Resilient notification support in non-terrestrial network (NTN) access

Abstract

A method performed by a user equipment (UE) is provided. The method includes sending information to a network that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message. The method includes monitoring both a paging channel for the paging message associated with the mobile terminated service, and a dedicated paging alert channel for the resilient notification triggered by detection of the paging failure of the paging message associated with the mobile terminated service. And the method includes receiving the resilient notification associated with the paging message on the dedicated paging alert channel triggered by the detection of the paging failure of the paging message.

Description

RESILIENT NOTIFICATION SUPPORT IN NON-TERRESTRIAL NETWORK (NTN) ACCESSTECHNOLOGICAL FIELD

[0001] The present disclosure relates generally to telecommunications and, in particular, to resilient notification in a telecommunications system.BACKGROUND

[0002] A telecommunications system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations and / or other nodes by providing carriers between the various entities involved in the communications path. A telecommunications system can be provided for example by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, video, electronic mail (email), text message, multimedia and / or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

[0003] In a wireless telecommunications system, at least a part of a communication session between at least two stations occurs over a wireless link. Examples of wireless telecommunications systems comprise public land mobile networks (PLMN), satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN). Some wireless systems can be divided into cells, and are therefore often referred to as cellular systems.

[0004] A user can access the telecommunications system by means of an appropriate communication device or terminal. A communication device of a user may be referred to as user equipment (UE) or user device. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station, for example a base station of a cell, and transmit and / or receive communications on the carrier.

[0005] The telecommunications system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the communication system are permitted to do and how operations should be achieved. Communication protocols and / or parameters which shall be used for connection of the various entities are also typically defined. One 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 the so-called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3 GPP).BRIEF SUMMARY

[0006] Example implementations of the present disclosure are directed to telecommunications and, in particular, to resilient notification in a telecommunications system. The present disclosure includes, without limitation, the following example implementations.

[0007] Some example implementations provide an apparatus to implement a user equipment (UE), the apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: send information to a network that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message; monitor both a paging channel for the paging message associated with the mobile terminated service, and a dedicated paging alert channel for the resilient notification triggered by detection of the paging failure of the paging message associated with the mobile terminated service; and receive the resilient notification associated with the paging message on the dedicated paging alert channel triggered by the detection of the paging failure of the paging message.

[0008] Some example implementations provide a method performed by a user equipment (UE), the method comprising: sending information to a network that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message; monitoring both a paging channel for the paging message associated with the mobileterminated service, and a dedicated paging alert channel for the resilient notification triggered by detection of the paging failure of the paging message associated with the mobile terminated service; and receiving the resilient notification associated with the paging message on the dedicated paging alert channel triggered by the detection of the paging failure of the paging message.

[0009] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: receive information from a user equipment (UE) that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message; validate a subscription of the UE to the resilient notification service; detect the paging failure of the paging message for the mobile terminated service; and send a resilient notification associated with the paging message to a radio access network (RAN) serving the UE for the RAN to send the resilient notification to the UE on a dedicated paging alert channel triggered by the detection of the paging failure of the paging message.

[0010] Some example implementations provide a method comprising: receiving information from a user equipment (UE) that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message; validating a subscription of the UE to the resilient notification service; detecting the paging failure of the paging message for the mobile terminated service; and sending a resilient notification associated with the paging message to a radio access network (RAN) serving the UE for the RAN to send the resilient notification to the UE on a dedicated paging alert channel triggered by the detection of the paging failure of the paging message.

[0011] Some example implementations provide an apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least: send information to a network that indicates a radio access network (RAN) capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service for a user equipment (UE) triggers a resilient notification associated withthe paging message; receive the resilient notification from the network triggered by the paging failure of the paging message for the mobile terminated service; and send the resilient notification to the UE on a dedicated paging alert channel.

[0012] Some example implementations provide a method comprising: sending information to a network that indicates a radio access network (RAN) capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service for a user equipment (UE) triggers a resilient notification associated with the paging message; receiving the resilient notification from the network triggered by the paging failure of the paging message for the mobile terminated service; and sending the resilient notification to the UE on a dedicated paging alert channel.

[0013] These and other features, aspects, and advantages of the present disclosure will be apparent from a reading of the following detailed description together with the accompanying figures, which are briefly described below. The present disclosure includes any combination of two, three, four or more features or elements set forth in this disclosure, regardless of whether such features or elements are expressly combined or otherwise recited in a specific example implementation described herein. The present disclosure is intended to be read holistically such that any separable features or elements of the disclosure, in any of its aspects and example implementations, should be viewed as combinable unless the context of the disclosure clearly dictates otherwise.

[0014] It will therefore be appreciated that this Brief Summary is provided merely for purposes of summarizing some example implementations so as to provide a basic understanding of some aspects of the disclosure. Accordingly, it will be appreciated that the above described example implementations are merely examples and should not be construed to narrow the scope or spirit of the disclosure in any way. Other example implementations, aspects and advantages will become apparent from the following detailed description taken in conjunction with the accompanying figures which illustrate, by way of example, the principles of some described example implementations.BRIEF DESCRIPTION OF THE FIGURE(S)

[0015] Having thus described example implementations of the disclosure in general terms, reference will now be made to the accompanying figures, which are not necessarily drawn to scale, and wherein:

[0016] FIG. 1 illustrates a telecommunications system that includes one or more public land mobile networks (PLMNs) coupled to one or more external data networks, according to some example implementations of the present disclosure;

[0017] FIG. 2 illustrates a deployment of a PLMN, according to some example implementations;

[0018] FIG. 3 illustrates a deployment of a non-terrestrial network (NTN) in the deployment of FIG. 2, according to some example implementations;

[0019] FIG. 4 illustrates a signaling chart of registration and resilient notification service procedures, according to some example implementations;

[0020] FIG. 5 illustrates a signaling chart of a registration procedure to enable the resilient notification service, according to some example implementations;

[0021] FIG. 6 illustrates a signaling chart of a procedure to enable the resilient notification service during radio resource control (RRC) release, according to some example implementations;

[0022] FIG. 7 illustrates a signaling chart of a procedure to notify a core network of a radio access network (RAN) capability to support the resilient notification service, according to some example implementations;

[0023] FIG. 8 is a flowchart illustrating various steps in a method performed by a user equipment (UE), according to various example implementations;

[0024] FIGS. 9A, 9B and 9C are flowcharts illustrating various steps in a method according to various example implementations;

[0025] FIG. 10 is a flowchart illustrating various steps in a method according to various example implementations; and

[0026] FIG. 11 illustrates an apparatus according to some example implementations.DETAILED DESCRIPTION

[0027] Some implementations of the present disclosure will now be described more fully hereinafter with reference to the accompanying figures, in which some, but not all implementations of the disclosure are shown. Indeed, various implementations of the disclosure may be embodied in many different forms and should not be construed as limited to the implementations set forth herein; rather, these example implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout.

[0028] Unless specified otherwise or clear from context, references to first, second or the like should not be construed to imply a particular order. A feature described as being above another feature (unless specified otherwise or clear from context) may instead be below, and vice versa; and similarly, features described as being to the left of another feature else may instead be to the right, and vice versa. Also, while reference may be made herein to quantitative measures, values, geometric relationships or the like, unless otherwise stated, any one or more if not all of these may be absolute or approximate to account for acceptable variations that may occur, such as those due to engineering tolerances or the like.

[0029] As used herein, unless specified otherwise or clear from context, the “or” of a set of operands is the “inclusive or” and thereby true if and only if one or more of the operands is true, as opposed to the “exclusive or” which is false when all of the 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. Further, the articles “a” and “an” mean “one or more,” unless specified otherwise or clear from context to be directed to a singular form. Furthermore, it should be understood that unless otherwise specified, the terms “data,” “content,” “digital content,” “information,” and similar terms may be at times used interchangeably. The term “network” may refer to a group of interconnected computers including clients and servers; and within a network, these computers may be interconnected directly or indirectly by various means including via one or more switches, routers, gateways, access points or the like.

[0030] The present disclosure discusses systems and architectures that, while specific terms may be used, are broadly applicable across various technologies. For instance, while the present disclosure may reference technologies from 3 GPP such as Global System for Mobile Communications (GSM), UMTS, LTE, LTE Advanced, 5GNR, 5G Advanced, and 6G, thepresent disclosure is equally relevant to non-3GPP technologies like IEEE 802, Bluetooth, and Bluetooth Low Energy. Example implementations of the present disclosure described herein also mention public land mobile networks (PLMNs) and mobile network operators (MNOs), but example implementations are similarly applicable to standalone non-public networks (SNPNs) and the private entities operating these networks. Furthermore, although some examples and figures focus on radio access networks (RANs) and 3GPP access, example implementations are applicable to any type of network access. This includes not only 5G or 6G 3GPP access but also non-3GPP access, such as wireline access, untrusted non-3GPP access, and trusted non-3GPP access using wireless access gateway function (W-AGF), non-3GPP interworking function (N3IWF), or trusted non-3GPP gateway function (TNGF) to connect to a 5G or 6G core network.

[0031] Further, as used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry); (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions); or (c) hardware circuit(s) and / or processor(s), such as a microprocessor(s) or a portion of a microprocessor s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0032] The above definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0033] FIG. 1 illustrates a telecommunications system 100 according to various example implementations of the present disclosure. The telecommunications system generally includesone or more telecommunications networks. As shown, for example, the system includes one or more PLMNs 102 coupled to one or more other external data networks 104 - notably including a wide area network (WAN) such as the Internet. As will be appreciated, a PLMN may be deployed in a number of different manners. Some deployments of 4G LTE and 5G NR in particular are considered standalone (SA) deployments. Other deployments combine 4G LTE and 5 G technologies, and are referred to as non-standalone (NSA) deployments.

[0034] Each of the PLMNs 102 includes a core network (CN) 106 backbone, such as the Evolved Packet Core (EPC) of 4G LTE, the 5G core network (5GC) (at times referred to as the NGC) of 5G NR, and the 6G core network (6GC) of 6G; and each of the core networks and the Internet are coupled to one or more RANs 108, air interfaces or the like that implement one or more radio access technologies (RATs). Examples of these RANs include the evolved UMTS terrestrial radio access network (E-UTRAN) of 4G LTE, the next generation (NG) radio access network (NG-RAN) of 5G NR, and the 6G RAN. As used herein, a “network device” refers to any suitable device at a network side of a telecommunications network. Examples of suitable network devices are described in greater detail below.

[0035] Examples of RATs include 3 GPP radio access technologies such as GSM, CDMA2000 IxEV-DO (HRPD), CDMA2000 lx (IxRTT), UTRA, E-UTRA, 5GNR, 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), and the like. Generally, a RAT may refer to any 2G, 3G, 4G, 5G, 6G or higher generation RAT and their different versions, as well as to any other RAT that may be arranged to interwork with such a mobile communication technology to provide access to the CN 106 of a MNO.

[0036] The telecommunications system 100 also includes one or more radio units that may be varyingly known as user equipment (UE) 110, terminal device, terminal equipment, mobile station or the like. The UE is generally a device configured to communicate with a network device or a further UE in a telecommunications network. The UE may be a portable computer (e.g., laptop, notebook, tablet computer), mobile phone (e.g., cell phone, smartphone), wearable computer (e.g., smartwatch), or the like. In other examples, the UE may be an Internet of things (loT) device, an industrial loT (IIoT device), a vehicle equipped with a vehicle-to- everything (V2X) communication technology, or the like. In some examples, asreferenced by 3 GPP, the UE may be a narrowband loT (NB-IoT) device, an enhanced machine-type communication (eMTC) device, a reduced capability (RedCap) device, an ambient loT device, or the like.

[0037] In operation, these UEs 110 may connect to one or more of theRANs 108 according to their particular RATs to thereby access a particular CN 106 of a PLMN 102, or to access one or more of the external data networks 104 (e.g., the Internet). The external data network may provide Internet access, operator services, 3rd party services, etc. For example, the International Telecommunication Union (ITU) has classified 5G mobile network services into three categories: enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine type communications (mMTC) or massive internet of things (MIoT).

[0038] In various examples, a RAN 108 may be configured as one or more macrocells, microcells, picocells, femtocells or the like. The RAN may generally include one or more RAN nodes that interact with UEs 110. In various examples, a RAN node may be referred to as a base station (BS), access point (AP), base transceiver station (BTS), Node B (NB), evolved NB (eNB), macro BS, 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), or the like. The term ‘gNB’ in 5G NR may correspond to the eNB in 4G LTE. Also, a NG-RAN node may refer to a gNB or a ng-eNB. And unless otherwise specified, a gNB in 5G NR or a 6gNB in 6G may at times be more generally referred to as a (6)gNB or more simply a gNB.

[0039] The RAN 108 may include some type of network controlling / governing entity responsible for control of the RAN nodes. The network controlling / governing entity and RAN node may be separate or integrated into a single apparatus. The network controlling / governing entity may include processing circuity configured to carry out various management functions, etc. The processing circuity may be associated with a memory, computer-readable storage medium or database for maintaining information required in the management functions.

[0040] FIG. 2 illustrates a deployment of a PLMN 102, such as a 4G LTE, 5G NR or 6G deployment. As shown, the RAN 108 (e.g., E-UTRAN, NG-RAN, 6GRAN) includes one or more RAN nodes 202 configured to connect one or more UEs 110 to the RAN to thereby access the CN 106 (e.g., EPC, 5GC, 6GC). In 5GNR, the NG-RAN and 5GC are at timescollectively referred to as the 5G system (5GS). In some deployments, operations of a gNB or other a RAN node may be distributed or functionally split into components including one or more remote radio head (RRHs) or radio units (RUs), and a baseband unit (BBU); and in some architectures, the BBU may be split into a central / centralized unit (CU) (central node) and a distributed unit (DU) (distributed node). The CU may be, for example, a server, host or node. In some architectures, the RRH / RU and DU may be collocated. It is also possible that node operations may be distributed among a plurality of servers, hosts or nodes.

[0041] It should also be understood that the distribution of work between core network operations and RAN node operations may vary depending on implementation. A 5G network architecture may be based on a so-called CU-DU split. One gNB-CU (a CU) may control one or more gNB-DUs (DUs). The gNB-CU may control a plurality of spatially separated gNB-DUs, acting at least as transmit / receive (Tx / Rx) nodes. In some example implementations, however, the gNB-DUs may include, for example, a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the gNB-CU may include the layers above the RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC), and an internet protocol (IP) layer. Other functional splits are also possible. It is considered that skilled person is familiar with the OSI model and the functionalities within each layer.

[0042] In the radio protocol stack, operation of the RRC in particular is guided by a state machine which defines certain specific states that a UE 110 may be present in. The different states in the RRC state machine have different amounts of radio resources associated with them and these are the resources that the UE may use when the UE is present in each state. Since different amounts of resources are available at different states, the quality of the service that the user experiences and the energy consumption of the UE are influenced by this state machine. Relative to previous generations, 5G NR supplemented RRC IDLE and RRC CONNECTED states by an RRC INACTIVE state, which offers light connectivity with major power saving methods integrated into the state.

[0043] In some example implementations, the server or CU may generate a virtual network through which the server communicates with the radio node. In general, virtual networking may involve a process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network.Such virtual network may provide flexible distribution of operations between the server and the radio head / node. In practice, any digital signal processing task may be performed in either the CU or the DU, and the boundary where the responsibility is shifted between the CU and the DU may be selected according to implementation.

[0044] The CN 106 may include a number of network functions (NFs) divided between the control plane (CP) and the user plane (UP). In particular, the CN may include, for example, NFs for mobility management (MM) 204 (at times referred to as a MM NF) and session management (SM) 206 (at times referred to as a SM NF), as well as a user plane function (UPF) 208. The MM may be, for example, a mobility management entity (MME) in the EPC, an access and mobility management function (AMF) in the 5GC, or a 6G MM in the 6GC. Similarly, the SM may be, for example, a serving gateway (S-GW) and / or packet gateway (P-GW) in the EPC, a session management function (SMF) in the 5GC, or a 6G SM in the 6GC. Other examples of suitable NFs include a unified data management (UDM) 210 (or a home subscriber server (HSS) or the like in the EPC), a policy and charging function (PCF), a network data analytics function (NWDAF), an application function (AF), and the like.

[0045] Also shown is the IP multimedia subsystem (IMS) 212 as specified by 3 GPP for enabling IP multimedia services, such as voice, video, messaging, data and web-based services. In the context of IMS, the RAN 108 and / or CN 106 form an IP connectivity access network (IP-CAN) to transport multimedia signaling and bearer traffic for the IP multimedia services. As currently specified, examples of an IP-CAN include the EPC and E-UTRAN in 4G LTE, and the 5GS access network in 5G NR.

[0046] Networks are now also starting to support non-terrestrial networks (NTNs). In an NTN system, a RAN node 202 or RAN node functionality may be deployed onboard satellites or other aerospace platforms in a regenerative deployment (or architecture), or relayed by RAN nodes in a transparent deployment. The NTN may therefore provide communication coverage over a very large area that may be otherwise unreachable by a terrestrial radio access network alone. Such functionality can be used to globally connect loT devices, as well as provide personal communication in remote areas and in disaster relief

[0047] FIG. 3 illustrates a deployment 300 of an NTN 302 in the PLMN 102 of FIG. 2, according to some example implementations. As shown, the NTN may include an aerospace platform, such as a satellite 304, connected to a UE 110 by a service link 306 (radio link), andconnected to an NTN gateway 308 by a feeder link 310 (radio link). In a regenerative deployment, the satellite (or other aerospace platform) may host a RAN node 202 or part of a RAN node, such as a DU. The NTN gateway may then be connected to the CN 106; and in some examples involving a CU-DU split, the NTN may host or be connected to a CU, which is in turn connected to the CN. In some examples, the NTN gateway and the gNB may be colocated. The UEs that support the NTN may be global navigation satellite system (GNSS)-capable UEs.

[0048] In various examples, the aerospace platform may be a spaceborne or airborne platform, vehicle or the like. As indicated, the aerospace platform may be a satellite 304. In other more specific examples, the aerospace platform may be a low-earth orbit (LEO) satellite, medium-earth orbit (MEO) satellite, geostationary earth orbit (GEO) satellite, or the like. Likewise, in more specific examples, the aerospace platform may be an unmanned aircraft system (UAS), such as a tethered UAS (TUA), lighter than air UAS (LTA), heavier than air UAS (HTA), high altitude platforms (HAP), or the like. Some example implementations of the present disclosure may be described in the context of a satellite or UAS, but it should be understood that those example implementations are equally applicable to other aerospace platforms.

[0049] In particular examples in which aerospace platform is a satellite 304 of the NTN 302, the satellite may generate radio coverage beams with respective footprints 312 over a given service area bounded by its field of view 314 and onboard antenna technology. The respective footprints of the radio beams are typically of elliptic shape. The field of view of the satellite may depend on an onboard antenna diagram and / or minimum elevation angle. One radio beam may carry the signals of a cell, and several satellite radio beams may carry the signals of a single cell or multiple cells.

[0050] Communication between satellite 304 and UE 110 typically has very limited power margin and usually requires line of sight (LOS) for best performance. For mobile originated (MO) services, users are aware of the channel quality and can achieve LOS communication by consciously adjusting the spot of signal transmission / reception. But for mobile terminated (MT) services, such as calls and messages, users are unaware of their channel quality may miss important calls / messages due to poor downlink channel quality. Satellite access may be alast option when the terrestrial network (TN) is not available, and it may be beneficial to improve user reachability in an NTN 302 to achieve better user experience.

[0051] To improve user reachability in an NTN 302 may involve the satellite 304 (RAN node) being able to notify a user / UE 110 about a missed MT service (e.g., call, message) when the user is not reachable. In this context, the resilient notification service refers to a service in which a paging failure of a paging message for a MT service triggers a notification associated with the paging message. The notification may be sent to the UE on a dedicated paging alert channel (PAC) (at times referred to as the resilient notification channel), which in some examples may be a NTN downlink channel from a satellite 304 (or other aerospace platform in the NTN). In other examples, the dedicated PAC may be a TN downlink channel from a RAN node 202, such as an eNB, ng-eNB, (6)gNB or the like.

[0052] The resilient notification may inform the user that a paging message destined for the user has been sent, and their cooperation may be needed in order to receive the paging message. When a user is in a low signal-to-noise ratio (SNR) environment such as indoor coverage, or the user’s UE 110 is inside a backpack, the resilient notification service may be used to notify the user of a paging message so that the UE may move their UE to a better reception location to receive the paging message. The resilient notification service is a highly -reliable and efficient notification service that delivers notifications directly to UEs via satellite access. The service may ensure that notifications of high priority calls / messages reach users in areas where normal connectivity failed or is compromised.

[0053] In view of the foregoing, example implementations of the present disclosure provide solutions for the UE 110, RAN 108 and CN 106 to enable and carry out the resilient notification service for a MT service (e.g., call / message). According to some example implementations, a user’s UE may be capable of supporting the resilient notification service for MT service, such as high-priority MT service, may inform the network (e.g., CN) of its capability. In various examples, the UE may inform the network of the UE capability during an initial registration of the UE with the network, a mobility registration update to update a registration of the UE with the network, or a packet data unit (PDU) session establishment for at least one PDU session for the UE.

[0054] The network (e.g., MM 204) may validate the user’s subscription for the resilient notification service. The network may informs the UE 110 to monitor both the normal pagingchannel (PCH) for a paging message for a MT service, and a dedicated PAC for a resilient notification triggered by detection of a paging failure of the paging message. In some examples, the network may also check if the RAN 108 serving the UE supports the resilient notification service (capable of sending resilient notifications on the dedicated PAC), which in some further examples may be limited to one or more tracking areas.

[0055] The network may trigger a resilient notification to the UE 110 upon detection of a paging failure of a paging message for a MT service. In this regard, the network may trigger the resilient notification to the UE when normal paging fails for the MT service, such as due to a low SNR or non-LOS (NLOS) condition. In some examples, the network may alert or expose an application function when the UE is unable to receive normal paging and a resilient notification is sent to UE.

[0056] To further illustrate some example implementations, FIG. 4 illustrates a signaling chart 400 of registration and resilient notification service procedures, according to some example implementations. As shown, the procedures involve a UE 110, a RAN 108, a CN 106 (including, e g., a MM 204, SM 206, UPF 208 and UDM 210), and an IMS 212. The RAN may include a RAN node 202 to perform the steps of the RAN; and in some examples, the RAN node may be deployed onboard a satellite 304 in an NTN 302.

[0057] As shown, the UE may at step 401 send a registration request to the network (initial or mobility), and the registration request may include information that indicates a UE capability for the resilient notification service. In some examples, this information may be based on either or both the UE capability and / or use’s consent to receive resilient notifications.

[0058] The MM 204 in the CN 106 may receive the registration request including the information that indicates the UE capability. The MM may at step 402 validate a subscription of the UE to the resilient notification service, such as by checking the user subscription with the UDM 210 to determine whether the user has a subscription for the resilient notification service. If the user / UE has a subscription to the resilient notification service, the MM may at step 403 save the information that indicates the UE capability locally in the UE context for the UE.

[0059] The MM 204 may at step 404 send a registration accept message to the UE 110, and the registration accept message may include information that indicates the resilient notification service is supported and enabled by the network. In some examples, theinformation may also include one or more registration tracking areas (TAs) where the resilient notification service is applicable.

[0060] The UE may at step 405 transition to RRC IDLE (or RRC INACTIVE), such as due to inactivity. In the RRC IDLE state, the UE may monitor both the PCH for a paging message for a MT service, and a dedicated PAC for a resilient notification triggered by detection of a paging failure of the paging message.

[0061] The UPF 208 may at step 406 receive from the IMS 212 a session initiation protocol (SIP) invite or other signaling related to an IMS MT call for the UE 110. The UPF may send information to the SM 206 that indicates a downlink data notification for the UE. The SM may at step 407 determine a service type of the MT call (e.g., high priority). The SM may at step 408 send an N1N2 message for the MT call to the MM 204, and the N1N2 message may indicate the service type of the MT call for which the resilient notification service is applicable, such as by setting a flag to indicate applicability of the resilient notification service.

[0062] The MM 204 may at step 409 send a paging message to the UE 110 on the PCH. The MM may send the repeated paging message based on a last-known TA and cell identifier (ID) to the last known RAN 108 serving the UE, or to all RANs in the last known TA(s) of the UE (the registration TA(s) at step 404). If the MM does not receive a response to the paging message from the UE, the MM may at step 410 repeat the paging message to the UE one or more times. But as shown at step 411, a paging failure may be experienced, such as due to a low SNR or non-LOS (NLOS) condition.

[0063] The MM 204 may at step 412 detect the paging failure once all of its paging attempts are exhausted, and the detected paging failure (and the service type of the MT call) may trigger a resilient notification associated with the paging message. The MM may at step 413 send a resilient notification to the RAN 108 for the RAN to send the resilient notification to the UE on the PAC at step 414. The RAN may respond to the MM after successfully sending the resilient notification to the UE. The MM may in turn at step 415 inform the SM 206 about the paging failure and successful resilient notification. That is, the MM may send information to the SM that indicates the paging failure detected and the resilient notification sent to the UE.

[0064] If the SM 206 has subscription from an AF or PCF, the SM alert the AF and PCF about the successful resilient notification. In some examples, the AF may be a proxy call session control function (P-CSCF) of the IMS 212, which may take further action to either inform the calling party (e.g., call forwarding, voice mail, etc..). For simplicity, the AF (P-CSCF) subscription to the PCF or the SMF is not shown in the signaling chart 400. Also not separately shown, in some examples, a NWDAF in the CN 106 may subscribe to one or more events to keep statistical track of paging failures and resilient notification in certain geography(ies). This may in turn help the MM to fine tune the number of paging attempts before triggering resilient notification.

[0065] FIG. 5 illustrates a signaling chart 500 of a registration procedure to enable the resilient notification service, according to some example implementations. As shown, similar to before, the UE 110 may at step 401 send a registration request to the network (initial or mobility), and the registration request may include information that indicates a UE capability for the resilient notification service. In some examples, this information may be based on either or both the UE capability and / or use’s consent to receive resilient notifications.

[0066] The MM 204 in the CN 106 may receive the registration request including the information that indicates the UE capability. The MM may at step 402 validate a subscription of the UE to the resilient notification service, such as by checking the user subscription with the UDM 210 to determine whether the user has a subscription for the resilient notification service.

[0067] If the user / UE 110 has a subscription to the resilient notification service, the MM may at step 503 check with the RAN 108 whether the RAN supports the resilient notification service, such as by arming the UE resilient notification capability when for the first time creating the UE context for the UE. As shown, for example, the MM may send the RAN (e.g., RAN node 202, satellite 304) an initial context setup request (ICSR) message that includes a registration accept message for the UE, and that separately includes information that indicates the UE capability for the resilient notification service. In other examples, a downlink non-access stratum (NAS) transport message may be used.

[0068] Similar to above, the registration accept message may include information that indicates the resilient notification service is supported and enabled by the network. In some examples, the information may also include one or more registration tracking areas (TAs)where the resilient notification service is applicable. The RAN 108 may at step 504 send the registration accept message from the MM 204 to the UE 110. In turn, the UE may at step 505 send a registration complete message to the RAN. The RAN may at step 506 send the registration complete message to the MM in an uplink NAS transport message. The RAN may also include information that indicates the RAN supports the resilient notification service which is enabled at the RAN, such as based on the cell configuration where the UE is being served. In some examples, the RAN may indicate support for the resilient notification service in one or more TAs, such as based on its cell configuration.

[0069] The MM 204 may at step 507 save the information that indicates the UE capability locally in the UE context for the UE 110, the same as or similar to step 403.

[0070] FIG. 6 illustrates a signaling chart 600 of a procedure to enable the resilient notification service during RRC release, according to some example implementations. As shown, the procedure may include steps 401, 402 and 503-505, as described above with reference to FIG. 5. In the procedure shown in FIG. 6, however, the RAN 108 may indicates the resilient notification possibility, only when the UE transitions to the RRC IDLE state, and based on the last TA in which the UE was active. As shown, similar to step 506, the RAN may at step 606 send the registration complete message from the UE to the MM in an uplink NAS transport message, but the RAN may omit the information that indicates the resilient notification service is supported and enabled at the RAN.

[0071] The UE 110 may at step 607 transition to RRC IDLE (or RRC INACTIVE), such as due to inactivity. The UE may at step 608 send an RRC release message to the RAN 108. In response, the RAN may at step 609 send a release complete message to the UE, and the release complete message may include an indication for the UE to monitor the dedicated PAC. The UE, in the RRC IDLE state, may then monitor both the PCH for a paging message for a MT service, and a dedicated PAC for a resilient notification triggered by detection of a paging failure of the paging message.

[0072] The RAN 108 may at step 611 send a UE context release message to the MM 204, and the UE context release message may include the information that indicates the resilient notification service is supported and enabled at the RAN, such as for one or more TAs. In some examples, the information may also indicate if one or more TAs or cells do not support the resilient notification service, which may help the MM during resilient notification triggerto RAN to select appropriate TA(s) and cell ID(s). The MM may at step 612 save information in the UE context that indicates resilient notification is possible for the UE.

[0073] FIG. 7 illustrates a signaling chart 700 of a procedure to notify a CN 106 of a RAN capability to support the resilient notification service, according to some example implementations. As shown, the RAN 108 may at step 701 send a NG setup or RAN configuration update message to the MM 204, and the message may include information that indicates the RAN supports the resilient notification service. The information may also indicate one or more TAs for which the resilient notification service is supported, such as by TA identifies (TAIs) of the TAs. In some examples, the information may additionally or alternatively indicate one or more TAs for which the resilient notification service is not supported.

[0074] The MM 204 may at steps 702, 703 save the information from the RAN 108 based on the indicated support for the resilient notification service, and use the information to trigger resilient notifications to only the supported RAN and supported TA(s) in the supported RAN. The MM may at step 704 send a NG setup response or RAN configuration update response. In some examples, the RAN may also at a later time disable resilient notification support in one or more TAs, which may help the MM change the local UE context information.

[0075] FIG. 8 is a flowchart illustrating various steps in a method 800 performed by a user equipment (UE), according to various example implementations. The method includes sending information to a network that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message, as shown at block 802. The method includes monitoring both a paging channel for the paging message associated with the mobile terminated service, and a dedicated paging alert channel for the resilient notification triggered by detection of the paging failure of the paging message associated with the mobile terminated service, as shown at block 804. And the method includes receiving the resilient notification associated with the paging message on the dedicated paging alert channel triggered by the detection of the paging failure of the paging message, as shown at block 806.

[0076] In some examples, the information that indicates the UE capability for the resilient notification service is sent at block 802 to the network during an initial registration of the UE with the network, a mobility registration update to update a registration of the UE with thenetwork, or a packet data unit (PDU) session establishment for at least one PDU session for the UE.

[0077] In some examples, the method 800 further includes receiving information from the network that indicates the resilient notification service is supported and enabled. In some of these examples, the dedicated paging alert channel is monitored at block 804 based on the UE capability and the information from the network.

[0078] In some examples, the dedicated paging alert channel that is monitored for the resilient notification at block 804 is a non-terrestrial network (NTN) downlink channel.

[0079] In some examples, the paging channel and the dedicated paging alert channel are both monitored at block 804 when the UE is in a radio resource control (RRC) idle state or a RRC inactive state.

[0080] In some examples, the method 800 further includes receiving a release complete message from a radio access network (RAN) serving the UE in connection with a RRC release of the UE to the RRC idle state, the release complete message including an indication for the UE to monitor the dedicated paging alert channel.

[0081] FIGS. 9A- 9C are flowcharts illustrating various steps in a method 900 according to various example implementations. The method includes receiving information from a user equipment (UE) that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message, as shown at block 902 of FIG. 9A. The method includes validating a subscription of the UE to the resilient notification service, as shown at block 904. The method includes detecting the paging failure of the paging message for the mobile terminated service, as shown at block 906. And the method includes sending a resilient notification associated with the paging message to a radio access network (RAN) serving the UE for the RAN to send the resilient notification to the UE on a dedicated paging alert channel triggered by the detection of the paging failure of the paging message, as shown at block 908.

[0082] In some examples, the information that indicates the UE capability for the resilient notification service is received at block 902 from the UE during an initial registration of the UE with the network, a mobility registration update to update a registration of the UE with thenetwork, or a packet data unit (PDU) session establishment for at least one PDU session for the UE.

[0083] In some examples, the method 900 further includes saving the information that indicates the UE capability in a UE context for the UE.

[0084] In some examples, the method 900 further includes sending information to the UE that indicates the resilient notification service is supported and enabled.

[0085] In some examples, the method 900 further includes verifying that the RAN serving the UE supports the resilient notification service.

[0086] In some examples, the method 900 further includes receiving information from the RAN serving the UE that indicates the RAN supports the resilient notification service in one or more tracking areas, as shown at block 910 of FIG. 9B. In some of these examples, the method also includes determining the UE is located in a tracking area of the one or more tracking areas, as shown at block 912.

[0087] In some examples, the method 900 further includes receiving information from the RAN serving the UE that indicates a radio resource control (RRC) release of the UE to an RRC idle state in which the UE is to monitor the dedicated paging alert channel for the resilient notification.

[0088] In some examples, the method 900 further includes receiving information from a session management network function that indicates the mobile terminated service is a service type for which the resilient notification service is applicable, as shown at block 914 of FIG.9C. In some of these examples, the method also includes determining to send the resilient notification based on the service type of the mobile terminated service, as shown at block 916.

[0089] In some examples, the dedicated paging alert channel on which the resilient notification is sent is a non-terrestrial network (NTN) downlink channel.

[0090] In some examples, the method 900 further includes sending information to a session management network function that indicates the paging failure detected and the resilient notification sent to the UE.

[0091] FIG. 10 is a flowchart illustrating various steps in a method 1000 according to various example implementations. The method includes sending information to a network that indicates a radio access network (RAN) capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service for a user equipment(UE) triggers a resilient notification associated with the paging message, as shown at block 1002. The method includes receiving the resilient notification from the network triggered by the paging failure of the paging message for the mobile terminated service, as shown at block 1004. And the method includes sending the resilient notification to the UE on a dedicated paging alert channel, as shown at block 1006.

[0092] In some examples, the information sent to the network at block 1002 indicates the RAN supports the resilient notification service in one or more tracking areas, and the one or more tracking areas include a tracking area in which the UE is located.

[0093] In some examples, the method 1000 further includes sending a release complete message to the UE in connection with a radio resource control (RRC) release of the UE to an RRC idle state, and the release complete message includes an indication for the UE to monitor the dedicated paging alert channel.

[0094] In some examples, the method 1000 further includes sending information to the network that indicates a radio resource control (RRC) release of the UE to an RRC idle state in which the UE is to monitor the dedicated paging alert channel.

[0095] In some examples, the dedicated paging alert channel on which the resilient notification is sent is a non-terrestrial network (NTN) downlink channel.

[0096] In some examples, the method is performed by a RAN node deployed onboard an aerospace platform in the NTN.

[0097] According to example implementations of the present disclosure, a telecommunications system 100 or PLMN 102, and its components such as a UE 110, CN 106, RAN 108, RAN node 202, MM 204, SM 206, UPF 208, UDM 210, NDN 302, satellite 304 and / or NTN gateway 308 may be implemented by various means. Means for implementing the system and its components may include hardware, firmware, software, or combinations thereof. In some examples, one or more apparatuses may be configured to function as or otherwise implement the system and its components shown and described herein. In examples involving more than one apparatus, the respective apparatuses may be connected to or otherwise in communication with one another in a number of different manners, such as directly or indirectly via a wired or wireless network or the like.

[0098] According to some example implementations, at least some of the method 800 described with respect to FIG. 8 may be carried out by an apparatus comprising means for1performing functions corresponding steps of the method. Similarly, at least some of the method 900 described with respect to FIGS. 9A - 9C may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. And at least some of the method 1000 described with respect to FIG. 10 may be carried out by an apparatus comprising means for performing functions corresponding steps of the method. Examples of a suitable apparatus may include a user equipment, user device, user terminal or the like. Other examples of a suitable apparatus may include a MM, a RAN node (e.g., gNB, gNB-DU, gNB-CU) or any suitable apparatus, such as a server, host or node.

[0099] FIG. 11 illustrates an apparatus 1100 in which means for performing various functions includes hardware, alone or under direction of one or more computer programs from a computer-readable storage medium or other memory, such as computer memory, according to some example implementations of the present disclosure. The apparatus may include one or more of each of a number of components such as, for example, processing circuitry 1102 connected to computer- readable storage medium or other memory 1104.

[0100] The processing circuitry 1102 may be composed of one or more processors alone or in combination with one or more computer-readable storage media. The processing circuitry is generally any piece of computer hardware that is capable of processing information such as, for example, data, computer programs and / or other suitable electronic information. The processing circuitry is composed of a collection of electronic circuits some of which may be packaged as an integrated circuit or multiple interconnected integrated circuits (an integrated circuit at times more commonly referred to as a “chip”). The processing circuitry may be configured to execute computer programs, which may be stored onboard the processing circuitry or otherwise stored in the memory 1104 (of the same or another apparatus).

[0101] The processing circuitry 1102 may be a number of processors, a multi-core processor or some other type of processor, depending on the particular implementation.Further, the processing circuitry may be implemented using a number of heterogeneous processor systems in which a main processor is present with one or more secondary processors on a single chip. As another illustrative example, the processing circuitry may be a symmetric multi-processor system containing multiple processors of the same type. In yet another example, the processing circuitry may be embodied as or otherwise include one or moreASICs, FPGAs or the like. Thus, although the processing circuitry may be capable of executing a computer program to perform one or more functions, the processing circuitry of various examples may be capable of performing one or more functions without the aid of a computer program. In either instance, the processing circuitry may be appropriately programmed to perform functions or operations according to example implementations of the present disclosure.

[0102] The memory 1104 is generally any piece of computer hardware that is capable of storing information such as, for example, data, computer programs, instructions 1106 (e.g., computer-readable program code) and / or other suitable information either on a temporary basis and / or a permanent basis. The memory may include volatile and / or non-volatile memory, and may be fixed or removable. Examples of suitable memory include recording media, random access memory (RAM), read-only memory (ROM), a hard drive, a flash memory, a thumb drive, a removable computer diskette, an optical disk or some combination thereof.

[0103] The memory 1104 is a non-transitory device capable of storing information. One example of a suitable memory is a computer-readable storage medium, which is distinguishable from a computer-readable transmission medium capable of carrying information from one location to another. Examples of suitable computer-readable transmission media comprise electronic carrier signals, telecommunications signals, or some combination thereof. As used herein, the term “non-transitory” is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM versus ROM). A computer-readable medium as described herein generally refers to a computer-readable storage medium or computer-readable transmission medium. A computer-readable medium is any entity or device capable in which information, such as one or more computer programs or portions thereof, may be stored and carried.

[0104] In addition to the memory 1104 (e.g., computer-readable storage medium), the processing circuitry 1102 may also be connected to one or more interfaces for displaying, transmitting and / or receiving information. The interfaces may include a communications interface 1108 and / or one or more user interfaces. The communications interface may be configured to transmit and / or receive information, such as to and / or from other apparatus(es), network(s) or the like. The communications interface may be configured to transmit and / or receive information by physical (wired) and / or wireless communications links. Examples ofsuitable communication interfaces include a network interface controller (NIC), wireless NIC (WNIC) or the like.

[0105] The user interfaces may include a display 1110 and / or one or more user input interfaces 1112. The display may be configured to present or otherwise display information to a user, suitable examples of which include a liquid crystal display (LCD), light-emitting diode (LED) display, organic LED (OLED) display, active-matrix OLED (AMOLED) or the like. The user input interfaces may be wired or wireless, and may be configured to receive information from a user into the apparatus, such as for processing, storage and / or display. Suitable examples of user input interfaces include a microphone, image or video capture device, keyboard or keypad, joystick, touch-sensitive surface (separate from or integrated into a touchscreen), biometric sensor or the like. The user interfaces may further include one or more interfaces for communicating with peripherals such as printers, scanners or the like.

[0106] Execution of the instructions 1106 by the processing circuitry 1102, or storage of the instructions in the memory 1104, supports combinations of operations for implementing example implementations of the present disclosure. In this manner, an apparatus 1100 may comprise at least one processing circuitry and at least one memory coupled to the at least one processing circuitry, where the at least one processing circuitry is configured to execute instructions stored in the at least one memory. It will also be understood that one or more functions, and combinations of functions, may be implemented by special purpose hardwarebased computer systems and / or processing circuitry which perform the specified functions, or combinations of special purpose hardware and program code instructions.

[0107] Some example implementations of the present disclosure may also be carried out in the form of a computer process defined by one or more computer programs or portions thereof. Example implementations of the present disclosure may be carried out by executing at least one portion of a computer program comprising instructions. The computer program may be in source code form, object code form, or in some intermediate form. The computer program may be stored in a computer-readable medium that is readable by a computer, processing circuitry or other suitable apparatus. As indicated above, for example, the computer program may be stored in a memory, such as a computer-readable storage medium.Additionally or alternatively, for example, the computer program may be stored in a computer-readable transmission medium. The coding of software for carrying out exampleimplementations of the present disclosure is well within the scope of a person of ordinary skill in the art.

[0108] As will be appreciated, any suitable instructions may be loaded onto a computer, a processing circuitry or other programmable apparatus from a memory or a computer-readable medium (e.g., computer-readable storage medium, computer-readable transmission medium) to produce a particular machine, such that the particular machine becomes a means for implementing the functions specified herein. The instructions may also be stored in a computer-readable medium that can direct a computer, a processing circuitry or other programmable apparatus to function in a particular manner to thereby generate a particular machine or particular article of manufacture. In some examples, the instructions stored in the computer-readable medium may produce an article of manufacture, where the article of manufacture becomes a means for implementing functions described herein. The instructions may be retrieved from a computer-readable medium and loaded into a computer, processing circuitry or other programmable apparatus to configure the computer, processing circuitry or other programmable apparatus to execute operations to be performed on or by the computer, processing circuitry or other programmable apparatus.

[0109] Retrieval, loading and execution of instructions comprising program code instructions may be performed sequentially such that one instruction is retrieved, loaded and executed at a time. In some example implementations, retrieval, loading and / or execution may be performed in parallel such that multiple instructions are retrieved, loaded, and / or executed together. Execution of the program code instructions may produce a computer-implemented process such that the instructions executed by the computer, processing circuitry or other programmable apparatus provide operations for implementing functions described herein.

[0110] As explained above and reiterated below, the present disclosure includes, without limitation, the following example implementations.

[0111] Clause 1. A method performed by a user equipment (UE), the method comprising: sending information to a network that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message; monitoring both a paging channel for the paging message associated with the mobile terminated service, and a dedicated paging alert channel for the resilient notification triggered by detection of the paging failure of thepaging message associated with the mobile terminated service; and receiving the resilient notification associated with the paging message on the dedicated paging alert channel triggered by the detection of the paging failure of the paging message.

[0112] Clause 2. The method of clause 1, wherein the information that indicates the UE capability for the resilient notification service is sent to the network during an initial registration of the UE with the network, a mobility registration update to update a registration of the UE with the network, or a packet data unit (PDU) session establishment for at least one PDU session for the UE.

[0113] Clause 3. The method of clause 1 or clause 2, wherein the method further comprises receiving information from the network that indicates the resilient notification service is supported and enabled, and wherein the dedicated paging alert channel is monitored based on the UE capability and the information from the network.

[0114] Clause 4. The method of any of clauses 1 to 3, wherein the dedicated paging alert channel that is monitored for the resilient notification is a non-terrestrial network (NTN) downlink channel.

[0115] Clause 5. The method of any of clauses 1 to 4, wherein the paging channel and the dedicated paging alert channel are both monitored when the UE is in a radio resource control (RRC) idle state or a RRC inactive state.

[0116] Clause 6. The method of any of clauses 1 to 5, wherein the method further comprises receiving a release complete message from a radio access network (RAN) serving the UE in connection with a RRC release of the UE to the RRC idle state, the release complete message including an indication for the UE to monitor the dedicated paging alert channel.

[0117] Clause 7. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to perform the method of any of clauses 1 to 6.

[0118] Clause 8. An apparatus comprising means for performing the method of any of clauses 1 to 6.

[0119] Clause 9. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 1 to 6.

[0120] Clause 10. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 1 to 6.

[0121] Clause 11. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 1 to 6.

[0122] Clause 12. A method comprising: receiving information from a user equipment (UE) that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message; validating a subscription of the UE to the resilient notification service; detecting the paging failure of the paging message for the mobile terminated service; and sending a resilient notification associated with the paging message to a radio access network (RAN) serving the UE for the RAN to send the resilient notification to the UE on a dedicated paging alert channel triggered by the detection of the paging failure of the paging message.

[0123] Clause 13. The method of clause 12, wherein the information that indicates the UE capability for the resilient notification service is received from the UE during an initial registration of the UE with the network, a mobility registration update to update a registration of the UE with the network, or a packet data unit (PDU) session establishment for at least one PDU session for the UE.

[0124] Clause 14. The method of clause 12 or clause 13, wherein the method further comprises saving the information that indicates the UE capability in a UE context for the UE.

[0125] Clause 15. The method of any of clauses 12 to 14, wherein the method further comprises sending information to the UE that indicates the resilient notification service is supported and enabled.

[0126] Clause 16. The method of any of clauses 12 to 15, wherein the method further comprises verifying that the RAN serving the UE supports the resilient notification service.

[0127] Clause 17. The method of any of clauses 12 to 16, wherein the method further comprises: receiving information from the RAN serving the UE that indicates the RAN supports the resilient notification service in one or more tracking areas; and determining the UE is located in a tracking area of the one or more tracking areas.

[0128] Clause 18. The method of any of clauses 12 to 17, wherein the method further comprises receiving information from the RAN serving the UE that indicates a radio resource control (RRC) release of the UE to an RRC idle state in which the UE is to monitor the dedicated paging alert channel for the resilient notification.

[0129] Clause 19. The method of any of clauses 12 to 18, wherein the method further comprises: receiving information from a session management network function that indicates the mobile terminated service is a service type for which the resilient notification service is applicable; and determining to send the resilient notification based on the service type of the mobile terminated service.

[0130] Clause 20. The method of any of clauses 12 to 19, wherein the dedicated paging alert channel on which the resilient notification is sent is a non-terrestrial network (NTN) downlink channel.

[0131] Clause 21. The method of any of clauses 12 to 20, wherein the method further comprises sending information to a session management network function that indicates the paging failure detected and the resilient notification sent to the UE.

[0132] Clause 22. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to perform the method of any of clauses 12 to 21.

[0133] Clause 23. An apparatus comprising means for performing the method of any of clauses 12 to 21.

[0134] Clause 24. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 12 to 21.

[0135] Clause 25. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 12 to 21.

[0136] Clause 26. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 12 to 21.

[0137] Clause 27. A method comprising: sending information to a network that indicates a radio access network (RAN) capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service for a user equipment (UE) triggers a resilient notification associated with the paging message; receiving the resilient notification from the network triggered by the paging failure of the paging message for the mobile terminated service; and sending the resilient notification to the UE on a dedicated paging alert channel.

[0138] Clause 28. The method of clause 27, wherein the information sent to the network indicates the RAN supports the resilient notification service in one or more tracking areas, and the one or more tracking areas include a tracking area in which the UE is located.

[0139] Clause 29. The method of clause 27 or clause 28, wherein the method further comprises sending a release complete message to the UE in connection with a radio resource control (RRC) release of the UE to an RRC idle state, and the release complete message includes an indication for the UE to monitor the dedicated paging alert channel.

[0140] Clause 30. The method of any of clauses 27 to 29, wherein the method further comprises sending information to the network that indicates a radio resource control (RRC) release of the UE to an RRC idle state in which the UE is to monitor the dedicated paging alert channel.

[0141] Clause 31. The method of any of clauses 27 to 30, wherein the dedicated paging alert channel on which the resilient notification is sent is a non-terrestrial network (NTN) downlink channel.

[0142] Clause 32. The method of clause 31, wherein the method is performed by a RAN node deployed onboard an aerospace platform in the NTN.

[0143] Clause 33. An apparatus comprising: at least one memory configured to store instructions; and at least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to perform the method of any of clauses 27 to 32.

[0144] Clause 34. An apparatus comprising means for performing the method of any of clauses 27 to 32.

[0145] Clause 35. A computer-readable medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 27 to 32.

[0146] Clause 36. A computer-readable storage medium comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 27 to 32.

[0147] Clause 37. A computer program comprising instructions that, in response to execution by at least one processing circuitry, causes an apparatus to perform the method of any of clauses 27 to 32.

[0148] Many modifications and other implementations of the disclosure set forth herein will come to mind to one skilled in the art to which the disclosure pertains having the benefit of the teachings presented in the foregoing description and the associated figures. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claims. Moreover, although the foregoing description and the associated figures describe example implementations in the context of certain example combinations of elements and / or functions, it should be appreciated that different combinations of elements and / or functions may be provided by alternative implementations without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and / or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

WE CLAIM:

1. An apparatus to implement a user equipment (UE), the apparatus comprising: at least one memory configured to store instructions; andat least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least:send information to a network that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message;monitor both a paging channel for the paging message associated with the mobile terminated service, and a dedicated paging alert channel for the resilient notification triggered by detection of the paging failure of the paging message associated with the mobile terminated service; andreceive the resilient notification associated with the paging message on the dedicated paging alert channel triggered by the detection of the paging failure of the paging message.

2. The apparatus of claim 1, wherein the information that indicates the UE capability for the resilient notification service is sent to the network during an initial registration of the UE with the network, a mobility registration update to update a registration of the UE with the network, or a packet data unit (PDU) session establishment for at least one PDU session for the UE.

3. The apparatus of claim 1 or claim 2, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further receive information from the network that indicates the resilient notification service is supported and enabled, andwherein the dedicated paging alert channel is monitored based on the UE capability and the information from the network.

4. The apparatus of any of claims 1 to 3, wherein the dedicated paging alert channel that is monitored for the resilient notification is a non-terrestrial network (NTN) downlink channel.

5. The apparatus of any of claims 1 to 4, wherein the paging channel and the dedicated paging alert channel are both monitored when the UE is in a radio resource control (RRC) idle state or a RRC inactive state.

6. The apparatus of any of claims 1 to 5, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further receive a release complete message from a radio access network (RAN) serving the UE in connection with a RRC release of the UE to the RRC idle state, the release complete message including an indication for the UE to monitor the dedicated paging alert channel.

7. An apparatus comprising:at least one memory configured to store instructions; andat least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least:receive information from a user equipment (UE) that indicates a UE capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service triggers a resilient notification associated with the paging message;validate a subscription of the UE to the resilient notification service;detect the paging failure of the paging message for the mobile terminated service; and send a resilient notification associated with the paging message to a radio access network (RAN) serving the UE for the RAN to send the resilient notification to the UE on a dedicated paging alert channel triggered by the detection of the paging failure of the paging message.

8. The apparatus of claim 7, wherein the information that indicates the UE capability for the resilient notification service is received from the UE during an initial registration of the UE with the network, a mobility registration update to update a registrationof the UE with the network, or a packet data unit (PDU) session establishment for at least one PDU session for the UE.

9. The apparatus of claim 7 or claim 8, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further save the information that indicates the UE capability in a UE context for the UE.

10. The apparatus of any of claims 7 to 9, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further send information to the UE that indicates the resilient notification service is supported and enabled.

11. The apparatus of any of claims 7 to 10, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further verify that the RAN serving the UE supports the resilient notification service.

12. The apparatus of any of claims 7 to 11, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further at least: receive information from the RAN serving the UE that indicates the RAN supports the resilient notification service in one or more tracking areas; anddetermine the UE is located in a tracking area of the one or more tracking areas.

13. The apparatus of any of claims 7 to 12, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further receive information from the RAN serving the UE that indicates a radio resource control (RRC) release of the UE to an RRC idle state in which the UE is to monitor the dedicated paging alert channel for the resilient notification.

14. The apparatus of any of claims 7 to 13, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further at least:receive information from a session management network function that indicates the mobile terminated service is a service type for which the resilient notification service is applicable; anddetermine to send the resilient notification based on the service type of the mobile terminated service.

15. The apparatus of any of claims 7 to 14, wherein the dedicated paging alert channel on which the resilient notification is sent is a non-terrestrial network (NTN) downlink channel.

16. The apparatus of any of claims 7 to 15, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further send information to a session management network function that indicates the paging failure detected and the resilient notification sent to the UE.

17. An apparatus comprising:at least one memory configured to store instructions; andat least one processing circuitry configured to access the at least one memory, and execute the instructions to cause the apparatus to at least:send information to a network that indicates a radio access network (RAN) capability for a resilient notification service in which a paging failure of a paging message for a mobile terminated service for a user equipment (UE) triggers a resilient notification associated with the paging message;receive the resilient notification from the network triggered by the paging failure of the paging message for the mobile terminated service; andsend the resilient notification to the UE on a dedicated paging alert channel.

18. The apparatus of claim 17, wherein the information sent to the network indicates the RAN supports the resilient notification service in one or more tracking areas, and the one or more tracking areas include a tracking area in which the UE is located.

19. The apparatus of claim 17 or claim 18, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further send a release complete message to the UE in connection with a radio resource control (RRC) release of the UE to an RRC idle state, and the release complete message includes an indication for the UE to monitor the dedicated paging alert channel.

20. The apparatus of any of claims 17 to 19, wherein the at least one processing circuitry is configured to execute the instructions to cause the apparatus to further send information to the network that indicates a radio resource control (RRC) release of the UE to an RRC idle state in which the UE is to monitor the dedicated paging alert channel.

21. The apparatus of any of claims 17 to 20, wherein the dedicated paging alert channel on which the resilient notification is sent is a non-terrestrial network (NTN) downlink channel.

22. The apparatus of claim 21, wherein the method is performed by a RAN node deployed onboard an aerospace platform in the NTN.

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