Method, apparatus and computer program

Abstract

Embodiments of the present disclosure relate to a method, an apparatus, and a computer program. A non-terrestrial core network entity is provided. The non-terrestrial core network entity includes: receiving data from a user equipment, wherein the data includes: control plane (CP) data, or non-internet protocol delivery (NIDD) data; buffering the data during a period in which the non-terrestrial core network entity is not connected to the terrestrial core network entity; when the non-terrestrial core network entity is connected to the terrestrial network entity, the data is sent to the terrestrial core network entity.

Description

Technical Field

[0001] Various example embodiments of the present disclosure relate to methods, apparatuses, systems, and computer programs for communication networks. Some examples can be used to send information in communication networks including satellites that have discontinuous connectivity to ground stations. Background Art

[0002] A communication network can be regarded as a facility that enables communication between two or more communication devices or provides access of a communication device to a data network. A mobile or wireless communication network is an example of a communication network. A communication device can be served by an application server.

[0003] Such communication networks operate according to standards such as those provided by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). An example of a standard is the so-called 5G (Fifth Generation) standard provided by 3GPP. Summary of the Invention

[0004] Some example embodiments of the present disclosure will be described with respect to certain aspects. These aspects are not intended to indicate the key or fundamental features of the embodiments of the present disclosure, nor are they intended to be used to limit its scope. Given the present disclosure, other features, aspects, and elements will be obvious to those skilled in the art.

[0005] According to a first aspect, a non-terrestrial core network entity for a communication network is provided. The non-terrestrial core network entity includes components for: receiving data from a user equipment, where the data includes: control plane (CP) data, or non-Internet protocol delivery (NIDD) data; buffering the data during a period when the non-terrestrial core network entity is not connected to a terrestrial core network entity; and sending the data to the terrestrial core network entity when the non-terrestrial core network entity is connected to the terrestrial network entity.

[0006] According to some examples of the first aspect, the buffering includes: buffering the data when a user equipment context for the user equipment includes an indication that the non-terrestrial core network entity is to store and forward data received from the user equipment.

[0007] According to some examples of the first aspect, the non-terrestrial core network is configured to at least perform: detecting the indication based on at least one of a configuration of the non-terrestrial core network entity, subscriber information for a subscriber associated with the device, location information for the device, and an access and mobility policy; and storing the indication in the user equipment context at the non-terrestrial core network entity.

[0008] According to some examples of the first aspect, the component is further configured to: determine a periodic update timer value for a user equipment for at least one of periodic registration update and tracking area update, wherein the periodic update timer value is increased when the indication exists in the context information for the user equipment as compared to when the indication does not exist in the context information for the user equipment.

[0009] According to some examples of the first aspect, the component is further configured to: determine the reachability of the user equipment based on the presence of an indication in the user equipment context, wherein when the indication exists in the user equipment context, the user equipment is determined to be reachable via store-and-forward operations.

[0010] According to some examples of the first aspect, the component is further configured to: determine a timer value for the user equipment to detach from the network when not connected to a terrestrial network function, wherein the timer value is increased when the indication exists in the context information for the user equipment as compared to when the indication does not exist in the context information for the user equipment.

[0011] According to some examples of the first aspect, the component is further configured to: in response to receiving data from the user equipment, send an acknowledgement message to the user equipment, wherein the acknowledgement message includes a non-access stratum protocol message.

[0012] According to some examples of the first aspect, data sent to a terrestrial core network entity is protected in a non-access stratum container, and the terrestrial core network entity is configured to decrypt the non-access stratum container using the security context of the user equipment.

[0013] According to some examples of the first aspect, the non-terrestrial core network entity includes an Access and Mobility Management Function (AMF), and the terrestrial core network entity includes an AMF.

[0014] According to some examples of the first aspect, the non-terrestrial core network entity includes a Mobility Management Entity (MME), and the terrestrial core network entity includes an MME.

[0015] According to a second aspect, there is provided an apparatus for a satellite of a non-terrestrial network, the apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive data from a user equipment, wherein the data includes: control plane (CP) data, or non-Internet protocol delivery (NIDD) data; buffer the data at the satellite during a period when the non-terrestrial core network entity is not connected to the terrestrial core network entity; and send the data from the satellite to the terrestrial core network entity when the non-terrestrial core network entity is connected to the terrestrial network entity.

[0016] According to some examples of the second aspect, the buffering includes buffering data when the user equipment context for the user equipment includes an indication that a non-terrestrial core network entity is to store and forward the data received from the user equipment.

[0017] According to some examples of the second aspect, when executed by at least one processor, the instruction further causes the apparatus to: detect the indication based on at least one of a configuration of the non-terrestrial core network entity, subscriber information for a subscriber associated with the device, location information for the apparatus, and an access and mobility policy; and store the indication in the user equipment context at the non-terrestrial core network entity.

[0018] According to some examples of the second aspect, when executed by at least one processor, the instruction further causes the apparatus to determine a periodic update timer value for the user equipment for at least one of periodic registration updates and tracking area updates, wherein the periodic update timer value is increased when the indication is present in the context information for the user equipment as compared to when the indication is not present in the context information for the user equipment.

[0019] According to some examples of the second aspect, when executed by at least one processor, the instruction further causes the apparatus to determine, at the satellite, the user equipment reachability of the user equipment based on the presence indicated in the user equipment context, wherein when the indication is present in the user equipment context, the user equipment is determined to be reachable via the store and forward operation.

[0020] According to some examples of the second aspect, when executed by at least one processor, the instruction further causes the apparatus to determine, at the satellite, a timer value for the user equipment to detach from the network when not connected to a terrestrial network function, wherein the timer value is increased when the indication is present in the context information for the user equipment as compared to when the indication is not present in the context information for the user equipment.

[0021] According to some examples of the second aspect, when executed by at least one processor, the instruction further causes the apparatus to send an acknowledgement message to the user equipment in response to receiving data from the user equipment, wherein the acknowledgement message includes a non-access stratum protocol message.

[0022] According to some examples of the second aspect, data sent to the terrestrial core network entity is protected in a non-access stratum container, wherein the terrestrial core network entity is configured to decrypt the non-access stratum container using the security context of the user equipment.

[0023] According to some examples of the second aspect, the non-terrestrial core network entity includes an access and mobility management function (AMF), and the terrestrial core network entity includes an AMF.

[0024] According to some examples of the second aspect, the non-terrestrial core network entity includes a Mobility Management Entity (MME), and the terrestrial core network entity includes an MME.

[0025] According to a third aspect, a method is provided, including: at a satellite, receiving data from a user equipment, where the data includes: control plane (CP) data, or non-Internet Protocol Delivery (NIDD) data; at the satellite, buffering the data during a period when the non-terrestrial core network entity at the satellite is not connected to the terrestrial core network entity; when the non-terrestrial core network entity is connected to the terrestrial network entity, sending the data from the satellite to the terrestrial core network entity.

[0026] According to some examples of the third aspect, the buffering includes: buffering the data when the user equipment context for the user equipment includes an indication that the non-terrestrial core network entity is to store and forward the data received from the user equipment.

[0027] According to some examples of the third aspect, the method includes: detecting the indication based on at least one of the configuration of the non-terrestrial core network entity, the subscriber information for the subscriber associated with the device, the location information for the device, and the access and mobility policy; at the non-terrestrial core network entity, storing the indication in the user equipment context.

[0028] According to some examples of the third aspect, the method includes: at the satellite, determining a periodic update timer value for the user equipment for at least one of periodic registration update and tracking area update, where when the indication is present in the context information for the user equipment, the periodic update timer value is increased relative to when the indication is not present in the context information for the user equipment.

[0029] According to some examples of the third aspect, the method includes: at the satellite, determining the user equipment reachability of the user equipment based on the presence of an indication in the user equipment context, where when the indication is present in the user equipment context, the user equipment is determined to be reachable via a store and forward operation.

[0030] According to some examples of the third aspect, the method includes: at the satellite, determining a timer value for the user equipment to detach from the network when not connected to the terrestrial network function, where when the indication is present in the context information for the user equipment, the timer value is increased relative to when the indication is not present in the context information for the user equipment.

[0031] According to some examples of the third aspect, the method includes: in response to receiving data from the user equipment, sending an acknowledgement message to the user equipment, where the acknowledgement message includes a non-access stratum protocol message.

[0032] According to some examples of the third aspect, data sent to a terrestrial core network entity is protected in a non-access stratum container, where the terrestrial core network entity is configured to decrypt the non-access stratum container using the security context of the user equipment.

[0033] According to some examples of the third aspect, the non-terrestrial core network entity includes an access and mobility management function (AMF), and the terrestrial core network entity includes an AMF.

[0034] According to some examples of the third aspect, the non-terrestrial core network entity includes a mobility management entity (MME), and the terrestrial core network entity includes an MME.

[0035] According to the fourth aspect, there is provided a computer-readable medium including instructions that, when executed by a device (e.g., a computing device or a computing system), cause the device (e.g., a computing device or a computing system) to perform at least the following: receive data from a user equipment, where the data includes: control plane (CP) data, or non-internet protocol delivery (NIDD) data; buffer the data during a period when the non-terrestrial core network entity is not connected to the terrestrial core network entity; and send the data to the terrestrial core network entity when the non-terrestrial core network entity is connected to the terrestrial network entity.

[0036] According to the fifth aspect, there is provided a terrestrial core network entity of a non-terrestrial network, the terrestrial core network entity including components for: connecting to a non-terrestrial core network entity; after connecting to the non-terrestrial core network entity, receiving data from the non-terrestrial core network entity, the data being buffered at the non-terrestrial core network entity during a period when the device is not connected to the non-terrestrial core network entity, where the data is received at the non-terrestrial core network entity from the user equipment, and where the data includes: control plane (CP) data, or non-internet protocol delivery (NIDD) data.

[0037] According to some examples of the fifth aspect, the components are further for: receiving second data for sending to the user equipment from a network entity at a first time; determining that a second non-terrestrial core network entity will be configured to connect to the user equipment and the device at a second time, where the second time is after the first time; buffering the second data at the device until the second time; and sending the second data to the second non-terrestrial core network entity at the second time, or after the second time, and while the second non-terrestrial core network entity is connected to the user equipment and the device.

[0038] According to some examples of the fifth aspect, the components are further for: performing buffering of the second data when indicated as being present in the user equipment context for the user equipment.

[0039] According to some examples of the fifth aspect, the component is further configured to: detect the indication based on at least one of the configuration of the device, the subscriber information of the device, the location information of the device, and the access and mobility policies of the device; store the indication in a user equipment context for the user equipment.

[0040] According to some examples of the fifth aspect, the component is further configured to: determine a periodic update timer value for the user equipment for at least one of periodic registration update and tracking area update, wherein when the indication exists in the user equipment context for the user equipment, the periodic update timer value is increased as compared to when the indication does not exist in the context information for the user equipment.

[0041] According to some examples of the fifth aspect, the component is further configured to: determine a timer value for the user equipment to detach from the network when not connected to the device, wherein when the indication exists in the context information for the user equipment, the timer value is increased as compared to when the indication does not exist in the context information for the user equipment.

[0042] According to some examples of the fifth aspect, data received from a non-terrestrial core network entity deployed on a satellite is protected in a non-access stratum container, and the terrestrial core network entity is configured to at least perform: use the security context of the user equipment to decrypt the non-access stratum container to determine the payload of the non-access stratum container.

[0043] According to some examples, the component is further configured to: send the payload to a third non-terrestrial core network entity having connectivity to the device.

[0044] According to some examples of the fifth aspect, the non-terrestrial core network entity includes an access and mobility management function (AMF), and the terrestrial core network entity includes an AMF.

[0045] According to some examples of the fifth aspect, the non-terrestrial core network entity includes a mobility management entity (MME), and the terrestrial core network entity includes an MME.

[0046] According to the sixth aspect, a terrestrial core network entity is provided, including at least one processor and at least one memory, the at least one memory storing instructions that, when executed by the at least one processor, cause the terrestrial core network entity to at least: connect to a non-terrestrial core network entity; after connecting to the non-terrestrial core network entity, receive data from the non-terrestrial core network entity, the data being buffered at the terrestrial core network entity during a period when the device is not connected to the non-terrestrial core network entity, wherein the data is received from the user equipment at the non-terrestrial core network entity, and wherein the data includes: control plane (CP) data, or non-internet protocol delivery (NIDD) data.

[0047] According to some examples of the sixth aspect, when executed by at least one processor, the instruction further causes the terrestrial core network entity to: receive, at a first time, second data for sending to a user equipment from a network entity; determine that a second non-terrestrial core network entity deployed on a second satellite will be configured to connect to the user equipment and the apparatus at a second time, where the second time is after the first time; buffer the second data at the apparatus until the second time; and send the second data to the second non-terrestrial core network entity at the second time, or after the second time, and while the second non-terrestrial core network entity is configured to connect to the user equipment and the terrestrial core network entity.

[0048] According to some examples of the sixth aspect, when executed by at least one processor, the instruction further causes the terrestrial core network entity to: perform buffering of the second data when an indication is present in a user equipment context for the user equipment.

[0049] According to some examples of the sixth aspect, when executed by at least one processor, the instruction further causes the terrestrial core network entity to: detect the indication based on at least one of a configuration of the user equipment, subscriber information for the user equipment, location information for the user equipment, and an access and mobility policy for the user equipment; and store the indication in a user equipment context for the user equipment at the terrestrial core network entity.

[0050] According to some examples of the sixth aspect, when executed by at least one processor, the instruction further causes the terrestrial core network entity to: determine a periodic update timer value for the user equipment for at least one of periodic registration update and tracking area update, where the periodic update timer value is increased when the indication is present in the user equipment context for the user equipment as compared to when the indication is not present in the context information for the user equipment.

[0051] According to some examples of the sixth aspect, when executed by at least one processor, the instruction further causes the terrestrial core network entity to: determine a timer value for the user equipment to detach from the network when not connected to the apparatus, where the timer value is increased when the indication is present in the context information for the user equipment as compared to when the indication is not present in the context information for the user equipment.

[0052] According to some examples of the sixth aspect, data received from a non-terrestrial core network entity is protected in a non-access stratum container, and when executed by at least one processor, the instruction further causes the terrestrial core network entity to: decrypt the non-access stratum container at the terrestrial core network entity using a security context of the user equipment to determine a payload of the non-access stratum container.

[0053] According to some examples of the sixth aspect, when executed by at least one processor, the instruction further causes the terrestrial core network entity: to send a payload from the terrestrial core network entity to a third non-terrestrial core network entity deployed on a third satellite having connectivity to the device.

[0054] According to the seventh aspect, a method is provided, including: connecting a terrestrial core network entity to a non-terrestrial core network entity; after connecting to the non-terrestrial core network entity, receiving data from the non-terrestrial core network entity, the data being buffered at the terrestrial core network entity during a period when the terrestrial core network entity was not connected to the non-terrestrial core network entity, wherein the data is received at the non-terrestrial core network entity from a user equipment, and wherein the data includes: control plane (CP) data, or non-internet protocol delivery (NIDD) data.

[0055] According to some examples of the seventh aspect, the method includes: at the terrestrial core network entity, receiving second data for sending to a user equipment from a network entity at a first time; at the terrestrial core network entity, determining that a second non-terrestrial core network entity deployed on a second satellite will be configured to connect to the user equipment and the device at a second time, wherein the second time is after the first time; buffering the second data at the device at the terrestrial core network entity until the second time; at the second time, or after the second time, and while the second non-terrestrial core network entity deployed on the second satellite is configured to connect to the user equipment and the device, sending the second data to the second non-terrestrial core network entity.

[0056] According to some examples of the seventh aspect, the method includes: performing buffering of the second data when an indication is present in the user equipment context for the user equipment.

[0057] According to some examples of the seventh aspect, the method includes: at the terrestrial core network entity, detecting the indication based on at least one of a configuration of the user equipment, subscriber information for the user equipment, location information for the user equipment, and an access and mobility policy for the user equipment; at the terrestrial core network entity, storing the indication in the user equipment context for the user equipment.

[0058] According to some examples of the seventh aspect, the method includes: at the terrestrial core network entity, determining a periodic update timer value for the user equipment for at least one of periodic registration update and tracking area update, wherein when the indication is present in the user equipment context for the user equipment, the periodic update timer value is increased relative to when the indication is not present in the context information for the user equipment.

[0059] According to some examples of the seventh aspect, the method includes: at a terrestrial core network entity, determining a timer value for a user equipment to detach from the network when not connected to a device, wherein when an indication exists in the context information for the user equipment, the timer value is increased relative to when the indication does not exist in the context information for the user equipment.

[0060] According to some examples of the seventh aspect, data received from a non-terrestrial core network entity deployed on a satellite is protected in a non-access stratum container. The method includes: at a terrestrial core network entity, using the security context of the user equipment to decrypt the non-access stratum container to determine the payload of the non-access stratum container.

[0061] According to some examples of the seventh aspect, the method includes: sending a payload from a terrestrial core network entity to a third non-terrestrial core network entity deployed on a third satellite having connectivity to the terrestrial core network entity.

[0062] According to the eighth aspect, there is provided a computer-readable medium including instructions that, when executed by a device (e.g., a computing device or a computing system), cause the device (e.g., a computing device or a computing system) to perform at least the following: connect a terrestrial core network entity to a non-terrestrial core network entity; after connecting to the non-terrestrial core network entity, receive data from the non-terrestrial core network entity, the data being buffered at the terrestrial core network entity during a period when the terrestrial core network entity is not connected to the non-terrestrial core network entity, wherein the data is received at the non-terrestrial core network entity from the user equipment, and wherein the data includes: control plane (CP) data, or non-internet protocol delivery (NIDD) data.

[0063] According to the ninth aspect, there is provided a non-transitory computer-readable medium including program instructions that, when executed by a device (e.g., a computing device or a computing system), cause the device (e.g., a computing device or a computing system) to perform at least the method according to any of the foregoing aspects.

[0064] In the foregoing, many different embodiments have been described. It should be understood that additional embodiments may be provided by any combination of two or more of the above embodiments. Description of the Drawings

[0065] Some example embodiments will now be described with reference to the drawings, by way of non-limiting and illustrative examples only, in which:

[0066] Figure 1 An example non-terrestrial network is shown;

[0067] Figure 2 An example non-terrestrial network is shown;

[0068] Figure 3 shows an example message flow for the RRC connection establishment procedure;

[0069] Figure 4 shows an example of a non-terrestrial network including two non-terrestrial network nodes and one terrestrial network node network during three time periods;

[0070] Figure 5 shows an example of signaling and operations that occur when a UE requests a service provided by an NTN configured for store-and-forward operations;

[0071] Figure 6 shows an example of signaling and operations that occur when a UE attaches to an NTN configured for store-and-forward operations;

[0072] Figure 7 shows an example method performed by a non-terrestrial core network entity;

[0073] Figure 8 shows an example method performed by a terrestrial core network entity;

[0074] Figure 9 shows for some example embodiments for Figure 1 or Figure 2 representation of a core network entity of a communication system;

[0075] Figure 10 shows a representation of a communication device according to some example embodiments; and

[0076] Figure 11 shows a schematic diagram of a non-volatile memory medium storing instructions that, when executed by a processor, allow the processor to perform one or more steps of the methods disclosed herein. Detailed Description

[0077] A non-terrestrial network (NTN) is a wireless communication system in which at least a part of the network is located above the surface of the Earth. NTN may involve satellites at low Earth orbit (LEO), medium Earth orbit (MEO), and geostationary orbit (GEO), high-altitude platforms (HAPS), and unmanned aerial vehicles. Due to the high cost of satellite launch and operation, it is expected that NTN includes satellite networks with incomplete satellite constellations. Such satellite networks are generally cost-effective for launch and operation and can contribute to non-time-critical applications (e.g., Internet of Things (IoT) NTN with sparse LEO or MEO constellations and a limited number of ground stations). A satellite network with incomplete satellite connectivity may have discontinuous satellite connectivity with user equipment (UE) and / or may have discontinuous connectivity with ground stations (e.g., ground station connectivity) due to coverage gaps caused by satellites missing from a complete satellite constellation or due to the lack of ground station connectivity at certain locations. A satellite network with an incomplete satellite constellation may not be able to guarantee always having ground station connectivity to a ground station via a feeder link and may also not be able to guarantee providing continuous coverage to UEs in the satellite network (instead, only intermittent coverage may be available). A satellite may be able to establish a connection to a ground station (a "ground station connection") at certain points in the satellite orbit for sending control plane (CP) data and / or signaling and may not be able to establish a land station connection at other points. Similarly, a satellite may be able to establish a connection at certain points in the satellite orbit for sending CP data and / or signaling to a UE and may not be able to establish such a connection at other points. Thus, in some cases, a satellite may have ground station connectivity (e.g., connectivity to a ground station via a feeder link) or satellite connectivity (e.g., connectivity to a UE via a satellite link), but not both at the same time.

[0078] In an NTN with discontinuous satellite connectivity to a UE or a ground station, it may be useful to use store-and-forward operations in the NTN. When store-and-forward operations are used in the network, downlink CP data and / or signaling can be uploaded by the ground station to the satellite, buffered at the satellite, and then transmitted to the UE when the satellite further travels in its orbit to a point where a connection to the UE can be established. This enables the next hop to the UE for the stored payload. When store-and-forward operations are used in the NTN, uplink CP data and / or signaling can be similarly buffered at the satellite such that the CP data and / or signaling are sent by the UE to the satellite, buffered at the satellite, and then transmitted to the ground station once the satellite further travels in its orbit to a point where a ground station connection to the ground station can be established. This enables the next hop to the ground station for the stored payload. The ground station connection between the ground station and the satellite can be considered to be established over a "feeder link". When the satellite does not have a ground station connection, the satellite will have discontinuous connectivity to the core network (CN).

[0079] An example scenario where a satellite may provide coverage for a UE on a ship at sea but may not have a ground station connection to the satellite of other network functions (NFs) or network entities deployed at a ground station can occur when a LEO or MEO satellite provides a cell covering the UE on the ship at sea but the ground station connection of the satellite to other network functions (NFs) or network entities deployed at the ground station is not available.

[0080] The procedures for mobile-originated (MO) and mobile-terminated (MT) data using store-and-forward operations are discussed below.

[0081] As described above, an NF deployed on a satellite can receive a message from a ground station and store the message in a memory (buffer the message) until the satellite establishes a connection with the UE, and then send the message to the UE. An NF deployed on a satellite can also be used to buffer data sent in the reverse direction from the UE to the ground station until the satellite establishes a connection with the ground station. Peer core network entities can be used to perform such store-and-forward operations. These peer core network functions can include network functions or network entities of the core network, where one is deployed in the satellite (non-terrestrial) and the other is deployed in a ground station connected to the satellite (terrestrial). Examples of peer core network entities are network functions configured for access and mobility management of the UE (e.g., the access and mobility management function (AMF) of 5GC), or network entities configured for mobility management of the UE (e.g., the mobility management entity (MME) of the evolved packet core (EPC)). The non-terrestrial AMF is referred to as AMF-N in this document, and the terrestrial AMF is referred to as AMF-T in this document. The non-terrestrial MME is referred to as MME-N in this document, and the terrestrial MME is referred to as MME-T in this document.

[0082] In the examples described herein, a non-terrestrial core network peer entity can intelligently handle non-access stratum (NAS) protocol communications by using the ability to encode and decode NAS messages. Such a non-terrestrial core network peer entity on a satellite can use higher-level protocol functions, such as NAS protocol-related security parameters, radio access network (RAN) security keys, and NAS message sequence numbers (SN).

[0083] In the following, various example embodiments are explained with reference to a UE that can communicate with a communication system of a communication network. In some examples, the UE can include an IoT device.

[0084] The examples described herein include core network entities (e.g., AMF or MME) partially deployed in satellites. With this deployment, a single public land mobile network (PLMN) operator can deploy this architecture in the network without affecting roaming partner PLMNs.

[0085] In some examples described herein, it is assumed that the UE is registered to a PLMN. This registration can be performed when both the UE coverage and the serving AMF / MME have terrestrial station connectivity.

[0086] In some examples, mobile-originated (MO) and / or mobile-terminated (MT) data can be buffered at an NF deployed at an orbiting satellite, and MT data can be buffered at an NF deployed at a terrestrial station. The core network entity (e.g., AMF or MME) is split such that a peer core network entity is deployed as one peer core network entity deployed at a terrestrial device and one peer core network entity deployed at a satellite. The peer core network entities can detect that a store-and-forward operation is necessary based on the configuration of the peer core network entities, and then can process data buffering (e.g., data buffering) to enable the store-and-forward operation. In some examples, cellular IoT (CIoT) CP data delivery is used by a user plane function UPF or a serving gateway (S-GW) to send MT data (e.g., CloT CP data) to the UE, and the MT data (e.g., CloT CP data) is buffered at the satellite. In some examples, CIoT non-IP data delivery (NIDD) is used to send MO data (e.g., CloT NID), and the MO data is buffered at the satellite.

[0087] The configuration may include a configuration known to a core network entity (e.g., an AMF or an MME) that indicates that a certain cell belongs to a specific type, identified by the Cell ID of the cell. In some examples, the configuration may be static. Based on this configuration, the core network entity may determine that a certain Cell ID corresponds to a certain RAT type. For example, the core network entity may determine based on the configuration that a certain cell is on a LEO satellite in an incomplete satellite constellation, and thus the core network entity may determine that store-and-forward operations are required when communicating via that cell. The same core network entity in the same PLMN may have a satellite cell on a GEO satellite, where the connectivity is continuous. When the UE is accessing the GEO cell, the core network entity determines based on the identifier of the cell (the cell ID of the cell) that no store-and-forward operations are required.

[0088] In some examples, the core network entity may determine that store-and-forward operations are necessary for the UE (e.g., should be used for or are applicable to the UE) based on the subscriber information for the UE. The subscriber information for the UE may be stored in a Unified Data Management (UDM) or a Unified Data Repository (UDR) for the subscriber associated with the UE. In some examples, the subscriber information for the UE may include an indication that store-and-forward operations are necessary (e.g., should be used for or are applicable to the UE). In some examples, the core network entity may determine that store-and-forward operations are necessary for the UE (e.g., should be used for or are applicable to the UE) based on the information included in the subscriber information for the UE. For example, the subscriber information for the UE may include information indicating that the UE is subscribed to a RAT type or TA that includes satellite cells with an incomplete satellite constellation, and the core network entity may determine based on this information that store-and-forward operations are necessary for the UE (e.g., should be used for or are applicable to the UE). For example, the subscription to store-and-forward operations may apply to a Cellular IoT (CIoT) network, where a dedicated satellite telemetry subscription will only be allowed to access in a specific RAT type (NR LEO, NR MEO), or a specific set of tracking areas (TAs) deployed on satellites (by subscription).

[0089] Peer core network entities (terrestrial and non-terrestrial) that are used to buffer data and / or signaling may include a peer AMF for a 5G System (5GS), or a peer MME for an Evolved Packet System (EPS). In this document, core network entities deployed at a ground station are referred to as terrestrial core network entities. For example, an AMF deployed at a ground station is referred to as AMF-T, and an MME deployed at a ground station is referred to as MME-T ("T" stands for terrestrial). The corresponding core network entities deployed on a satellite are referred to as non-terrestrial core network entities. An AMF deployed on a satellite is referred to as AMF-N, and an MME deployed on a satellite is referred to as MME-N ("N" stands for non-terrestrial). Terrestrial and non-terrestrial core network entities may be considered "peer" core network entities.

[0090] After UE registration and associated security procedures, a target UE in NTN may be at least occasionally within the direct coverage of a satellite such that registration and mobility updates can be performed via the terrestrial network, or when the satellite has ground station connectivity. The store-and-forward procedures discussed in this document may be used in some examples for the transmission of CIoT CP data when the UE is served by a satellite cell that at least occasionally loses its ground station connectivity. According to some examples, CIoT CP data may be smaller relative to user plane data. An indication of the use of store-and-forward operations may be detected at registration, during UE mobility updates, or at periodic update times. In a 5GS system, the examples disclosed in this document may be used for user plane function (UPF) CIoT CP data transmission and / or NIDD. In an EPS system, the examples disclosed in this document may be used for packet network data gateway (P-GW) anchored CP data and / or NIDD.

[0091] A core network entity of a peer core network entity (e.g., AMF or MME) can determine whether a store-and-forward operation is applicable to a UE based on at least one of the following: the configuration of the core network entity (e.g., AMF or MME); the subscriber information of the subscriber associated with the UE; the access and mobility (AM) policy; the location information of the UE. If the core network entity determines that the store-and-forward operation is applicable to the UE based on at least one of the following: the configuration of the core network entity (e.g., AMF or MME); the subscriber information of the subscriber associated with the UE; the AM policy sent by the PCF to the AMF for each subscriber and each RAT type to guide the AMF to process the access and mobility parameters of the UE; the location information of the UE; then the core network entity can set a store-and-forward indication included in the UE context for the UE to indicate that the store-and-forward operation is applicable to the UE. Otherwise, if the core network entity determines, based on the configuration of the core network entity (e.g., AMF or MME), the subscriber information of the subscriber associated with the UE, the access and mobility (AM) policy, and the location information of the UE, that the store-and-forward operation for the UE is not applicable, then the core network entity sets a store-and-forward indication to indicate that the store-and-forward operation is not applicable to the UE. Examples of the AM policy are described in 3GPP TS23.501 and TS23.502.

[0092] If a 5GS registration procedure is performed, the core network entity (e.g., AMF) notifies the UDM (e.g., provides the store-and-forward indication to the UDM) of the store-and-forward indication during 5GS registration. If an EPS attachment or TAU procedure is performed, the core network entity (e.g., MME) notifies the home subscriber server (HSS) of the store-and-forward indication during the EPS attachment or TAU procedure.

[0093] In addition to the already specified criteria, the understanding of "UE reachability" by the AMF and the UDM (or the MME and the HSS) (see "UE reachability", Table 4.15.3.1-1 in clause 4.15.3.1 of 3GPP TS23.502) can also be enhanced by considering the store-and-forward indication. If the store-and-forward indication indicates that the store-and-forward operation is not applicable to the UE (e.g., the store-and-forward indication has a value of "NOT SET"), then the AMF and the UDM (or the MME and the HSS) determine the UE reachability according to known methods. If the store-and-forward indication indicates that the store-and-forward operation is applicable to the UE (e.g., the store-and-forward indication has a value of "IS SET"), then the AMF and the UDM (or the MME and the HSS) can consider the UE reachable (via the store-and-forward operation), even if it would not be reachable according to the known UE reachability criteria.

[0094] For 5GS, when a core network entity (e.g., AMF-N) receives a registration request from a UE, the core network entity (e.g., AMF-N) accepts the UE's registration and includes a store-and-forward indication for the UE in the REGISTRATION ACCEPT message and sends the REGISTRATION ACCEPT message to the UE. The store-and-forward indication notifies the UE that an immediate end-to-end response to data and / or signaling sent from the UE is not possible. Optionally, an extended NAS timer may also be indicated for the store-and-forward operation. For EPS, when the MME receives an ATTACH request or a TAU request from the UE, the MME includes a store-and-forward indication for the UE in the ATTACH ACCEPT or TAU ACCEPT (tracking area update accept) message sent to the UE. This indicates to the UE that an immediate end-to-end response to data and / or signaling sent from the UE is not possible. Optionally, an extended NAS timer may also be indicated for the store-and-forward operation for the UE.

[0095] When a terrestrial core network entity (e.g., AMF-T, MME-T) or a non-terrestrial core network entity (e.g., AMF-N, MME-N) has stored a store-and-forward indication for a UE, the store-and-forward indication may be considered by the core network entity when determining the value of the periodic update timer for the UE (commonly referred to as the periodic update timer value) to ensure that the UE does not need to perform overly frequent periodic registration updates or TAUs. When the store-and-forward indication indicates that the store-and-forward operation applies to the UE as opposed to the time when the store-and-forward indication is set to indicate that the store-and-forward operation does not apply to the UE, the core network entity may increase the periodic update timer value (e.g., increase the value of the periodic update timer).

[0096] When a terrestrial core network entity (e.g., AMF-T, MME-T) has a store-and-forward indication and the store-and-forward indication indicates that the store-and-forward operation applies to the UE (e.g., the corresponding indicator in the UE context stored in the terrestrial core network entity has been set to a value indicating that the store-and-forward operation applies to the UE), the terrestrial core network entity (e.g., AMF-T, MME-T) may take this into account when determining the implicit detach timer value for the UE to ensure that the UE is not implicitly detached due to a long store-and-forward delay. The implicit detach timer may include a timer for measuring a time period at the end of which the network detaches the UE without notifying the UE. When the store-and-forward indication indicates that the store-and-forward operation applies to the UE, the implicit detach timer value may be increased.

[0097] An example of an implicit detach timer is described below. The UE can leave the network by sending a deregistration request and the network responding to the request. In addition to this option, the core network entity can also run an error handling process. When the UE re-registers, the core network entity (MME or AMF) can set a timer that is longer than the periodic registration update timer assigned to the UE. If the UE, for example, runs out of battery or flies away in an airplane and quickly loses coverage, the CN will not keep the UE registered indefinitely. After the periodic update timer on the network side expires, the core network entity can start the implicit detach timer. If the implicit detach timer expires, the CN will deregister the UE locally without any signaling. The store-and-forward operation S can increase the long delay for the UE to get the opportunity to perform the next mobility update or periodic update. If it is determined that the store-and-forward operation is necessary, the core network entity can apply an extended periodic update timer value, or an implicit detach timer value, or both, to avoid implicitly detaching UEs that are unable to perform periodic updates due to no satellite coverage or an unavailable feeder link from the satellite to the ground station.

[0098] When a non-terrestrial core network entity (e.g., AMF-N, MME-N) has a store-and-forward indication and the store-and-forward indicator indicates that the store-and-forward operation applies to the UE (e.g., the corresponding indicator in the UE context stored at the terrestrial core network entity has been set to a value indicating that the store-and-forward operation applies to the UE), the terrestrial core network entity can take this into account when determining the detach timer value or the periodic update timer for the UE to ensure that the UE is not detached due to the long store-and-forward delay. When the store-and-forward indication indicates that the store-and-forward operation applies to the UE, the detach timer value can be increased.

[0099] For MO data or NIDD data, when the store-and-forward indication indicates that the store-and-forward operation applies to the UE and no terrestrial connection is available, a non-terrestrial core network entity instance deployed on the satellite (e.g., AMF-N or MME-N) receives and can acknowledge the MO CP data or NIDD data from the UE. The acknowledgement can be performed using the NAS protocol (e.g., sent by the UE in a NAS message). The non-terrestrial core network entity can buffer the MO CP data or NIDD data until the non-terrestrial core network entity regains ground station connectivity (e.g., is connected to the ground station via a feeder link). After the non-terrestrial core network entity regains ground station connectivity, it continues to send the CP data and / or NIDD data via the peer terrestrial core network entity on the ground (e.g., AMF-T, MME-T).

[0100] For MT data or NIDD data, when the store-and-forward indication indicates that the store-and-forward operation applies to the UE and the terrestrial core network entity instances on the ground (e.g., AMF-T, MME-T) cannot directly reach the UE, the terrestrial core network entity can discover a peer non-terrestrial core network entity instance (e.g., AMF-N, MME-N) on the satellite, which has, or will have, a ground station connection and is expected to reach the UE later. When the terrestrial core network entity instance at the device deployed at the ground station has discovered its peer non-terrestrial core network entity instance deployed at the satellite, the terrestrial core network entity sends the CP data / NIDD data to the non-terrestrial core network entity instance deployed at the satellite when connectivity with the satellite is obtained at the ground station. The MT data and / or signaling is buffered (e.g., stored) in the terrestrial core network entity, or alternatively, buffered in the SMF (for 5G systems) or SGW (in 4G systems) for an extended buffering duration until the satellite has connectivity with the ground station. When connectivity with the satellite is available, the terrestrial core network entity triggers the delivery of the MT data to the non-terrestrial core network entity on the satellite. The non-terrestrial core network entity instance on the satellite can buffer the CP MT data and / or NIDD data until the target UE is within the coverage of the satellite. Then, the non-terrestrial core network entity sends the MT data to the target UE. In some examples, the non-terrestrial core network entity on the satellite may only be discoverable by the terrestrial core network entity on the ground and the network entity deployed at the satellite (e.g., NG-RAN node (e.g., gNB or eNB)).

[0101] Figure 1 A communication network including a non-terrestrial network is shown, which non-terrestrial network includes a RAN node 100 and a non-terrestrial core network entity 102 (e.g., AMF-N 102) deployed at a satellite 104 of the NTN. According to some examples, the satellite 104 of the NTN can be in LEO or MEO. The non-terrestrial core network entity 102 includes a core network entity instance deployed at the satellite 104. According to some examples, Figure 1 the communication network shown in can be used to send CIoT CP data and / or NIDD data to the UPF anchor of the core network deployed at the ground station 103a (e.g., at the device deployed at the ground station 103a). Figure 1 The communication network of can include a 5G network.

[0102] An instance 103 of a terrestrial core network entity (e.g., AMF-T) deployed at a ground station 103a (e.g., at a device deployed at the ground station 103a) interfaces with an instance 102 of a non-terrestrial core network entity (e.g., AMF-N) on a satellite 104 (e.g., deployed at the satellite 104). The terrestrial core network entity 103 may have access to satellite orbit data such that the terrestrial core network entity 103 knows the satellite coverage in terms of feeder link availability. The terrestrial core network entity 103 may support the forwarding of other NFs on the ground for a core network entity role (e.g., AMF role). The home PLMN (H-PLMN) and the virtual PLMN (V-PLMN) are shown in Figure 1 and the core network functions of these networks are also shown. As shown in Figure 1 , the NFs may include an authentication server function (AUSF), UDM, virtual session management function (V-SMF), home session management function (H-SMF), NEF, AF, (multiple) UPFs, a data network (DN). In some examples, the ground station 103a may include at least one of these NFs, as well as the terrestrial core network entity 103. The terrestrial core network entity 103 may support an interface to a satellite-specific core network entity (e.g., AMF) function. This interface may know the latency of the transmission of data to / from the terrestrial core network entity 103 and the satellite-specific core network entity. The non-terrestrial core network entity 102 on the satellite 104 may pick up CP data or NIDD data at message delivery and carry it to the UE 106 without having a feeder link, which includes the link between the non-terrestrial core network entity 102 and the terrestrial core network entity 103.

[0103] The core network entity (non-terrestrial core network entity 102 (e.g., AMF-N) and / or terrestrial core network entity 103 (e.g., AMF-T)) may store a "store and forward" indication in the context information for the UE 106 at the time of UE registration (e.g., when the UE registers to the core network). The non-terrestrial core network entity 102 may instruct the UDM via the terrestrial core network entity 103 that the non-terrestrial core network entity 102 uses the store and forward operation. The terrestrial core network entity 103 may determine the next core network entity (e.g., the next AMF-N 102) that can reach the UE 106. When there is a feeder link between the non-terrestrial core network entity 102 and the terrestrial core network entity 103, the terrestrial core network entity 103 may send CP data or NIDD data to the non-terrestrial core network entity 102. When the UE 106 is within the coverage of the satellite 104, the non-terrestrial core network entity 102 sends CP data or NIDD data to the UE 106.

[0104] According to some examples, when the non-terrestrial core network entity 102, the terrestrial core network entity 103, and the UE 106 are connected, the UE 106 is registered to Figure 1 the core network. The non-terrestrial core network entity 102 and the terrestrial core network entity 103 can detect the need to support store-and-forward operations, for example, when the UE is registered to the core network.

[0105] According to some examples, the non-terrestrial core network entity 102 can have a storage capacity to store the messages it sends between the UE 106 and the terrestrial core network entity 103 (e.g., CIoT CP data, NIDD data, or Short Message Service (SMS) data). According to some examples, the non-terrestrial core network entity 102 can have a storage capacity sufficient to store control plane small data. In some examples, the non-terrestrial core network entity 102 can have the security parameters required for NAS procedures. NAS security can be terminated in the terrestrial core network entity 103 or the non-terrestrial core network entity 102. When NAS security is terminated in the non-terrestrial core network entity 102, the non-terrestrial core network entity can use the security parameters and message sequence numbers required to encode NAS messages.

[0106] The store-and-forward operations performed at the non-terrestrial core network entity 102 or the terrestrial core network entity 103 can be controlled by a store-and-forward indication, which is detected by the non-terrestrial core network entity 102 or the terrestrial core network entity 103 based on a configuration, subscriber information, an access management (AM) policy provided by the Policy Control Function (PCF) of the core network to the core network entity 102 or the terrestrial core network entity 103, or the UE location. During the registration process, the store-and-forward indication is stored in the UE context in the core network entity (e.g., AMF) and in the UDM. This parameter triggers the necessary data buffering functions in the terrestrial core network entity (for MT data) and the non-terrestrial core network entity (for MO data).

[0107] The non-terrestrial core network entity 102 or the terrestrial core network entity 103 can use the store-and-forward indication as a trigger to assign a longer periodic update timer value to the UE 106 to avoid overly frequent periodic registration updates and may also avoid other NAS timer values. The non-terrestrial core network entity 102 or the terrestrial core network entity 103 uses the store-and-forward indication as a trigger to assign a longer implicit detach timer value to the UE 106 in order to avoid implicitly detaching the UE due to long store-and-forward delays.

[0108] The UDM concept stores and forwards indications modifying the core network entities (e.g., AMF-N 102 and AMF-T 103 peers) and UE reachability. If the store-and-forward indication specifies that the store-and-forward operation applies to the registered UE 106, the core network entities and the UDM consider the UE 106 reachable even if the UE 106 is not directly reachable but only reachable via the store-and-forward operation.

[0109] For MO UPF-anchored CP data and NIDD data, while the satellite 104 provides coverage for the UE 106, as long as the satellite 104 has no connectivity to the ground and the store-and-forward indication specifies that the store-and-forward operation applies to the UE 106, the non-terrestrial core network entity 102 receives MO data from the UE 106 and buffers it until the satellite 104 travels further in its orbit to reach its next available ground station. Once the satellite 104 regains ground station connectivity, the non-terrestrial core network entity 102 sends the MO data to the terrestrial core network entity 103, which can continue with the following processes:

[0110] · For UPF-anchored CP data, the terrestrial core network entity 103 (e.g., AMF-T) continues with the processes specified in step 4 and later of clause 4.24.1 of 3GPP TS 23.502.

[0111] · For NIDD data, the terrestrial core network entity 103 (e.g., AMF-T) continues with the process specified in step 1 of clause 4.25.4 of 3GPP TS 23.502, which refers back to clause 4.24.1 above.

[0112] For MT UPF anchored CP data and NIDD data, if UE 106 is not directly reachable and the terrestrial core network entity 103 has a store-and-forward indication indicating that the store-and-forward operation is applicable to the target UE 106, the terrestrial core network entity (e.g., AMF-T) 103 discovers an instance of the non-terrestrial core network entity 102 on the satellite 104 that is expected to reach the UE (e.g., AMF-N) later. The MT data and / or signaling are buffered in the terrestrial core network entity 103, or alternatively, based on the control of the terrestrial core network entity 103, the existing high-latency communication (HLcom) process is reused to extend the buffering duration in the SMF until the terrestrial core network entity establishes connectivity with the satellite. Then, the terrestrial core network entity 103 can send the MT UPF anchored CP data (dotted line) or MT NIDD data (dotted line) to the non-terrestrial core network entity 102. The non-terrestrial core network entity 102 buffers the MT UPF anchored CP data or MT NIDD data until it can reach the target UE 106. When the target UE 106 becomes reachable, the non-terrestrial core network entity 102 continues to send the MT UPF anchored CP data or MT NIDD data (dashed line) to the UE 106, as follows:

[0113] · The non-terrestrial core network entity 102 continues with the MT UPF anchored CP data procedure as specified in clause 4.24.2 of 3GPP TS23.502. The procedure for delivering UPF anchored CP (CIoT) data is specified in clause 4.24.1 (MO data) and clause 4.24.2

[0114] (MT data) of 3GPP TS23.502. The UE context in the AMF is specified in clause 5.2.2.2.2 of 3GPP TS23.502.

[0115] · The non-terrestrial core network entity 102 continues with the MT NIDD procedure as specified in step 9 of clause 4.25.5 of 3GPP TS23.502.

[0116] Figure 2 A communication network is shown that includes a RAN node 200 with a non-terrestrial core network entity 212 (e.g., MME-N) deployed on a satellite 204. According to some examples, the satellite 204 can be LEO or MEO. The non-terrestrial core network entity 202 includes a core network instance on the satellite 204. According to some examples, Figure 2 the system architecture can be used for P-GW anchored data and / or NIDD. Figure 2 the communication network can include an EPS network.

[0117] A core network instance (e.g., MME-T) deployed at a terrestrial device interfaces with a peer core network instance (e.g., MME-N 212) deployed on satellite 204. For example, a terrestrial core network entity 213 deployed on the ground may have access to satellite orbit data such that the terrestrial core network entity 213 knows the satellite coverage in terms of feeder link availability. The terrestrial core network entity 213 may support a core network entity role (e.g., MME role) to forward other NFs on the ground. As Figure 2 shown, the other NFs may include IWK Service Capability Exposure Function (IWK-SCEF), Home Subscriber Server (HSS), SCEF, Service Capability Server (SCS), S-GW, P-GW, DN. The terrestrial core network entity 213 may support an interface with a satellite-specific core network entity (e.g., MME) function. The interface may know the latency of the transmission of data to / from the terrestrial core network entity 103 and the satellite-specific core network entity. The non-terrestrial core network entity 212 on the satellite 204 may select CP data or NIDD and send the CP data or NIDD to the UE 206 upon message delivery without having a feeder link, where the feeder link includes a link between the non-terrestrial core network entity 212 and the terrestrial core network entity 213.

[0118] When the UE sends an ATTACH request or a TAU update request, any of the peer core network entities (e.g., MME-N 212 and / or MME-T 213) and the HSS may store a store-and-forward indication in the context information for the UE 206. The non-terrestrial core network entity 212 may indicate to the HSS via the terrestrial core network entity 213 that the MME uses a store-and-forward operation in communicating with the target UE. The terrestrial core network entity 213 may determine the next MME-N that can reach the UE 206. When there is a feeder link between the non-terrestrial core network entity 212 and the terrestrial core network entity 213, the terrestrial core network entity 213 may send CP data or NIDD data to the non-terrestrial core network entity 212. When the UE 206 is within the coverage of the satellite 204, the non-terrestrial core network entity 212 sends the CP data or NIDD data to the UE 206.

[0119] According to some examples, when the non-terrestrial core network entity 212, the terrestrial core network entity 213, and the UE 206 are connected, the UE 206 is registered to Figure 2 the network. The non-terrestrial core network entity 212 and the terrestrial core network entity 213 may detect the need to support a store-and-forward operation, e.g., during the registration process.

[0120] According to some examples, the non-terrestrial core network entity 212 may have a storage capacity to store the messages it sends between the UE 206 and the terrestrial core network entity 213. In some examples, the non-terrestrial core network entity may have the security parameters required for NAS procedures.

[0121] The store-and-forward operations performed at the non-terrestrial core network entity 212 or the terrestrial core network entity 213 may be controlled by a store-and-forward indication detected by the non-terrestrial core network entity 212 or the terrestrial core network entity 213 (based on configuration, subscriber data, AM policy, or location). During the registration process of the UE, the store-and-forward indication is stored in the UE mobility management context in the MME and the HSS. This parameter triggers the necessary data buffering functions in the terrestrial core network entity (for MT data) and the non-terrestrial core network entity (for MO data).

[0122] The non-terrestrial core network entity 212 or the terrestrial core network entity 213 may use the store-and-forward indication as a trigger to assign an extended periodic update timer value to the UE 206 to avoid overly frequent periodic registration updates. The non-terrestrial core network entity 212 or the terrestrial core network entity 213 uses the store-and-forward indication as a trigger to assign a longer implicit detach timer value to the UE 206 to avoid implicitly detaching the UE due to long store-and-forward delays.

[0123] The store-and-forward indication described herein changes the concept of the core network entity (e.g., the MME includes MME-N 202 and MME-T 203 peers) and the HSS for UE reachability. When the store-and-forward indication indicates that the store-and-forward operation applies to the UE 206 and the UE 206 is unreachable by the satellite deploying the MME-T 203, the core network entity and the HSS consider the UE 206 reachable.

[0124] For MO P-GW anchored CP data and NIDD data, when the satellite 204 provides coverage for the UE 206 and as long as the satellite 204 has no connectivity to the ground station and the store-and-forward indication indicates that the store-and-forward operation applies to the UE 206, the non-terrestrial core network entity 212 receives MO data from the UE 206 and buffers the MO data until the satellite 204 travels further in its orbit to reach its next available ground station. Once the satellite 204 regains ground station connectivity, the non-terrestrial core network entity 212 sends the MO data to the terrestrial core network entity 213 and continues with the following process:

[0125] · For P-GW anchored CP data, the terrestrial core network entity 213 continues to perform the procedures specified in clause 4.24.1 step 4 and later of 3GPP TS 23.401. In the control plane CIoT EPS optimization with P-GW connectivity, the procedures for MO and MT data transfer are specified in clause 5.3.4B of 3GPP TS 23.401.

[0126] · For NIDD data, the terrestrial core network entity 213 continues to perform the procedures specified in clause 5.13.4 step 1 of 3GPP TS

[0127] 23.682.

[0128] For MT P-GW anchored CP data and NIDD data, if the UE 206 is not directly reachable and the terrestrial core network entity 213 has a store-and-forward indication specifying that the store-and-forward operation applies to the target UE 206, the terrestrial core network entity 213 discovers an instance of the non-terrestrial core network entity 212 on the satellite 204 that is expected to reach the UE 204 at a later time (e.g., the non-terrestrial core network entity 212). The MT data is buffered in the terrestrial core network entity 213 or, alternatively, during control re-use of the existing procedures in the SGW to extend the buffering time until the terrestrial core network entity 213 obtains connectivity with the satellite 204. The terrestrial core network entity 213 can then send the MT P-GW anchored CP data (dashed line) or MT NIDD data (dashed line) to the non-terrestrial core network entity 212. The non-terrestrial core network entity MME-N212 buffers the MT P-GW anchored CP data or MT NIDD data until it can reach the target UE 206. When the target UE 206 becomes reachable, the non-terrestrial core network entity 212 continues the procedure by sending the MT P-GW anchored CP data (dotted line) to the UE 206 as follows:

[0129] · The non-terrestrial core network entity 212 continues the MT P-GW anchored CP data procedure as described in clause 5.3.4B.3 of 3GPP TS 23.401;

[0130] · The non-terrestrial core network entity 212 continues the MT NIDD procedure as described in clause 5.13.3 step 8 of 3GPP TS 23.682.

[0131] 3GPP TS 36.300 states that for Control Plane CIoT EPS optimizations (as defined in TS 24.301) and Control Plane CIoT 5GS optimizations (as defined in TS 24.501), UL NAS signaling messages or UL NAS messages carrying data can be sent in UL RRC container messages, and DL NAS signaling or DL NAS data can be sent in DL RRC container messages. 3GPP TS 36.300 further states that for NB-IoT, RRC connection reconfiguration is not supported and AS security is not used.

[0132] Figure 3 An example message flow for the RRC connection establishment procedure for CP CIoT optimization is shown. When connecting to a RAN node 314 of 5GS (e.g., an eNB or gNB of EPS), the RRC connection establishment procedure can be established by the UE 306. At 301, the UE 306 sends a random access preamble to the RAN node 314. At 303, in response to receiving the random access preamble, a random access response is sent from the RAN node 314 to the UE 306. At 305, the UE 306 sends an RRC connection request to the RAN node 314. At 307, the RAN node 314 sends an RRC connection setup message RRC connection request to the UE 306. At 309, the UE 306 sends an indication that the RRC connection has been completed. The indication sent at 309 can be included in an uplink NAS message sent by the UE 306 to the RAN node 314.

[0133] Figure 4 An example of a non-terrestrial network including non-terrestrial network nodes (e.g., satellites) and terrestrial network nodes during three different time periods is shown. The non-terrestrial network nodes (e.g., satellites) include a non-terrestrial core network entity 412a and a RAN node 400b (illustrated as RAN 400b). It should be noted that the peer core network entity is Figure 4 shown as a peer MME in

[0134] but in other examples, the peer core network entity can be a peer AMF in a 5G network, or any other suitable peer core network function.

[0135] In Figure 4In the example shown, there are two non-terrestrial network nodes (e.g., two satellites), which are shown at different times T1, T2, and T3. The first non-terrestrial network node (e.g., the first satellite shown in black and solid lines) includes a first non-terrestrial core network entity (MME-N-1) 412a and a first RAN node 400a (shown as RAN 400a). The non-terrestrial network node (e.g., the second satellite shown in white) includes a second non-terrestrial core network entity (MME-N-2) 412b and a second RAN node 400b (shown as RAN 400b).

[0136] In Figure 4 the example, the first non-terrestrial network node (e.g., the first satellite) has ground station connectivity when located in Rennes (e.g., is connected to the ground station 420 located in Rennes when the ground station 420 is within the coverage area of the first non-terrestrial network node), and has ground station connectivity when located in Orleans (e.g., is connected to the ground station 424 located in Orleans when the ground station 424 is within the coverage area of the first non-ground network node), but has no ground station connectivity when passing through (e.g., going through) Le Mans. The second non-terrestrial network node (e.g., the second satellite) has ground station connectivity when located in Rennes (e.g., is connected to the ground station 420 located in Rennes when the ground station 420 is within the coverage area of the second non-terrestrial network node), and has ground station connectivity when located in Orleans (e.g., is connected to the ground station 424 located in Orleans when the ground station 424 is within the coverage area of the second non-terrestrial network node), but has no ground station connectivity when passing through (e.g., going through) Le Mans. For illustration, T1 is between 10.00 - 10.20, and T2 is between 10.40 - 11.00.

[0137] At time T1, the first non-terrestrial network node including the first non-terrestrial core network entity (MME-N-1) 412a and the first RAN node 400a (e.g., the first satellite) covers Le Mans (e.g., is located above Le Mans), while the second non-terrestrial network node including the second non-terrestrial core network entity (MME-N-2) 412b and the RAN node 400b (e.g., the second satellite) provides coverage for Rennes (e.g., is located above Rennes and has ground station connectivity). At time T2, the first non-terrestrial network node (e.g., the first satellite shown in black) will provide coverage for Orleans (e.g., will be located above Orleans and have ground station connectivity), while the second non-terrestrial network node (e.g., the second satellite) will cover Le Mans. At time T3, the second non-terrestrial network node (e.g., the second satellite) will have ground station connectivity with Orleans (e.g., will establish connectivity with the ground station 424 located in Orleans) and synchronize with the terrestrial core network entity (MME-T) 413 of the terrestrial network node.

[0138] Figure 5 Shows an example of signaling and operations that occur when a UE requests a service provided by an NTN configured for store-and-forward operation. The NTN includes a first RAN node (RAN-1) 500a deployed at a first satellite and a first non-terrestrial core network entity (MME-NT-1 512a), a second RAN node (RAN-2) 500b deployed at a second satellite, a second non-terrestrial core network entity (MME-NT-2) 512b, and a third MME (MME-T) 513 deployed at a ground station. In Figure 5 the example, the UE context of UE 506 may include a store-and-forward indication that indicates that the store-and-forward operation is applicable to UE 506. The time periods T1, T2, and T3 discussed above with respect to Figure 4 and the locations of the first RAN node (RAN-1) 500a and the first non-terrestrial core network entity (MME-NT-1) 512a at T1, T2, and T3, and the locations of the second RAN (RAN-2) 500b and the second non-terrestrial core network entity (MME-NT-2) 512b discussed with respect to Figure 4 at T1, T2, and T3 are applicable to Figure 5 the example shown in Figure 5 It should be noted that the peer core network entity is shown as a peer MME in

[0139] At 531, UE 506 sends a service request to the first RAN node (RAN-1) 500a. The service request may be forwarded by the first RAN (RAN-1) 500a to the first non-terrestrial core network entity (MME-NT-1 512a). According to some examples, the service request may be included in a NAS container of a NAS UL transport message, and the NAS UL transport message may be included in an RRC message sent to the first RAN node (RAN-1) 500. The RRC message may be or include plaintext, and the NAS UL transport message may be partially plaintext, and the NAS container is protected using a security context received by UE 106 when UE 106 registered with the NTN. The NAS container may contain CIoT data or NAS-SMS data.

[0140] At 533, the first non-terrestrial core network entity (MME-NT-1) 512a will be able to decrypt the service request but not the NAS container. Thus, the first non-terrestrial core network entity (MME-NT-2) 512a checks the message type of the NAS message and determines that the message type is an initial message (i.e., the service request). The first non-terrestrial core network entity (MME-NT-2) cannot decrypt the NAS container at 533 because, in this example, the first non-terrestrial core network entity (MME-NT-1) 512a does not have the security context for UE106. The first non-terrestrial core network entity (MME-NT-1) 512a stores the NAS container until T2 (until the first non-terrestrial core network entity (MME-NT-1) 512a reaches Orleans).

[0141] At 535, when the first non-terrestrial core network entity (MME-NT-1) 512a reaches Orleans at T2, the first non-terrestrial core network entity (MME-NT-1) 512a forwards the NAS container (or the service request together with the NAS container) to the terrestrial core network entity (MME-T) 513. At 537, the terrestrial core network entity (MME-T) 513 having the security context for UE 506 will decrypt the NAS container. If the NAS container includes CIoT data, the terrestrial core network entity (MME-T) 513 forwards the NAS container (e.g., the NAS payload of the NAS container containing CloT data) to the SCEF. If the NAS container includes NAS-SMS data, the terrestrial core network entity (MME-T) 513 forwards the NAS container (e.g., the NAS payload of the NAS container containing NAS-SMS data) to the SMSC.

[0142] At 539, if the terrestrial core network entity (MME-T) 513 receives an SMS confirmation or any DL NAS transport message that includes a NAS payload with CIoT data or NAS-SMS data for the UE 506, the terrestrial core network entity (MME-T) 513 will send the SMS confirmation or any DL NAS transport message for the UE 506 in plain text to the second non-terrestrial core network entity (MME-NT-2) 512b, which is then above Rennes and has connectivity with the ground station 420 (time T3). The terrestrial core network entity (MME-T) 513 will provide the security context for the UE 106 together with the SN number to the second non-terrestrial core network entity (MME-N-2) 512b. According to some examples, at 539, the terrestrial core network entity (MME-T) 513 also provides a security key for the gNB (represented as (KgNB)), and a NAS key for the UE 506. At 541, the terrestrial core network entity (MME-T) 513 marks the second non-terrestrial core network entity (MME-NT-2) 512b as the owner of the UE context for the UE 506.

[0143] At 543, the UE 506 may send a service request or a TAU to the second non-terrestrial core network entity (MME-NT-2) 512b. In some examples, this is sent when discontinuous coverage is supported by the UE 506 and / or the second non-terrestrial network (MME-NT-2) 512b.

[0144] At 545, the second non-terrestrial core network entity (MME-NT-2) 512b may send an Initial Context Setup Request (ICSR) and the KgNB for the UE 506 to the second node (RAN-2) 500b. At 547, the second (RAN-2) 500b sends an RRC connection reconfiguration to the UE506. At 549, the second non-terrestrial core network entity (MME-NT-2) 512b may send a DL NAS transport after successful establishment of the RRC via a service request procedure or via network-initiated paging. At 549, a DL NAS transport message (e.g., the NAS payload includes NAS-SMS data or CIoT data) is sent from the second non-terrestrial core network entity (MME-NT-2) 512b to the UE 506.

[0145] After receiving the received security context together with the current SN, the second non-terrestrial core network entity (MME-NT-2) 512b may encrypt and integrity protect the NAS payload. The NAS payload may then be sent to the UE 506 in a downlink (DL) NAS transport message. The NAS payload may include SMS or CIoT data.

[0146] At 551, at T3, the second non-terrestrial core network entity (MME-NT-2) 512b sends the undelivered NAS payload and the last used SN back (e.g., returns) to the terrestrial core network entity (MME-T) 513. After serving the UE 506 and sending a DL transport message, the second non-terrestrial core network entity (MME-NT-2) 512b reports the delivery status and the active security context (including the current SN) to the terrestrial core network entity (MME-T) 513 after regaining ground connectivity at Orleans. The second non-terrestrial core network entity (MME-N-2) 512a synchronizes its own security context and releases its second ownership of the non-terrestrial core network entity (MME-NT-2) 512b from the UE context of the UE 506.

[0147] Figure 6 Shows an example of the signaling and operations that occur when a UE attaches to an NTN configured for store-and-forward operation. Figure 6 The NTN 6 shown in includes a first satellite 604a, a second satellite 604b, a ground station, a satellite security key generator 670, and other terrestrial core network entities 672 (e.g., HSS, UDM). The first satellite 604a includes a first RAN node (illustrated as RAN1) 600a and a first non-terrestrial core network entity (MME-NT-1) 612a. The second satellite 604b includes a second RAN node (illustrated as RAN2) 600b and a second non-terrestrial core network entity (MME-NT-2) 612b. The ground station includes a terrestrial core network entity 613. It should be noted that the peer core network entities are shown as peer MMEs in Figure 6 but in other examples, the peer core network entities may be peer AMFs in a 5G network or any other suitable network.

[0148] As described above regarding Figure 4 the time periods T1, T2, and T3 and the positions of the first RAN node (RAN-1) and the first non-terrestrial core network entity (MME-NT-1) at T1, T2, and T3, and regarding Figure 4 the positions of the second RAN node (RAN 2) 600b and the second non-terrestrial core network entity (MME-NT-2) 612b at T1, T2, and T3 discussed in Figure 6Example of

[0149] At 661, the UE attaches to the NTN via satellite 604a. During the attachment of UE 606 to the NTN, at 663, the terrestrial core network entity 613 may ensure successful authentication, and the NAS key may be available for the terrestrial core network entity (MME-T) 613 for UE 606.

[0150] At 665 to 671, the terrestrial core network entity (MME-T) 613 evaluates and re-evaluates which satellite has ground station connectivity and shares the NAS key for UE 606 with the satellite having ground station connectivity.

[0151] At 665, the first satellite 604a has a connection to the ground station (GS) (e.g., to the terrestrial core network entity (MME-T) 613). The UE context of UE 606 includes security information and a store-and-forward indication for UE 606, and the store-and-forward indication for UE 606 is sent from the terrestrial core network entity (MME-T) 613 to the first non-terrestrial core network entity (MME NT-1) 612a. At 667, the UE context of UE 606 is shared by the first non-terrestrial core network entity (MME-NT-1) 612a with satellite 604a.

[0152] At 669, the first satellite 604a has a connection to UE 606 (e.g., the connectivity of the satellite to UE 606), and the store-and-forward security context for each "relevant" satellite is shared with UE 606. In some examples, the "relevant" satellites for UE 606 may include satellites that are likely to serve UE 606 in the future. In some examples, the "relevant" satellites for UE 606 may include satellites that are authenticated and / or authorized to serve UE 606.

[0153] At 671, the second satellite 604b has a connection to the ground station (e.g., the terrestrial core network entity (MME-T) 613). The store-and-forward security context for the second satellite 604b can be downloaded from the satellite security key generator 670.

[0154] At 673 (T1), the first satellite 604a has a connection to UE 606. The MO data from UE 606 can be sent to the first RAN node (RAN1) 600a using the initial NAS encryption and NAS count from 669.

[0155] At 675 (T2), the first satellite 604a has a connection with the UE 606. MO data can be forwarded from the first non-terrestrial core network entity (MME-NT-1) 612a to the second non-terrestrial core network entity (MME-NT-2) 612b.

[0156] At 677 (T2), the second satellite 604b has a connection with the UE 606. MO data from the UE 606 can be sent to the second RAN (RAN2) 600b using NAS encryption and NAS counting from 673.

[0157] At 679, the case of NAS integrity failure is considered. If NAS integrity fails at any non-terrestrial core network entity (e.g., MME-NT-1 612a or MME-NT-2 612b), the terrestrial core network entity (MME-T) 613 performs a security mode procedure to share its security key with the UE 606. During the security mode procedure, the terrestrial core network entity (MME-T) 613 can enable NAS security by exchanging encryption and integrity keys with the UE 606. At 681, after receiving the NAS security mode command, the UE 606 resets its UL NAS count. The second non-terrestrial core network entity (MME-NT-2) 612b resets its DL NAS COUNT after the completion of the security mode procedure. Any message sent after the security mode procedure should be encrypted and integrity protected in each direction.

[0158] At 683, the second satellite 604b has a connection with the ground station and forwards the MO data to the terrestrial core network entity (MME-T) 613.

[0159] At Figure 6 If any non-terrestrial core network entity (e.g., the first non-terrestrial core network entity (MME-NT-1) 612a and / or the second non-terrestrial core network entity (MME-NT-2) 612b) that receives the initial UE message does not have a security context for the UE 606, the non-terrestrial core network entity assumes the UE is unauthenticated.

[0160] Figure 7 An example method performed by a non-terrestrial core network entity (e.g., AMF-N or MME-N) is shown.

[0161] At 700, the method includes: receiving data from a user equipment at a satellite, where the data includes CP data or NIDD data.

[0162] At 702, the method includes buffering data at the satellite during a period when the non-terrestrial core network entity at the satellite is not connected to the terrestrial core network entity.

[0163] At 704, the method includes sending the data from the satellite to the terrestrial core network entity when the non-terrestrial core network entity is connected to the terrestrial network entity.

[0164] Figure 8 An example performed by a terrestrial core network entity (e.g., AMF-T or MME-T) is shown.

[0165] At 800, the method includes connecting, by the terrestrial core network entity, to the non-terrestrial core network entity.

[0166] At 802, the method includes, after connecting to the non-terrestrial core network entity, receiving, at the terrestrial core network entity, data buffered at the terrestrial core network entity during a period when the device is not connected to the non-terrestrial core network entity, wherein the data is received at the non-terrestrial core network entity from a user equipment, and wherein the data includes CP data or NIDD data.

[0167] Figure 9 An example of a core network entity is illustrated, e.g., Figure 1 and / or Figure 2 the non-terrestrial core network entity (e.g., MME-NT or AMF-NT) or the terrestrial core network entity (e.g., MME-T or AMF-T) shown in Figure 7 The core network entity 900 may include at least one random access memory (RAM) 911a, at least one read-only memory (ROM) 911b, at least one processor 912, 913, and a network interface 914. The at least one processor 912, 913 may be coupled to the RAM 911a and the ROM 911b. The at least one processor 912, 913 may be configured to execute software code 915, or may execute instructions of the software code 915. Execution of the software code 915 (or execution of the instructions of the software code 915) may, for example, cause the core network entity to perform operations. For example, when the core network entity is a non-terrestrial core network entity ((e.g., MME-NT or AMF-NT), execution of the software code 915 (or execution of the instructions of the software code 915) causes the non-terrestrial core network entity to perform Figure 8The methods shown and described herein. The software code 915 can be stored in the ROM 911b. The apparatus 900 can be interconnected with another apparatus 900 that includes or implements other network functions of the 5GC. In some embodiments, the apparatus is deployed at a ground station, and the software code 915 is software code (e.g., MME-N or AMF-N). In some embodiments, the apparatus is deployed at a satellite and includes or implements one network function (e.g., MME-T or AMF-T). In alternative embodiments, the apparatus 900 can include or implement two or more network functions.

[0168] Figure 10 An example of a communication device 1000 is illustrated, such as Figure 1 the UE 106 shown in Figure 2 or the UE206 shown in. Non-limiting examples of the communication device 1000 include user equipment (e.g., UE 106, 206), a mobile station (MS), or a mobile device, such as a mobile phone or a so-called "smartphone", a computer provided with a wireless interface card or other wireless interface facilities (e.g., a USB dongle), a personal data assistant (PDA) or a tablet computer provided with wireless communication capabilities, a machine type communication (MTC) device, an Internet of Things (IoT) type communication device, or any combination of these and the like. The communication device 1000 can include a transceiver for transmitting and / or receiving, for example, wireless signals (e.g., radio signals) carrying communications. The communication can be one or more of voice, email, text messages, multimedia data, machine data, etc.

[0169] The communication device 1000 can receive wireless signals (e.g., radio signals) via an appropriate device for receiving over the air or a radio interface 1007, and can transmit wireless signals via an appropriate device for transmitting radio signals. In Figure 10 the apparatus is schematically designated by the block 1006. The apparatus 1006 can include, for example, a radio section, associated antenna means, and a transceiver. The antenna means can be arranged inside or outside the mobile device and can include one or more antenna elements. The antenna means can be a multiple input multiple output (MIMO) antenna.

[0170] The communication device 1000 may be provided with at least one processor 1001, at least one memory ROM 1002a, at least one RAM 1002b, and other possible components 1003 for software and hardware assistance in performing the tasks it is designed to perform, including control of access to and communication with access nodes (e.g., RAN nodes 400a, 400b, 500a, 500b) and other communication devices. The at least one processor 1001 is coupled to the RAM 1002b and the ROM 1002a. The at least one processor 1001 may be configured to execute appropriate software code 1008. The software code 1008 may, for example, permit execution of one or more operations of the communication device. The software code 1008 may be stored in the ROM 1002a.

[0171] The processor, ROM, RAM, transceiver, and other circuitry (e.g., modem) of the communication device may be provided in a circuit board, chipset, or system-on-chip. The circuit board, chipset, or system-on-chip is denoted by reference numeral 1004. The communication device 1000 may optionally have a user interface such as a keyboard 1005, touch screen or touchpad, combinations thereof, etc. Depending on the type of communication device, optionally, one or more of a display, speaker, and microphone may be provided.

[0172] Figure 11 A schematic diagram of non-volatile storage media 1100a (e.g., computer optical disc (CD) or digital versatile disc (DVD)) and 1100b (e.g., universal serial bus (USB) memory stick) is shown, storing instructions and / or parameters 1102, which, when executed by a processor, permit the processor to execute one or more steps of any method flow described herein.

[0173] It should be understood that the references to various network functions (e.g., AMF, SMF, TNF, etc.) above may include means for performing at least some of the functions associated with those network functions. Additionally, the means including the network functions may include virtual network function instances of the network functions.

[0174] It should be understood that these means may include or be coupled to other units or modules for transmission and / or reception, such as radio components or radio heads. Although these means have been described as one entity, different modules and memories may be implemented in one or more physical or logical entities.

[0175] It should be noted that although some embodiments have been described in relation to 5G networks, similar principles can be applied to other networks and communication systems. Thus, although certain embodiments have been described above by way of example with reference to certain exemplary architectures for wireless networks, technologies, and standards, the embodiments can be applied to any other suitable form of communication system other than those shown and described herein.

[0176] It should also be noted herein that although the exemplary embodiments have been described above, various changes and modifications can be made to the disclosed solutions without departing from the scope of the present invention.

[0177] As used herein, "at least one of the following: <list of two or more elements>" and "at least one of <list of two or more elements>" and similar phrases, where the list of two or more elements is joined by "and" or "or", means at least any one element, or at least any two or more elements, or at least all elements.

[0178] In general, the various embodiments can be implemented in hardware or in special circuit systems, software, logic, or any combination thereof. Some aspects of the present disclosure can be implemented in hardware, while other aspects can be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device, although the present disclosure is not limited thereto. Although the various aspects of the present disclosure can be shown and described by block diagrams, flowcharts, or using some other graphical representation, it is fully understood that, by way of non-limiting example, the blocks, devices, systems, technologies, or methods described herein can be implemented in hardware, software, firmware, special circuits or logic, general hardware or a controller or other computing device, or some combination thereof.

[0179] As used herein, the term "circuitry" can refer to one or more or all of the following:

[0180] (a) Only hardware circuit implementations (such as, only in analog and / or digital circuit implementations); and

[0181] (b) Combinations of hardware circuits and software, such as (where applicable):

[0182] (i) Combinations of (multiple) analog and / or digital hardware circuits with software / firmware, and

[0183] (ii) Any part of (multiple) hardware processors (including (multiple) digital signal processors) with software and (multiple) memories, which work together to enable a device (such as a mobile phone or a server) to perform various functions; and

[0184] (c) (Multiple) hardware circuits and / or (multiple) processors (such as (multiple) microprocessors or a part of (multiple) microprocessors) that require software (e.g., firmware) to operate, but the software may not exist when the operation does not require software.

[0185] This definition of circuitry applies to all uses of the term "component" in this document, including in any claim. As a further example, as used herein, the term circuitry also encompasses implementations of only hardware circuits or processors (or multiple processors), or a part of a hardware circuit or processor and its (their) attendant software and / or firmware. For example, and if applicable to a particular claim element, the term circuitry also encompasses a baseband integrated circuit or a processor integrated circuit for a mobile device or a similar integrated circuit in a server, a cellular network device, or other computing or network devices.

[0186] Embodiments of the present disclosure can be implemented by computer software executable by a data processor of a mobile device (such as in a processor entity), or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products) include software routines, applets, and / or macros, can be stored in any device-readable data storage medium, and they include program instructions for performing specific tasks. A computer program product can include one or more computer-executable components that are configured to perform embodiments when the program is run. The one or more computer-executable components can be at least one software code or a part thereof.

[0187] In this regard, it should also be noted that any box in the logical flow shown in the figures can represent a program step, or interconnected logical circuits, boxes, and functions, or a combination of program steps and logical circuits, boxes, and functions. Software can be stored on a physical medium, such as a memory chip or a memory block implemented within a processor, a magnetic medium (such as a hard disk or a floppy disk), and an optical medium (such as, for example, a DVD and its data variant CD). The physical medium is a non-transitory medium.

[0188] The term "non-transitory" used herein is a limitation of the medium itself (i.e., tangible, rather than a signal), rather than a limitation of data storage persistence (e.g., RAM vs. ROM).

[0189] The memory can be of any type suitable for the local technical environment and can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The data processor can be of any type suitable for the local technical environment and, by way of non-limiting example, can include one or more of the following: general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), FPGAs, gate-level circuits, and processors based on multi-core processor architectures.

[0190] Various example embodiments of the present disclosure can be practiced in various components, such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Sophisticated and powerful software tools can be used to transform a logic-level design into a semiconductor circuit design ready for etching and formation on a semiconductor substrate.

[0191] The scope of protection sought for various example embodiments of the present disclosure is set forth by the independent claims. Example embodiments and features thereof described in the present disclosure that are not within the scope of the independent claims (if any) should be construed as examples to facilitate understanding of the various example embodiments of the present disclosure.

[0192] The foregoing description has provided a complete and informative description of various example embodiments of the present disclosure by way of non-limiting and illustrative examples. However, various modifications and adaptations may become apparent to those skilled in the relevant art in view of the foregoing description when read in conjunction with the drawings and the claims. However, all such modifications of such and similar teachings will still fall within the various example embodiments of the present disclosure set forth in the claims. By way of non-limiting and illustrative examples, there are additional example embodiments, including combinations of one or more example embodiments with any other example embodiments previously discussed.

Claims

1. A non-terrestrial core network entity for a communication network, the non-terrestrial core network entity comprising components for: receiving data from a user device, wherein the data comprises: Control Plane (CP) data, or Non-Internet Protocol Delivery (NIDD) data; as well as buffering the data during a time period when the non-terrestrial core network entity is not connected to a terrestrial core network entity; When the non-terrestrial core network entity is connected to the terrestrial network entity, the data is sent to the terrestrial core network entity.

2. The non-terrestrial core network entity according to claim 1, wherein the buffering comprises: When the user equipment context for the user equipment includes an indication that the non-terrestrial core network entity is to store and forward data received from the user equipment, the data is buffered.

3. The non-terrestrial core network entity according to claim 2, wherein the component is further configured to: detecting the indication based on at least one of a configuration of the non-terrestrial core network entity, subscriber information for a subscriber associated with the device, location information for the apparatus, and access and mobility policies; and At the non-terrestrial core network entity, the indication is stored in the user equipment context.

4. The non-terrestrial core network entity according to claim 2, wherein the component is further configured to: Determine a periodic update timer value for the user equipment for at least one of a periodic registration update and a tracking area update, wherein when the indication is present in the context information for the user equipment, the periodic update timer value is increased relative to when the indication is not present in the context information for the user equipment.

5. The non-terrestrial core network entity according to claim 2, wherein the component is further configured to: Based on the presence of the indication in the user equipment context, user equipment reachability of the user equipment is determined, wherein when the indication is present in the user equipment context, the user equipment is determined to be reachable via a store and forward operation.

6. The non-terrestrial core network entity according to claim 2, wherein the component is further configured to: Determining a timer value for the user equipment to detach from the network when not connected to the land network function, wherein when the indication is present in the context information for the user equipment, the timer value is increased relative to when the indication is not present in the context information for the user equipment.

7. The non-terrestrial core network entity according to claim 1, wherein the component is further configured to: In response to receiving the data from the user equipment, sending an acknowledgement message to the user equipment, wherein the acknowledgement message comprises a non-access stratum protocol message.

8. The non-terrestrial core network entity of claim 1 , wherein the data sent to the terrestrial core network entity is protected in a non-access stratum container, wherein the terrestrial core network entity is configured to decrypt the non-access stratum container using a security context of the user equipment.

9. The non-terrestrial core network entity of claim 1, wherein the non-terrestrial core network entity comprises an access and mobility management function (AMF), and the terrestrial core network entity comprises an AMF.

10. The non-terrestrial core network entity of claim 1, wherein the non-terrestrial core network entity comprises a mobility management entity (MME), and the terrestrial core network entity comprises the MME.

11. A method for a non-terrestrial core network entity of a communication network, the method comprising: receiving data from a user equipment, wherein the data comprises: control plane (CP) data, or non-Internet protocol delivery (NIDD) data; buffering the data at the satellite during a time period when the non-terrestrial core network entity is not connected to the terrestrial core network entity; and When the non-terrestrial core network entity is connected to the terrestrial network entity, the data is sent to the terrestrial core network entity.

12. The method of claim 11, wherein the buffering comprises: When the user equipment context for the user equipment includes an indication that the non-terrestrial core network entity is to store and forward data received from the user equipment, the data is buffered.

13. The method according to claim 12, comprising: detecting the indication based on at least one of a configuration of the non-terrestrial core network entity, subscriber information for a subscriber associated with the device, location information for the apparatus, and access and mobility policies; as well as The indication is stored in the user equipment context.

14. The method according to claim 12, wherein the method comprises: Determine a periodic update timer value for the user equipment for at least one of a periodic registration update and a tracking area update, wherein when the indication is present in the context information for the user equipment, the periodic update timer value is increased relative to when the indication is not present in the context information for the user equipment.

15. The method according to claim 12, wherein the method comprises: Based on the presence of the indication in the user equipment context, user equipment reachability of the user equipment is determined, wherein when the indication is present in the user equipment context, the user equipment is determined to be reachable via a store and forward operation.

16. The method according to claim 12, wherein the method comprises: Determining a timer value for the user equipment to detach from the network when not connected to the land network function, wherein when the indication is present in the context information for the user equipment, the timer value is increased relative to when the indication is not present in the context information for the user equipment.

17. The method according to claim 12, wherein the method comprises: In response to receiving the data from the user equipment, sending an acknowledgement message to the user equipment, wherein the acknowledgement message comprises a non-access stratum protocol message.

18. The method of claim 11, wherein the data sent to the terrestrial core network entity is protected in a non-access stratum container, wherein the terrestrial core network entity is configured to decrypt the non-access stratum container using a security context of the user equipment.

19. The method of claim 11, wherein the non-terrestrial core network entity comprises an access and mobility management function (AMF), and the terrestrial core network entity comprises an AMF.

20. The method of claim 11, wherein the non-terrestrial core network entity comprises a mobility management entity (MME), and the terrestrial core network entity comprises the MME.

21. A computer program product comprising instructions, wherein when the computer program product is executed by at least one processor of a non-terrestrial core network entity, the non-terrestrial core network entity is caused to perform the method according to any one of claims 11 to 20.

22. A terrestrial core network entity for a non-terrestrial network of a communication network, the terrestrial core network entity comprising means for: Connecting to a non-terrestrial core network entity; and receiving data from the non-terrestrial core network entity after connecting to the non-terrestrial core network entity, the data being buffered at the non-terrestrial core network entity during a time period when the terrestrial core network entity was not connected to the non-terrestrial core network entity, wherein the data is received at the non-terrestrial core network entity from a user equipment, and wherein the data comprises: Control Plane (CP) data, or Non-Internet Protocol Delivery (NIDD) data.

23. The terrestrial core network entity according to claim 22, wherein the component is further configured to: receiving, at a first time, second data from a network entity for transmission to the user equipment; determining that a second non-terrestrial core network entity is to be configured to connect to the user equipment and the terrestrial core network entity at a second time, wherein the second time is after the first time; buffering the second data at the terrestrial core network entity until the second time; as well as At or after the second time and while the second non-terrestrial core network entity is connected to the user equipment and the terrestrial core network entity, the second data is sent to the second non-terrestrial core network entity.

24. The terrestrial core network entity according to claim 23, wherein the component is further configured to: The buffering of the second data is performed when an indication is present in a user equipment context for the user equipment.

25. The terrestrial core network entity of claim 24, wherein the component is further configured to: detecting the indication based on at least one of a configuration of the terrestrial core network entity, subscriber information for the terrestrial core network entity, location information for the terrestrial core network entity, and an access and mobility policy for the terrestrial core network entity; The indication is stored in the user equipment context for the user equipment.

26. The terrestrial core network entity according to claim 25, wherein the component is further configured to: Determine a periodic update timer value for the user equipment for at least one of a periodic registration update and a tracking area update, wherein when the indication is present in the context information for the user equipment, the periodic update timer value is increased relative to when the indication is not present in the context information for the user equipment.

27. The terrestrial core network entity of claim 25, wherein the component is further configured to: Determining a timer value for the user equipment to detach from the network when not connected to the land network function, wherein when the indication is present in the context information for the user equipment, the timer value is increased relative to when the indication is not present in the context information for the user equipment.

28. The terrestrial core network entity of claim 22, wherein the data received from the deployed non-terrestrial core network entity is protected in a non-access stratum container, and wherein the component is further configured to: The non-access stratum container is decrypted using the security context of the user equipment to determine a payload of the non-access stratum container.

29. The terrestrial core network entity according to claim 28, wherein the component is further configured to: The payload is sent to a third said non-terrestrial core network entity having connectivity to the terrestrial core network entity.

30. The terrestrial core network entity of claim 22, wherein the non-terrestrial core network entity comprises an access and mobility management function (AMF), and the terrestrial core network entity comprises the AMF.

31. The terrestrial core network entity of claim 22, wherein the non-terrestrial core network entity comprises a mobility management entity (MME), and the terrestrial core network entity comprises the MME.

32. A method for communication, the method comprising: A terrestrial core network entity is connected to a non-terrestrial core network entity; as well as After connecting to the non-terrestrial core network entity, data from the non-terrestrial core network entity is received at the terrestrial core network entity, the data being buffered at the terrestrial core network entity during a time period when the terrestrial core network entity is not connected to the non-terrestrial core network entity, wherein the data is received at the non-terrestrial core network entity from a user equipment, and wherein the data comprises: control plane (CP) data, or non-Internet protocol delivery (NIDD) data.

33. The method of claim 32, comprising: receiving, at the terrestrial core network entity, second data for transmission to the user equipment from a network entity at a first time; determining, at the terrestrial core network entity, that a second non-terrestrial core network entity deployed on a second satellite is to be configured to connect to the user equipment at a second time, wherein the second time is after the first time; buffering the second data at the terrestrial core network entity until the second time; as well as The second data is sent by the terrestrial core network entity to the second non-terrestrial core network entity at or after the second time and while the second non-terrestrial core network entity deployed on the second satellite is configured to be connected to the user equipment.

34. The method of claim 33, comprising: Said buffering of said second data is performed by said terrestrial core network entity when an indication is present in a user equipment context for said user equipment.

35. The method of claim 34, comprising: detecting, at the terrestrial core network entity, the indication based on at least one of a configuration of the user equipment, subscriber information for the user equipment, location information for the user equipment, and an access and mobility policy for the user equipment; The indication is stored in the user equipment context for the user equipment at the terrestrial core network entity.

36. The method of claim 35, comprising: At the terrestrial core network entity, a periodic update timer value for the user equipment is determined for at least one of a periodic registration update and a tracking area update, wherein when the indication is present in the user equipment context for the user equipment, the periodic update timer value is increased relative to when the indication is not present in the context information for the user equipment.

37. The method of claim 35, comprising: At the terrestrial core network entity, a timer value is determined for the user equipment to detach from the network when not connected to the terrestrial core network entity, wherein when the indication is present in the context information for the user equipment, the timer value is increased relative to when the indication is not present in the context information for the user equipment.

38. The method of claim 32, wherein the data received from the non-terrestrial core network entity is protected in a non-access stratum container, the method comprising: The non-access stratum container is decrypted at the terrestrial core network entity using the security context of the user equipment to determine a payload of the non-access stratum container.

39. The method of claim 38, comprising: The payload is transmitted from the terrestrial core network entity to a third non-terrestrial core network entity deployed on a third satellite having connectivity to the apparatus.

40. The method of claim 32, wherein the non-terrestrial core network entity comprises an access and mobility management function (AMF), and the terrestrial core network entity comprises an AMF.

41. The method of claim 32, wherein the non-terrestrial core network entity comprises a mobility management entity (MME) and the terrestrial core network entity comprises an MME.

42. A computer readable medium comprising instructions which, when executed by at least one processor of a terrestrial core network entity, cause the terrestrial core network entity to perform the method according to any one of claims 32 to 41.

43. A computer program product comprising instructions, wherein when the computer program product is executed by at least one processor of a terrestrial core network entity, the terrestrial core network entity is caused to perform the method according to any one of claims 32 to 41.

44. A computer program product comprising instructions, wherein when the computer program product is executed by at least one processor of a non-terrestrial core network entity, the non-terrestrial core network entity is caused to perform the method according to any one of claims 11 to 20.

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