004] Other exemplary embodiments are directed to a user equipment (UE) having: a transceiver configured to communicate with a plurality of networks; and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include: establishing a first type of connection to a first public land mobile network (PLMN), wherein the first type of connection has a first NAS count pair corresponding to a non-access stratum (NAS) security context associated with an access and mobility management function (AMF) of the first PLMN; reestablishing the second type of connection to the first PLMN after previously transitioning the second type of connection to a second PLMN; and receiving a second NAS count pair from the AMF of the first PLMN, wherein the second NAS count pair corresponds to the second type of connection.

[0005] Still other exemplary embodiments relate to a user equipment (UE) having: a transceiver configured to communicate with a plurality of networks; and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include: establishing a first type of connection to a first public land mobile network (PLMN), wherein the first type of connection has a first NAS count pair corresponding to a non-access stratum (NAS) security context associated with an access and mobility management function (AMF) of the first PLMN; reestablishing a second type of connection to the first PLMN after previously transitioning the second type of connection to a second PLMN; and determining a new security context for both the first type of connection and the second type of connection.

[0006] Additional exemplary embodiments relate to a user equipment (UE) having: a transceiver configured to communicate with a plurality of networks; and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include: establishing a first type of connection to a first public land mobile network (PLMN), wherein the first type of connection has a first NAS count pair corresponding to a first non-access stratum (NAS) security context associated with an access and mobility management function (AMF) of the first PLMN; establishing a second type of connection to a second PLMN, wherein the second type of connection has a third NAS count pair corresponding to a second NAS security context associated with the AMF of the second PLMN, wherein a previous second type of connection was with the first PLMN and included a second NAS count pair corresponding to the first NAS security context; and storing the first NAS count pair, the second NAS count pair, and the third NAS count pair.

[0007] Additional exemplary embodiments relate to a network component implementing an access and mobility management function (AMF) of a core network, the network component comprising one or more processors configured to perform operations. The operations include: when a user equipment (UE) has switched a second type of connection from a first public land mobile network (PLMN) to a second PLMN, receiving a request from the UE for deregistration of a first type of connection or a second type of connection between the UE and the first PLMN; and deregistering one of the first type of connection or the second type of connection based on the request.

[0008] Some exemplary embodiments also relate to a network component implementing an access and mobility management function (AMF) of a core network, the network component comprising one or more processors configured to perform operations. The operations include: receiving a request from a user equipment (UE) to reestablish a second type of connection to a first public land mobile network (PLMN) after the UE has previously transitioned the second type of connection to a second PLMN, and wherein the UE additionally has a first type of connection to the first PLMN; and transmitting to the UE a NAS security mode command (SMC) comprising a second non-access stratum (NAS) count pair, wherein the second NAS count pair is associated with a NAS security context corresponding to the first type of connection and the second type of connection with the first PLMN. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Exemplary network arrangements are shown according to various exemplary embodiments.

[0010] Figure 2 An exemplary UE according to various exemplary embodiments is shown.

[0011] FIG. 3A to FIG. 3C A diagram illustrating a UE establishing multiple connection access to a PLMN according to various exemplary embodiments is shown.

[0012] Figure 4 Methods of managing non-3GPP connections according to various exemplary embodiments are shown.

[0013] Figure 5 Methods of managing NAS count pairs associated with non-3GPP connections are shown according to various exemplary embodiments.

[0014] Figure 6 Methods of managing multiple connectivity access of a UE to a PLMN according to various exemplary embodiments are shown.

[0015] Figure 7 Methods of managing multiple NAS count pairs according to various exemplary embodiments are shown. DETAILED DESCRIPTION

[0016] The exemplary embodiments may be further understood with reference to the following description and associated drawings, wherein similar elements have the same reference numerals. The exemplary embodiments describe an approach for a user equipment (UE) to handle multiple connection establishments with one or more public land mobile networks (PLMNs).

[0017] The exemplary embodiments are described with reference to a network including a 5G New Radio NR radio access technology (RAT). However, the exemplary embodiments may be implemented in other types of networks using the principles described herein.

[0018] The exemplary embodiments are also described with reference to a UE. However, the use of a UE is for illustrative purposes only. The exemplary embodiments can 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 electronic component.

[0019] As described above, the UE may establish a 3GPP connection (e.g., a 5G wireless connection) and a non-3GPP connection (e.g., a WiFi connection) with the same PLMN. Although both connections have the same security context and are encrypted using the same access and mobility management function (AMF) key, each connection is encrypted using a non-access stratum (NAS) count pair, one NAS count for the uplink (UL) and one NAS count for the downlink (DL) on the connection.

[0020] Currently, 3GPP standards (e.g., TS 31.102) allow only one NAS count pair to be stored per connection type on the UE's Universal Subscriber Identity Module (USIM). Consider the following scenario with this limitation. When the UE establishes a 3GPP and non-3GPP connection to a first PLMN, the UE stores a first NAS count pair for the 3GPP connection and a second NAS count pair for the non-3GPP connection. When the UE switches the non-3GPP connection to a second PLMN, a third NAS count pair for the connection is established. The 3GPP connection to the first PLMN remains active. However, if the UE attempts to reestablish a non-3GPP connection to the first PLMN, the AMF of the first PLMN will attempt to activate the security context of the active 3GPP connection on the non-3GPP connection. The UE loses the second NAS count pair associated with the non-3GPP connection via the first PLMN because it is replaced by the third NAS count pair associated with the non-3GPP connection via the second PLMN, and the reconnection to the first PLMN will fail because the UE does not know whether the security context received from the AMF of the first PLMN is valid.

[0021] According to some exemplary embodiments, when the UE establishes a non-3GPP connection with the second PLMN, the UE deregisters its non-3GPP connection with the first PLMN. In some cases, if the UE's current non-3GPP connection has been idle for longer than a predetermined period of time, the UE deregisters the connection. In other scenarios, when the UE moves its non-3GPP connection to the second PLMN, the UE will communicate with the AMF of the first PLMN to deregister its non-3GPP connection with the first PLMN.

[0022] According to other exemplary embodiments, when the UE attempts to reestablish a non-3GPP connection with the PLMN, the AMF of the PLMN transmits to the UE a stored NAS count pair previously established for the non-3GPP connection. The UE then determines how to process the received AMF NAS count pair based on whether the UE has a corresponding stored NAS count pair and, if so, whether the stored NAS count pair is the same as the received AMF NAS count pair.

[0023] According to further exemplary embodiments, when the UE attempts to register two types of connections (3GPP and non-3GPP) with a PLMN and has only one NAS count pair corresponding to one of these connections stored on its USIM, the UE performs a primary authentication with the AMF of the PLMN to derive a new security context for both types of connections. According to further exemplary embodiments, the UE may store multiple NAS security contexts for multiple PLMNs locally or on the USIM.

[0024] Figure 1 An exemplary network arrangement 100 according to various exemplary embodiments is shown. The exemplary network arrangement 100 includes a UE 110. It should be noted that any number of UEs may be used in the network arrangement 100. Those skilled in the art will appreciate that the UE 110 may alternatively 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, for illustrative purposes, only the number of a single UE 110 is provided.

[0025] 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 New Radio (NR) radio access network (5GNR-RAN) 120, LTE radio access network (LTE-RAN) 122, and wireless local area network (WLAN) 124. However, it should be understood that UE 110 may also communicate with other types of networks, and UE 110 may also communicate with the network through a wired connection. Therefore, UE 110 may include a 5G NR chipset that communicates with 5G NR-RAN 120, an LTE chipset that communicates with LTE-RAN 122, and an ISM chipset that communicates with WLAN 124.

[0026] 5G NR-RAN 120 and LTE-RAN 122 may be parts of cellular networks that may be deployed by cellular providers (e.g., Verizon, AT&T, T-Mobile, etc.). These networks 120, 122 may include, for example, cells or base stations (NodeB, eNodeB, HeNB, eNB, gNB, gNodeB, macrocell base stations, microcell base stations, small cell base stations, femtocell base stations, etc.) configured to send and receive traffic from UEs equipped with appropriate cellular chipsets. WLAN 124 may include any type of wireless local area network (WiFi, hotspot, IEEE 802.11x network, etc.).

[0027] UE 110 may be connected to 5G NR-RAN 120 via gNB 120A and / or gNB 120B. During operation, UE 110 may be within range of multiple gNBs. Thus, simultaneously or alternatively, UE 110 may be connected to 5G NR-RAN 120 via gNBs 120A and 120B. In addition, UE 110 may communicate with eNB 122A of LTE-RAN 122 to transmit and receive control information for downlink and / or uplink synchronization with respect to 5G NR-RAN 120 connection.

[0028] Those skilled in the art will appreciate that any relevant process may be performed for the UE 110 to connect to the 5G NR-RAN 120. For example, as described above, the 5G NR-RAN 120 may be associated with a particular cellular provider, where the UE 110 and / or its user has a protocol and credential information (e.g., stored on a SIM card). Upon detecting the presence of the 5G NR-RAN 120, the UE 110 may transmit corresponding credential information in order to associate with the 5G NR-RAN 120. More specifically, the UE 110 may be associated with a particular base station (e.g., gNB 120A of the 5G NR-RAN 120).

[0029] In addition to networks 120, 122, and 124, network arrangement 100 also includes a cellular core network 130, the Internet 140, an IP multimedia subsystem (IMS) 150, and a network service backbone 160. Cellular core network 130 also manages traffic flowing between the cellular network and the Internet 140. Cellular core network 130 can be viewed as an interconnected collection of components that manage the operation and traffic of a cellular network. In this example, the components include an access and mobility management function (AMF) 131. However, an actual cellular core network may include a variety of other components that perform any of a variety of different functions.

[0030] AMF 131 performs operations related to mobility management, such as, but not limited to, paging, non-access stratum (NAS) management, and registration process management between UE 110 and cellular core network 130. Reference to a single AMF 131 is for illustrative purposes only, and an actual network arrangement may include any appropriate number of AMFs.

[0031] As described above, UE 110 may also establish a non-3GPP connection (e.g., a WiFi connection) via 5G NR-RAN 120. In such a scenario, a non-3GPP access network (e.g., WLAN 124) may be connected to cellular core network 130. The control plane functionality and user plane functionality of cellular core network 130 may then be used by UE 110 to access the functionality of the non-3GPP connection, e.g., access a data network.

[0032] Figure 2 An exemplary UE 110 is shown according to various exemplary embodiments. Figure 1 100 is used to describe the UE 110. The UE 110 may represent any electronic device and 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. The other components 230 may include, for example, an audio input device, an audio output device, a battery providing a limited power source, a data acquisition device, a port for electrically connecting the UE 110 to other electronic devices, one or more antenna panels, etc. For example, the UE 110 may be coupled to industrial equipment via one or more ports.

[0033] Processor 205 may be configured to execute multiple engines of UE 110. For example, the engines may include NAS count management engine 235. As will be described in more detail below, NAS count management engine 235 may perform various operations related to managing registration of 3GPP and non-3GPP connections to one or more PLMNs.

[0034] The above-described engine as an application (e.g., program) executed by the processor 205 is merely exemplary. The functions associated with the engine may also be represented as an independent 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, an integrated circuit may include an input circuit system for receiving a signal and a processing circuit system for processing signals and other information. The engine may also be embodied as an application or multiple separate applications. In addition, in some UEs, the functionality described for the processor 205 is shared 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.

[0035] 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 user 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 122, WLAN 124, etc. Thus, the transceiver 225 may operate on multiple different frequencies or channels (e.g., a continuous set of frequencies).

[0036] FIG. 3A to FIG. 3C A diagram illustrating a UE establishing multiple connection access to a PLMN according to various exemplary embodiments is shown. FIG. 3A to FIG. 3C A progression of steps is shown as the UE 110 switches one of its connections from the first PLMN 302A to the second PLMN 302B and back to the first PLMN 302A.

[0037] like Figure 3A As shown, UE 110 establishes a first type of connection 304a and a second type of connection 304b with a first PLMN 302A. In some embodiments, the first type of connection 304a is a 3GPP connection (e.g., a 5G wireless connection) and the second type of connection 304b is a non-3GPP connection (e.g., a WiFi connection). Because the two types of connections 304a and 304b go to the same PLMN, these connections can share a common AMF security key (K AMF The NAS security context includes a first NAS count pair associated with uplink (UL) and downlink (DL) communications of the first type of connection 304a and a second NAS count pair associated with UL and DL communications of the second type of connection 304b.

[0038] like Figure 3B As shown, at a later time, UE 110 may establish a second type of connection 304c (e.g., non-3GPP) to a different PLMN (second PLMN 302B). Therefore, UE 110 now has a first type of connection 304a to first PLMN 302A and a second type of connection 304c to second PLMN 302B. Because the second type of connection (e.g., non-3GPP connection) is now with a different PLMN, a new NAS security context with a third NAS count pair is established. Based on current 3GPP standards (3GPP TS 31.102), because UE 110 now has a third NAS count pair, the second NAS count pair may be deleted.

[0039] like Figure 3C As shown, UE 110 attempts to re-establish a second type of connection 304b with first PLMN 302A. Figures 4 to 7 The discussion of describes how the UE 110 re-establishes this second type of connection 304b with the first PLMN 302A.

[0040] Figure 4 A method 400 for managing non-3GPP connections according to various exemplary embodiments is shown. At 405, the UE 110 establishes a first type of connection 304a (eg, a 3GPP connection) with the first PLMN 302A, such as Figure 3A At 410, UE 110 establishes a second type of connection 304b (e.g., a non-3GPP connection) with first PLMN 302A, also as shown. Figure 3A At 415, UE 110 establishes a second type of connection 304c (e.g., non-3GPP) with a second PLMN 302B, such as Figure 3B At 420, the UE 110 deregisters the second type of connection 304b that it has with the first PLMN 302A. Because the UE 110 explicitly deregisters the second type of connection 304b, when the UE 110 attempts to reestablish the connection, the AMF 131 will not attempt to reestablish the connection using the same NAS security context as the first type of connection 304a. Instead, when the UE 110 attempts to reestablish the second type of connection 304b, the UE 110 re-registers with the AMF 131 of the first PLMN 302A.

[0041] In some embodiments, the deregistration in 420 is based on a predetermined time period during which the UE 110 has entered idle mode for a second type of connection (non-3GPP). For example, if the UE 110 has entered idle mode in a second type of connection 304b with the first PLMN 302A, the UE 110 will deregister the connection.

[0042] In some embodiments, the UE 110 or the AMF 131 may deregister the second type of connection 304b. In some embodiments, when the UE 110 establishes the second type of connection 304c with the second PLMN 302B, the UE 110 transmits a deregistration request to the AMF 131 of the first PLMN 302A to deregister the second type of connection 304b. The deregistration request may be sent via the first type of connection 304a, which is still active when the UE 110 establishes its second type of connection 304c with the second PLMN 320B. In some embodiments, the AMF 131 of the first PLMN 302A may alternatively deregister the UE's second type of connection 304b with the first PLMN 302A in response to an indication sent by the UE 110. In some embodiments, the indication may be sent by the UE 110 via the first type of connection 304a and cause the AMF 131 to initiate the deregistration process.

[0043] Figure 5 A method 500 of managing NAS count pairs associated with non-3GPP connections according to various exemplary embodiments is shown. At 505, UE 110 establishes a first type of connection 304a (e.g., a 3GPP connection) with a first PLMN 302A, such as Figure 3A At 510, UE 110 establishes a second type of connection 304b (e.g., a non-3GPP connection) with first PLMN 302A, also as shown. Figure 3A At 515, UE 110 establishes a second type of connection 304c (e.g., non-3GPP) with a second PLMN 302B, such as Figure 3BAs shown. At 520, the UE 110 attempts to reestablish the second type of connection 304b with the first PLMN 302A. In response, at 525, the UE 110 receives a second NAS count pair from the AMF 131 of the first PLMN 302A. In some embodiments, the second NAS count pair is sent by the AMF 131 in a security mode command (SMC). The second NAS count pair is stored on the AMF 131 of the first PLMN 302A and corresponds to the NAS security context for the active first type of connection 304a that the UE 110 still has with the first PLMN 302A. At 530, the UE 110 determines whether it has a stored NAS count pair corresponding to the NAS security context of the first type of connection 304a.

[0044] If the UE 110 does not have a stored NAS count pair corresponding to the NAS security context of the first type of connection 304a, then at 535, the UE 110 adopts the second NAS count pair received from the AMF to re-establish the second type of connection 304b, or sets the second NAS count pair to 0 (reset the NAS count) to re-establish the second type of connection 304b.

[0045] However, if the UE 110 does have a stored NAS count pair corresponding to the NAS security context of the first type of connection 304a, then at 540, the UE 110 determines whether the stored NAS count pair is equal to the second NAS count pair received from the AMF 131. If the stored NAS count pair is equal to the second NAS count pair received from the AMF, then at 545, the UE 110 adopts the second NAS count pair received from the AMF 131 to re-establish the second type of connection 304b. However, if the stored NAS count pair is not equal to the second NAS count pair received from the AMF 131, then at 550, the UE 110 re-establishes the second type of connection 304b by one of the following: 1) rejecting the NASSMC procedure of sending the received NAS count pair; 2) adopting the second NAS count pair received from the AMF, or 3) setting the second NAS count pair to 0 (resetting the NAS count).

[0046] Figure 6 A method 600 for managing multiple connection access of a UE to a PLMN according to various exemplary embodiments is shown. At 605, the UE 110 establishes a first type of connection 304a (e.g., a 3GPP connection) with a first PLMN 302A, such as Figure 3A At 610, UE 110 establishes a second type of connection 304b (e.g., a non-3GPP connection) with first PLMN 302A, also as shown. Figure 3A At 615, UE 110 establishes a second type of connection 304c (e.g., non-3GPP) with a second PLMN 302B, such as Figure 3B As shown. At 620, the UE 110 attempts to reestablish the second type of connection 304b with the first PLMN 302A. When the UE 110 attempts to reestablish the connection and detects only one stored NAS count pair for only one type of connection (first or second), at 625, the UE 110 performs a primary authentication with the AMF 131 of the first PLMN 302A and derives a new security context for both the first type of connection 304a and the second type of connection 304b. Therefore, the UE 110 will receive two new NAS count pairs, each corresponding to one type of connection.

[0047] Figure 7 A method 700 for managing multiple NAS count pairs according to various exemplary embodiments is shown. At 705, UE 110 establishes a first type of connection 304a (eg, a 3GPP connection) with a first PLMN 302A, such as Figure 3A At 710, UE 110 establishes a second type of connection 304b (e.g., a non-3GPP connection) with first PLMN 302A, also as shown. Figure 3A At 715, UE 110 establishes a second type of connection 304c (e.g., non-3GPP) with a second PLMN 302B, such as Figure 3B As shown. At 720, UE 110 stores NAS count pairs for both the second type of connection 304b with the first PLMN 302A and the second type of connection 304c with the second PLMN 302B. Thus, UE 110 avoids failure in reestablishment of the second type of connection 304b with the first PLMN 302A. In some embodiments, UE 110 stores multiple NAS count pairs on its USIM. In some embodiments, UE 110 may alternatively store multiple NAS count pairs locally on the UE itself.

[0048] 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. In other examples, the exemplary embodiments of the above methods may be embodied as a program including lines of code stored on a non-transitory computer-readable storage medium, which, when compiled, may be executed on a processor or microprocessor.

[0049] Although this patent application describes various combinations of various aspects, each with different features, those skilled in the art will understand that any feature of one aspect may be combined with features of other aspects or features that are not functionally or logically inconsistent with the operation or function of the device of the aspects disclosed in the present invention in any manner not publicly denied.

[0050] 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.

[0051] 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, the present disclosure is intended to cover modifications and variations of the present disclosure, provided that these modifications and variations are within the scope of the appended claims and their equivalents.

Claims

1. A user equipment UE for managing multiple wireless connections, comprising: a transceiver configured to communicate with a plurality of networks; and a processor communicatively coupled to the transceiver and configured to perform operations including: establishing a first type of connection to a first public land mobile network PLMN, the first type of connection having a first NAS count pair corresponding to a first non-access stratum NAS security context associated with the first PLMN; establishing a second type of connection to a second PLMN, wherein a previous second type of connection was established with the first PLMN, wherein the previous second type of connection has a second NAS count pair corresponding to the first NAS security context, and wherein the second type of connection has a third NAS count pair corresponding to a second NAS security context associated with the second PLMN; as well as deregistering the previous second type of connection with the first PLMN to reset the second NAS count pair at the first PLMN, The first type of connection is a 3rd Generation Partnership Project 3GPP wireless connection, and the second type of connection is a non-3GPP wireless connection.

2. The UE according to claim 1, wherein the deregistration of the previous second type of connection comprises: upon establishing the second type of connection to the second PLMN, transmitting a deregistration request to an access and mobility management function AMF of the first PLMN, The deregistration request is transmitted via the first type of connection with the first PLMN.

3. The UE according to claim 1, wherein the deregistration of the previous second type of connection comprises: transmitting a request to the AMF of the first PLMN, the request triggering the AMF to initiate a deregistration procedure, The request is transmitted via the first type of connection with the first PLMN.

4. A user equipment UE for managing multiple wireless connections, comprising: a transceiver configured to communicate with a plurality of networks; and a processor communicatively coupled to the transceiver and configured to perform operations including: establishing a first type of connection to a first Public Land Mobile Network, PLMN, wherein the first type of connection has a first NAS count pair corresponding to a Non-Access Stratum, NAS, security context associated with an Access and Mobility Management Function, AMF, of the first PLMN; reestablishing a connection of the second type to the first PLMN after previously switching the connection of the second type to the second PLMN; as well as receiving a second NAS count pair from the AMF of the first PLMN, wherein the second NAS count pair corresponds to the second type of connection, The first type of connection is a 3rd Generation Partnership Project 3GPP wireless connection, and the second type of connection is a non-3GPP wireless connection.

5. The UE according to claim 4, wherein: When the UE does not have a stored second NAS count pair, or when the UE has a stored second NAS count pair that is different from the second NAS count pair received from the AMF of the first PLMN, the operations further include: Adopting the second NAS count pair received from the AMF of the first PLMN.

6. The UE according to claim 4, wherein: When the UE does not have a stored second NAS count pair, or when the UE has a stored second NAS count pair that is different from the second NAS count pair received from the AMF of the first PLMN, the operations further include: A second NAS count pair associated with the second type of connection is set to zero.

7. The UE according to claim 4, wherein: When the UE does not have a stored second NAS count pair, or when the UE has a stored second NAS count pair that is different from the second NAS count pair received from the AMF of the first PLMN, the operations further include: rejecting a NAS Security Mode Command SMC including the second NAS count pair from the AMF of the first PLMN.

8. The UE according to claim 4, wherein: When the UE has a stored second NAS count pair, the operation further includes: determining whether the stored second NAS count pair is identical to the second NAS count pair received from the AMF of the first PLMN.

9. The UE according to claim 7, wherein: When the UE determines that the stored second NAS count pair is equal to the second NAS count pair received from the AMF of the first PLMN, the operations further include: The second type of connection with the first PLMN is reestablished using the second NAS count pair received from the AMF of the first PLMN.

10. A user equipment UE for managing multiple wireless connections, comprising: a transceiver configured to communicate with a plurality of networks; and a processor communicatively coupled to the transceiver and configured to perform operations including: establishing a first type of connection to a first Public Land Mobile Network, PLMN, wherein the first type of connection has a first NAS count pair corresponding to a Non-Access Stratum, NAS, security context associated with an Access and Mobility Management Function, AMF, of the first PLMN; reestablishing a connection of the second type to the first PLMN after previously switching the connection of the second type to the second PLMN; as well as determining a new security context for both the first type of connection and the second type of connection, The first type of connection is a 3rd Generation Partnership Project 3GPP wireless connection, and the second type of connection is a non-3GPP wireless connection.

11. The UE of claim 10, wherein the new security context is determined when the UE determines that the UE has only one NAS count pair corresponding to one of the first type of connection or the second type of connection.

12. A user equipment UE for managing multiple wireless connections, comprising: a transceiver configured to communicate with a plurality of networks; and a processor communicatively coupled to the transceiver and configured to perform operations including: establishing a first type of connection to a first Public Land Mobile Network (PLMN), wherein the first type of connection has a first NAS count pair corresponding to a first Non-Access Stratum (NAS) security context associated with an Access and Mobility Management Function (AMF) of the first PLMN; establishing a second type of connection to a second PLMN, wherein the second type of connection has a third NAS count pair corresponding to a second NAS security context associated with the AMF of the second PLMN, wherein a previous second type of connection was with the first PLMN and included a second NAS count pair corresponding to the first NAS security context; as well as storing the first NAS count pair, the second NAS count pair, and the third NAS count pair, The first type of connection is a 3rd Generation Partnership Project 3GPP wireless connection, and the second type of connection is a non-3GPP wireless connection. 13 . The UE according to claim 12 , wherein the first NAS count pair, the second NAS count pair and the third NAS count pair are stored on a Universal Subscriber Identity Module (USIM) of the UE.

14. The UE according to claim 12, further comprising: A memory configured to locally store the first NAS count pair, the second NAS count pair, and the third NAS count pair.

15. A network element for managing a plurality of radio connections, the network element implementing an access and mobility management function (AMF) of a core network and comprising: One or more processors configured to perform operations including: When a user equipment UE has switched a second type of connection from a first public land mobile network PLMN to a second PLMN, receiving from the UE a request for deregistration of a first type of connection or a second type of connection between the UE and the first PLMN; as well as deregistering one of the first type of connection or the second type of connection based on the request, The first type of connection is a 3rd Generation Partnership Project 3GPP wireless connection, and the second type of connection is a non-3GPP wireless connection.

16. The network component of claim 15, wherein the request is for a deregistration of the non-3GPP wireless connection.

17. The network component of claim 16, wherein the request is a deregistration request.

18. The network component of claim 16, wherein the request is for requesting the AMF to initiate the deregistration of the non-3GPP wireless connection.

19. A network element for managing a plurality of radio connections, the network element implementing an access and mobility management function (AMF) of a core network and comprising: One or more processors configured to perform operations including: receiving a request from a user equipment UE to re-establish a connection of the second type to a first PLMN after the UE has previously switched the connection of the second type to a second public land mobile network PLMN, and wherein the UE additionally has a connection of the first type to the first PLMN; as well as transmitting to the UE a NAS security mode command SMC including a second non-access stratum NAS count pair, wherein the second NAS count pair is associated with a NAS security context corresponding to the first type of connection and the second type of connection with the first PLMN, The first type of connection is a 3rd Generation Partnership Project 3GPP wireless connection, and the second type of connection is a non-3GPP wireless connection.

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