METHOD AND SYSTEM FOR CONTROLLING SA CAPABILITY OF UE

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method for controlling standalone access (SA) capability performed by a terminal, includes: detecting that at least one subscriber identity module (SIM) card is available in the terminal; determining whether the at least one SIM card supports SA capability available in the terminal; enabling the SA capability in the terminal based on determining that the at least one SIM card supports the SA capability; and disabling the SA capability in the terminal based on determining that the at least one SIM card does not support the SA capability.

FIELD OF INVENTION

The present disclosure relates to wireless communication, and more particularly to a method and a system for controlling standalone access (SA) capability of a User Equipment (UE).

BACKGROUND

In general, fifth generation standalone access (5G SA) describes standalone operation of a 5G network. During standalone operation, the 5G network is not reliant on any other network infrastructure and can operate independently. In recent times, many operators started 5G SA commercialization. In few scenarios, a user equipment (UE)supports 5G SA but a SIM card fails to support the 5G SA. Thereby leading to unnecessary Radio Access Technology (RAT) scans for the SA when the SIM card fails to support the 5G SA capability, and increasing the time required for initial registration with a network. In few other scenarios, the UE chipset supports the 5G SA, but the SA capability is disabled in software since no network supports the SA capability in a particular region. In such cases, the UE may need to go through Maintenance Release (MR) to enable the SA support. Also, the UE might require a dynamic way to enable/disable the SA capability based on the SIM card inserted into the UE. Further additional software upgrade is required to enable the 5G SA capability during MR. In few exceptional cases, while moving the SIM card from fourth-generation (4G) to the 5G SA network, the SIM card is not SA capable, but the UE uses a mapped 5G Global Unique Temporary Identifier (GUTI) to camp on a SA network. However, the UE may be allowed by the network to register on the 5G SA network without having a valid SIM card to be authenticated over the SA network.

In related art methods and systems, most commercial network operators reject a registration request from a UE which does not send a Subscription concealed identifier (SUCI) (a key identifier used in the 5G SA). This is in contrast to LTE, in which an international mobile subscriber identity (IMSI) sent in the clear is acceptable during the initial registration. Therefore, it is required to control the UE access to the SA network based on the SIM card's capability. A SUCI is a version of a SUPI that is protected with asymmetric cryptography. A SUPI is a generic name of an international mobile subscriber identity (IMSI) in 5G networks.

Thus, it is desired to address the above mentioned disadvantages or other shortcomings or at least provide a useful alternative.

OBJECT OF INVENTION

Embodiments provide a method and a system for controlling standalone access (SA) capability of a User Equipment (UE). The method includes determining whether a SIM card supports a subscription identifier privacy support service (Service no 124) and/or a subscription concealed identifier (SUCI) calculation service (Service no 125) by a Universal Subscriber Identity Module (USIM), when the SIM card is detected. Therefore, the proposed method does not require additional software upgrade to enable the 5G SA capability in the UE as the SIM card's capability is determined.

Another object of the embodiments herein is to dynamically enable/disable SA based on the SIM card services. The proposed method avoids unauthorized access to operator's 5G SA network using a mapped Global Unique Temporary Identifier (GUTI) from a fourth-generation(4G)/Long term evolution (LTE) system. The proposed method avoids unnecessary Radio Access Technology (RAT) scans for the SA when the SIM card cannot support 5G SA services, thereby reducing the time required for initial registration with the network and saving battery life especially for no service scenarios or roaming scenarios where 5G SA network/subscription might not be available.

According to an aspect of the disclosure, a method for controlling standalone access (SA) capability performed by a terminal, includes: detecting that at least one subscriber identity module (SIM) card is available in the terminal; determining whether the at least one SIM card supports SA capability available in the terminal: enabling the SA capability in the terminal based on determining that the at least one SIM card supports the SA capability: and disabling the SA capability in the terminal based on determining that the at least one SIM card does not support the SA capability.

The determining whether the at least one SIM card supports the SA capability may include: based on the at least one SIM card being detected, determining whether the at least one SIM card supports at least one of a subscription identifier privacy support service and a subscription concealed identifier (SUCI) calculation service performed by a universal subscriber identity module (USIM): based on determining that the at least one SIM card supports at least one of the subscription identifier privacy support service and the SUCI calculation service: determining SA support for the terminal, and enabling the SA capability in the terminal; and based on determining that the at least one SIM card does not support at least one of the subscription identifier privacy support service and the SUCI calculation service, disabling the SA capability in the terminal.

The method may further include, based on a capability of the at least one SIM card changing: enabling the SA capability in the terminal based on the capability of the at least one SIM card changing to support at least one of the subscription identifier privacy support service and the SUCI calculation service: and disabling the SA capability in the terminal based on the capability of the at least one SIM card changing to not support at least one of the subscription identifier privacy support service and the SUCI calculation service.

The enabling the SA capability may include: adding the SA capability to a radio access technology (RAT) priority list, wherein the terminal is configured to prioritize an SA RAT over a plurality of RATs: and moving the terminal to an SA network using a mapped global unique temporary identifier (GUTI) or a SUCI.

The disabling the SA capability in the terminal may include: blocking the SA capability in the terminal: removing the SA capability from a radio access technology (RAT) priority list: and scanning for an alternate RAT among a plurality of RATs and camp on the alternate RAT until the at least one SIM card supports at least one of the subscription identifier privacy support service and the SUCI calculation service.

The method may further include, after the scanning for the alternate RAT over the plurality of RATs and the camping on the alternate RAT: acquiring a network by the terminal on the alternate RAT: and updating the at least one SIM card in response to the network on the alternate RAT using a SIM over-the-air (OTA) procedure to enable the SA capability in the terminal.

The method may further include: determining an NULL SUCI is allowed in a public land mobile network (PLMN) as per data maintained by the terminal, wherein the PLMN is a current PLMN: enabling the SA capability in the terminal based on the NULL SUCI being allowed in the current PLMN as per the data maintained by the terminal; determining whether SA registration with the NULL SUCI is successful in the terminal; based on determining that the SA registration with the NULL SUCI is successful, adding SA registration with the NULL SUCI to an allowed list of the PLMN to enable the SA capability with the NULL SUCI in a database maintained by the terminal; and based on determining that the SA registration with the NULL SUCI is unsuccessful, starting a predefined timer at a configurable interval in the terminal to enable SA registration with the NULL SUCI in the terminal.

According to an aspect of the disclosure a terminal includes: a memory: a communicator; a processor operatively coupled to the memory and the communicator; and a standalone access (SA) capability management controller operatively coupled to the memory, the processor and the communicator, the SA capability management controller configured to: detect whether at least one subscriber identity module (SIM) card is available in the terminal; determine whether the at least one SIM card supports a standalone access (SA) capability available in the terminal: enable the SA capability in the terminal based on determining that the at least one SIM card supports the SA capability: and disable the SA capability in the terminal based on determining that the at least one SIM card does not support the SA capability.

The SA capability management controller may be further configured to determine the SA capability by: based on the at least one SIM card being detected, determining whether the at least one SIM card supports at least one of a subscription identifier privacy support service and a subscription concealed identifier (SUCI) calculation service performed by a universal subscriber identity module (USIM): based on determining that the at least one SIM card supports at least one of the subscription identifier privacy support service and the SUCI calculation service, determining SA support for the terminal, and enabling the SA capability in the terminal; and based on the at least one SIM card not supporting at least one of the subscription identifier privacy support service or the SUCI calculation service, disabling the SA capability in the terminal.

The SA capability management controller may be further configured to, based on a capability of the at least one SIM card changing: enable the SA capability in the terminal based on the capability of the at least one SIM card changing to support at least of the subscription identifier privacy support service and the SUCI calculation service; and disable the SA capability in the terminal based on the capability of the at least one SIM card changing to not support at least one of the subscription identifier privacy support service and the SUCI calculation service.

The SA capability management controller may be further configured to enable the SA capability by: adding the SA capability to a radio access technology (RAT) priority list, wherein the terminal is configured to prioritize an SA RAT over a plurality of RATs; and moving the terminal to an SA network using the GUTI or a SUCI.

The SA capability management controller may be further configured to disable the SA capability in the terminal by: blocking the SA capability in the terminal; removing the SA capability from a radio access technology (RAT)priority list; and wherein the terminal may be further configured to: scan for an alternate RAT over a plurality of RATs, and camp on the alternate RAT until the at least one SIM card supports at least one of the subscription identifier privacy support service and the SUCI calculation service.

The terminal may be further configured to, after scanning for the alternate RAT over the plurality of RATs and camping on the alternate RAT: acquire a network on the alternate RAT: and update the at least one SIM card with respect to the network on the alternate RAT using a SIM over-the-air (OTA) procedure to enable the SA capability in the terminal.

The terminal may be further configured to: determine that a NULL SUCI is allowed in a public land mobile network (PLMN) based on data maintained by the terminal, wherein the PLMN is a current PLMN; enable the SA capability in the terminal based on the NULL SUCI being allowed in the PLMN based on the data maintained by the terminal; determine whether SA registration with the NULL SUCI is successful in the terminal; based on determining that the SA registration with NULL SUCI is successful, add SA registration with the NULL SUCI to an allowed list of PLMNs to enable the SA capability with the NULL SUCI in a database maintained by the terminal; and based on determining that the SA registration with NULL SUCI is unsuccessful, start a predefined timer at a configurable interval in the terminal to enable SA registration with the NULL SUCI in the terminal.

DETAILED DESCRIPTION OF INVENTION

The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another. As used herein, expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression, “at least one of a, b, and c,” should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

Accordingly the embodiments herein disclose a method for controlling standalone access (SA) capability of a terminal. The method includes detecting whether a SIM card is available in terminal. The method includes determining SA capability of the SIM card available in the terminal. Further, the method includes enabling the SA capability in the terminal if the SIM card supports the SA capability, and disabling the SA capability in the terminal (400) if the SIM card fails to support the SA capability.

Further, the SA capability of the SIM card available in the terminal is determined by determining whether the SIM card supports at least one of a subscription identifier privacy support service (Service no 124) and a subscription concealed identifier (SUCI) calculation service (Service no 125) by a Universal Subscriber Identity Module (USIM), when the SIM card is detected. The method includes performing one of (i) determining SA support for the UE when the SIM card supports at least one of the subscription identifier privacy support service and the SUCI calculation service by the USIM, (ii) enabling the SA capability in the terminal in case that the SIM card supports at least one of the subscription identifier privacy support service and the SUCI calculation service by the USIM, and (iii) disabling the SA capability in the terminal in case that the SIM card fails to support at least one of the subscription identifier privacy support service and the SUCI calculation service by the USIM.

Accordingly the embodiments herein disclose a system for controlling SA capability of the terminal. The system includes a memory, a processor coupled to the memory, a communicator coupled to the memory and the processor, and a SA capability management controller coupled to the memory, the processor and the communicator. The SA capability management controller is configured to detect whether the SIM card is available in the terminal, and determine the SA capability of the SIM card available in the terminal. Further, the SA capability management controller is configured to enable the SA capability in the terminal if the SIM card supports the SA capability, and disable the SA capability in the UE if the SIM card fails to support the SA capability.

Related art methods and systems provide SA support using a maintenance release (MR) as shown inFIG.1. Referring toFIG.1, considering a scenario where a UE device chipset supports 5G SA, but disables SA in software because of unpreparedness of network's SA support in some particular regions. In such cases, UE may need to go through MR to enable the SA support. At step110, the related art method determines that the UE fails to support the SA capability. At step120, the method determines that a network operator starts supporting the SA capability. At step130, MR is additionally used to enable SA support in the UE and the UE starts supporting SA based on the MR. However, the related art method requires additional software upgrade (Maintenance release) to enable 5G SA capability in the UE, which is time consuming and increases cost for upgrading the software.

Related art methods and systems provide SA support using MR-New operator support as shown inFIG.2. Referring toFIG.2, considering a scenario where the UE chipset supports 5G SA, but the 5G SA is enabled based on a public land mobile network (PLMN) allow list. The UE enables support only for limited operators based on the PLMN allow list. In such cases, the UE may need to go through the MR to enable SA support for specific PLMN (new operator). At step210, the related art method determines that the UE supports SA on specific PLMN based on an allow list (PLMN1,PLMN2). At step220, the related art method determines that the UE starts supporting SA on a new operator (PLMN3) by adding the new operator (PLMN3) in the specific allow list using MR. At step230, the UE starts supporting SA on the new operator (PLMN3). However, using MR to add a new operator (PLMN3) in the specific allow list requires an additional software upgrade to enable the 5G SA capability, which is time consuming and increases cost for upgrading the software.

Further, in related art methods and systems, the UE camps on a Fourth-generation Long term evolution (4G LTE) to enable SA in few exceptional cases as shown inFIG.3. In such cases, the SIM card is not SA capable or SA subscribed, but the UE uses the mapped 5G Global Unique Temporary Identifier (GUTI) to camp on the SA network (while moving from 4G to 5G SA). The mapped GUTI is associated with a unique ID of the UE, and so is referred to as a mapped GUTI. The unique ID of the UE may be a permanent equipment identifier (PEI). Referring toFIG.3, at step310, the UE enables 5G SA on SIM detection, and initially camps on the LTE network. At step320, the UE moves to a 5G SA area. At step330, the UE tries registration on the SA network using the mapped GUTI and may register successfully even when the SIM card is not capable to support the 5G SA or a user is not subscribed for 5G SA service, resulting in revenue loss for an operator. Additionally, the registration of the UE using the mapped GUTI may lead to registration failure when the SIM card does not support the 5G services or when the SIM card is not upgraded by the operator to support the 5G SA services, causing registration delays on the alternate RATs.

The proposed method solves the above mentioned issues as follows:i. If the UE is 5G SA capable and the network has requested SA to be enabled at an initial launch, then the software will have 5G SA enabled by default.ii. When a new SIM card is inserted or SIM swap happens, the UE requests for the availability of the services (Subscription identifier privacy support service or SUCI calculation service by the USIM) in the SIM.iii. If the SIM card supports any of the Subscription identifier privacy support service or SUCI calculation service by the USIM, then the UE enables the SA capability.iv. If the SIM card fails to support any of the Subscription identifier privacy support service or SUCI calculation service by the USIM, then the UE disables the SA capabilities before registration on the network.v. Alternatively, if the SA services supported SIM is inserted in a SA disabled UE, then after reading the SIM services, the UE re-enables the SA capabilities before registration on the network.

Unlike the related art methods and systems, the proposed method enables/disables the 5G SA capability in the UE in a cost effective manner. The proposed method uses a dynamic UE SIM differentiation solution to efficiently manage the 5G SA capabilities of the UE, thereby avoiding unnecessary over-the-air (OTA) signaling between the UE and the Network. Further, unnecessary Radio Access Technology (RAT) scans for the SA when the SIM card fails to support the 5G SA services can be avoided. Thereby, reducing the time required for initial registration with the network and saving battery life. Also, the additional software upgrade to enable the 5G SA capability can be avoided as the proposed method determines the 5G SA capability by the SIM card's capability.

Referring now to the drawings and more particularly toFIGS.4through7, where similar reference characters denote corresponding features consistently throughout the figure, these are shown as example embodiments.

FIG.4is a block diagram of the UE (400) for controlling SA capability based on the SIM subscription, according to one or more embodiments.

Referring to theFIG.1, the UE (400) may be but not limited to a terminal, a laptop, a palmtop, a desktop, a mobile phone, a smart phone, Personal Digital Assistant (PDA), a tablet, a wearable device, an Internet of Things (IOT) device, a virtual reality device, a foldable device, a flexible device, a display device, and an immersive system.

In an embodiment, the UE (400) includes a memory (410), a processor (420), a communicator (430), a SA capability management controller (440), and a display (450).

The memory (410) is configured to store subscription identifier privacy support service by a Universal Subscriber Identity Module (USIM) and a subscription concealed identifier (SUCI) calculation service by the USIM. The memory (410) can include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the memory (410) may, in some examples, be considered a non-transitory storage medium. The term “non-transitory” may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term “non-transitory” should not be interpreted that the memory (410) is non-movable. In some examples, the memory (410) is configured to store larger amounts of information. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache).

The processor (420) may include one or a plurality of processors. The one or the plurality of processors may be a general-purpose processor, such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and/or an AI-dedicated processor such as a neural processing unit (NPU). The processor (420) may include multiple cores and is configured to process the subscription identifier privacy support service and the SUCI calculation service by the USIM stored in the memory (410).

In an embodiment, the communicator (430) includes an electronic circuit specific to a standard that enables wired or wireless communication. The communicator (430) is configured to communicate internally between the memory (410), the processor (420), and the SA capability management controller (440) of the UE (400) and with external devices via one or more networks.

In an embodiment, the SA capability management controller (440) includes a detection unit (441), a service determination unit (442), a SA enabling unit (443), and a SA disabling unit (444). As mentioned below, each unit may be implemented by a processor and memory and/or custom hardware such as an application specific integrated circuit (ASIC).

In an embodiment, the detection unit (441) is configured to detect whether the SIM card is available or not available in the UE (400).

In an embodiment, the service determination unit (442) is configured to determine whether the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM, when the detection unit (441) detects that the SIM card is available in the UE (400).

In an embodiment, the SA enabling unit (443) is configured to determine SA support for the UE (400) when the service determination unit (442) determines that the SIM card supports at least one of the subscription identifier privacy support service and the SUCI calculation service by the USIM. The SA enabling unit (443) is configured to enable the SA capability in the UE (400) in response to determining SA support for the UE (400) when the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM.

In an embodiment, the SA disabling unit (444) is configured to disable the SA capability in the UE (400) when the service determination unit (442) determines that the SIM card fails to support at least one of the subscription identifier privacy support service and the SUCI calculation service by the USIM.

The SA capability management controller (440) is implemented by processing circuitry such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits, or the like, and may optionally be driven by firmware. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like.

At least one of the plurality of modules/components of the SA capability management controller (440) may be implemented through an AI model. A function associated with the AI model may be performed through memory (410) and the processor (420). The one or a plurality of processors controls the processing of the input data in accordance with a predefined operating rule or the AI model stored in the non-volatile memory and the volatile memory. The predefined operating rule or artificial intelligence model is provided through training or learning.

Here, being provided through learning means that, by applying a learning process to a plurality of learning data, a predefined operating rule or AI model of a desired characteristic is made. The learning may be performed in a device itself in which AI according to an embodiment is performed, and/or may be implemented through a separate server/system.

The learning process is a method for training a predetermined target device (for example, a robot) using a plurality of learning data to cause, allow, or control the target device to make a determination or prediction. Examples of learning processes include, but are not limited to, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning.

In an embodiment, the display (450) is configured to display one of the subscription identifier privacy support service and the SUCI calculation service by the USIM supported by the UE (400). The display (450) is implemented using touch sensitive technology and comprises one of liquid crystal display (LCD), light emitting diode (LED), etc.

Although theFIG.4shows the hardware elements of the UE (400) but it is to be understood that other embodiments are not limited thereon. In other embodiments, the UE (400) may include less or more number of elements. Further, the labels or names of the elements are used only for illustrative purpose and does not limit the scope of the disclosure. One or more components can be combined together to perform same or substantially similar function.

FIG.5is a flow chart (200) illustrating a method for controlling the SA capability of the UE (400), according to one or more embodiments.

Referring to theFIG.5, at step502, the method includes the UE (400) detecting whether the SIM card is available in the UE (400). For example, in the UE (400) as illustrated in theFIG.1, the SA capability management controller (440) is configured to detect whether the SIM card is available in the UE (400).

At step504, the method includes the UE (400) determining whether the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM, when the SIM card is detected. For example, in the UE (400) as illustrated in theFIG.1, the SA capability management controller (440) is configured to determine whether the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM, when the SIM card is detected.

At step506, the method includes the UE (400) disabling the SA capability in the UE (400) when the SIM card fails to support one of the subscription identifier privacy support service and the SUCI calculation service by the USIM. For example, in the UE (400) as illustrated in theFIG.1, the SA capability management controller (440) is configured to disable the SA capability in the UE (400) when the SIM card fails to support one of the subscription identifier privacy support service and the SUCI calculation service by the USIM.

At step508, the method includes the UE (400) providing the SA services via SIM Over-The-Air (OTA) procedure. The SIM OTA procedure updates and changes data in the SIM card without having to reissue the SIM card. The method includes the UE (400) re-enabling the SA capability after SIM refresh as the SA services are available in the SIM card after SIM OTA update. For example, in the UE (400) as illustrated in theFIG.1, the SA capability management controller (440) is configured to provide the SA services via the SIM OTA procedure. The SIM OTA procedure updates and changes data in the SIM card without having to reissue the SIM card. The SA capability management controller (440) is configured to re-enable the SA capability after SIM refresh as the SA services are available in the SIM card after SIM OTA update.

At step510, the method includes the UE (400) determining SA support for the UE (400) when the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM. For example, in the UE (400) as illustrated in theFIG.1, the SA capability management controller (440) is configured to determine SA support for the UE (400) when the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM.

At step512, the method includes the UE (400) enabling SA capability in the UE, when the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM. For example, in the UE (400) as illustrated in theFIG.1, the SA capability management controller (440) is configured to enable SA capability in the UE, when the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM.

FIG.6is a step-by-step procedure illustrating a method for controlling the SA capability based on the SIM subscription, according to one or more embodiments.

Referring toFIG.6, at step600, the method includes detecting that the SIM card is available in the UE (400). The UE (400) is powered up once the SIM card is detected in the UE (400).

At step610, the method includes determining that the UE (400) is a SA capable device in response to detecting the SIM card in the UE (400) and powering up the UE (400).

At step620, the method includes determining whether the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM, when the SIM card is detected. When the SIM card fails to support one of the subscription identifier privacy support service and the SUCI calculation service by the USIM, the SA capability is blocked in the UE (400) and the SA capability is removed from a RAT priority list.

At step630, the UE (400) scans for an alternate RAT over the plurality of RATs and camps on the alternate RAT until the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM.

At step640, upon scanning for the alternate RAT over the plurality of RATs and camping on the alternate RAT, the UE (400) acquires a network on the alternate RAT.

At step650, the method includes updating the SIM card in response to the acquired network on the alternate RAT using the SIM OTA procedure to enable the SA capability in the UE (400).

At step660, the SIM card is updated and refreshed and the SA capability is enabled in the UE (400).

At step670, when the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM, the method includes adding the SA capability to the RAT priority list to enable the SA capability in the UE (400).

At step680, the UE (400) prioritizes SA RAT over a plurality of RATs to enable the SA capability in the UE (400), after adding the SA capability to the RAT priority list.

At step690, the UE (400) acquires the service on the 5G SA based on inserted SIM card, when the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM.

Further to the user equipment interactions with the network shown inFIG.6, in some embodiments of acquiring service at operation690, a mapped GUTI is associated with an identifier of the terminal. In some embodiments, an identifier of the terminal is a permanent equipment identifier (PEI) in operation690. In some embodiments of operation690, the USIM is an application performed by the SIM card. In some embodiments of operation690, the SUCI is based on a subscription permanent identifier (SUPI). In some embodiments, the NULL SUCI is based on an unconcealed SUPI (also seeFIG.7operation740, discussed below). Some embodiments of operation690further include sending, after the enabling the SA capability at operation670, an encrypted subscription permanent identifier (SUPI) to the network in the form of a subscription concealed identifier (SUCI).

FIG.7is a flow diagram illustrating a method for handling exceptional cases when a network allows registration with NULL SUCI, according to one or more embodiments.

Referring toFIG.7, at step710, the method includes determining that the UE (400) is the SA capable device in response to detecting the SIM card in the UE (400) and powering up the UE (400).

At step720, the method includes determining whether the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM, when the SIM card is detected.

At step730, the method includes enabling the SA capability in the UE (400), when the SIM card supports one of the subscription identifier privacy support service and the SUCI calculation service by the USIM.

At step740, when the SIM card fails to support any of the subscription identifier privacy support service and the SUCI calculation service by the USIM, the method includes determining NULL SUCI is allowed in the current PLMN as per the data maintained by the UE (400). The NULL SUCI is based on an unconcealed SUPI.

At step750, the method includes disabling the SA capability in the UE (400) when NULL SUCI is not allowed as per the data maintained by UE (400).

At step760, the method includes enabling the SA capability in the UE (400) when NULL SUCI is allowed in a current Public Land Mobile Network (PLMN) as per the data maintained by the UE (400) and trying SA registration with NULL SUCI in the UE (400).

At step770, the method includes determining whether the SA registration with NULL SUCI is successful in the UE (400). When SA registration with NULL SUCI is not successful, the SA capability in the UE (400) is disabled and a predefined timer is started at a configurable interval in the UE (400) to enable SA registration with NULL SUCI in the UE (400) for the given PLMN and disable the SA on the PLMN until expiry of the predefined timer.

At step780, when SA registration with NULL SUCI is successful, the UE (400) adds SA registration with the NULL SUCI to an allowed list of the PLMN to enable the SA capability with NULL SUCI in a database maintained by the UE(400).

At step790, the SA registration information with NULL SUCI is updated on the PLMN.

In some embodiments ofFIG.7, if a NULL SUCI is allowed, logic flows to operation760regardless of the value of a timer (T_SARetry).

Also, in some embodiments ofFIG.7, at operation770, if the SA registration is not successful and the value of a timer (T_SARetry) is not expired, logic flows to operation740, otherwise (when the timer has expired), the logic flows to operation750.