Network provisioning of concealed subscription identifiers to constrained devices

Abstract

Embodiments include methods for an identification server configured to provide concealed identifiers for user subscriptions to a communication network. Such methods include receiving, from a first network function (NF) of the communication network, a message including a first concealed identifier of a user subscription to the communication network. Such methods include, based on determining that the first concealed identifier needs to be updated, determining a second concealed identifier of the user subscription, including performing an encryption a non-concealed identifier of the user subscription, using a public part of an asymmetric key pair. Such methods include determining a secured second concealed identifier of the user subscription, based on the second concealed identifier and a symmetric key that is known to a user equipment (UE) associated with the user subscription. Such methods include sending the secured second concealed identifier to the first NF.

Description

[0001] NETWORK PROVISIONING OF CONCEALED SUBSCRIPTION IDENTIFIERS TO CONSTRAINED DEVICES

[0002] TECHNICAL FIELD

[0003] The present disclosure relates generally to the field of communication networks, and more specifically to techniques for a communication network to provision concealed user subscription identifiers to devices that required them but lack processing resources needed to compute them.

[0004] BACKGROUND

[0005] Internet of Things (loT) describes the network of physical objects — “things” — that are embedded with sensors, software, and other technologies for the purpose of connecting and exchanging data with other devices and systems over the internet. These devices range from ordinary household objects to sophisticated industrial tools. By using technologies such as low- cost computing, wireless communications, cloud computing, big data, and analytics, loT devices can collect and share data with minimal human intervention. With more than 7 billion connected loT devices today, experts are expecting this number to grow to 10 billion by 2020 and 22 billion by 2025.

[0006] In some applications, such as monitoring temperature of foodstuffs, loT devices may have small batteries that are disposable (e.g., organic, compostable), rechargeable, or have very limited capacity. However, the need to change battery and battery lifetime are concerns for applications such as asset tracking and environmental / industrial sensors. For such applications, there has been significant interest in so-called zero-energy loT (ZE-IoT) devices, which do not require battery replacement and often “harvest” energy from the environment.

[0007] In general, ZE-IoT devices can be built in very small form factors - even via printing - and have ultra-low energy consumption fulfilled on energy-harvesting from ambient energy sources or from back-scattering communication. That is, instead of relying on a built-in battery to provide energy for communication, ZE-IoT devices harvest this energy from sources such as vibrations, solar radio, radio frequency (RF) emissions, etc. In a technique referred to as “backscattering”, a carrier wave is transmitted to the ZE-IoT device, which harvests energy from the carrier wave and reflects back a modulated version to a reader. These harvesting techniques facilitate autonomous operation during the lifetime of ZE-IoT devices without need for manual replacement or charging of a battery.

[0008] Currently the fifth generation (5G) of cellular systems, also referred to as New Radio (NR), is being standardized within the Third-Generation Partnership Project (3GPP). 5G / NR is developed for maximum flexibility to support a variety of use cases. These include enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device-to-device (D2D), and several other use cases. 5G / NR was first specified in Release 15 (Rel-15) and continues to evolve through subsequent releases.

[0009] At a high level, the 5G System (5GS) consists of an Access Network (AN) and a Core Network (CN). The AN provides user equipment (UEs) connectivity to the CN, e.g., via base stations such as gNBs or ng-eNBs. The 5G CN (also called “5GC”) includes a variety of Network Functions (NF) that provide a wide range of different functionalities such as session management, connection management, charging, authentication, etc.

[0010] Two types of user identifiers are used in 5G networks. Subscription Permanent Identifier (SUPI) is a unique identifier that represents a subscriber's permanent identity in a 5G network. It is intended to provide enhanced privacy and security compared to the International Mobile Subscriber Identity (IMSI) used in fourth-generation (4G) and earlier networks. Subscription Concealed Identifier (SUCI) is a temporary identifier used to conceal a subscriber's SUPI in a 5G network, e.g., to avoid sending the SUPI over the air. SUCI contains several concatenated values including a Protection Scheme Output that is generated cryptographically by the UE and decrypted by the 5G network to determine the corresponding SUPI.

[0011] 3GPP initiated a study on “Ambient loT”, as further described in 3GPP documents RP- 222685, TR 22.840 (v2.0.0), and TR 38.848 (vl 8.0.0). The study targets a new loT technology suitable for deployment in a 3 GPP network, based on ultra-low complexity devices with ultra-low power consumption for very low-end loT applications. The study is intended to address use cases and scenarios that cannot otherwise be fulfilled based on existing 3GPP low-power wide-area (LPWA) technology such as narrowband loT (NB-IoT), even with reduced peak transmit (Tx) power. As such, it is expected that the radio interface and protocols for this new loT technology will differ from existing 3 GPP radio access technologies (RATs) such as NR and NB-IoT.

[0012] SUMMARY

[0013] It is also expected that many Ambient loT devices will be very resource-constrained, with these devices also being referred to as “constrained devices.” As such, constrained devices may have insufficient computing resources for cryptographic calculations needed to generate SUCI from SUPI. Conventional techniques that could be used instead to generate SUCI suffer from well-known security flaws and / or require significant new functionality in the 5G network.

[0014] An object of embodiments of the present disclosure address these and other problems, issues, and / or difficulties by providing secure techniques for SUCI that are suitable for constrained devices yet have minimal impact to 5G network resources. Some embodiments of the present disclosure include methods (e.g., procedures) for an identification server configured to provide concealed identifiers for user subscriptions to a communication network.

[0015] These exemplary methods include receiving, from a first NF of the communication network, a message including a first concealed identifier of a user subscription to the communication network. These exemplary methods also include, based on determining that the first concealed identifier needs to be updated, determining a second concealed identifier of the user subscription, including performing an encryption a non-concealed identifier of the user subscription, using a public part of an asymmetric key pair. These exemplary methods also include determining a secured second concealed identifier of the user subscription, based on the second concealed identifier and a symmetric key that is known to a user equipment (UE) associated with the user subscription. These exemplary methods also include sending the secured second concealed identifier to the first NF.

[0016] In some embodiments, determining the secured second concealed identifier includes encrypting the second concealed identifier using the symmetric key. In other embodiments, determining the secured second concealed identifier includes calculating a message authentication code (MAC) for the second concealed identifier using the symmetric key. In such case, the secured second concealed identifier comprises the second concealed identifier and the MAC.

[0017] In some embodiments, these exemplary methods also include determining an authentication vector including an authentication token (AUTN) and a random value (RAND) that are usable by the UE to authenticate the identification server. The authentication vector is sent to the first NF together with the secured second concealed identifier. In some of these embodiments, these exemplary methods also include generating the symmetric key based on the random value (RAND) and a primary key (K) associated with the user subscription.

[0018] In some embodiments, determining that the first concealed identifier needs to be updated is based on one or more of the following: a first indication included in the message from the first NF, a second indication received from a second NF of the communication network, and a configuration of the identification server.

[0019] In some embodiments, the UE is a constrained UE that is unable to determine a concealed identifier of the user subscription based on the non-concealed identifier of the user subscription. In some embodiments, the public-key encryption of the non-concealed identifier uses one of the following as an input: a pseudo-random string, a counter, or a current time.

[0020] In some embodiments, the identification server is a unified data management function (UDM), and the first NF is an authentication server function (AUSF). In other embodiments, the identification server is an authentication server function (AUSF) and the first NF is an access and mobility management function (AMF). Also, these exemplary methods also include receiving, from a UDM of the communication network, security materials used to determine the second concealed identifier and the secured second concealed identifier.

[0021] Other embodiments include identification severs (e.g., UDM, AUSF, etc.), or network equipment arranged to implement such servers, that are configured to perform operations corresponding to any of the exemplary methods described herein. Other embodiments include non-transitory, computer-readable media storing computer-executable instructions that, when executed by processing circuitry, configure such identification servers to perform operations corresponding to any of the exemplary methods described herein.

[0022] Embodiments may provide various benefits and / or advantages. For example, embodiments may require minimal changes in network-side functionality compared to pseudonym-type techniques. As a more specific example, embodiments may avoid requiring the network to maintain state, so there are no synchronization problems where a device and the network disagree on the device’s current pseudonym. As another example, embodiments may facilitate a uniform network approach to de-concealment of SUCIs for all Ambient loT devices, including those able to generate SUCI and those unable to generate SUCI. As another example, since the network determines unique SUCIs for each UE, embodiments may avoid identifier collisions that are common with pseudonym-based solutions. More generally, embodiments may facilitate deployment of Ambient loT in conjunction with 3 GPP networks (e.g., 5G).

[0023] These and other objects, features, and advantages of the present disclosure will become apparent upon reading the following Detailed Description in view of the Drawings briefly described below.

[0024] BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figures 1-2 illustrate various aspects of an exemplary 5G network architecture.

[0026] Figure 3-4 show signaling diagrams of procedures for a constrained UE to obtain a precomputed SUCI, according to various embodiments of the present disclosure.

[0027] Figure 5 shows an exemplary method (e.g., procedure) for an identification server, according to various embodiments of the present disclosure.

[0028] Figure 6 shows an exemplary method (e.g., procedure) for a UE, according to various embodiments of the present disclosure.

[0029] Figure 7 shows an exemplary method (e.g., procedure) for an AMF, according to various embodiments of the present disclosure.

[0030] Figure 8 shows a communication system according to various embodiments of the present disclosure. Figure 9 shows a UE according to various embodiments of the present disclosure.

[0031] Figure 10 shows a network node according to various embodiments of the present disclosure.

[0032] Figure 11 is a block diagram of a virtualization environment in which some embodiments of the present disclosure may be virtualized.

[0033] DETAILED DESCRIPTION

[0034] Embodiments briefly summarized above will now be described more fully with reference to the accompanying drawings. These descriptions are provided by way of example to explain the subject matter to those skilled in the art and should not be construed as limiting the scope of the subject matter to only the embodiments described herein. More specifically, examples are provided below that illustrate the operation of various embodiments according to the advantages discussed above.

[0035] In general, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or is implied from the context in which it is used. All references to a / an / the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The operations of any methods and / or procedures disclosed herein do not have to be performed in the exact order disclosed, unless an operation is explicitly described as following or preceding another operation and / or where it is implicit that an operation must follow or precede another operation. Any feature of any embodiment disclosed herein can apply to any other disclosed embodiment, as appropriate. Likewise, any advantage of any embodiment described herein can apply to any other disclosed embodiment, as appropriate.

[0036] Furthermore, the following terms are used throughout the description given below:

[0037] • Radio Access Node: As used herein, a “radio access node” (or equivalently “radio network node,” “radio access network node,” or “RAN node”) can be any node in a radio access network (RAN) that operates to wirelessly transmit and / or receive signals. Some examples of a radio access node include, but are not limited to, a base station (c.g, gNB in a 3 GPP 5G / NR network or an enhanced or eNB in a 3GPP Long-Term Evolution (LTE) network), base station distributed components (e.g., CU and DU), a high-power or macro base station, a low-power base station (c.g, micro, pico, femto, or home base station, or the like), an integrated access backhaul (IAB) node, a transmission point (TP), a transmission reception point (TRP), a remote radio unit (RRU or RRH), and a relay node. • Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a serving gateway (SGW), a PDN Gateway (P-GW), a Policy and Charging Rules Function (PCRF), an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a Charging Function (CHF), a Policy Control Function (PCF), an Authentication Server Function (AUSF), a location management function (LMF), or the like.

[0038] • Wireless Device: As used herein, a “wireless device” (or “WD” for short) is any type of device that is capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other wireless devices. Communicating wirelessly can involve transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information through air. Unless otherwise noted, the term “wireless device” is used interchangeably herein with the term “user equipment” (or “UE” for short), with both of these terms having a different meaning than the term “network node”.

[0039] • Radio Node: As used herein, a “radio node” can be either a “radio access node” (or equivalent term) or a “wireless device.”

[0040] • Network Node: As used herein, a “network node” is any node that is either part of the radio access network (e.g., a radio access node or equivalent term) or of the core network (e.g., a core network node discussed above) of a cellular communications network. Functionally, a network node is equipment capable, configured, arranged, and / or operable to communicate directly or indirectly with a wireless device and / or with other network nodes or equipment in the cellular communications network, to enable and / or provide wireless access to the wireless device, and / or to perform other functions (e.g., administration) in the cellular communications network.

[0041] • Node: As used herein, the term “node” (without prefix) can be any type of node that can in or with a wireless network (including RAN and / or core network), including a radio access node (or equivalent term), core network node, or wireless device. However, the term “node” may be limited to a particular type (e.g., radio access node) based on its specific characteristics in any given context.

[0042] The above definitions are not meant to be exclusive. In other words, various ones of the above terms may be explained and / or described elsewhere in the present disclosure using the same or similar terminology. Nevertheless, to the extent that such other explanations and / or descriptions conflict with the above definitions, the above definitions should control. Note that the description given herein focuses on a 3 GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is often used. However, the concepts disclosed herein are not limited to a 3GPP system and can be applied in any system that can benefit from the concepts, principles, and / or embodiments described herein.

[0043] Figure 1 shows a high-level view of an exemplary 5G network architecture, including a Next Generation Radio Access Network (NG-RAN, 199) and a 5GC (198). As shown in the figure, the NG-RAN can include gNBs (e.g., 110a,b) and ng-eNBs (e.g., 120a, b) that are connected via respective Xn interfaces. The gNBs and ng-eNBs are also connected to the 5GC via the NG interfaces, more specifically to access and mobility management function (AMFs, e.g., 130a, b) via respective NG-C interfaces and to user plane functions (UPFs, e.g., 140a, b) via respective NG- U interfaces. Moreover, the AMFs can communicate with one or more policy control functions (PCFs, e.g., 150a, b) and network exposure functions (NEFs, e.g., 160a, b).

[0044] Each of the gNBs can support the NR radio interface including frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof. In contrast, each of ng-eNBs can support the 4G LTE radio interface but, unlike conventional LTE eNodeBs (eNBs), connect to the 5GC via the NG interface. Each of the gNBs and ng-eNBs can serve a geographic coverage area including one more cells (e.g., l l la-b, 121a-b). The gNBs and ng-eNBs can also use various directional beams to provide coverage in the respective cells. Depending on the cell in which it is located, a UE (105) can communicate with the gNB or ng-eNB serving that cell via the NR or LTE radio interface, respectively. Although Figure 1 shows gNBs and ng-eNBs separately, it is also possible that a single NG-RAN node provides both types of functionality.

[0045] Each gNB can include a central (or centralized) unit (CU or gNB-CU) and one or more distributed (or decentralized) units (DU or gNB-DU), which can be viewed as logical nodes. CUs host higher-layer protocols and perform various gNB functions such controlling the operation of DUs, which host lower-layer protocols and can include various subsets of the gNB functions. A CU connects to its associated DUs over respective Fl logical interfaces. Each of the CUs and DUs can include various circuitry needed to perform their respective functions, including processing circuitry, communication interface circuitry (e.g., for communication via Xn, NG, radio, etc. interfaces), and power supply circuitry.

[0046] In the 5GC, traditional peer-to-peer interfaces and protocols found in earlier-generation networks are modified and / or replaced by a Service Based Architecture (SBA) in which Network Functions (NFs) provide one or more services to one or more service consumers. This can be done, for example, by Hyper Text Transfer Protocol / Representational State Transfer (HTTP / REST) application programming interfaces (APIs). In general, the various services are self-contained functionalities that can be changed and modified in an isolated manner without affecting other services.

[0047] Figure 2 shows an exemplary non-roaming reference architecture for a 5G network (200). These include the following 3GPP-defined NFs and service-based interfaces:

[0048] • Application Function (AF, with Naf interface) - interacts with the 5GC to provision information to the network operator and to subscribe to certain events happening in operator's network. An AF offers applications for which service is delivered in a different layer (i.e., transport layer) than the one in which the service has been requested (i.e., signaling layer), the control of flow resources according to what has been negotiated with the network. An AF communicates dynamic session information to PCF (via N5 interface), including description of media to be delivered by transport layer.

[0049] • Policy Control Function (PCF, with Npcf interface) - supports unified policy framework to govern the network behavior, via providing PCC rules (e.g., on the treatment of each service data flow that is under PCC control) to the SMF via the N7 reference point. PCF provides policy control decisions and flow based charging control, including service data flow detection, gating, QoS, and flow-based charging (except credit management) towards the SMF. The PCF receives session and media related information from the AF and informs the AF of traffic (or user) plane events.

[0050] • User Plane Function (UPF) - supports handling of user plane traffic based on the rules received from SMF, including packet inspection and different enforcement actions (e.g., event detection and reporting). UPFs communicate with the RAN (e.g., NG-RNA) via the N3 reference point, with SMFs (discussed below) via the N4 reference point, and with an external packet data network (PDN) via the N6 reference point. The N9 reference point is for communication between two UPFs.

[0051] • Session Management Function (SMF, with Nsmf interface) - interacts with the decoupled traffic (or user) plane, including creating, updating, and removing Protocol Data Unit (PDU) sessions and managing session context with the User Plane Function (UPF), e.g., for event reporting. For example, SMF performs data flow detection (based on filter definitions included in PCC rules), online and offline charging interactions, and policy enforcement.

[0052] • Charging Function (CHF, with Nchf interface) - responsible for converged online charging and offline charging functionalities. It provides quota management (for online charging), re-authorization triggers, rating conditions, etc. and is notified about usage reports from the SMF. Quota management involves granting a specific number of units (e.g., bytes, seconds) for a service. CHF also interacts with billing systems. Access and Mobility Management Function (AMF, 220, with Namf interface) - terminates the RAN CP interface and handles all mobility and connection management of UEs (210). AMFs communicate with UEs via the N1 reference point and with the RAN (e.g., NG-RAN) via the N2 reference point.

[0053] • Network Exposure Function (NEF, with Nnef interface) - acts as the entry point into operator's network, by securely exposing to AFs the network capabilities and events provided by 3GPP NFs and by providing ways for the AF to securely provide information to 3GPP network. For example, NEF provides a service that allows an AF to provision specific subscription data (e.g., expected UE behavior) for various UEs.

[0054] • Network Repository Function (NRF, 230, with Nnrf interface) - provides service registration and discovery, enabling NFs to identify appropriate services available from other NFs.

[0055] • Network Slice Selection Function (NSSF, with Nnssf interface) - a “network slice” is a logical partition of a 5G network that provides specific network capabilities and characteristics, e.g., in support of a particular service. A network slice instance is a set of NF instances and the required network resources (e.g., compute, storage, communication) that provide the capabilities and characteristics of the network slice. The NSSF enables other NFs (e.g., AMF) to identify a network slice instance that is appropriate for a UE’s desired service.

[0056] • Authentication Server Function (AUSF, 230, with Nausf interface) - based in a user’s home network (HPLMN), it performs user authentication and computes security key materials for various purposes.

[0057] • Network Data Analytics Function (NWDAF, with Nnwdaf interface) - provides network analytics information (e.g., statistical information of past events and / or predictive information) to other NFs on a network slice instance level.

[0058] • Location Management Function (LMF, with Nlmf interface) - supports various functions related to determination of UE locations, including location determination for a UE and obtaining any of the following: DL location measurements or a location estimate from the UE; UL location measurements from the NG RAN; and non-UE associated assistance data from the NG RAN.

[0059] • Unified Data Management function (UDM, 240, with Nudm interface) -) supports generation of 3GPP authentication credentials, user identification handling, access authorization based on subscription data, and other subscriber-related functions. To provide this functionality, the UDM uses subscription data (including authentication data) stored in the 5GC unified data repository (UDR). In addition, UDR supports storage and retrieval of policy data by the PCF, as well as storage and retrieval of application data by NEF.

[0060] 3GPP initiated a study on “Ambient loT”, as further described in 3GPP documents RP- 222685, TR 22.840 (v2.0.0), and TR 38.848 (vl8.0.0). The study targets a new loT technology suitable for deployment in a 3 GPP network, based on ultra-low complexity devices with ultra-low power consumption for very low-end loT applications. The study is intended to address use cases and scenarios that cannot be fulfilled based on existing cellular loT (CIoT) technologies such as narrowband loT (NB-IoT), even with reduced peak transmit (Tx) power. As such, it is expected that the radio interface and protocols for this new loT technology will differ in some ways from existing 3 GPP radio access technologies (RATs) such as NR and NB-IoT.

[0061] It is also expected that Ambient loT devices will have reduced processing and complexity, such that these devices may also be referred to as “constrained devices.” These constrained devices may have a simplified physical layer (LI), and higher layer (L2 / L3) protocols that are simplified (or “lightweight”) relative to existing 3GP L2 / L3 protocols for UEs. This includes both access stratum (AS) and non-access stratum (NAS) protocols, which should be far more simplified than existing CIoT protocols. This is consistent with past standardization of NB-IoT technologies. For example, 3GPP Rel-15 control plane early data transmission (CP-EDT) has reduced Uu interface functionality compared to mobile broadband (MBB), such as no PDCP functions and with transparent mode (TM) radio link control (RLC).

[0062] Connection management in existing 3GPP networks consists of two connection levels, a NAS connection between UE and core network (CN, e.g., 5GC) and an AS (or radio resource control, RRC) connection between UE and serving RAN node (e.g., gNB). To establish a NAS signaling connection, UE needs to have a radio resource control (RRC) connection so that the serving RAN node can deliver NAS control information between UE and CN in a secure and reliable way. This signaling (or “handshaking”) between UE and network is relative complex (or “heavy”) and was not designed with loT devices in mind. Significant efforts were made to reduce the 4G / LTE signaling overhead needed for transmission of a small amount of data for NB-IoT and LTE M.

[0063] The simplified protocol functionality may motivate a shift from fully connection- oriented AS (e.g., RRC) and NAS signaling between UE and network to connectionless transmission, which can reduce protocol and signaling overhead associated with handshaking communication. For example, RLC sublayer can be omitted (similar to NB-IoT CP-EDT) and the segmentation function, if needed, can be moved to another sublayer, such as medium access control (MAC) or NAS. As another example, most current PDCP functionalities can be eliminated for a user plane (UP) based solution, with only AS security and header compression the only PDCP functions needed for constrained devices.

[0064] As briefly mentioned above, two types of user identifiers are used in 5G networks. Subscription Permanent Identifier (SUPI) is a unique identifier that represents a subscriber's permanent identity in a 5G network. It is intended to provide enhanced privacy and security compared to the International Mobile Subscriber Identity (IMSI) used in 4G and earlier networks. Subscription Concealed Identifier (SUCI) is a temporary identifier used to conceal a subscriber's SUPI in a 5G network, e.g., to avoid sending the SUPI over the air. SUCI contains several concatenated values including a Protection Scheme Output that is generated cryptographically by the UE and decrypted by the 5G network to determine the corresponding SUPI.

[0065] However, constrained devices may have insufficient computing resources to support the cryptographic calculations needed to generate SUCI from SUPI. Nevertheless, sending SUPI (or similar long-term identifier) over the air still represents an undesirable security and / or privacy risk for constrained devices. Conventional techniques that could be used instead to generate SUCI suffer from well-known security flaws and / or require significant new functionality in the 5G network.

[0066] For example, a (symmetric) shared group key could be used for a group of constrained devices to protect their long-term identifiers against group outsiders. However, an outsider can compromise any single device in the group to learn the key.

[0067] As another example, each constrained device may hold a unique long-term symmetric key that is shared with the network (e.g., like root key in typical subscriber identity cards). The device may then send a randomized encryption to the 5G network to identify itself. Without additional information, however, the network would need to try all possible keys to determine which one was used for encryption by the device. This would be highly resource intensive, especially when many constrained devices are deployed.

[0068] As another example, “pseudonyms” can be regularly provisioned to devices and used for identification instead of SUPI or other long-term device identifier. In general, however, a pseudonym-based solution for constrained devices requires new functionality and state management on the network side, such as lookup tables to resolve or map temporary pseudonyms to long-term identifiers.

[0069] Embodiments of the present disclosure address these and other problems, issues, and / or difficulties with techniques by which the network can determine that a constrained device (or UE) requires a fresh pre-computed SUCI for future identification (possibly based on obtaining an indication) and a way for the network to provision it to the UE. Embodiments facilitate uniform de-concealment of SUCIs for Ambient loT where some Ambient loT devices can generate a SUCI and some Ambient loT devices cannot. Beyond the functionality for determining that a UE requires a pre-computed SUCI, computation of said SUCI and provisioning it to the UE, there is no new additional functionality required on the network side to support this. In particular, de-concealment of SUCIs and identification of UEs is the same regardless of whether a UE computes its own SUCI or obtains its SUCI from the network.

[0070] Embodiments may provide various benefits and / or advantages. For example, embodiments may require minimal changes in network-side functionality compared to pseudonym-type techniques. As a more specific example, embodiments may avoid requiring the network to maintain state, so there are no synchronization problems where a device and the network disagree on the device’s current pseudonym. In contrast, 3GPP TR 33.899 (vl.3.0) section 5.7.4 describes several conventional pseudonym-based solutions for UE identification, all of which suffer from common problems or issues including need for the network to maintain lookup tables, potential synchronization issues, pseudonym collisions, etc.

[0071] As another example, embodiments may facilitate a uniform network approach to deconcealment of SUCIs for all Ambient loT devices, including those able to generate SUCI and those unable to generate SUCI. As another example, since the network determines unique SUCIs for each UE, embodiments may avoid identifier collisions that are common with pseudonymbased solutions. More generally, embodiments may facilitate deployment of Ambient loT in conjunction with 3GPP networks (e.g., 5G).

[0072] Although embodiments are described herein based on the context of Ambient loT, skilled persons will understand that underlying principles are applicable to other services, device classes, etc. such as eMBB, URLLC, massive-MTC, URLLC, time sensitive networking (TSN), etc.

[0073] Embodiments are described below in the context of a UE that, unlike conventional UEs, is unable to compute SUCI or similar concealed user subscription identifier. This UE may be operational in a network together with other UEs that are able to compute SUCI or similar concealed user identifier.

[0074] In some embodiments, the UE may use a null-encryption SUCI scheme the first time the UE attaches or identifies itself to the network. This effectively means that the SUPI is sent in the clear over the air.

[0075] In other embodiments, the UE may be configured “out-of-band” with a pre-computed SUCI to use the first time the UE attaches or identifies itself to the network (“first attach”). In contrast, a conventional UE computes a SUCI when needed to attach to the network. If the precomputed SUCI is not updated or replaced, then the UE may re-use it multiple times when attaching to the network, depending on privacy settings. Figure 3 shows a signaling diagram of a procedure for a constrained UE to obtain a precomputed SUCI, according to some embodiments of the present disclosure. The procedure involves a constrained UE (310), an AMF (320), an AUSF (330), and a UDM (340). Although the operations shown in Figure 3 are given numerical labels, this is done to facilitate the following description rather than to require or imply any specific operational order, unless expressly stated otherwise.

[0076] In operation 1, the UE sends a concealed long-term identifier (e.g., SUCI) to the to the AMF, using a NAS message such as Registration Request or Identity Response. In operation 2, the AMF uses the Nausf UEAuthentication Authenticate service operation to request authentication data for the UE from the AUSF, including the received SUCI in the service operation. In operation 3, the AUSF requests authentication data from the UDM using the Nudm UEAuthentication Get service operation, including the received SUCI in the service operation.

[0077] In operation 4, during processing the received message, the UDM determines that a fresh pre-computed SUCI (referred to as SUCI’) is required for the UE. This may be based on an indication configured in the UDM or received from another node or function. SUCI is considered fresh if it contains a value that can be considered different from a previous value in SUCI. For example, the value for SUCI’ could be generated based on a pseudo-random string, a counter, or a timestamp (i.e., of the current time).

[0078] Based on this determination, the UDM looks up authentication data and computes a fresh SUCI’, which is a concealed SUPI. This concealed SUPI may be an encryption of SUPI using a public key encryption scheme, such as ECIES defined in 3GPP TS 33.501 (vl8.2.0). The UDM also encrypts the fresh SUCI’ to form an encrypted SUCI (ESUCI), using a key known by both UE and UDM. For example, the key used to compute ESUCI can be generated from the RAND of the associated authentication vector and a symmetric key, such as the primary key K that is stored on the UE’ s USIM and in the UDM.

[0079] After computing ESUCI, the UDM sends to the AUSF a response including authentication data. This may be in the form of an Authentication Vector (AV) that comprises an authentication token (AUTN) and a random value (RAND) that may be used by the UE to authenticate the network. RAND ensures freshness of the generated keys to the AUSF. In addition, the UDM includes the ESUCI in the response to AUSF. For example, the response may be a Nudm UEAuthentication Get Response service operation. The combination of RAND, AUTN, and ESUCI may be considered an enhanced authentication vector. In some embodiments, ESUCI may be used as another input when computing the MAC in the AUTN of the authentication vector. This makes it possible for the UE to get assurance that the ESUCI was generated by a UDM that knows the UE’s primary key K.

[0080] Although Figure 3 shows the computation and encryption of SUCI’ being performed by UDM, in other embodiments these operations may be performed by another node or function that shares key material with the UE through the 5G Authentication and Key Agreement (AKA) hierarchy. For example, this could be AUSF or a newly defined function for identity management.

[0081] In operation 5, the AUSF responds to the AMF with the received enhanced authentication vector including ESUCI, e.g., using a Nausf UEAuthentication Authenticate Response service operation. Note that this is different than current 5G AKA in which the authentication vector sent to AMF includes RAND and AUTN but not ESUCI.

[0082] In operation 6, the AMF authenticates the UE and sends the AUTN, RAND, and ESUCI to the UE. Although Figure 3 shows ESUCI being delivered in the same message as the AUTN and RAND, ESUCI could also be delivered in a separate message from AUTN and RAND. Since ESUCI is present with the authentication vector, the UE computes XMAC in the same way the UDM computed MAC. If XMAC and MAC match, and other 5G AKA related verifications are successful, the UE decrypts ESUCI into SUCI’ using the same key the UDM used to encrypt SUCI’ into ESUCI. The UE stores SUCI’ to be used for future identification / attachment to the 5G network. In conjunction with these actions, the UE sends an authentication response to the AMF in operation 7.

[0083] Figure 4 shows a signaling diagram of a procedure for a constrained UE to obtain a precomputed SUCI, according to other embodiments of the present disclosure. The procedure involves a constrained UE ( 10), an AMF (420), an AUSF (430), and a UDM (440). Although the operations shown in Figure 4 are given numerical labels, this is done to facilitate the following description rather than to require or imply any specific operational order, unless expressly stated otherwise.

[0084] Operations 1-3 are substantially identical to corresponding operations 1-3 in Figure 3, described above. Operation 4 is similar to operation 4 in Figure 3, except that instead of encrypting SUCI’ to form ESUCI, the UDM computes a message authentication code of SUCI’ - called T - using a symmetric key known by both the UE and UDM. For example, the symmetric key can be generated from the RAND of the authentication vector and the UE’s primary key K.

[0085] Although Figure 4 shows the computation of SUCI’ and T being performed by UDM, in other embodiments these operations may be performed by another node or function that shares key material with the UE through the 5G AKA hierarchy. For example, this could be AUSF or a newly defined function for identity management. After computing SUCI’ and T, the UDM sends to the AUSF a response including authentication data. This may be in the form of an Authentication Vector (AV) that comprises AUTN and RAND discussed above, along with SUCI’ and T. For example, the response may be a Nudm UEAuthentication Get Response service operation. The combination of RAND, AUTN, SUCI’, and T may be considered an enhanced authentication vector.

[0086] In operation 5, the AUSF responds to the AMF with the received enhanced authentication vector including SUCI’ and T, e.g., using a Nausf UEAuthentication Authenticate Response service operation. Note that this is different than current 5G AKA in which the authentication vector sent to AMF includes RAND and AUTN but not SUCI’ and T.

[0087] In operation 6, the AMF authenticates the UE and sends the conventional authentication vector including AUTN and RAND to the UE, e.g., using an Authentication Request message or service operation. In operation 7, the UE responds to the AMF, e.g., using an Authentication Response message or service operation.

[0088] After a NAS security context is established between the UE and the AMF, in operation 8 the AMF provides SUCI’ and T received from AUSF to the UE. For example, this information could be added to an existing message such as Registration Accept. The UE verifies the message authentication code T using the same key used by the UDM to compute T. The UE stores SUCI’ for future identification to the network.

[0089] By waiting until after NAS security context establishment to provide SUCI’ and T, the AMF prevents eavesdroppers receiving it and using it to identify the UE or the user. In other words, the established security context provides confidentiality protection of SUCI’ and T sent over the air.

[0090] In general, embodiments require many-times-writable non-volatile memory in the UE to store the provisioned SUCIs. However, this is also a requirement for conventional solutions in which the network provisions the UE with opaque pseudonyms. How much many-times-writable non-volatile memory to be required by 3GPP for this purpose is a matter of further technical study.

[0091] If a provisioned SUCI is corrupted in the UE, then the UE may not be able to identify itself to the network without sacrificing privacy. However, this is also an issue for conventional solutions in which the network provisions the UE with opaque pseudonyms. In some embodiments, the identification server (e.g., UDM, AUSF) applies an error correcting code during SUCI determination to make the SUCI more resilient to corruptions in device storage, which may be more prevalent for constrained Ambient loT devices than for conventional UEs. Expected rate of corruption and requirements for error correcting codes are matters of further technical study.

[0092] The embodiments described above can be further illustrated with reference to Figures 5-7, which depict exemplary methods e.g., procedures) for an identification server, a UE, and an AMF, respectively. Put differently, various features of the operations described below correspond to various embodiments described above. The exemplary methods shown in Figures 5-7 can be complementary to each other such that they can be used cooperatively to provide benefits, advantages, and / or solutions to problems described herein. Although the exemplary methods are illustrated in Figures 5-7 by specific blocks in particular orders, the operations corresponding to the blocks can be performed in different orders than shown and can be combined and / or divided into operations having different functionality than shown. Optional blocks and / or operations are indicated by dashed lines.

[0093] More specifically, Figure 5 illustrates an exemplary method (e.g., procedure) for an identification server configured to provide concealed identifiers for user subscriptions to a communication network, according to various embodiments of the present disclosure. The exemplary method shown in Figure 5 can be performed by a UDM, an AUSF, or similar function (or network equipment configured to implement such functions) as described elsewhere herein.

[0094] The exemplary method includes the operations of block 510, where the identification server receives, from a first NF of the communication network, a message including a first concealed identifier (e.g. SUCI) of a user subscription to the communication network. The exemplary method also includes the operations of blocks 520-530, where based on determining that the first concealed identifier needs to be updated, the identification server determines a second concealed identifier (e.g., SUCI) of the user subscription, including performing an encryption a non-concealed identifier of the user subscription, using a public part of an asymmetric key pair. The exemplary method also includes the operations of block 560, where the identification server determines a secured second concealed identifier of the user subscription, based on the second concealed identifier and a symmetric key that is known to a UE associated with the user subscription. The exemplary method also includes the operations of block 580, where the identification server sends the secured second concealed identifier to the first NF.

[0095] In general, the first and second concealed identifiers may be long-term identifiers associated with the user subscription to the communication network. SUCI discussed above is one example of such a long-term identifier. A long term identifier identifies a user subscription in the communication network, but may indirectly identify the corresponding user / subscriber. The user subscription may be associated with the device used to connect to the communication network based on embedding or inserting subscription credentials and a non-concealed subscription identifier (e.g., SUPI) in the device itself or in a Universal Subscriber Identifier Module (USIM) that may be inserted into and removed from the device. The term “user subscription” used herein applies to cases where the device user is identical to the subscriber (i.e., registered owner of the subscription) or different than the subscriber. In some embodiments, determining the secured second concealed identifier in block 560 includes the operations of sub-block 561, where the identification server encrypts the second concealed identifier using the symmetric key. In other embodiments, determining the secured second concealed identifier in block 560 includes the operations of sub-block 562, where the identification server calculates a message authentication code (MAC) for the second concealed identifier using the symmetric key. In such case, the secured second concealed identifier comprises the second concealed identifier and the MAC.

[0096] In some embodiments, the exemplary method also includes the operations of block 540, where the identification server determines an authentication vector including an authentication token (AUTN) and a random value (RAND) that are usable by the UE to authenticate the identification server. The authentication vector is sent to the first NF together with the secured second concealed identifier. In some of these embodiments, the exemplary method also includes the operations of block 550, where the identification server generates the symmetric key based on the random value (RAND) and a primary key (K) associated with the user subscription.

[0097] In some embodiments, determining that the first concealed identifier needs to be updated in block 520 is based on one or more of the following: a first indication included in the message from the first NF, a second indication received from a second NF of the communication network, and a configuration of the identification server.

[0098] In some embodiments, the UE is a constrained UE that is unable to determine a concealed identifier of the user subscription based on the non-concealed identifier of the user subscription. In some embodiments, the public-key encryption of the non-concealed identifier uses one of the following as an input: a pseudo-random string, a counter, or a current time.

[0099] In some embodiments, the identification server is a unified data management function (UDM), and the first NF is an authentication server function (AUSF). Figures 3-4 show examples of these embodiments. In other embodiments, the identification server is an authentication server function (AUSF) and the first NF is an access and mobility management function (AMF). Also, the exemplary method also includes the operations of block 505, where the identification server receives, from a UDM of the communication network, security materials used to determine the second concealed identifier and the secured second concealed identifier.

[0100] In addition, Figure 6 illustrates an exemplary method (e.g., procedure) for a UE configured to operate in a communication network, according to various embodiments of the present disclosure. The exemplary method shown in Figure 6 can be performed by a UE (e.g., wireless device, AIoT device, ZE-IoT device, UE, etc.) such as described elsewhere herein.

[0101] The exemplary method includes the operations of block 610, where the UE sends, to an AMF of the communication network, a first message including a first concealed identifier of a user subscription to the communication network. The exemplary method also includes the operations of block 640, where the UE receives from the AMF a second message that includes a secured second concealed identifier, of the user subscription, that was generated by an identification server of the communication network.

[0102] In some embodiments, the exemplary method also includes the operations of blocks 650- 660, where the UE determines a second concealed identifier of the user subscription from the secured second concealed identifier and uses the determined second concealed identifier when attaching to the communication network.

[0103] In some of these embodiments, determining the second concealed identifier in block 650 includes the operations of sub-block 652, where the UE decrypts the secured second concealed identifier using a symmetric key also used by the identification server to generate the secured second concealed identifier. In some variants of these embodiments, the secured second concealed identifier is received in or with an authentication vector, which includes an authentication token (AUTN) and a random value (RAND) that are usable by the UE to authenticate the identification server.

[0104] In other of these embodiments, the secured second concealed identifier comprises the second concealed identifier and a first MAC, and determining the second concealed identifier in block 650 includes the operations of sub-blocks 653-654, where the UE calculates a second MAC based on the second concealed identifier and a symmetric key also used by the identification server to generate the first MAC, and verifies that the calculated second MAC matches the first MAC. In some variants of these embodiments, the exemplary method also includes the following operations, labelled with corresponding block numbers:

[0105] • (620) in response to the first message, receiving from the AMF a third message including an authentication vector, which includes an authentication token (AUTN) and a random value (RAND) that are usable by the UE to authenticate the identification server; and

[0106] • (630) establishing a security context with the AMF based on the authentication vector. The second message is received after the security context is established.

[0107] In some of the variants described above, determining the second concealed identifier in block 650 also includes the operations of sub-block 651, where the UE generates the symmetric key based on the random value (RAND) and a primary key (K) associated with the user subscription.

[0108] In some embodiments, the identification server is a UDM. Figures 3-4 show examples of these embodiments. In other embodiments, the identification server is an AUSF. In some embodiments, the exemplary method also includes the operations of block 615, where the UE sends to the AMF a first indication that the first concealed identifier needs to be updated. In some of these embodiments, the first indication is included in the first message.

[0109] In some embodiments, the UE is a constrained UE that is unable to determine a concealed identifier of the user subscription based on a non-concealed identifier of the user subscription.

[0110] In addition, Figure 7 illustrates an exemplary method (e.g., procedure) for an AMF of a communication network, according to various embodiments of the present disclosure. The exemplary method shown in Figure 7 can be performed by an AMF (or network equipment configured to implement the same) such as described elsewhere herein.

[0111] The exemplary method includes the operations of block 710, where the AMF receives, from a UE, a first message including a first concealed identifier of a user subscription to the communication network. The exemplary method also includes the operations of block 720, where the AMF sends, to an AUSF of the communication network, an authentication request that includes the first concealed identifier. The exemplary method also includes the operations of block 730, where the AMF receives from the AUSF an authentication response that includes a secured second concealed identifier, of the user subscription, that was generated by an identification server of the communication network. The exemplary method also includes the operations of block 760, where the AMF sends to the UE a second message that includes the secured second concealed identifier.

[0112] In some embodiments, the authentication response also includes an authentication vector, which includes an authentication token (AUTN) and a random value (RAND) that are usable by the UE to authenticate the identification server. In some of these embodiments, the secured second concealed identifier comprises an encrypted second concealed identifier, and the authentication vector is included in the second message with the encrypted second concealed identifier.

[0113] In other of these embodiments, the secured second concealed identifier comprises the second concealed identifier and a MAC, and the exemplary method also includes the operations of blocks 740-750, where the AMF sends to the UE a third message that includes the authentication vector and establishes a security context with the UE based on the authentication vector. The second message is sent to the UE after the security context is established.

[0114] In some embodiments, the identification server is a UDM function. Figures 3-4 show examples of these embodiments. In other embodiments, the identification server is the AUSF. In some embodiments, the UE is a constrained UE that is unable to determine a concealed identifier of the user subscription based on a non-concealed identifier of the user subscription.

[0115] In some embodiments, the exemplary method also includes the operations of block 715, where the AMF receives from the UE a first indication that the first concealed identifier needs to be updated. The first indication is included in the authentication request sent in block 720. In some of these embodiments, the first indication is received in the first message in block 710.

[0116] Although various embodiments are described above in terms of methods, apparatus, devices, computer-readable medium and receivers, the person of ordinary skill will readily comprehend that such methods can be embodied by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, etc.

[0117] Figure 8 shows an example of a communication system 800 in accordance with some embodiments. In this example, communication system 800 includes a telecommunication network 802 that includes an access network 804 (e.g., RAN) and a core network 806, which includes one or more core network nodes 808. Access network 804 includes one or more access network nodes, such as network nodes 810a-b (one or more of which may be referred to as network nodes 810), or any other similar 3 GPP access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor.

[0118] As such, network nodes may include disaggregated implementations or portions thereof. For example, in some embodiments, telecommunication network 802 includes one or more Open- RAN (ORAN) network nodes. An ORAN network node is a node in telecommunication network 802 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in telecommunication network 802, including one or more network nodes 810 and / or core network nodes 808.

[0119] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU- CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance or comparable technologies. Network nodes 810 facilitate direct or indirect connection of UEs, such as by connecting UEs 812a-d (one or more of which may be referred to as UEs 812) to core network 806 over one or more wireless connections.

[0120] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, communication system 800 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. Communication system 800 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0121] UEs 812 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with network nodes 810 and other communication devices. Similarly, network nodes 810 are arranged, capable, configured, and / or operable to communicate directly or indirectly with UEs 812 and / or with other network nodes or equipment in telecommunication network 802 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in telecommunication network 802.

[0122] In the depicted example, core network 806 connects network nodes 810 to one or more hosts, such as host 816. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. Core network 806 includes one or more core network nodes (e.g., 808) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are applicable to the corresponding components of core network node 808. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0123] Host 816 may be under the ownership or control of a service provider other than an operator or provider of access network 804 and / or telecommunication network 802, and may be operated by the service provider or on behalf of the service provider. Host 816 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0124] As a whole, communication system 800 of Figure 8 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0125] In some examples, telecommunication network 802 is a cellular network that implements 3GPP standardized features. Accordingly, telecommunication network 802 may support network slicing to provide different logical networks to different devices that are connected to telecommunication network 802. For example, telecommunication network 802 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0126] In some examples, UEs 812 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to access network 804 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from access network 804. Additionally, a UE may be configured for operating in single- or multi -RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0127] In the example, hub 814 communicates with access network 804 to facilitate indirect communication between one or more UEs (e.g., 812c and / or 812d) and network nodes (e.g., 810b). In some examples, hub 814 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, hub 814 may be a broadband router enabling access to core network 806 for the UEs. As another example, hub 814 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 810, or by executable code, script, process, or other instructions in hub 814. As another example, hub 814 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, hub 814 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, hub 814 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which hub 814 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, hub 814 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0128] Hub 814 may have a constant / persistent or intermittent connection to network node 810b. Hub 814 may also allow for a different communication scheme and / or schedule between hub 814 and UEs (e.g., 812c and / or 812d), and between hub 814 and core network 806. In other examples, hub 814 is connected to core network 806 and / or one or more UEs via a wired connection. Moreover, hub 814 may be configured to connect to an M2M service provider over access network 804 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with network nodes 810 while still connected via hub 814 via a wired or wireless connection. In some embodiments, hub 814 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to network node 810b. In other embodiments, hub 814 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 810b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0129] In some embodiments, core network node 808 and / or host 816 may be configured to perform operations attributed to an AMF, an AUSF, or a UDM in the above descriptions of the procedures shown in Figures 3-7. For example, respective core network nodes 808 may be configured to perform the operations attributed to an AMF, to an AUSF, and to a UDM. In some embodiments, one or more UEs 812 may be configured to perform operations attributed to a UE in the above descriptions of the procedures shown in Figures 3-7. For example, one or more UEs 812 may be Ambient loT devices and / or constrained devices.

[0130] Figure 9 shows a UE 900 in accordance with some embodiments. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by 3 GPP, including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0131] A LTE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0132] UE 900 includes processing circuitry 902 that is operatively coupled via bus 904 to input / output interface 906, power source 908, memory 910, communication interface 912, and optionally to one or more other components not explicitly shown. Certain UEs may utilize all or a subset of the components shown in Figure 9. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0133] Processing circuitry 902 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in memory 910. Processing circuitry 902 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general -purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, processing circuitry 902 may include multiple central processing units (CPUs).

[0134] In the example, input / output interface 906 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into UE 900. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0135] In some embodiments, power source 908 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. Power source 908 may further include power circuitry for delivering power from power source 908 itself, and / or an external power source, to the various parts of UE 900 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of power source 908. Power circuitry may perform any formatting, converting, or other modification to the power from power source 908 to make the power suitable for the respective components of UE 900 to which power is supplied.

[0136] Memory 910 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, memory 910 includes one or more application programs 914, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 916. Memory 910 may store, for use by UE 900, any of a variety of various operating systems or combinations of operating systems.

[0137] Memory 910 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ Memory 910 may allow UE 900 to access instructions, application programs and the like, stored on transitory or non- transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in memory 910, which may be or comprise a device-readable storage medium.

[0138] Processing circuitry 902 may be configured to communicate with an access network or other network using communication interface 912. Communication interface 912 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 922. Communication interface 912 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 918 and / or a receiver 920 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, transmitter 918 and receiver 920 may be coupled to one or more antennas (e.g., antenna 922) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0139] In the illustrated embodiment, communication functions of communication interface 912 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0140] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 912, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0141] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0142] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to UE 900 shown in Figure 9.

[0143] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3 GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0144] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators. In some embodiments, UE 900 may be configured to perform operations attributed to a UE in the above descriptions of the procedures shown in Figures 3-7. For example, UE 900 may be an Ambient loT device and / or a constrained device.

[0145] Figure 10 shows a network node 1000 in accordance with some embodiments. Examples of network nodes include, but are not limited to, access points (e.g., radio access points), base stations (e.g., radio base stations, Node Bs, eNBs, gNBs), and 0-RAN nodes or components of an 0-RAN node (e.g, 0-RU, 0-DU, O-CU).

[0146] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an 0-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0147] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0148] Network node 1000 includes processing circuitry 1002, memory 1004, communication interface 1006, and power source 1008. Network node 1000 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node 1000 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 1000 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1004 for different RATs) and some components may be reused (e.g., a same antenna 1010 may be shared by different RATs). Network node 1000 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1000, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1000.

[0149] Processing circuitry 1002 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 1000 components, such as memory 1004, to provide network node 1000 functionality.

[0150] In some embodiments, processing circuitry 1002 includes a system on a chip (SOC). In some embodiments, processing circuitry 1002 includes radio frequency (RF) transceiver circuitry 1012 and / or baseband processing circuitry 1014. In some embodiments, RF transceiver circuitry 1012 and / or baseband processing circuitry 1014 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1012 and / or baseband processing circuitry 1014 may be on the same chip or set of chips, boards, or units.

[0151] Memory 1004 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by processing circuitry 1002. Memory 1004 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions (collectively denoted computer program 1004a, which may be in the form of a computer program product) capable of being executed by processing circuitry 1002 and utilized by network node 1000. Memory 1004 may be used to store any calculations made by processing circuitry 1002 and / or any data received via communication interface 1006. In some embodiments, processing circuitry 1002 and memory 1004 is integrated.

[0152] Communication interface 1006 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, communication interface 1006 comprises port(s) / terminal(s) 1016 to send and receive data, for example to and from a network over a wired connection. Communication interface 1006 also includes radio frontend circuitry 1018 that may be coupled to, or in certain embodiments a part of, antenna 1010. Radio front-end circuitry 1018 comprises filters 1020 and amplifiers 1022. Radio front-end circuitry 1018 may be connected to an antenna 1010 and processing circuitry 1002. The radio front-end circuitry may be configured to condition signals communicated between antenna 1010 and processing circuitry 1002. Radio front-end circuitry 1018 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. Radio front-end circuitry 1018 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1020 and / or amplifiers 1022. The radio signal may then be transmitted via antenna 1010. Similarly, when receiving data, antenna 1010 may collect radio signals which are then converted into digital data by radio front-end circuitry 1018. The digital data may be passed to processing circuitry 1002. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0153] In certain alternative embodiments, network node 1000 does not include separate radio front-end circuitry 1018, instead, processing circuitry 1002 includes radio front-end circuitry and is connected to antenna 1010. Similarly, in some embodiments, all or some of RF transceiver circuitry 1012 is part of communication interface 1006. In still other embodiments, communication interface 1006 includes one or more ports or terminals 1016, radio front-end circuitry 1018, and RF transceiver circuitry 1012, as part of a radio unit (not shown), and communication interface 1006 communicates with baseband processing circuitry 1014, which is part of a digital unit (not shown).

[0154] Antenna 1010 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. Antenna 1010 may be coupled to radio front-end circuitry 1018 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, antenna 1010 is separate from network node 1000 and connectable to network node 1000 through an interface or port.

[0155] Antenna 1010, communication interface 1006, and / or processing circuitry 1002 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, antenna 1010, communication interface 1006, and / or processing circuitry 1002 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment. Power source 1008 provides power to the various components of network node 1000 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1008 may further comprise, or be coupled to, power management circuitry to supply the components of network node 1000 with power for performing the functionality described herein. For example, network node 1000 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of power source 1008. As a further example, power source 1008 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0156] Embodiments of network node 1000 may include additional components beyond those shown in Figure 10 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, network node 1000 may include user interface equipment to allow input of information into network node 1000 and to allow output of information from network node 1000. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1000.

[0157] In some embodiments, network node 1100 may be configured to perform operations attributed to an AMF, an AUSF, or a UDM in the above descriptions of the procedures shown in Figures 3-7. For example, respective network nodes 1100 may be configured to perform the operations attributed to an AMF, to an AUSF, and to a UDM.

[0158] Figure 11 is a block diagram illustrating a virtualization environment 1100 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1100 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1100 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface. Applications 1102 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1100 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein. For example, various virtual nodes 1102 may be configured to perform operations attributed to an AMF, an AUSF, and a UDM in the above descriptions of the procedures shown in Figures 3-7.

[0159] Hardware 1104 includes processing circuitry, memory that stores software and / or instructions (collectively denoted computer program 1104a, which may be in the form of a computer program product) executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1106 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1108a-b (one or more of which may be referred to as VMs 1108), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. Virtualization layer 1106 may present a virtual operating platform that appears like networking hardware to the VMs 1108.

[0160] VMs 1108 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1106. Different embodiments of the instance of a virtual appliance 1102 may be implemented on one or more of VMs 1108, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0161] In the context of NFV, each VM 1108 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each VM 1108, and that part of hardware 1104 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1108 on top of the hardware 1104 and corresponds to the application 1102.

[0162] Hardware 1104 may be implemented in a standalone network node with generic or specific components. Hardware 1104 may implement some functions via virtualization. Alternatively, hardware 1104 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration function 1110, which, among others, oversees lifecycle management of applications 1102. In some embodiments, hardware 1104 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1112 which may alternatively be used for communication between hardware nodes and radio units.

[0163] The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures that, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the spirit and scope of the disclosure. Various exemplary embodiments may be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art.

[0164] The term unit, as used herein, can have conventional meaning in the field of electronics, electrical devices and / or electronic devices and can include, for example, electrical and / or electronic circuitry, devices, modules, processors, memories, logic solid state and / or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and / or displaying functions, and so on, as such as those that are described herein.

[0165] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory may include program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according to one or more embodiments of the present disclosure. As described herein, device and / or apparatus may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device or apparatus, instead of being hardware implemented, be implemented as a software module such as a computer program or a computer program product comprising executable software code portions for execution or being run on a processor. Furthermore, functionality of a device or apparatus may be implemented by any combination of hardware and software. A device or apparatus may also be regarded as an assembly of multiple devices and / or apparatuses, whether functionally in cooperation with or independently of each other. Moreover, devices and apparatuses may be implemented in a distributed fashion throughout a system, so long as the functionality of the device or apparatus is preserved. Such and similar principles are considered known to a skilled person.

[0166] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0167] In addition, certain terms used in the present disclosure, including the specification and drawings, may be used synonymously in certain instances (e.g., “data” and “information”). It should be understood that although such terms may be used synonymously herein, there can be instances when such terms are not intended to be used synonymously.

[0168] Al . A method for an identification server configured to provide concealed identifiers for user subscriptions to a communication network, the method comprising: receiving, from a first network function (NF) of the communication network, a message including a first concealed identifier of a user subscription to the communication network; based on determining that the first concealed identifier needs to be updated, determining a second concealed identifier of the user subscription, including performing an encryption a non-concealed identifier of the user subscription, using a public part of an asymmetric key pair; determining a secured second concealed identifier of the user subscription, based on the second concealed identifier and a symmetric key that is known to a user equipment (UE) associated with the user subscription; and sending the secured second concealed identifier to the first NF. A2. The method of embodiment Al, wherein determining the secured second concealed identifier comprises encrypting the second concealed identifier using the symmetric key.

[0169] A3. The method of embodiment Al, wherein determining the secured second concealed identifier comprises calculating a message authentication code (MAC) for the second concealed identifier using the symmetric key, wherein the secured second concealed identifier comprises the second concealed identifier and the MAC.

[0170] A4. The method of any of embodiments A1-A3, further comprising determining an authentication vector including an authentication token (AUTN) and a random value (RAND) that are usable by the UE to authenticate the identification server, wherein the authentication vector is sent to the first NF together with the secured second concealed identifier.

[0171] A5. The method of embodiment A4, further comprising generating the symmetric key based on the random value (RAND) and a primary key (K) associated with the user subscription.

[0172] A6. The method of any of embodiments A1-A5, wherein determining that the first concealed identifier needs to be updated is based on one or more of the following: a first indication included in the message from the first NF, a second indication received from a second NF of the communication network, and a configuration of the identification server.

[0173] A7. The method of any of embodiments A1-A6, wherein the UE is a constrained UE that is unable to determine a concealed identifier of the user subscription based on the non-concealed identifier of the user subscription.

[0174] A8. The method of any of embodiments A1-A7, wherein the public-key encryption of the non-concealed identifier uses one of the following as an input: a pseudo-random string, a counter, or a current time.

[0175] A9. The method of any of embodiments A1-A8, wherein the identification server is a unified data management function (UDM), and the first NF is an authentication server function (AUSF).

[0176] A10. The method of any of embodiments A1-A8, wherein: the identification server is an authentication server function (AUSF) and the first NF is an access and mobility management function (AMF); and the method further comprises receiving, from a unified data management function (UDM) of the communication network, security materials used to determine the second concealed identifier and the secured second concealed identifier.

[0177] B 1. Network equipment arranged to implement an identification server configured to provide concealed identifiers for user subscriptions to a communication network, the network equipment comprising: communication interface circuitry configured to communicate with a first network function (NF) of the communication network; and processing circuitry operably coupled to the communication interface circuitry, wherein the processing circuitry and interface circuitry are configured to perform operations corresponding to any of the methods of embodiments A1-A10.

[0178] B2. Network equipment arranged to implement an identification server configured to provide concealed identifiers for user subscriptions to a communication network, the network equipment being configured to perform operations corresponding to any of the methods of embodiments A1-A10.

[0179] B3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry associated with an identification server configured to provide concealed identifiers for user subscriptions to a communication network, configure the identification server to perform operations corresponding to any of the methods of embodiments A1-A10.

[0180] B4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry associated with an identification server configured to provide concealed identifiers for user subscriptions to a communication network, configure the identification server to perform operations corresponding to any of the methods of embodiments A1-A10.

Claims

CLAIMS1. A method for an identification server configured to provide concealed identifiers for user subscriptions to a communication network, the method comprising: receiving (510), from a first network function, NF, of the communication network, a message including a first concealed identifier of a user subscription to the communication network; based on determining (520) that the first concealed identifier needs to be updated, determining (530) a second concealed identifier of the user subscription, including performing an encryption a non-concealed identifier of the user subscription, using a public part of an asymmetric key pair; determining (560) a secured second concealed identifier of the user subscription, based on the second concealed identifier and a symmetric key that is known to a user equipment, UE, associated with the user subscription; and sending (580) the secured second concealed identifier to the first NF.

2. The method of claim 1, wherein determining (560) the secured second concealed identifier comprises encrypting (561) the second concealed identifier using the symmetric key.

3. The method of claim 1, wherein determining (560) the secured second concealed identifier comprises calculating (562) a message authentication code, MAC, for the second concealed identifier using the symmetric key, wherein the secured second concealed identifier comprises the second concealed identifier and the MAC.

4. The method of any of claims 1-3, further comprising determining (540) an authentication vector including an authentication token, AUTN, and a random value, RAND, that are usable by the UE to authenticate the identification server, wherein the authentication vector is sent to the first NF together with the secured second concealed identifier.

5. The method of claim 4, further comprising generating (550) the symmetric key based on the random value, RAND, and a primary key, K, associated with the user subscription.

6. The method of any of claims 1-5, wherein determining (520) that the first concealed identifier needs to be updated is based on one or more of the following: a first indicationincluded in the message from the first NF, a second indication received from a second NF of the communication network, and a configuration of the identification server.

7. The method of any of claims 1-6, wherein the UE is a constrained UE that is unable to determine a concealed identifier of the user subscription based on the non-concealed identifier of the user subscription.

8. The method of any of claims 1-7, wherein the public-key encryption of the nonconcealed identifier uses one of the following as an input: a pseudo-random string, a counter, or a current time.

9. The method of any of claims 1-8, wherein the identification server is a unified data management function, UDM, and the first NF is an authentication server function, AUSF.

10. The method of any of claims 1-8, wherein: the identification server is an authentication server function, AUSF, and the first NF is an access and mobility management function, AMF; and the method further comprises receiving, from a unified data management function, UDM, of the communication network, security materials used to determine the second concealed identifier and the secured second concealed identifier.

11. Network equipment (808, 1000, 1102) arranged to implement an identification server (230, 240, 330, 340, 430, 440) configured to provide concealed identifiers for user subscriptions to a communication network (200, 802), the network equipment comprising: communication interface circuitry (1006, 1104) configured to communicate with a first network function, NF (130, 220, 230, 320, 330, 420, 430) of the communication network; and processing circuitry (1002, 1104) operably coupled to the communication interface circuitry, wherein the processing circuitry and interface circuitry are configured to: receive, from the first NF, a message including a first concealed identifier of a user subscription to the communication network; based on a determination that the first concealed identifier needs to be updated, determine a second concealed identifier of the user subscription, includingperforming an encryption a non-concealed identifier of the user subscription, using a public part of an asymmetric key pair; determine a secured second concealed identifier of the user subscription, based on the second concealed identifier and a symmetric key that is known to a user equipment, UE, associated with the user subscription; and send the secured second concealed identifier to the first NF.

12. The network equipment of claim 11, wherein the processing circuitry and interface circuitry are further configured to perform operations corresponding to any of the methods of claims 2-10.

13. Network equipment (808, 1000, 1102) arranged to implement an identification server (230, 240, 330, 340, 430, 440) configured to provide concealed identifiers for user subscriptions to a communication network (200, 802), the network equipment being configured to: receive, from a first network function, NF (130, 220, 230, 320, 330, 420, 430) of the communication network, a message including a first concealed identifier of a user subscription to the communication network; based on a determination that the first concealed identifier needs to be updated, determine a second concealed identifier of the user subscription, including performing an encryption a non-concealed identifier of the user subscription, using a public part of an asymmetric key pair; determine a secured second concealed identifier of the user subscription, based on the second concealed identifier and a symmetric key that is known to a user equipment, UE, associated with the user subscription; and send the secured second concealed identifier to the first NF.

14. The network equipment of claim 13, being further configured to perform operations corresponding to any of the methods of claims 2-10.

15. Non-transitory, computer-readable medium (1004, 1104) storing computer-executable instructions that, when executed by processing circuitry (1002, 1104) associated with an identification server (230, 240, 330, 340, 430, 440) configured to provide concealed identifiers for user subscriptions to a communication network (200, 802), configure the identification server to perform operations corresponding to any of the methods of claims 1-10.

16. Computer program product (1004a, 1104a) comprising computer-executable instructions that, when executed by processing circuitry (1002, 1104) associated with an identification server (230, 240, 330, 340, 430, 440) configured to provide concealed identifiers for user subscriptions to a communication network (200, 802), configure the identification server to perform operations corresponding to any of the methods of claims 1-10.

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