Encrypting service information in resilient notifications

Abstract

Example embodiments of the present disclosure relate to encrypted service information in resilient notifications. A method performed by a user equipment (UE) is provided. The method includes sending a request to a core network, the request to activate delivery of resilient notifications for one or more mobile terminated services. The method includes receiving a broadcast message from a radio access network serving the UE, the broadcast message including information, the information including a resilient notification associated with a failure to deliver a mobile terminated service of the one or more mobile terminated services to the UE. The resilient notification includes ciphertext, the ciphertext including service information associated with the mobile terminated service. The method includes decrypting the ciphertext to recover the service information, and the method includes displaying the resilient notification including the service information.

Description

Technical Field

[0001] This disclosure relates generally to telecommunications, and more particularly to resilient notifications for mobile termination services in telecommunications systems. Background Technology

[0002] A telecommunications system can be considered as a facility that enables communication between two or more entities, such as between two user equipments (UEs), between a UE and a base station, between two base stations, between a UE and a network function of a communication network, and / or between a base station and other nodes. A telecommunications system may include a communication network and one or more UEs. A communication session may include, for example, the transmission of data used to carry the communication, such as voice, video, email, text messages, multimedia, and / or content data. Non-limiting examples of services provided include two-way or multi-way calling, data communication or multimedia services, and access to data network systems such as the Internet.

[0003] In telecommunications systems that include wireless communication networks, at least a portion of a communication session between at least two sites occurs over a wireless link. Examples of wireless communication networks include public terrestrial mobile networks (PLMNs), satellite-based communication networks, and various wireless local networks such as wireless local area networks (WLANs). Some wireless communication networks can be divided into cells and are therefore often referred to as cellular networks.

[0004] Users can access the telecommunications system through appropriate communication equipment or terminals. A user's communication equipment may be referred to as user equipment (UE) or user device. The communication device is provided with appropriate signal receiving and transmission means to enable communication, such as enabling access to a communication network or direct communication with other users. The communication device can access a carrier provided, for example, by a base station in a cell, and transmit and / or receive communication on that carrier.

[0005] Telecommunication systems and their associated equipment typically operate according to given standards or specifications that define the operations permitted to be performed by the various entities associated with the communication system and how those operations should be implemented. Communication protocols and / or parameters used to connect the various entities are also typically defined. An example of a telecommunications system is the Universal Mobile Telecommunications System (UMTS). Other examples of telecommunications systems are Long Term Evolution (LTE), LTE Advanced, and so-called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3GPP). Summary of the Invention

[0006] The example implementations of this disclosure relate to telecommunications, and more specifically, to resilient notifications for mobile termination services in telecommunications systems. This disclosure includes, but is not limited to, the following example implementations.

[0007] Some example implementations provide a user equipment (UE) including: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the UE to perform operations including: sending a request to a core network to activate the delivery of a resilient notification for one or more mobile termination services; receiving a broadcast message from a radio access network serving the UE, the information including a resilient notification associated with a failure to deliver one or more mobile termination services to the UE, the resilient notification including ciphertext containing service information associated with the mobile termination service; decrypting the ciphertext to restore the service information; and displaying the resilient notification including the service information.

[0008] Some example implementations provide a method performed by a user equipment (UE) comprising: sending a request to a core network to activate the delivery of a resilient notification for one or more mobile termination services; receiving a broadcast message from a radio access network serving the UE, the message including information including a resilient notification associated with a failure to deliver the one or more mobile termination services to the UE, the resilient notification including ciphertext including service information associated with the mobile termination service; decrypting the ciphertext to restore the service information; and displaying the resilient notification including the service information.

[0009] Some example implementations provide an apparatus including: at least one processor; and at least one memory storing instructions for an entity of a core network or Internet Protocol (IP) Multimedia Subsystem (IMS), the instructions causing the apparatus to perform operations when executed by the at least one processor, the operations including: generating or receiving a resilience notification associated with a failure to deliver a mobile termination service to a user equipment (UE), the resilience notification including service information associated with the mobile termination service; encrypting the service information in the resilience notification into ciphertext; and sending the resilience notification including the ciphertext to a radio access network serving the UE for the radio access network to broadcast a broadcast message including information to the UE, the information including the resilience notification.

[0010] Some example implementations provide a method performed by an entity of the core network or Internet Protocol (IP) Multimedia Subsystem (IMS), the method comprising: generating or receiving a resilience notification associated with a failure to deliver a mobile termination service to a user equipment (UE), the resilience notification including service information associated with the mobile termination service; encrypting the service information in the resilience notification into ciphertext; and sending the resilience notification including the ciphertext to a radio access network serving the UE for the radio access network to broadcast a broadcast message including information to the UE, the information including the resilience notification.

[0011] These and other features, aspects, and advantages of this disclosure will become apparent from the following detailed description and the accompanying drawings, which are briefly described below. This disclosure includes any combination of two, three, four, or more features or elements set forth herein, whether or not such features or elements are explicitly combined or otherwise described in the particular example implementation described herein. This disclosure is intended to be read holistically, such that any separable feature or element of this disclosure shall be considered composable in any aspect and example implementation thereof, unless the context of this disclosure expressly provides otherwise.

[0012] Therefore, it should be understood that the content of this invention is provided merely to summarize some exemplary implementations in order to provide a basic understanding of some aspects of this disclosure. Consequently, it should be understood that the above exemplary embodiments are merely examples and should not be construed as limiting the scope or spirit of this disclosure in any way. Other exemplary implementations, aspects, and advantages will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which illustrate the principles of some of the described exemplary implementations by way of example. Attached Figure Description

[0013] Having described above an example implementation of this disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, wherein: Figure 1 The present disclosure illustrates a telecommunications system comprising one or more public land mobile networks (PLMNs) coupled to one or more external data networks, according to some example implementations of this disclosure; Figure 2A A PLMN with an IP multimedia subsystem (IMS) is shown according to some example implementations; Figure 2B This shows an IMS implementation based on some examples; Figure 3 This shows implementations based on some examples. Figure 1 The non-terrestrial network (NTN) of the telecommunications system. Figure 4 This is a diagram illustrating the process for IMS authentication based on some example implementations; Figure 5 , Figure 6 , Figure 7 , Figure 8A and Figure 8B This is a diagram illustrating the process for providing resilient notifications for mobile termination services, based on various example implementations. Figure 9A and Figure 9B This is a diagram illustrating the process for providing resilient notifications for mobile termination services, based on some other example implementations. Figure 10A and Figure 10B This is a flowchart illustrating the individual steps in a method executed by the UE according to various example implementations; Figure 11 This is a flowchart illustrating the various steps in a method performed by an entity in the core network or IMS, according to various example implementations; and Figure 12 The apparatus is shown according to some example implementations. Detailed Implementation

[0014] Some implementations of this disclosure will now be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, implementations of this disclosure. In fact, various implementations of this disclosure may be embodied in many different forms and should not be construed as limited to the implementations set forth herein; rather, these exemplary implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. The same reference numerals throughout refer to the same elements.

[0015] Unless otherwise stated or clear from the context, references to first, second, etc., should not be construed as implying a particular order. Another feature described above a feature (unless otherwise stated or clear from the context) may alternatively be below, and vice versa; and similarly, another feature described to the left of a feature may alternatively be to the right, and vice versa. Furthermore, while this document may refer to quantitative measurements, values, geometric relationships, etc., any one or more of these (if not all) may be absolute or approximate to account for acceptable variations that may occur, such as those due to engineering tolerances, etc.

[0016] As used herein, unless otherwise stated or clearly understood from the context, an "OR" of a set of operands is an "inclusive OR" and is therefore true if and only if one or more operands are true, unlike an "exclusive OR" which is false if all operands are true. Thus, for example, "[A] OR [B]" is true if [A] is true, or if [B] is true, or if both [A] and [B] are true. Furthermore, "embodiment" and "an embodiment" mean "one or more embodiments" unless otherwise stated or clearly understood from the context to refer to the singular form. Additionally, it should be understood that, unless otherwise stated, the terms "data," "content," "digital content," "information," and similar terms are sometimes used interchangeably. The term "network" can refer to a group of interconnected computers including clients and servers; and within a network, these computers can be interconnected directly or indirectly via various means, including via one or more switches, routers, gateways, access points, etc.

[0017] This disclosure discusses telecommunications systems and mobile or cellular networks and their user equipment, and while specific terminology may be used, these terms are broadly applicable across a variety of technologies. For example, while this disclosure may refer to radio access technologies such as 5G NR and 5G Advanced, it is equally applicable to next-generation radio access technologies such as 6G. The exemplary implementations of this disclosure described herein also refer to public terrestrial mobile networks (PLMNs) and mobile network operators (MNOs), but the exemplary implementations are equally applicable to standalone non-public networks (SNPNs). Furthermore, although some examples and figures focus on radio access networks (RANs), and particularly on radio access networks used for NR operation in accordance with 3GPP standards (often referred to as 3GPP access or 3GPP access network), the exemplary implementations are applicable to any type of access network. This includes not only 3GPP access networks, but also non-3GPP access networks, such as wired access, untrusted non-3GPP access networks, and trusted non-3GPP access networks that connect to the core network of a mobile or cellular network (e.g., 5G core network (5GC) or 6G core network (6GC)) using a wireless access gateway function (W-AGF), a non-3GPP interworking function (N3IWF), or a trusted non-3GPP gateway function (TNGF).

[0018] Furthermore, as used in this application, the term "circuit" may refer to one or more or all of the following: (a) implemented solely by hardware circuitry (e.g., implemented with purely analog and / or digital circuitry); (b) a combination of hardware circuitry and software, such as (if applicable): (i) a combination of (multiple) analog and / or digital hardware circuitry and software / firmware, and (ii) any part of a hardware processor having software (including (multiple) digital signal processors, software, and (multiple) memories, which work together to enable a device (e.g., a mobile phone or a server) to perform various functions); or (c) (multiple) hardware circuitry and / or (multiple) processors that require software (e.g., firmware) for operation, such as (multiple) microprocessors or parts thereof, but where the software may be absent when operation does not require it.

[0019] The above definition of "circuit" applies to all uses of the term in this application. As a further example, as used in this application, the term "circuit" also covers only hardware circuitry or processors (or processors), or portions of hardware circuitry or servers and their accompanying software and / or firmware implementations. For example, where applicable to certain claim elements, the term "circuit" also covers baseband integrated circuits or processor integrated circuits for mobile devices or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0020] Figure 1 Telecommunication system 100 according to various example implementations of this disclosure is illustrated. Telecommunication system 100 (also referred to as system 100) typically includes one or more mobile or cellular networks. As shown, for example, system 100 includes one or more PLMNs 102 coupled to one or more other external data networks 104, which significantly include wide area networks (WANs) such as the Internet. As will be understood, the PLMN may be a standalone PLMN including a 5GC, or it may be a non-standalone PLMN including both a 5GC connected to a RAN and an Evolved Packet Core (EPC).

[0021] Each PLMN 102 includes a core network (CN) 106, such as an EPC, 5GC, or 6GC; and each CN is coupled to one or more RANs 108 implementing one or more radio access technologies (RATs). Examples of these RANs include the evolved UMTS terrestrial radio access network (E-UTRAN) for 4G LTE, the next-generation (NG) radio access network (NG-RAN) for 5G NR, and the 6G RAN. As used herein, “network equipment” refers to any suitable equipment in the RAN or core network of a telecommunications system. Examples of suitable network equipment will be described in more detail below.

[0022] Examples of RATs include 3GPP radio access technologies such as GSM, CDMA2000 1xEV-DO (HRPD), CDMA2000 1x (1xRTT), UTRA, E-UTRA, 5G NR, 5G Advanced, and 6G. Other examples of RATs include IEEE 802 technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.15 (including 802.15.1 (WPAN / Bluetooth), 802.15.4 (Zigbee), and 802.15.6 (WBAN)), Bluetooth, Bluetooth Low Energy (BLE), Ultra Wideband (UWB), etc. Generally, RAT can refer to any 2G, 3G, 4G, 5G, 6G, or higher generation RAT and its different versions, as well as any other RAT that can be configured to interconnect with such a RAT to provide access to CN 106 of the MNO.

[0023] Telecommunication system 100 also includes one or more communication devices, which may be referred to differently as user equipment (UE) 110, terminal equipment, terminal device, mobile station, etc. The UE is typically a device configured to communicate with network equipment (such as an access node such as a RAN node in RAN 108) or another UE in the telecommunications system. The UE can be a portable computer (e.g., a laptop, tablet), a mobile phone (e.g., a cellular phone, a smartphone), a wearable computer (e.g., a smartwatch), etc. In other examples, the UE can be an Internet of Things (IoT) device, an Industrial Internet of Things (IIoT) device, a vehicle equipped with vehicle-to-everything (V2X) communication technology, etc. In some examples, as mentioned by 3GPP, the UE can be a narrowband Internet of Things (NB-IoT) device, an enhanced machine-type communication (eMTC) device, a redcap device, an environmental IoT device, etc.

[0024] In operation, these UEs 110 can connect to one or more RAN nodes of RAN 108 according to their specific RAT, thereby accessing a specific CN 106 of PLMN 102, or accessing one or more external data networks 104 (such as the Internet) or services provided by the PLMN. External data networks can provide Internet access or third-party services. For example, the International Telecommunication Union (ITU) has classified 5G mobile network services (such as services provided by 5G mobile networks) into three categories: enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC) or massive Internet of Things (MIoT).

[0025] In various examples, RAN 108 can be configured to provide one or more macro cells, micro cells, pico cells, femto cells, etc. RAN 108 typically includes one or more RAN nodes that interact with UE 110. In various examples, RAN nodes can be referred to as base stations (BS), access points (AP), base transceiver stations (BTS). Examples of RAN nodes include Node B (NB), evolved NB (eNB), macro base station, NB (MNB) or eNB (MeNB), home BS, NB (HNB) or eNB (HeNB), next-generation NB (gNB), enhanced gNB (en-gNB), next-generation eNB (ng-eNB), 6G NB (6gNB), etc. In 5G NR, the term "gNB" can correspond to eNB in ​​4G LTE. In addition, NG-RAN nodes can refer to gNB or ng-eNB. And, unless otherwise stated, gNB in ​​5G NR or 6gNB in ​​6G can sometimes be more generally referred to as (6)gNB, or more simply as gNB.

[0026] RAN 108 may include some type of network control / management entity responsible for controlling the RAN nodes. The network control / management entity may be separate from the RAN nodes or may be integrated into a single device. The network control / management entity may include processing circuitry configured to perform various management functions for controlling the RAN nodes of RAN 108. This processing circuitry may be associated with memory, computer-readable storage media, or data storage devices including databases (for maintaining information required in the various management functions).

[0027] Figure 2AAn example of a PLMN 102, such as a 4G LTE PLMN, 5G NR PLMN, or 6G PLMN, is shown, which communicates with the UE 110 of the telecommunications system 100 and the external data network 104. As shown, the RAN 108 (e.g., E-UTRAN, NG-RAN, 6G RAN) includes one or more RAN nodes 202, which are configured to connect one or more UEs to the RAN, thereby accessing the core network (CN) 106 (e.g., EPC, 5GC, 6GC). In 5G NR, the UE, NG-RAN, and 5GC are sometimes collectively referred to as the 5G system (5GS). Similarly, in 6G, the UE, 6G RAN, and 6GC can sometimes be collectively referred to as the 6G system (6GS).

[0028] Communication between UE 110 and RAN 108 can be guided by a protocol including Radio Resource Control (RRC). RRC is guided by a state machine that defines certain specific states the UE can be in. Different states in the RRC state machine are associated with different amounts of radio resources, which are the resources the UE can use when it is in each state. In 5G NR, these RRC states include RRC IDLE, RRC CONNECTED, and RRC INACTIVE.

[0029] In some implementations, the operation of the gNB or other RAN node 202 can be distributed or functionally broken down into multiple components, including one or more remote radio heads (RRHs) or radio units (RUs) and baseband units (BBUs); and in some implementations, the BBU can be broken down into centralized / central units (CUs) (central nodes) and distributed units (DUs) (distributed nodes). A CU can be, for example, a server, a host, or a node. In some implementations, the RRH / RU and DU can be co-located at the network device. The operation of the gNB or RAN node can also be distributed among multiple servers, hosts, or nodes.

[0030] The core network (CN) 106 may include multiple network functions (NFs) that are partitioned between the control plane (CP) and the user plane (UP). Specifically, for example, the CN may include network functions for access and mobility management (MM) (sometimes referred to as MM NFs) and network functions for session management (SM) (sometimes referred to as SM NFs). An MM NF may be, for example, a Mobility Management Entity (MME) in the EPC, an Access and Mobility Management Function (AMF) 304 in the 5GC, or a 6G MM in the 6GC. Similarly, an SM NF may be, for example, a Serving Gateway (SGW) Control Plane Function (SGW-C) and / or a Packet Data Network Gateway (PGW) Control Plane Function (PGW-C) in the EPC, a Session Management Function (SMF) 306 in the 5GC, or a 6GSM in the 6GC.

[0031] The core network (CN) 106 may also include a user plane control NF for service (e.g., data) reception and transmission, sometimes referred to as a user plane function (UPF) 208. In the EPC, the UPF may be an SWG user plane function (SGW-U) and / or a PGW user plane function (PGW-U). Other examples of suitable NFs include a unified data management (UDM) 210 (or a Home Subscriber Server (HSS) in the EPC, etc.), a policy control (PC) NF, etc. A PC NF may be, for example, a policy and charging function (PCF) 212, a policy and charging rules function (PCRF), etc. Another example of a suitable network function is a network resource library function (NRF) 214. Additional examples include a gateway mobile switching center (MSC) (SMS-GMSC) 216 for short message service (SMS), a short message service (SMS) router 218, a short message store and forwarding function (SMSF) 220, a service center (SC) 222 (sometimes referred to as SMS-SC), etc. It should be noted that although the accompanying figures mention several 5GC NFs, such as AMF, SMF and UPF, the example implementations of this disclosure are also applicable to 6GC with equivalent core elements / NFs, or to EPC (where MME has similar functionality to AMF, HSS has similar functionality to UDM and PGW has similar functionality to SMF).

[0032] The document also illustrates the IP Multimedia Subsystem (IMS) 224, as defined by 3GPP, for enabling IP multimedia services such as voice, video, messaging, data, and web-based services. Within the IMS context, the core network (CN) 106 and RAN 108 can together form an IP connectivity access network (IP-CAN) for transmitting multimedia signaling and bearer services for IP multimedia services. According to current specifications, examples of IP-CAN include the Evolved Packet Core (EPC) with E-UTRAN in 4G, and the 5G Core (5GC) with NG-RAN (5GS access network) in 5G. Another example of IP-CAN could be the 6G Core (6GC) with 6G RAN (6GS access network) in 6G.

[0033] IMS 224 may include CP and UP. For example, in CP, IMS may include multiple Call Session Control Functions (CSCF) 226, such as Proxy-CSCF (P-CSCF) 228, Inquiry-CSCF (I-CSCF) 230, and Service-CSCF (S-CSCF) 232. IMS may also include IMS HSS 234, which may be implemented by the HSS in EPC (CN 106) and may interconnect with UDM 210 in a 5G network. In addition, as shown in the figure, IMS may also include one or more IMS Application Servers (AS) 236 (sometimes referred to as IMS AS).

[0034] Mobile or cellular networks, such as PLMN 102, are now also beginning to support non-terrestrial networks (NTNs). In an NTN, RAN node 202 or RAN node functionality can be deployed on satellites or other aerospace platforms in a regenerative deployment (or architecture), or relayed by RAN nodes in a transparent deployment. Therefore, NTNs can provide communication coverage over very large areas that might be unreachable by terrestrial RANs alone. This functionality can be used to globally connect IoT devices and provide communication for UEs in remote areas or during disaster relief situations.

[0035] Figure 3 It shows Figure 1Examples of PLMN 102 and UE 110 in telecommunications system 100, where PLMN 102 includes NTN 302. As shown, the NTN may include an aerospace platform, such as satellite 304, which is connected to UE 110 via serving link 306 (radio link) and to NTN gateway 308 via feeder link 310 (radio link). In regenerative deployments, the satellite (or other aerospace platform) may carry RAN node 202 or a portion of the RAN node, such as a DU. The NTN gateway may then be connected to CN 106; and in some examples involving CU-DU splitting, the NTN may carry or be connected to a CU, which in turn is connected to CN 106. In some examples, the NTN gateway and RAN node may be co-located. UE 110 supports access to and communication with the NTN.

[0036] In various examples, an aerospace platform can be a space vehicle or airborne vehicle, transportation vehicle, etc. As shown, an aerospace platform can be satellite 304. In other more specific examples, an aerospace platform can be a low Earth orbit (LEO) satellite, a medium Earth orbit (MEO) satellite, a geostationary orbit (GEO) satellite, etc. Similarly, in more specific examples, an aerospace platform can be an unmanned aerial system (UAS), such as a tethered UAS (TUA), a lighter-than-air UAS (LTA), a heavier-than-air UAS (HTA), a high-altitude platform (HAP), etc. Some example implementations of this disclosure can be described in the context of a satellite or UAS, but it should be understood that these example implementations are equally applicable to other aerospace platforms.

[0037] Communication between Satellite 304 and UE 110 typically has a very limited power margin and usually requires line-of-sight (LOS) for optimal performance. For mobile-originating (MO) services, users are aware of channel quality and can achieve LOS communication by consciously adjusting the points of signal transmission / reception. However, for mobile-terminated (MT) services, such as calls and messages, users are unaware of channel quality and may miss important calls / messages due to poor downlink channel quality. When the terrestrial RAN is unavailable, satellite access may be the last resort, and improving user accessibility in NTN 302 could contribute to a better user experience.

[0038] To improve user reachability in NTN 302, satellite 304 (RAN node) can notify the user / UE 110 of missed MT services (e.g., voice, video, data, messages) when the user is unreachable. In this context, the resilient notification service refers to the service that provides a resilient notification (sometimes more simply called a "notification") to the UE when it is determined that delivery of an initiator-initiated MT service to the UE has failed. In some cases, this failure may be due to a paging failure of the paging message to the UE for that MT service (or the UE's response to that paging message). It should be noted that although the use and request for resilient notifications are described for satellite use cases in this document, the use and request for resilient notifications can also occur in other non-NTN radio environments where the probability of (multiple) UEs missing termination services is higher than average. It should also be noted that, in turn, the IMS entity can determine whether to request the sending of a resilient notification for termination services based on the current radio access type serving the UE (e.g., based on the type of radio access network currently serving the UE).

[0039] Flexible notifications can be broadcast or otherwise sent to UEs in an RRC idle state on a dedicated paging alert channel (PAC) (sometimes called the flexible notification channel). In some examples, the PAC can be an NTN downlink channel from satellite 304 (or other aerospace platforms in NTN 302). In other examples, the dedicated PAC can be a terrestrial RAN downlink channel from RAN node 202 (such as an eNB, ng-eNB, (6) gNB, etc.). Flexible notifications can be sent via one or more RAN nodes on one or more cells to increase the likelihood of the flexible notification reaching the UE.

[0040] Resilient notifications can inform users of missed MT services (e.g., paging messages already sent to the user) and indicate that UE cooperation may be required to receive the MT service. When a user is in a low signal-to-noise ratio (SNR) environment, such as indoors, or when the user's UE 110 is inside a backpack, resilient notifications can be used to inform the UE of missed MT services, allowing the UE to move to a better receiving location to receive the MT service. The resilient notification service is a highly reliable and efficient service that delivers resilient notifications directly to the UE via satellite access or terrestrial RAN. The resilient notification service ensures that resilient notifications for high-priority calls / messages reach UEs located in areas where normal connectivity has failed or is compromised.

[0041] Elastic notifications may include service information associated with MT services, or more specifically, service information associated with failed MT services (i.e., MT services that failed to be delivered), and at least a portion of this service information may be considered private. For example, service information may include information identifying the initiator (e.g., the caller's identifier, often referred to as the caller ID), the service type indicating the MT service type (e.g., voice, video, data, messaging), and / or the priority of the MT service. In some cases, service information may be known only to the intended user of UE 110. This may raise privacy and security concerns for elastic notifications, as they are broadcast by one or more RAN nodes in one or more cells to increase the likelihood of the elastic notification reaching the UE.

[0042] In light of the foregoing, some example implementations of this disclosure provide procedures for UE 110, CN 106, RAN 108, and / or IMS 224 to enable and execute resilient notifications, including service information in the resilient notification that can be encrypted into ciphertext that can only be decrypted by the UE to which the resilient notification is intended (typically referred to as the intended UE). In some examples, the MT service is the MT IMS service. In other examples, the MT service can be a messaging service, such as SMS.

[0043] According to some example implementations, UE 110 may support a flexible notification service that provides flexible notifications for one or more MT services (such as high-priority MT IMS services, or non-IMS MT services, such as SMS). The UE may send a request to CN 106, or via CN 106 to IMS 224, to activate the delivery of flexible notifications for MT services. The request to activate the delivery of flexible notifications for MT services can be sent by the UE in several different ways. In some examples involving messaging services such as SMS, the request to activate the delivery of flexible notifications can be sent to CN106. In some other examples involving MT IMS services, the request to activate the delivery of flexible notifications can be sent to IMS 224 via CN106. In some of these other examples, the request to activate the delivery of flexible notifications for MT services can be sent during UE 110's registration or re-registration with IMS 224.

[0044] UE 110 can monitor both the regular paging channel (PCH) for paging messages for the MT service initiated by the initiator to the UE, and the dedicated PAC for a resilient notification for the MT service triggered (e.g., sent in response to the failure) upon detection of MT service delivery failure. In some examples, CN 106 or IMS 224 can trigger the sending of a resilient notification for the MT service to UE 110 when MT service delivery fails. In some examples, CN 106 or IMS 224 can determine that UE 110 cannot receive MT service delivery, and the resilient notification for the MT service is sent to UE 110 on the dedicated PAC. In some examples involving MT IMS services, IMS 224 can determine that UE 110 cannot receive MT service delivery, for example after multiple consecutive attempts to send incoming SIP messages (e.g., SIP INVITE or SIP MESSAGE) to UE 110 without receiving any response from the UE. As an example, failure to deliver MT service to the UE may be due to the UE 110 being unable to receive paging messages or being unable to establish a radio channel with the RAN. In some cases, the root cause of failure to deliver MT service to the UE may be low radio SNR or non-LOS (NLOS) radio conditions for the UE.

[0045] A resilient notification for a Mobile MT (Mobile Transmission) service may be a notification indicating that the delivery of an MT service initiated by the initiator has failed. In some examples, the resilient notification may include a UE identifier (ID) that identifies the UE, such as a Temporary Mobile Subscriber Identity (TMSI), an International Mobile Subscriber Identity (IMSI), or a Subscription Permanent Identifier (SUPI). The resilient notification may also include service information associated with the MT service, or more specifically, service information associated with the failed MT service. Service information may include, for example, information identifying the initiator, a service type indicating the type of MT service (e.g., voice, video, data, messaging), and / or the priority of the MT service. In some examples, the service information may include information from which the UE can create a Uniform Resource Identifier (URI), from which the UE can retrieve information such as the initiator, service type, and / or priority. In some examples, the resilient notification may also include a unique sequence number associated with the resilient notification.

[0046] At various times, such as during UE 110's registration with CN 106, access authentication or other authentication processes can be performed between UE 110 and CN 106. Access authentication or other authentication processes can be authentication and key agreement (AKA), such as 5G AKA, which can provide mutual authentication between UE 110 and CN 106. During this process, key materials can be generated, and these key materials can be used to generate cryptographic keys for subsequent processes between UE 110 and CN 106, including for encrypting and decrypting service information in resilient notifications. Similarly, as described in more detail below, IMS AKA can be performed during UE 110's registration with IMS 224. During IMS AKA, key materials can be used to generate cryptographic keys for subsequent processes between UE 110 and IMS 224, including for encrypting and decrypting service information in resilient notifications.

[0047] As explained in more detail below, a resilient notification for the MT service can be triggered (e.g., a request to send) by any one or more entities of CN 106 or IMS 224. This entity can determine that the MT service delivery has failed and generate the content of the resilient notification for the MT service, which may include the UE ID and service information associated with the MT service. The entities of CN106 or IMS 224 may encrypt the service information in the resilient notification into ciphertext and may retain the UE ID in plaintext.

[0048] Then, the entity of CN 106 or IMS 224 can send a resilient notification, including ciphertext (and the UE ID as plaintext), to RAN 108, so that RAN node 202 of RAN 108 can send a resilient notification for MT service to UE 110. More specifically, in the case of a resilient notification triggered by IMS 224, the entity of IMS 224 can send a request to CN (e.g., UDM 210 and / or HSS 234, PCF 212) to cause RAN node 202 of RAN 108 to send a resilient notification for MT service to UE 110, for example on a dedicated PAC.

[0049] Then, UE 110 can receive a resilient notification for MT services from CN 106 or IMS 224 (via the RAN node of RAN 108). UE 110 can detect that UE 110 is the target of the resilient notification based on the UE ID as plaintext in the resilient notification. The UE ID as plaintext in the resilient notification identifies UE 110. UE 110 can then decrypt the ciphertext to recover service information, such as a cryptographic key determined from key materials associated with the authentication process between the UE and CN 106 or IMS 224. UE 110 can then provide the resilient notification to its user, for example, by displaying the resilient notification including service information on UE 110's display.

[0050] In some examples where the MT service is an MT IMS service, a resilient notification for the MT service can be triggered (e.g., sent by) by the P-CSCF 228, which can determine that delivery of the initiator-initiated MT service to UE 110 has failed. More specifically, for example, the P-CSCF 228 can determine that delivery of the initiator-initiated MT service to UE 110 has failed based on information received from the PCF 212 indicating a paging failure of a paging message associated with the MT service. As another example, the P-CSCF 228 can determine that delivery of the initiator-initiated MT service to UE 110 has failed by determining that more attempts to deliver an incoming SIP message (e.g., a SIP invite) associated with the MT service to UE 110 have exceeded a threshold number (too many attempts). In some examples, the failure to deliver the initiator-initiated MT service to UE 110 can be indicated to the P-CSCF by a timeout associated with the incoming SIP message.

[0051] In some examples where P-CSCF 228 determines that MT service delivery has failed, P-CSCF 228 may generate information to be sent as part of an elasticity notification for MT service (e.g., information to be included in the elasticity notification for MT service), and may send a request to CN 106 to cause RAN node 202 of RAN 108 serving UE 110 to send an elasticity notification to UE 110. In some of these examples, referred to as a P-CSCF-initiated, PCF-based elasticity notification process, P-CSCF 228 may send a request to PCF 212, and the elasticity notification may be sent by PCF 212 to SMF 206, by SMF 206 to AMF 204, by AMF 204 to RAN node 202 of RAN 108, and by RAN node 202 of RAN 108 to UE 110.

[0052] In some other examples, P-CSCF 228 may send a SIP error message associated with the MT service to S-CSCF 228, which may determine that the delivery of the MT service to UE 110 has failed based on the SIP error message. S-CSCF 228 may trigger the generation of a resilience notification for the MT service and generate information to be sent as part of the resilience notification for the MT service (e.g., included in the resilience notification), and send a request to CN 106 to instruct RAN 108 to send the resilience notification for the MT service to UE 110. In some of these examples, sometimes referred to as an S-CSCF-assisted, UDM-based resilience notification process, S-CSCF may send a request to HSS 234 and / or UDM 210, and the resilience notification may be sent by HSS 234 and / or UDM 210 to AMF 204, by AMF to RAN node 202 of RAN 108, and by RAN node of RAN 108 to UE 110.

[0053] In some other examples, P-CSCF 228 can send SIP error messages associated with the MT service to S-CSCF 228, which in turn can send the corresponding SIP error messages to AS 236. AS 236 can determine that the MT service delivery has failed based on the corresponding SIP error message. AS 236 can trigger and generate information to be sent as part of (e.g., included in) a resilience notification for the MT service, and send a request to CN 106 (e.g., UDM 210 and / or HSS 234) to cause RAN node 202 of RAN 108 to send a resilience notification to UE 110. In some of these examples, sometimes referred to as an IMS AS-assisted, UDM-based resilience notification process, AS can send a request to HSS 234 and / or UDM 210, and the resilience notification can be sent by HSS and / or UDM to AMF 204, by AMF to the RAN node of the RAN, and by the RAN node of the RAN to the UE.

[0054] Again, UE 110, capable of receiving elastic notifications for one or more MT services, can inform CN 106 (e.g., AMF 204) of its ability to receive elastic notifications for one or more MT services. UE 110 can inform CN 106 (e.g., AMF 204) of its UE capabilities (e.g., during initial registration with IMS 224 and mobility registration with CN 106 (e.g., AMF 204)). When UE 110 registers with IMS 224, UE 110 can also provide its UE capabilities to IMS 224 (e.g., by providing its UE capabilities to entities within IMS 224, such as S-CSCF 232, AS 236).

[0055] IMS 224 may determine at some point that the delivery of MT service to UE 110 has failed, which may be due to paging failure or other failures. IMS 224 may generate a resilient notification based on the determination that the delivery of MT service to UE 110 has failed. The resilient notification for MT service is a notification regarding the failure to deliver MT service to UE 110. The resilient notification may also include the UE ID identifying the UE and service information associated with the MT service. Service information may include, for example, information identifying the initiator of the MT service, the service type indicating the type of MT service initiated by the initiator (e.g., voice, video, data, messaging), and / or the priority of the MT service. In some examples, the resilient notification may also include a unique sequence number associated with the resilient notification. IMS 224 may then send a request to CN 106 (e.g., PCF 212, HSS 234, and / or UDM 210) that triggers (e.g., an instruction or command) RAN node 202 of RAN 108 serving UE 110 to send the resilient notification for MT service to UE 110.

[0056] To further illustrate some example implementations, Figure 4This is a diagram illustrating the IMS authentication process according to some example implementations. As shown, in step 401, UE 110 may send a registration request to P-CSCF 228 to register UE 110 with IMS 224. The registration request may include a feature capability indicating that UE 110 is able to receive resilient notifications for one or more MT services. The registration request may also include one or more identifiers assigned to the user of the UE, such as IP multimedia private identity (IMPI), IP multimedia public user identity (IMPU), etc. In some examples, the registration request may be a SIP registration message including a capability feature tag, in which the feature capability is encoded. In some examples, the feature capability indicating that the UE is able to receive resilient notifications may be included in a request to activate the delivery of resilient notifications for MT services, or in a request to activate the delivery of resilient notifications for multiple MT services. At any time, when a UE user wishes to enable and / or disable resilient notifications for MT services, the UE can send a registration request to re-register with the IMS, and the registration request may include information indicating a request to activate or deactivate resilient notifications. The P-CSCF may send the registration request (including information indicating feature capabilities) to the S-CSCF 232 of the IMS 224 in step 402.

[0057] Upon receiving a registration request, S-CSCF 232 can use an authentication vector (AV) to authenticate and negotiate keys with UE 110. If S-CSCF does not have a valid AV, S-CSCF 232 can retrieve one or more AVs from HSS 234 in steps 403 and 404, such as using a Cx AV request procedure. Each AV may include a random number (RAND), an authentication token (AUTN), an expected response (XRES), an encryption key (CK), and an integrity key (IK). As mentioned above, the encryption key CK and integrity key IK can be key materials that can be used to generate cryptographic keys for subsequent processes between UE 110 and IMS 224, including for encrypting and decrypting service information in resilient notifications.

[0058] S-CSCF 232 can select one of the AVs, and S-CSCF 232 can send an authentication challenge to UE 110 in steps 405 and 406. The authentication challenge may include a random number RAND and an authentication token AUTN from the selected AV. S-CSCF 232 may also include an integrity key IK and an encryption key CK (for P-CSCF 228). Again, the encryption key CK and the integrity key IK can serve as key material to generate cryptographic keys for subsequent processes between UE 110 and IMS 224, including for encrypting and decrypting service information in resilient notifications.

[0059] Upon receiving a challenge, UE 110 can obtain an authentication token AUTN, which includes a message authentication code (MAC) and a sequence number (SQN). UE 110 can calculate the expected MAC (XMAC) and check whether the XMAC equals the MAC and whether the SQN is within the correct range. If both checks are successful, UE 110 selects a supported algorithm and calculates (e.g., computes) an authentication response. The UE can also calculate an encryption key CK and an integrity key IK at this stage. Again, these keys can serve as key material to generate cryptographic keys for subsequent processes between UE 110 and IMS 224, including for encrypting and decrypting service information in resilient notifications.

[0060] UE 110 can include the authentication response in the authorization header, and UE 110 can send it back to S-CSCF 232 in an encrypted registration message in steps 407 and 408. Upon receiving the encrypted registration message including the authentication response, S-CSCF 232 can retrieve the XRES for the AV, which S-CSCF 232 can use to check the authentication response. If the check is successful, the user has been authenticated, and the IMPU can be registered in S-CSCF 232. If the user of UE 110 has been successfully authenticated, S-CSCF 232 can send a SIP 200 (OK) message to UE 110 in steps 409 and 410.

[0061] As shown in step 411, S-CSCF 232 can also send a third-party registration request to AS 236 to notify AS that the user is available. S-CSCF can also send information to AS 236 indicating that resilient notification is required for UE 110. Upon receiving the third-party registration request, AS 236 can send a SIP subscription request to S-CSCF 232 in step 412, indicating a subscription event for the "reg" (registration) event packet to subscribe to registration status updates for the user to be notified against UE 110. S-CSCF can send a SIP notification message in step 413, indicating an event notification with registration information for the user (including the encryption key CK and integrity key IK (key material)). Therefore, AS 236 also obtains the key material, which can be used to generate cryptographic keys for subsequent procedures between UE 110 and IMS 224, including for encrypting and decrypting service information in the resilient notification.

[0062] Figure 5 This diagram illustrates a P-CSCF-initiated, PCF-based process for providing resilient notifications for MT services, according to some example implementations. As shown in step 500, this process can begin after UE 110 has registered with IMS 224. When UE 110 is in RRC idle state, the initiator (e.g., the caller) can initiate MT services, such as MT voice calls, to the user of UE 110. P-CSCF 228 can receive a SIP invite message for MT services in steps 501A and 501B and send the SIP invite message to UE 110. P-CSCF 228 can send the SIP invite message to UPF 208, and UPF 208 can send a downlink data notification (DDN) to SMF 206 in step 502 to indicate that downlink data for MT services for UE 110 has arrived. To ensure reachability to the UE, the SMF can inform the AMF 204 of downlink data in step 503, such as during the transmission of N1 and / or N2 information.

[0063] AMF 204 can initiate a paging procedure to locate UE 110. As part of the paging procedure, in step 504A, the AMF can send a paging message to the latest known RAN 108 serving the UE based on the latest known TA and cell identifier (ID), or send the paging message to all RANs of the UE's (multiple) latest known TAs (one or more registered TAs). The (multiple) RANs can broadcast the paging message on the (multiple) corresponding PCHs or other control channels in step 504B.

[0064] In some cases, paging failures or other MT service delivery failures may occur, such as due to low SNR or NLOS conditions of UE 110. AMF 204 can retry the paging process to the UE for MT service (including the paging message at step 504B). In various examples, AMF can (re)try the paging process via RAN node 202 of terrestrial RAN 108, satellites of NTN 302, or a combination of both terrestrial RAN RAN nodes and NTN satellites. Once all paging attempts of AMF (e.g., the configured maximum number of paging attempts) have been exhausted, AMF can detect a paging failure, and AMF can indicate to SMF 206 in step 505 that the failure to reach the UE has occurred.

[0065] SMF 206 may send information indicating failure to reach UE 110 (e.g., user unreachable) to PCF 212 in step 506, such as via SM policy control update service operation (Npcf_SMPolicyControl_Update), to update the SM policy association associated with the UE. PCF may send information indicating failure to reach UE to P-CSCF 228 in step 507, such as via policy authorization notification service operation (Npcf_PolicyAuthorization_Notify).

[0066] As shown in step 508, P-CSCF 228 can determine MT service delivery failure based on information indicating failure to reach UE 110. However, it should be understood that this is only an example of a triggering criterion, and other MT service delivery failure detection criteria exist. IMS 224 can determine that UE 110 cannot receive MT service delivery, for example, after multiple consecutive attempts to send incoming SIP messages (e.g., SIP INVITE or SIP MESSAGE) to UE 110 without receiving any response from UE 110. As an example, the failure could be due to UE 110's inability to receive paging messages or its inability to establish a radio channel with the RAN. In some cases, the root cause of the failure could be low radio SNR or NLOS radio conditions for the UE. In response to determining MT service delivery failure, P-CSCF 228 can check subscription information indicating that the user of UE 110 has subscribed to the Resilient Notification Service (received at step 408). P-CSCF 228 can then generate information to be sent as part of the Resilient Notification. Information sent as part of a resilient notification may include, for example, the UE ID identifying the UE 110, and service information such as information identifying the initiator (e.g., the caller's caller ID), the service type of the MT service (e.g., voice call), and / or the priority of the MT service. In some examples, the resilient notification may be sent along with a unique sequence number associated with the resilient notification.

[0067] The P-CSCF 228 can encrypt the service information to be sent as part of the resilient notification into ciphertext in step 508. In some examples, the P-CSCF 228 can determine a cryptographic key from the key material associated with the authentication process between the UE 110 and IMS 224, and the P-CSCF 228 can use this cryptographic key to encrypt the service information. In some examples, the P-CSCF 228 can encrypt both the service information and the unique sequence number associated with the resilient notification. The UE ID in the resilient notification can be in plaintext.

[0068] P-CSCF 228 may send a request to PCF 212 in step 510 to send a resilient notification including ciphertext (and the UE ID as plaintext). PCF 212 may send a request to SMF 206 in step 511 to send the resilient notification, such as via SM policy notification service operation (Npcf_SMPolicyNotify). SMF 206 may send a request to AMF 204 in step 512 to send the resilient notification, such as in a request for the transmission of N1 and / or N2 information; and AMF may determine in step 513 the identifier used to target the UE on the resilient notification radio channel and send the request to the latest known RAN 108 serving UE 110, or to all RANs of the UE's (multiple) latest known TAs. RAN nodes 202 of (multiple) RANs may broadcast the resilient notification on (multiple) corresponding dedicated PAC radio channels in step 514. In some examples, the resilience notification may be broadcast on the NTN downlink channel from satellite 304 (or other aerospace platforms in NTN 302). Alternatively, the resilience notification may be broadcast on the terrestrial RAN downlink channel from RAN node 202 of the terrestrial RAN.

[0069] UE 110 can receive a resilient notification. The UE can detect that UE 110 is the target of the resilient notification based on the UE ID as plaintext in the resilient notification. UE 110 can decrypt the ciphertext in step 515 to recover service information. In some examples, UE 110 can determine a cryptographic key from the key material associated with the authentication process between UE 110 and IMS 224, and UE 110 can use this cryptographic key to decrypt the ciphertext. Subsequently, UE 110 can display the resilient notification, including service information, on its display. In some examples where the resilient notification is sent along with a unique sequence number associated with the resilient notification, UE 110 can decrypt the ciphertext to recover the unique sequence number. The UE can use the unique sequence number to detect any copy of the resilient notification broadcast by RAN 108(s) and reject copies of the resilient notification without displaying them.

[0070] Figure 6 and Figure 7 This diagram illustrates an S-CSCF-assisted, UDM-based process for providing resilient notifications for MT services, based on some example implementations. Similar to previous methods, this process can begin after UE 110 registers with IMS 224. For Figure 6As shown in the example, SMF 206 can send information to UDM 210 during PDU session establishment, indicating a callback Uniform Resource Identifier (URI) for resilient notifications to the UE, such as in the service operation (Nudm_UECM_Reg) used to register User Equipment Context Management (UECM) with the UDM. For Figure 7 As shown in the example, AMF 204 can send information indicating a callback URI for a resilient notification for the UE to UDM 210 during 5GC registration, such as in a service operation (Nudm_UECM_Reg) for registering with the UDM for the UECM. The callback URI for the resilient notification for the UE is used by the UDM when requesting the AMF (step 712) or SMF (step 612A) to send a resilient notification to the UE on its behalf. As shown, at steps 501A to 505, the process may include the initiator (e.g., the caller) initiating an MT service to the UE's user, and the failure of the MT service to reach the UE (as described above).

[0071] In some examples, as previously described, SMF 206 may send a message indicating failure to reach UE110 to PCF 212 in step 506, and PCF may send a message indicating failure to reach UE to P-CSCF 228 in step 507. In other examples, the failure may be indicated by a timeout associated with a SIP invite message (or another incoming SIP message, such as a SIP MESSAGE message) received at step 501A. P-CSCF may send a SIP error message associated with the MT service to S-CSCF in step 608.

[0072] As shown in step 609, S-CSCF 232 can determine that MT service delivery failed based on the SIP error message. S-CSCF 232 can check the user's subscription information to determine whether the user has subscribed to receiving resilient notifications for the MT service (e.g., based on the information received at step 404). S-CSCF 232 can then generate and send a resilient notification for the MT service, which is a notification regarding the failure to deliver the MT service to UE 110. The resilient notification may include a UE ID identifying the UE, and service information such as information identifying the initiator (e.g., the caller ID of the caller), the service type of the MT service (e.g., voice call), and / or the priority of the MT service. In some examples, the resilient notification may be sent along with a unique sequence number associated with the resilient notification.

[0073] S-CSCF 232 can encrypt the service information in the resilient notification into ciphertext in step 610. In some examples, S-CSCF 232 can determine a cryptographic key from the key material associated with the authentication process between UE 110 and IMS 224, and S-CSCF 232 can use that cryptographic key to encrypt the service information. In some examples, S-CSCF 232 can encrypt both the service information and the unique sequence number associated with the resilient notification. The UE ID in the resilient notification can be in plaintext.

[0074] S-CSCF 232 may send a resilience notification, including ciphertext (and the UE ID as plaintext), to HSS 234 and / or UDM 210 in step 611. In some examples, the resilience notification may be sent to HSS 234, and HSS 234 may send the resilience notification to UDM 210. In some examples, the resilience notification may be carried (e.g., included) in a Cx server-assignment request (SAR) sent by S-CSCF 232 to HSS 234; and in some of these examples, S-CSCF 232 may receive a Cx server-assignment-answer (SAA) from HSS 234 in step 612 as a response to the CxSAR.

[0075] like Figure 6 As shown, in some examples, UDM 210 may send the elastic notification to SMF 206 in step 613A; and SMF 206 may send the elastic notification to AMF 204 in step 613B, such as in the transmission of N1 and / or N2 information. In other examples, such as Figure 7 As shown, the UDM can send the resilience notification more directly to the AMF in step 713, such as via a service operation (Namf_MT_Notify) for MT notifications used by the UE. In either example, the AMF 204 can send the resilience notification to RAN node 202 of the latest known RAN 108 serving the UE 110 in step 614, or to RAN nodes of all RANs in the UE 110's(multiple) latest known TAs. The(multiple) RAN nodes can broadcast the resilience notification on their respective(multiple) dedicated PACs in step 615, for example, in a manner similar to step 513.

[0076] UE 110 can receive a resilient notification. UE 110 can detect that it is the target of the resilient notification based on the UE ID, which identifies UE 110 in plaintext within the resilient notification. UE 110 can decrypt the ciphertext in step 616 to recover service information. In some examples, UE 110 can determine a cryptographic key from key materials associated with the authentication process between the UE and IMS 224, and UE 110 can use this cryptographic key to decrypt the ciphertext. UE 110 can then display the resilient notification, including service information, on its display. In some examples where the resilient notification is sent along with a unique sequence number associated with the resilient notification, UE 110 can decrypt the ciphertext to recover the unique sequence number. UE 110 can use the unique sequence number to detect any copies of the resilient notification broadcast by RAN 108(multiple) and reject copies of the resilient notification without displaying them.

[0077] Figure 8A and Figure 8B A diagram illustrates an IMS AS-assisted, UDM-based process for providing resilient notifications for MT services, according to some example implementations. Again, this process can begin after UE 110 registers with IMS 212. As shown, again, the process can include, at steps 501A through 505, an initiator (e.g., a caller) initiating the MT service to the UE's user, and a failure to reach the UE for that MT service (as described above). In some examples, also as previously stated, SMF 206 can send a message indicating failure to reach UE 110 to PCF at step 506, and PCF can send a message indicating failure to reach UE to P-CSCF 228 at step 507. In other examples, the failure can be indicated by a timeout associated with a SIP invite message (or another incoming SIP message) sent at step 501B.

[0078] like Figure 6 and Figure 7 In the process shown, P-CSCF 228 can send a SIP error message associated with the MT service to S-CSCF in step 608. In the process shown in Figure 8, S-CSCF can send the corresponding SIP error message associated with the MT service to AS 236 in step 809.

[0079] As shown in step 810, AS 236 can determine that MT service delivery has failed based on the corresponding SIP error message. Based on this determination, AS 236 can check the user's subscription information to determine if the user of UE 110 has subscribed to receiving resilient notifications for the MT service. AS 236 can then generate and send a resilient notification for the MT service, which is a notification regarding the MT service delivery failure. The resilient notification may include a UE ID identifying UE 110, and service information such as information identifying the initiator (e.g., the caller's caller ID), the service type of the MT service (e.g., voice call), and / or the priority of the MT service. In some examples, the resilient notification may be sent along with a unique sequence number associated with it.

[0080] AS 236 may encrypt the service information in the resilient notification into ciphertext in step 811. In some examples, AS 236 may determine a cryptographic key from key materials associated with the authentication process between UE 110 and IMS 224, and AS 236 may use that cryptographic key to encrypt the service information. In some examples, AS 236 may encrypt both the service information and the unique sequence number associated with the resilient notification. The UE ID in the resilient notification may be in plaintext.

[0081] AS 236 may send a resilient notification, including ciphertext (and the UE ID as plaintext), to HSS 234 and / or UDM 210 in step 811. Figure 7 In the illustrated process, UDM 210 can send the elastic notification more directly to the AMF in step 713. For example, UDM 210 can use the service operation (Namf_MT_Notify) for MT notifications for the UE to send the elastic notification for the MT service to the AMF. Similarly, the AMF can send the elastic notification to the latest known RAN node serving the UE in step 614, or to all RAN nodes in the UE(s) latest known TA(s) of the UE(s). The RAN nodes(s) can broadcast the elastic notification on the respective dedicated PAC(s) in step 615, in a manner similar to step 514.

[0082] UE 110 can receive elastic notifications. UE 110 can detect that the UE is the target of the elastic notification based on the UE ID presented as plaintext in the elastic notification. UE 110 can decrypt the ciphertext in step 616 to recover service information. In some examples, the UE can determine the cryptographic key from the key material associated with the authentication process between UE 110 and IMS 224, and UE 110 can use the cryptographic key to decrypt the ciphertext. UE 110 can display the elastic notification, including service information, on its display. In some examples where the elastic notification is sent along with a unique sequence number associated with the elastic notification, UE 110 can decrypt the ciphertext to recover the unique sequence number. UE 110 can use the unique sequence number to detect any copies of the elastic notification broadcast by RAN 108(multiple) and reject copies of the elastic notification without displaying them.

[0083] In the process described above, the elastic notification can be triggered by an entity of IMS 224, and the service information in the elastic notification can be encrypted by the same entity. However, in some examples, the elastic notification can be triggered by an entity of IMS 224, and the service information can be encrypted by an entity of CN 106 (such as AMF 204). In some of these examples, the entity of CN 106 can receive the elastic notification, which includes the UE ID identifying UE 110 and service information (and in some examples, a unique sequence number).

[0084] An entity of CN 106 (e.g., AMF 204) can encrypt the service information (and in some examples, a unique serial number) in the elastic notification into ciphertext, such as using a cryptographic key from the key material associated with the authentication process (e.g., 5GAKA) between UE 110 and CN 106. In some examples, the entity of CN 106 can encrypt both the service information and the unique serial number associated with the elastic notification. The UE ID in the elastic notification can be in plaintext. The entity of CN 106 can then send the elastic notification, including the ciphertext (and the UE ID as plaintext), to the latest known RAN node of RAN 108 serving the UE, or to all RAN nodes of the (multiple) latest known TAs of UE 110. The (multiple) RAN nodes can broadcast the elastic notification on (multiple) dedicated PACs. The UE can then receive the elastic notification, check the UE ID, and decrypt the service information (in the same or similar manner as described above regarding steps 515 and 616).

[0085] In other example implementations of MT services that are non-IMS MT services, such as messaging services (e.g., SMS), elastic notifications can be triggered by entities defined in CN 106, and the service information in the elastic notification can be encrypted by the same entity or another entity defined in CN 106. In this regard, Figure 9A and Figure 9B This diagram illustrates a process for providing resilient notifications for MT services, based on several other example implementations. As shown, the process involves UE 110, RAN 108, and AMF 204 of CN106. It also involves SC 222, SMS-GMSC 216, UDM 210, SMS router 218, NRF 214, and SMSF 220. It should be noted that the use of the SMS router and the service-based interface (SBI) operation between the SMS-GMSC and the UDM and / or SMSF are illustrative only. The same or similar processes can be performed without using an SMS router, or when the SBI between the SMS-GMSC and the UDM and / or SMSF is replaced by a diameter interface.

[0086] like Figure 9A As shown, in step 901, an MT SMS interaction for transmitting SMS messages can be performed between SC 222 and SMS-GMSC 216, such as the procedure defined in 3GPP TS 23.040. SMS-GMSC can invoke a service operation (e.g., Nnrf_NFDiscovery) of NRF 214 in step 902a to discover and select (multiple) UDM instances. If a UDM 210 supporting SMS SBI is discovered and selected, the NRF can return the IP address or fully qualified domain name (FQDN) of the serving UDM in step 902b to provide the SMS-GMSC with a service operation of the UDM (e.g., Nudm_UECM_SendRoutingInfoForSM). SMS-GMSC can invoke a service operation to the UDM in step 903 to obtain service node information for all access types of UE 110.

[0087] UDM 210 can check the registration flag and / or reachability flag in step 904 to identify potential target nodes, such as SMSF 220. For MT SM deliveries via SMS router 218, UDM can invoke the SMS router's service operation (e.g., Nrouter_SMService_RoutingInfo) to provide the SMS router with the SMSF instance ID. The address of the SMS router contacted by UDM can be configured locally. If any failure occurs, the SMS router can send a response to UDM in step 905 with an error reason associated with the failure.

[0088] If UDM 210 receives an error response from SMS router 218 in step 905, or if UDM 210 fails after step 903, for example, if no user is found in the UDM, then the UDM can respond to SMS-GMSC 216 in step 906 by sending a response to the service operation invoked at step 903, and this response may include the error reason. If no target node address is registered in UDM 210, a response with an error reason indicating the missing subscriber for Session Management (SM) can be sent to SMS-GMSC, and the process continues to step 915.

[0089] If a success response is returned in step 906, SMS-GMSC 216 can forward the SMS message to SMS router 218 in step 907 by invoking a service operation of the SMS router (e.g., Nrouter_SMService_MtForwardSm). The SMS router can then forward the SMS message to SMSF 220 in step 908, such as by invoking an SMSF service operation (e.g., Nsmsf_SMService_MtForwardSm). And as shown in step 909, the delivery process of the SMS message on the Non-Access Stratum (NAS) can be performed between SMSF 220, AMF 204, and UE 110, such as according to 3GPP TS 23.502. Figure 4 Steps 4a to 6b in .13.3.6-1.

[0090] In some cases, AMF 204 may fail to deliver SMS messages to UE 110, which can be considered a failure of MT SMS service delivery. If AMF informs SMSF 220 in step 909 that AMF cannot deliver SMS messages to UE, for example, UE 110 is unreachable, SMSF 220 may send a response to SMS router 218 in step 910 for the service operation invoked in step 908, and the response may include the reason for the error.

[0091] If SMS router 218 receives an error response from SMSF 220 in step 910 or if the SMS router fails after step 907, the SMS router may send a response to the service operation invoked in step 907 to SMS-GMSC 216 at step 911, and this response may include the cause of the error. SMS-GMSC may report the delivery status of the SMS message to UDM 210 in steps 912 and 913, such as by invoking a UDM service operation (e.g., Nudm_ReportSMDeliveryStatus_Request). The delivery status may indicate that the delivery of the MT SMS has failed (e.g., UE 110 is unreachable).

[0092] If SMS router 218 receives an error response from SMSF 220 in step 910, or if the SMS router fails after step 907, the SMS router may send a response to the service operation invoked in step 907 to SMS-GMSC 216 in step 911, and this response may include the cause of the error. SMS-GMSC may report the delivery status of the SMS message to UDM 210 in steps 912 and 913, such as by invoking a UDM service operation (e.g., Nudm_ReportSMDeliveryStatus_Request). The delivery status may indicate that the delivery of the MT SMS has failed (e.g., UE 110 is unreachable).

[0093] like Figure 9B As shown, after receiving a delivery status indicating that MT SMS delivery has failed, the UDM can determine to request the AMF 204 to send a resilient notification to the UE 110. The UDM can invoke a service operation (e.g., Namf_MT_Notify) of the AMF 204 in step 912b. In this service operation, the UDM can provide the resilient notification to the AMF, which may include, for example, a notification about the failure, the UE ID identifying the UE 110 (e.g., IMSI, SUPI), and service information such as information identifying the initiator (e.g., the caller's caller ID), the service type of the MT service (e.g., voice call), and / or the priority of the MT service. In some examples, the resilient notification may be sent along with a unique sequence number associated with the resilient notification.

[0094] AMF 204 can convert the UE ID into another UE ID (e.g., S-TMSI) for paging. AMF 204 can encrypt the service information in the elastic notification into ciphertext, such as using a cryptographic key determined from the key material of the most recent access authentication for the UE with CN 106. In some examples, AMF can encrypt both the service information and the unique sequence number associated with the elastic notification. The other UE ID used in the elastic notification can be in plaintext. Subsequently, AMF can send the elastic notification to RAN node 202 of the latest known RAN 108 serving UE 110 in step 912c, or to RAN nodes of all RANs in the (multiple) latest known TAs of UE 110. The (multiple) RAN nodes can broadcast the elastic notification on the corresponding (multiple) dedicated PACs in step 912d, such as in a manner similar to step 513.

[0095] As shown in step 912e, UE 110 can receive a resilient notification, check the UE ID, and decrypt the service information (in the same or similar manner as described above regarding steps 515 and 616). In some more specific examples, the UE can check whether the TMSI "paging" in the resilient notification belongs to the UE. If so, the UE can send the service information received from the resilient notification to the NAS layer (within the UE) for decryption, such as using a cryptographic key determined from the key material of the most recent access authentication between the UE and CN 106. The service information can then be displayed, for example, as an indication of a missed MT SMS.

[0096] Back Figure 9A If SMS-GMSC 216 receives an error response from the SMS router in step 906 or step 911, SMS-GMSC can send a failure report to SC 222 in step 914.

[0097] SMS-GMSC 216 may subscribe to UDM 210 in step 915 to be notified when UE 110 becomes SMS reachable (e.g., when UE 110 is in radio contact with AMF 204 while SMSF 220 is registered, or when SMSF 220 is registered), such as by using a UDM service operation (e.g., Nudm_EventExposure_Subscribe) to notify UE 110 of SMS reachability. Where applicable, UDM 210 may subscribe to AMF(s) to be notified of UE reachability events using AMF 204's event exposure service (e.g., Namf_EventExposure) and set the relevant reachability flags. UDM 210 may acknowledge the subscription created for SMS-GMSC 216.

[0098] Figure 10A and Figure 10B This is a flowchart illustrating the various steps of a method 1000 performed by a user equipment (UE) according to various example implementations. The method includes (e.g.) Figure 10A (As shown in box 1002): Sending a request to the core network to activate the delivery of a resilient notification for one or more mobile termination services. The method further includes (as shown in box 1004): Receiving a broadcast message from a radio access network serving the UE, the message including information including a resilient notification associated with a failure to deliver one or more mobile termination services to the UE, the resilient notification including ciphertext containing service information associated with the mobile termination service. The method further includes (as shown in box 1006): Decrypting the ciphertext to restore the service information. Furthermore, the method further includes (as shown in box 1008): Displaying the resilient notification including the service information.

[0099] In some examples, the mobile termination service is initiated by the initiator to the UE, and the service information includes at least one of the following: information identifying the initiator, service type indicating the type of mobile termination service, and priority of the mobile termination service.

[0100] In some examples, the elastic notification also includes a unique sequence number associated with the elastic notification. In some of these examples, method 1000 also includes (e.g.) Figure 10B (As shown in box 1010): Based on a unique sequence number, at least one copy of the resilient notification received from the radio access network serving the UE is determined. And in some of these examples, the method further includes (as shown in box 1012): rejecting at least one copy of the resilient notification.

[0101] In some examples, the resilient notification includes plaintext, and the plaintext includes information identifying the UE. In some of these examples, method 1000 further includes: determining, based on the information identifying the UE, that the UE is the intended recipient of the resilient notification.

[0102] In some examples, a request is sent to the core network at box 1002, and a resilient notification is received from the core network via a radio access network serving the UE at box 1004.

[0103] In some examples, method 1000 also includes determining a cryptographic key from key materials associated with the authentication process between the UE and the core network. In some of these examples, the cryptographic key is used to decrypt the ciphertext at box 1006.

[0104] In some examples, at box 1002, the request is sent to the Internet Protocol (IP) Multimedia Subsystem (IMS) via a radio access network node serving the UE, and the resilient notification originates from the IMS and is included in a broadcast message by the radio access network serving the UE.

[0105] In some examples, method 1000 further includes determining a cryptographic key from key materials associated with the authentication process between the UE and the IMS. In some of these examples, the cryptographic key is used to decrypt the ciphertext at box 1006.

[0106] Figure 11 This is a flowchart illustrating the steps of method 1100 performed by an entity of a core network or Internet Protocol (IP) Multimedia Subsystem (IMS) according to various example implementations. The method includes (as shown in box 1102): generating or receiving a resilience notification associated with a failure to deliver a mobile termination service to a user equipment (UE), the resilience notification including service information associated with the mobile termination service. The method further includes (as shown in box 1104): encrypting the service information in the resilience notification into ciphertext. Furthermore, the method further includes (as shown in box 1106): sending the resilience notification including the ciphertext to a radio access network serving the UE, for the radio access network to broadcast a broadcast message including information to the UE, the information including the resilience notification.

[0107] In some examples, the mobile termination service is initiated by the initiator to the UE, and the service information includes at least one of the following: information identifying the initiator, service type indicating the type of mobile termination service initiated by the initiator, and priority of the mobile termination service.

[0108] In some examples, the resilient notification also includes a unique sequence number associated with the resilient notification.

[0109] In some examples, the resilient notification also includes plaintext, which includes information identifying the UE.

[0110] In some examples, the entity is a core network entity, and method 1100 further includes determining a cryptographic key from key materials associated with the authentication process between the UE and the core network. In some of these examples, the cryptographic key is used to encrypt service information at box 1104.

[0111] In some examples, the entity is the access and mobility management network function of the core network, and the elastic notification sending request is received from at least one of the following: Short Message Service Disposition Function (SMSF), User Data Management (UDM) network function, and User Plane Control Network Function that generates elastic notifications.

[0112] In some examples, the entity is an IMS entity, and method 1100 also includes determining a cryptographic key from key materials associated with the authentication process between the UE and the IMS. In some of these examples, the cryptographic key is used to encrypt service information at box 1104.

[0113] In some examples, the entity is an IMS entity, and sending a resilience notification at box 1106 includes sending a request to the core network to cause the radio access network to broadcast a broadcast message to the UE, which includes the resilience notification.

[0114] In some examples, the entity is the IMS Proxy Call Session Control Function (P-CSCF), Service Call Session Control Function (S-CSCF), or IMS application server.

[0115] In some examples, the entity is the Proxy Call Session Control Function (P-CSCF) of IMS, and method 1100 further includes: determining a failure to deliver the mobile termination service. In some of these examples, the determination includes: receiving information from a policy control network function indicating that paging of a paging message associated with the mobile termination service has failed; or determining that there have been more than a threshold number of attempts to deliver an Incoming Session Initiation Protocol (SIP) message associated with the mobile termination service to the UE.

[0116] In some examples, the entity is the Service Call Session Control Function (S-CSCF) of IMS, and method 1100 also includes determining the failure to deliver the mobile termination service, which includes receiving a Session Initiation Protocol (SIP) error message associated with the mobile termination service from the Proxy Call Session Control Function (P-CSCF) of IMS.

[0117] In some examples, the entity is the IMS application server of IMS, and method 1100 also includes determining the failure to deliver the mobile termination service, which includes receiving a Session Initiation Protocol (SIP) error message associated with the mobile termination service from the IMS Service Call Session Control Function (S-CSCF).

[0118] According to the example implementations of this disclosure, the telecommunications system 100 or PLMN 102 and its components, such as UE 110, CN 106, RAN 108, RAN node 202, MM NF (e.g., AMF 204), SM NF (e.g., SMF 206), UPF 208, UDM 210, PC NF (e.g., PCF 212), NRF 214, SMS-GMSC 216, SMS router 218, SMSF 220, SC 222, IMS 224, CSCF 226, P-CSCF 228, I-CSCF 230, S-CSCF 232, HSS 234, AS 236, NTN 302, satellite 304, and / or NTN gateway 308, can be implemented in various ways. The components used to implement the system and its components can include hardware, firmware, software, or a combination thereof. In some examples, one or more devices may be configured to functionally implement, or otherwise implement, the systems and components shown and described herein. In examples involving more than one device, the respective devices may be connected to or otherwise communicate with each other in a variety of different ways, such as directly or indirectly connected via wired or wireless networks.

[0119] Based on some example implementations, regarding Figure 10A and Figure 10B At least a portion of the described method 1000 can be implemented by components including functions corresponding to the steps of the method. Similarly, regarding Figure 11 At least a portion of the described method 1100 can be implemented by components including functions corresponding to the method steps. Examples of suitable apparatus may include user equipment, user devices, user terminals, etc. Other examples of suitable apparatus may include a standalone computer, such as a server, host, or node, containing an entity of IMS (e.g., P-CSCF, S-CSCF, AS); a distributed computing system containing an entity of IMS; or a cloud computing system containing an entity of IMS. The entity of IMS may be implemented by the distributed computing system or cloud computing system as a virtual machine or container.

[0120] Figure 12An apparatus 1200 is shown according to some example implementations of the present disclosure, wherein components for performing various operations include hardware, which may exist independently or under the guidance of one or more computer programs from a computer-readable storage medium or other memory, such as computer memory. The apparatus may include one or more of several components, such as processing circuitry 1202 connected to a computer-readable storage medium or other memory 1204.

[0121] The processing circuitry 1202 may be comprised of one or more processors individually, or in combination with one or more computer-readable storage media. The processing circuitry is typically any computer hardware component capable of processing information, such as data, computer programs, computer code, and / or other suitable electronic information. The processing circuitry comprises a collection of electronic circuits, some of which may be packaged as integrated circuits or multiple interconnected integrated circuits (integrated circuits are sometimes more commonly referred to as "chips"). The processing circuitry may be configured to execute computer programs, which may be stored on the processing circuitry or otherwise stored in memory 1204 (on the same device or another device).

[0122] The processing circuitry 1202 may include multiple processors, multi-core processors, or other types of processors, such as central processing units, graphics processing units, tensor processing units, or accelerators, depending on the specific implementation. Furthermore, the processing circuitry may be implemented using a variety of heterogeneous processor systems, where a main processor and one or more secondary processors exist on a single chip. As another example, the processing circuitry may be a symmetric multiprocessor system containing multiple processors of the same type. In yet another example, the processing circuitry may be embodied as or otherwise include one or more application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), etc. Therefore, while the processing circuitry can perform one or more functions by executing a computer program, in various examples, the processing circuitry can also perform one or more functions without the assistance of a computer program. In either case, the processing circuitry may be appropriately programmed to perform functions or operations according to the exemplary implementations of this disclosure.

[0123] Memory 1204 is typically any computer hardware component capable of storing information, such as data, computer programs, instructions 1206 (e.g., computer-readable program code), and / or other suitable information, which may be stored temporarily and / or persistently. Memory may include volatile and / or non-volatile memory and may be fixed or removable. Suitable examples of memory include recording media, random access memory (RAM), read-only memory (ROM), hard disks, flash memory, USB flash drives, removable computer floppy disks, optical disks, or any combination thereof.

[0124] Memory 1204 is a non-transitory device capable of storing information. An example of a suitable memory is a computer-readable storage medium, which can be distinguished from a computer-readable transmission medium capable of carrying information from one location to another. Examples of suitable computer-readable transmission media include electronic carrier signals, telecommunication signals, or combinations thereof. As used herein, the term "non-transitory" is a limitation on the medium itself (i.e., tangible, not signaling), not a limitation on the persistence of data storage (e.g., the difference between RAM and ROM). As used herein, a computer-readable medium generally refers to a computer-readable storage medium or a computer-readable transmission medium. A computer-readable medium is any entity or device capable of storing and carrying information, such as one or more computer programs or portions thereof.

[0125] In addition to memory 1204 (e.g., computer-readable storage medium), processing circuitry 1202 may also be connected to one or more interfaces for displaying, transmitting, and / or receiving information. Interfaces may include communication interface 1208 and / or one or more user interfaces. Communication interfaces may be configured to transmit and / or receive information, such as transmitting information to and / or receiving information from other devices, networks, etc. Communication interfaces may be configured to transmit and / or receive information via physical (wired) and / or wireless communication links. Examples of suitable communication interfaces include network interface controllers (NICs), wireless NICs (WNICs), etc.

[0126] The user interface may include a display 1210 and / or one or more user input interfaces 1212. The display may be configured to present or otherwise display information to a user; suitable examples include liquid crystal displays (LCDs), light-emitting diode (LED) displays, organic LED (OLED) displays, active-matrix OLEDs (AMOLEDs), etc. The user input interfaces may be wired or wireless and may be configured to receive information from a user to the device, such as for processing, storing, and / or displaying. Suitable examples of user input interfaces include microphones, image or video capture devices, keyboards or keypads, joysticks, touch-sensitive surfaces (separate from or integrated into the touchscreen), biometric sensors, etc. The user interface may also include one or more interfaces for communicating with peripheral devices, such as printers, scanners, etc.

[0127] Instructions 1206 are executed by processing circuitry 1202 or stored in memory 1204, supporting combinations of operations for implementing exemplary implementations of this disclosure. In this manner, apparatus 1200 may include at least one processing circuit and at least one memory coupled to the at least one processing circuit, wherein the at least one processing circuit is configured to execute instructions stored in the at least one memory. It should also be understood that one or more functions, and combinations thereof, may be implemented by a dedicated hardware computer system and / or processing circuitry performing the specified functions, or by a combination of dedicated hardware and program code instructions.

[0128] Some exemplary implementations of this disclosure can also be implemented as a computer process defined by one or more computer programs or portions thereof. Exemplary implementations of this disclosure can be implemented by executing at least a portion of a computer program including instructions. The computer program can be in source code form, object code form, or some intermediate form. The computer program can be stored in a computer-readable medium readable by a computer, processing circuitry, or other suitable means. As mentioned above, for example, the computer program can be stored in memory, such as a computer-readable storage medium. Additionally or alternatively, for example, the computer program can be stored in a computer-readable transmission medium. The software coding used to implement the exemplary implementations of this disclosure is entirely within the capabilities of those skilled in the art.

[0129] As will be understood, any suitable instructions can be loaded from memory or a computer-readable medium (e.g., a computer-readable storage medium, a computer-readable transmission medium) onto a computer, processing circuitry, or other programmable means to produce a particular machine, such that the particular machine becomes a component for implementing the functions defined herein. Instructions can also be stored in a computer-readable medium capable of directing a computer, processing circuitry, or other programmable means to operate in a particular manner to produce a particular machine or a particular article of manufacture. In some examples, instructions stored in a computer-readable medium can produce an article of manufacture, wherein the article of manufacture becomes a component for implementing the functions described herein. Instructions can be retrieved from a computer-readable medium and loaded onto a computer, processing circuitry, or other programmable means to configure the computer, processing circuitry, or other programmable means to perform operations performed by or on the computer, processing circuitry, or other programmable means.

[0130] The retrieval, loading, and execution of instructions, including program code instructions, can be performed sequentially, such that one instruction is retrieved, loaded, and executed at a time. In some example implementations, retrieval, loading, and / or execution can be performed in parallel, such that multiple instructions are retrieved, loaded, and / or executed together. The execution of program code instructions can produce computer-implemented processes, such that the instructions, executed by a computer, processing circuitry, or other programmable device, provide operations for implementing the functions described herein.

[0131] As explained above and reiterated below, this disclosure includes, but is not limited to, the following example implementations.

[0132] Clause 1. A method performed by a user equipment (UE), the method comprising: sending a request to a core network to activate the delivery of a resilient notification for one or more mobile termination services; receiving a broadcast message from a radio access network serving the UE, the message including information, the information including the resilient notification, the resilient notification being associated with a failure to deliver one or more mobile termination services to the UE, the resilient notification including ciphertext, the ciphertext including service information associated with the mobile termination service; decrypting the ciphertext to restore the service information; and displaying the resilient notification including the service information.

[0133] Clause 2. The method according to Clause 1, wherein the mobile termination service is initiated by the initiator to the UE, and the service information includes at least one of the following: information identifying the initiator, service type indicating the type of mobile termination service, and priority of the mobile termination service.

[0134] Clause 3. The method according to Clause 1 or Clause 2, wherein the resilience notification further includes a unique sequence number associated with the resilience notification, and wherein the method further includes: determining, based on the unique sequence number, at least one copy of the resilience notification received from the radio access network serving the UE; and rejecting at least one copy of the resilience notification.

[0135] Clause 4. The method according to any one of Clauses 1 to 3, wherein the flexible notification includes plaintext, and the plaintext includes information identifying the UE, and wherein the method further includes: determining, based on the information identifying the UE, that the UE is the intended recipient of the flexible notification.

[0136] Clause 5. The method according to any one of Clauses 1 to 4, wherein the request is sent to the core network and the resilience notification is received from the core network via the radio access network serving the UE.

[0137] Clause 6. The method described in Clause 5 further includes: determining a cryptographic key from key material associated with an authentication process between the UE and the core network, wherein the ciphertext is decrypted using the cryptographic key.

[0138] Clause 7. The method according to any one of Clauses 1 to 6, wherein the request is sent to the Internet Protocol (IP) Multimedia Subsystem (IMS) via a radio access network node serving the UE, and the flexible notification originates from the IMS and is included in a broadcast message by the radio access network serving the UE.

[0139] Clause 8. The method according to Clause 7, wherein the method further comprises: determining a cryptographic key from key material associated with the authentication process between the UE and the IMS, and wherein the ciphertext is decrypted using the cryptographic key.

[0140] Clause 9. A user equipment (UE) comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the UE to perform a method according to any one of Clauses 1 to 8.

[0141] Clause 10. A user equipment (UE) configured to perform the method pursuant to any one of Clauses 1 to 8.

[0142] Clause 11. A user equipment (UE) including components for performing the method according to any one of Clauses 1 to 8.

[0143] Clause 12. A computer-readable medium comprising instructions that, in response to execution by at least one processor, cause a user equipment (UE) to perform a method according to any one of Clauses 1 to 8.

[0144] Clause 13. A computer-readable storage medium comprising instructions that, in response to execution by at least one processor, cause a user equipment (UE) to perform a method according to any one of Clauses 1 to 8.

[0145] Clause 14. A computer program comprising instructions that, in response to execution by at least one processor, cause a user equipment to perform the method according to any one of Clauses 1 to 8.

[0146] Clause 15. A method performed by an entity of a core network or Internet Protocol (IP) Multimedia Subsystem (IMS), the method comprising: generating or receiving a resilience notification associated with a failure to deliver a mobile termination service to a user equipment (UE), the resilience notification including service information associated with the mobile termination service; encrypting the service information in the resilience notification into ciphertext; and sending the resilience notification including the ciphertext to a radio access network serving the UE for the radio access network to broadcast a broadcast message including information to the UE, the information including the resilience notification.

[0147] Clause 16. The method according to Clause 15, wherein the mobile termination service is initiated by the initiator to the UE, and the service information includes at least one of the following: information identifying the initiator, service type indicating the type of mobile termination service initiated by the initiator, and priority of the mobile termination service.

[0148] Clause 17. The method described in accordance with Clause 15 or Clause 16, wherein the resilience notification also includes a unique serial number associated with the resilience notification.

[0149] Clause 18. The method according to any one of Clauses 15 to 17, wherein the flexibility notification further includes plaintext, and the plaintext includes information identifying the UE.

[0150] Clause 19. The method according to any one of Clauses 15 to 18, wherein the entity is an entity of the core network, and the method further comprises: determining a cryptographic key from key material associated with an authentication process between the UE and the core network, and wherein service information is encrypted using the cryptographic key.

[0151] Clause 20. The method according to any one of Clauses 15 to 19, wherein the entity is an access and mobility management network function of the core network, and the elastic notification sending request is received from at least one of: Short Message Service (SMS) Disposition Function (SMSF), User Data Management (UDM) network function, and User Plane Control Network Function that generates elastic notifications.

[0152] Clause 21. The method according to any one of Clauses 15 to 20, wherein the entity is an entity of the IMS, and the method further comprises: determining a cryptographic key from key material associated with the authentication process between the UE and the IMS, and wherein service information is encrypted using the cryptographic key.

[0153] Clause 22. The method according to any one of Clauses 15 to 21, wherein the entity is an entity of IMS, and wherein sending a resilient notification comprises: sending a request to the core network to cause the radio access network to broadcast a broadcast message including broadcast information, the broadcast information including the resilient notification, to the UE.

[0154] Clause 23. The method according to any one of Clauses 15 to 22, wherein the entity is the Proxy Call Session Control Function (P-CSCF), Service Call Session Control Function (S-CSCF), or IMS application server of IMS.

[0155] Clause 24. The method according to any one of Clauses 15 to 23, wherein the entity is the proxy call session control function (P-CSCF) of IMS, and wherein the method further comprises: determining a failure to deliver the mobile termination service, the determination comprising: receiving information from the policy control network function indicating that: paging of a paging message associated with the mobile termination service has failed; or determining that there have been more than a threshold number of attempts to deliver an incoming session initiation protocol (SIP) message associated with the mobile termination service to the UE.

[0156] Clause 25. The method according to any one of Clauses 15 to 24, wherein the entity is the Service Call Session Control Function (S-CSCF) of IMS, and wherein the method further comprises: determining a failure to deliver the mobile termination service, and determining including receiving a Session Initiation Protocol (SIP) error message associated with the mobile termination service from the Proxy Call Session Control Function (P-CSCF) of IMS.

[0157] Clause 26. The method according to any one of Clauses 15 to 25, wherein the entity is an IMS application server of IMS, and wherein the method further comprises: determining a failure to deliver the mobile termination service, including receiving a Session Initiation Protocol (SIP) error message associated with the mobile termination service from the Service Call Session Control Function (S-CSCF) of IMS.

[0158] Clause 27. An apparatus comprising: at least one processor; and at least one memory storing instructions of an entity of a core network or Internet Protocol (IP) Multimedia Subsystem (IMS), the instructions, when executed by the at least one processor, causing the apparatus to perform the method according to any one of Clauses 15 to 26.

[0159] Clause 28. An entity of a core network or Internet Protocol (IP) Multimedia Subsystem (IMS), the entity being configured to perform the methods pursuant to any one of Clauses 15 to 26.

[0160] Clause 29. An apparatus comprising components for performing the method according to any one of Clauses 15 to 26.

[0161] Clause 30. A computer-readable medium comprising instructions that, in response to execution by at least one processor, cause a device to perform the method according to any one of Clauses 15 to 26.

[0162] Clause 31. A computer-readable storage medium comprising instructions that, in response to execution by at least one processor, cause a device to perform the method according to any one of Clauses 15 to 26.

[0163] Clause 32. A computer program comprising instructions that, in response to execution by at least one processor, cause a device to perform the method according to any one of Clauses 15 to 26.

[0164] Benefiting from the teachings presented in the foregoing description and associated drawings, those skilled in the art to which this disclosure pertains will conceive of numerous modifications and other implementations of the disclosure set forth herein. Therefore, it should be understood that this disclosure is not limited to the specific implementations disclosed, and that modifications and other specific implementations are intended to be included within the scope of the appended claims. Furthermore, although the foregoing description and associated drawings describe exemplary implementations in the context of certain exemplary combinations of elements and / or functions, it should be understood that different combinations of elements and / or functions can be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, combinations of elements and / or functions different from those explicitly described above are also contemplated as being set forth in some of the appended claims. Although specific terminology is used herein, it is used only in a general and descriptive sense and not for limiting purposes.

[0165] Furthermore, the various implementations of this disclosure can be described with reference to the following examples, and their features can be combined in any reasonable manner.

[0166] Example 1. A user equipment (UE) includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the UE to perform operations including: sending a request to a core network to activate the delivery of a resilient notification for one or more mobile termination services; receiving a broadcast message including information from a radio access network serving the UE, the information including the resilient notification, the resilient notification being associated with a failure to deliver one or more mobile termination services to the UE, the resilient notification including ciphertext including service information associated with the mobile termination service; decrypting the ciphertext to restore the service information; and displaying the resilient notification including the service information.

[0167] Example 2. According to the user equipment of Example 1, the mobile termination service is initiated by the initiator to the UE, and the service information includes at least one of the following: information identifying the initiator, service type indicating the type of mobile termination service, and priority of mobile termination service.

[0168] Example 3. A user equipment according to Example 1 or Example 2, wherein the resilient notification further includes a unique sequence number associated with the resilient notification, and wherein the operation further includes: determining at least one copy of the resilient notification received from the radio access network serving the UE based on the unique sequence number; and rejecting at least one copy of the resilient notification.

[0169] Example 4. A user equipment according to any one of Examples 1 to 3, wherein the resilient notification includes plaintext, and the plaintext includes information identifying the UE, and wherein the operation further includes: determining, based on the information identifying the UE, that the UE is the intended recipient of the resilient notification.

[0170] Example 5. A user equipment according to any one of Examples 1 to 4, wherein a request is sent to the core network and a resilience notification is received from the core network via a radio access network serving the UE.

[0171] Example 6. The user equipment according to Example 5, wherein the operation further includes: determining a cryptographic key from key material associated with an authentication process between the UE and the core network, and wherein the ciphertext is decrypted using the cryptographic key.

[0172] Example 7. A user equipment according to any one of Examples 1 to 6, wherein a request is sent to the Internet Protocol (IP) Multimedia Subsystem (IMS) via a radio access network serving the UE, and a flexible notification originates from the IMS and is included in a broadcast message by the radio access network serving the UE.

[0173] Example 8. The user equipment according to Example 7, wherein the operation further includes: determining a cryptographic key from key material associated with the authentication process between the UE and the IMS, and wherein the ciphertext is decrypted using the cryptographic key.

[0174] Example 9. An apparatus for communication, comprising: at least one processor; and at least one memory storing instructions for an entity of a core network or Internet Protocol (IP) Multimedia Subsystem (IMS), the instructions causing the apparatus to perform operations when executed by the at least one processor, the operations including: generating or receiving a resilient notification associated with a failure to deliver a mobile termination service to a user equipment (UE), the resilient notification including service information associated with the mobile termination service; encrypting the service information in the resilient notification into ciphertext; and sending the resilient notification including the ciphertext to a radio access network serving the UE for the radio access network to broadcast a broadcast message including information to the UE, the information including the resilient notification.

[0175] Example 10. The apparatus according to Example 9, wherein the mobile termination service is initiated by an initiator to the UE, and the service information includes at least one of the following: information identifying the initiator, a service type indicating the type of mobile termination service initiated by the initiator, and a priority of the mobile termination service.

[0176] Example 11. The apparatus according to Example 9 or Example 10, wherein the resilient notification also includes a unique serial number associated with the resilient notification.

[0177] Example 12. The apparatus according to any one of Examples 9 to 11, wherein the resilient notification further includes plaintext, and the plaintext includes information identifying the UE.

[0178] Example 13. An apparatus according to any one of Examples 9 to 12, wherein the entity is an entity of the core network, and the operation further includes: determining a cryptographic key from key material associated with an authentication process between the UE and the core network, and wherein service information is encrypted using a cryptographic key pair.

[0179] Example 14. An apparatus according to any one of Examples 9 to 13, wherein the entity is an access and mobility management network function of the core network, and the elastic notification sending request is received from at least one of: Short Message Service (SMS) Disposition Function (SMSF), User Data Management (UDM) network function, and User Plane Control Network Function that generates elastic notifications.

[0180] Example 15. An apparatus according to any one of Examples 9 to 14, wherein the entity is an entity of the IMS, and the operation further includes: determining a cryptographic key from key material associated with an authentication process between the UE and the IMS, and wherein service information is encrypted using the cryptographic key.

[0181] Example 16. An apparatus according to any one of Examples 9 to 15, wherein the entity is an entity of IMS, and wherein sending a resilient notification comprises: sending a request to the core network to cause the radio access network to broadcast a broadcast message including information, the information including a resilient notification, to the UE.

[0182] Example 17. An apparatus according to any one of Examples 9 to 16, wherein the entity is an IMS proxy call session control function (P-CSCF), a service call session control function (S-CSCF), or an IMS application server.

[0183] Example 18. An apparatus according to any one of Examples 9 to 17, wherein the entity is a proxy call session control function (P-CSCF) of IMS, and wherein the operation further includes: determining a failure to deliver a mobile termination service, the determination including: receiving information from a policy control network function indicating that: paging of a paging message associated with the mobile termination service has failed; or determining that there have been more than a threshold number of attempts to deliver an incoming session initiation protocol (SIP) message associated with the mobile termination service to the UE.

[0184] Example 19. An apparatus according to any one of Examples 9 to 18, wherein the entity is a Service Call Session Control Function (S-CSCF) of an IMS, and wherein the operation further includes: determining a failure to deliver a mobile termination service, and determining that a Session Initiation Protocol (SIP) error message associated with the mobile termination service is received from a Proxy Call Session Control Function (P-CSCF) of an IMS.

[0185] Example 20. An apparatus according to any one of Examples 9 to 19, wherein the entity is an IMS application server of IMS, and wherein the operation further includes: determining a failure to deliver the mobile termination service, and determining including receiving a Session Initiation Protocol (SIP) error message associated with the mobile termination service from the Service Call Session Control Function (S-CSCF) of IMS.

Claims

1. A user equipment (UE), comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the UE to perform operations, the operations including: Send a request to the core network to activate the delivery of resilient notifications for one or more mobile termination services; Receive a broadcast message including information from the radio access network serving the UE, the information including a resilience notification associated with a failure to deliver one or more mobile termination services to the UE, the resilience notification including ciphertext including service information associated with the mobile termination service; Decrypt the ciphertext to recover the service information; and The elastic notification displays the service information.

2. The user equipment according to claim 1, wherein the mobile termination service is initiated by an initiator to the UE, and the service information includes at least one of the following: information identifying the initiator, a service type indicating the type of the mobile termination service, and the priority of the mobile termination service.

3. The user equipment according to claim 1 or claim 2, wherein the elastic notification further includes a unique serial number associated with the elastic notification, and wherein the operation further includes: Based on the unique sequence number, at least one copy of the resilient notification received from the radio access network serving the UE is determined; as well as Reject at least one copy of the elastic notification.

4. The user equipment according to claim 1 or claim 2, wherein the flexible notification includes plaintext, and the plaintext includes information identifying the UE, and The operation also includes: Based on the information identifying the UE, it is determined that the UE is the intended recipient of the elastic notification.

5. The user equipment of claim 1 or claim 2, wherein the request is sent to the core network and the resilient notification is received from the core network via the radio access network serving the UE.

6. The user equipment according to claim 5, wherein the operation further comprises: The cryptographic key is determined from the key material associated with the authentication process between the UE and the core network, and The ciphertext is decrypted using the cryptographic key.

7. The user equipment according to claim 1 or claim 2, wherein the request is sent to the Internet Protocol (IP) Multimedia Subsystem (IMS) via the radio access network serving the UE, and the resilient notification originates from the IMS and is included in the broadcast message by the radio access network serving the UE.

8. The user equipment according to claim 7, wherein the operation further comprises: The cryptographic key is determined from the key material associated with the authentication process between the UE and the IMS, and The ciphertext is decrypted using the cryptographic key.

9. A device for communication, comprising: At least one processor; as well as At least one memory storing instructions for an entity of a core network or Internet Protocol (IP) Multimedia Subsystem (IMS), the instructions causing the device to perform operations when executed by the at least one processor, the operations including: Generate or receive a resilient notification associated with a failure to deliver a mobile termination service to a user equipment (UE), the resilient notification including service information associated with the mobile termination service; The service information in the elastic notification is encrypted into ciphertext. as well as The resilient notification, including the ciphertext, is sent to the radio access network serving the UE, for the radio access network to broadcast a broadcast message including information to the UE, the information including the resilient notification.

10. The apparatus of claim 9, wherein the mobile termination service is initiated by an initiator to the UE, and the service information includes at least one of the following: information identifying the initiator, a service type indicating the type of mobile termination service initiated by the initiator, and a priority of the mobile termination service.

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