Apparatus, method and computer program

Abstract

There is provided an 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: provide data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network, and receive first information from the first base station, the first information includes an indication of at least one further base station from which feedback information associated with the data is to be provided at a later point in time, the at least one further base station having a discontinuous connection with the core network.

Description

Technical Field

[0001] The present application relates to a method, apparatus, system and computer program, particularly but not limited to providing feedback time / satellite in a store-and-forward non-terrestrial network (NTN). Background Art

[0002] A communication system may be viewed as a facility for enabling communication sessions between two or more entities (such as user terminals, base stations, and / or other nodes) by providing carrier waves between the various entities involved in the communication path. For example, a communication system may be provided by means of a communication network and one or more compatible communication devices. A communication session may include, for example, communications for carrying data such as voice, video, electronic mail (email), text messaging, multimedia, and / or content data. Non-limiting examples of the services provided include two-way or multi-way calls, data communications or multimedia services, and access to data network systems (such as the Internet).

[0003] In a wireless communication system, at least a portion of a communication session between at least two stations occurs over a wireless link. Examples of wireless systems include: Public Land Mobile Networks (PLMNs), satellite-based communication systems, and different wireless local area networks, such as Wireless Local Area Networks (WLANs). Some wireless systems may be divided into cells, and are therefore often referred to as cellular systems.

[0004] A user can access a communication system with the aid of an appropriate communication device or terminal. A user's communication device may be referred to as a user equipment (UE) or user device. A communication device is equipped with appropriate signal receiving and sending means for enabling communication, such as enabling access to a communication network or communicating directly with other users. A communication device may access a carrier provided by a station (e.g., a base station of a cell) and send and / or receive communications on the carrier.

[0005] Communication systems and related equipment typically operate according to a given standard or specification that specifies what the various entities associated with the system are allowed to do and how it should be achieved. Communication protocols and / or parameters for the connection are also typically defined. An example of a communication system is UTRAN (3G radio). Other examples of communication systems are the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology and the so-called 5G or New Radio (NR) networks. NR is being standardized by the Third Generation Partnership Project (3GPP). Summary of the invention

[0006] In a first aspect, a device is provided, comprising: at least one processor and at least one memory storing instructions, wherein the instructions, when executed by the at least one processor, cause the device to at least: provide data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network, and receive first information from the first base station, the first information comprising an indication of at least one other base station, feedback information associated with the data to be provided from the at least one other base station at a later point in time, the at least one other base station having a discontinuous connection with the core network.

[0007] The first information may comprise an indication of a time at which the at least one further base station will provide coverage to the user equipment.

[0008] The indication of the at least one further base station may comprise an indication of a cell or tracking area associated with the at least one further base station.

[0009] The apparatus may be caused to receive the first information in user equipment specific signaling or in broadcast information.

[0010] The first base station and the at least one further base station may comprise mobile base stations.

[0011] Mobile base stations can be installed on non-terrestrial satellites.

[0012] The apparatus may also be caused to: receive second information from the at least one further base station, the second information comprising an indication that the feedback information is deferred.

[0013] The second information may include an indication of a second further non-base station from which the feedback information is to be provided.

[0014] The second information may comprise an indication of a time at which the at least one second further base station will provide coverage to the user equipment.

[0015] The indication of the at least one second further base station may comprise an indication of a cell or tracking area associated with the at least one second further base station.

[0016] The apparatus may be caused to receive the second information in user equipment specific signaling or in broadcast information.

[0017] In a second aspect, a device is provided, comprising: at least one processor and at least one memory storing instructions, wherein the instructions, when executed by the at least one processor, cause the device to receive data from a user equipment at least at a first base station, the first base station having a discontinuous connection with a core network, and provide first information from the first base station to the user equipment and the core network, the first information including an indication of at least one other base station, feedback information associated with the received data to be provided from the at least one other base station at a later point in time, the at least one other base station having a discontinuous connection with the core network.

[0018] The apparatus may be caused to: receive location information of a gateway of the core network, and determine the at least one further base station based on the location information.

[0019] The apparatus may be caused to: receive at least one of location information and coverage information of the first base station and a plurality of further base stations, and determine the at least one further base station based on the at least one of the location information and coverage information.

[0020] The apparatus may be caused to determine the at least one further base station based on predicted movement of the user equipment.

[0021] The apparatus may be caused to receive an indication of the at least one further base station from the core network.

[0022] The first information may comprise an indication of a time at which the at least one further base station will provide coverage to the user equipment.

[0023] The indication of the at least one further base station may comprise an indication of a cell, or a tracking area, associated with the at least one further base station.

[0024] The apparatus may be caused to provide the first information in user equipment specific signaling or in broadcast information.

[0025] The first base station and the at least one further base station may comprise mobile base stations.

[0026] Mobile base stations can be installed on non-terrestrial satellites.

[0027] The apparatus may also be caused to: provide second information to the user equipment, the second information comprising: an indication that the feedback information is postponed.

[0028] The second information may include an indication of a second further non-base station from which the feedback information is to be provided.

[0029] The second information may comprise an indication of a time at which the at least one second further base station will provide coverage to the user equipment.

[0030] The indication of the at least one second further base station may comprise an indication of a cell or tracking area associated with the at least one second further base station.

[0031] The apparatus may be caused to provide the second information in user equipment specific signaling or in broadcast information.

[0032] In a third aspect, a method is provided, the method comprising providing data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network, and receiving first information from the first base station, the first information comprising: an indication of at least one other base station, feedback information associated with the data will be provided from the at least one other base station at a later point in time, the at least one other base station having a discontinuous connection with the core network.

[0033] The first information may comprise an indication of a time at which the at least one further base station will provide coverage to the user equipment.

[0034] The indication of the at least one further base station may comprise an indication of a cell or tracking area associated with the at least one further base station.

[0035] The method may include receiving the first information in user equipment specific signaling, or in broadcast information.

[0036] The first base station and the at least one further base station may comprise mobile base stations.

[0037] Mobile base stations can be installed on non-terrestrial satellites.

[0038] The method may include receiving second information from the at least one further base station, the second information comprising an indication that feedback information is deferred.

[0039] The second information may include an indication of a second further non-base station from which the feedback information is to be provided.

[0040] The second information may comprise an indication of a time at which the at least one second further base station will provide coverage to the user equipment.

[0041] The indication of the at least one second further base station may comprise an indication of a cell or tracking area associated with the at least one second further base station.

[0042] The method may include receiving the second information in user equipment specific signaling or in broadcast information.

[0043] In a fourth aspect, a method is provided, the method comprising: receiving data from a user equipment at a first base station, the first base station having a discontinuous connection with a core network, and providing first information from the first base station to the user equipment and the core network, the first information comprising: an indication of at least one other base station, feedback information associated with the received data will be provided from the at least one other base station at a later point in time, the at least one other base station having a discontinuous connection with the core network.

[0044] The method may include receiving location information of a gateway of the core network, and determining the at least one further base station based on the location information.

[0045] The method may include receiving at least one of location information and coverage information of the first base station and a plurality of further base stations, and determining the at least one further base station based on the at least one of the location information and coverage information.

[0046] The method may comprise determining the at least one further base station based on a predicted movement of the user equipment.

[0047] The method may comprise receiving an indication of the at least one further base station from the core network.

[0048] The first information may comprise an indication of a time at which the at least one further base station will provide coverage to the user equipment.

[0049] The indication of the at least one further base station may comprise an indication of a cell or tracking area associated with the at least one further base station.

[0050] The method may include providing the first information in user equipment specific signaling or in broadcast information.

[0051] The first base station and the at least one further base station may comprise mobile base stations.

[0052] Mobile base stations can be installed on non-terrestrial satellites.

[0053] The method may include providing second information to the user equipment, the second information including an indication that the feedback information is deferred.

[0054] The second information may include an indication of a second further non-base station from which the feedback information is to be provided.

[0055] The second information may comprise an indication of a time at which the at least one second further base station will provide coverage to the user equipment.

[0056] The indication of the at least one second further base station may comprise an indication of a cell or tracking area associated with the at least one second further base station.

[0057] The method may include providing the second information in user equipment specific signaling or in broadcast information.

[0058] In a fifth aspect, a device is provided, comprising: a component for providing data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network; and a component for receiving first information from the first base station, the first information comprising: an indication of at least one other base station, feedback information associated with the data will be provided from the at least one other base station at a later point in time, the at least one other base station having a discontinuous connection with the core network.

[0059] The first information may comprise an indication of a time at which the at least one further base station will provide coverage to the user equipment.

[0060] The indication of the at least one further base station may comprise an indication of a cell or tracking area associated with the at least one further base station.

[0061] The apparatus may include means for receiving the first information in user equipment specific signaling or in broadcast information.

[0062] The first base station and the at least one further base station may comprise mobile base stations.

[0063] Mobile base stations can be installed on non-terrestrial satellites.

[0064] The apparatus may include means for receiving second information from the at least one other base station, the second information including an indication that feedback information is deferred.

[0065] The second information may include an indication of a second further non-base station from which the feedback information is to be provided.

[0066] The second information may comprise an indication of a time at which the at least one second further base station will provide coverage to the user equipment.

[0067] The indication of the at least one second further base station may comprise an indication of a cell or tracking area associated with the at least one second further base station.

[0068] The apparatus may include means for receiving the second information in user equipment specific signaling or in broadcast information.

[0069] In a sixth aspect, a device is provided, comprising: a component for receiving data from a user equipment at a first base station, the first base station having a discontinuous connection with a core network; and a component for providing first information from the first base station to the user equipment and the core network, the first information comprising: an indication of at least one additional base station, feedback information associated with the received data will be provided from the at least one additional base station at a later point in time, the at least one additional base station having a discontinuous connection with the core network.

[0070] The apparatus may include means for receiving location information of a gateway of the core network, and determining the at least one additional base station based on the location information.

[0071] The apparatus may include means for receiving at least one of location information and coverage information of a first base station and a plurality of additional base stations, and means for determining the at least one additional base station based on the at least one of the location information and coverage information.

[0072] The apparatus may include means for determining the at least one further base station based on predicted movement of the user equipment.

[0073] The apparatus may include means for receiving an indication of the at least one further base station from the core network.

[0074] The first information may comprise an indication of a time at which the at least one further base station will provide coverage to the user equipment.

[0075] The indication of the at least one further base station may comprise an indication of a cell or tracking area associated with the at least one further base station.

[0076] The apparatus may include: means for providing the first information in user equipment specific signaling or in broadcast information.

[0077] The first base station and the at least one further base station may comprise mobile base stations.

[0078] Mobile base stations can be installed on non-terrestrial satellites.

[0079] The apparatus may include means for providing second information to the user equipment, the second information including an indication that the feedback information is deferred.

[0080] The second information may include an indication of a second further non-base station from which the feedback information is to be provided.

[0081] The second information may comprise an indication of a time at which the at least one second further base station will provide coverage to the user equipment.

[0082] The indication of the at least one second further base station may comprise an indication of a cell or tracking area associated with the at least one second further base station.

[0083] The apparatus may include means for providing the second information in user equipment specific signaling or in broadcast information.

[0084] In a seventh aspect, a computer-readable medium is provided, comprising program instructions for causing an apparatus to perform at least the following: providing data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network, and receiving first information from the first base station, the first information comprising: an indication of at least one other base station, feedback information associated with the data will be provided from the at least one other base station at a later point in time, the at least one other base station having a discontinuous connection with the core network.

[0085] The first information may comprise an indication of a time at which the at least one further base station will provide coverage to the user equipment.

[0086] The indication of the at least one further base station may comprise an indication of a cell or tracking area associated with the at least one further base station.

[0087] The apparatus may be caused to: perform receiving the first information in user equipment specific signaling or in broadcast information.

[0088] The first base station and the at least one further base station may comprise mobile base stations.

[0089] Mobile base stations can be installed on non-terrestrial satellites.

[0090] The apparatus may be caused to perform receiving second information from the at least one further base station, the second information comprising an indication that the feedback information is deferred.

[0091] The second information may include an indication of a second further non-base station from which the feedback information is to be provided.

[0092] The second information may comprise an indication of a time at which the at least one second further base station will provide coverage to the user equipment.

[0093] The indication of the at least one second further base station may comprise an indication of a cell or tracking area associated with the at least one second further base station.

[0094] The apparatus may be caused to: perform receiving the second information in user equipment specific signaling or in broadcast information.

[0095] In an eighth aspect, a computer-readable medium is provided, comprising program instructions for causing an apparatus to perform at least the following: receiving data from a user equipment at a first base station, the first base station having a discontinuous connection with a core network, and providing first information from the first base station to the user equipment and the core network, the first information comprising: an indication of at least one additional base station, feedback information associated with the received data will be provided from the at least one additional base station at a later point in time, the at least one additional base station having a discontinuous connection with the core network.

[0096] The apparatus may be caused to: perform receiving location information of a gateway of the core network, and determining the at least one further base station based on the location information.

[0097] The apparatus may be configured to: receive at least one of location information and coverage information of the first base station and a plurality of further base stations, and determine the at least one further base station based on the at least one of the location information and coverage information.

[0098] The apparatus may be caused to perform determining the at least one further base station based on predicted movement of the user equipment.

[0099] The apparatus may be caused to perform receiving an indication of the at least one further base station from the core network.

[0100] The first information may comprise an indication of a time at which the at least one further base station will provide coverage to the user equipment.

[0101] The indication of the at least one further base station may comprise an indication of a cell or tracking area associated with the at least one further base station.

[0102] The apparatus may be caused to perform providing the first information in user equipment specific signaling or in broadcast information.

[0103] The first base station and the at least one further base station may comprise mobile base stations.

[0104] Mobile base stations can be installed on non-terrestrial satellites.

[0105] The apparatus may be caused to perform providing second information to the user equipment, the second information comprising an indication that the feedback information is deferred.

[0106] The second information may include an indication of a second further non-base station from which the feedback information is to be provided.

[0107] The second information may comprise an indication of a time at which the at least one second further base station will provide coverage to the user equipment.

[0108] The indication of the at least one second further base station may comprise an indication of a cell or tracking area associated with the at least one second further base station.

[0109] The apparatus may be caused to perform providing the second information in user equipment specific signaling or in broadcast information.

[0110] In a ninth aspect, a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium comprising: program instructions for causing an apparatus to at least execute the method according to the third aspect or the fourth aspect.

[0111] In the above, many different embodiments have been described. It should be understood that other embodiments can be provided by combining any two or more of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0112] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0113] Figure 1 A schematic diagram of an example 5GS communication system is shown;

[0114] Figure 2 A schematic diagram of an example mobile communication device is shown;

[0115] Figure 3 A schematic diagram of an example control device is shown;

[0116] Figure 4 shows the NTN scenario for a given time interval;

[0117] Figure 5 A block diagram of a DTN ground network is shown;

[0118] Figure 6 A flow chart showing a method according to an example embodiment is shown;

[0119] Figure 7 A flow chart showing a method according to an example embodiment is shown;

[0120] Figure 8 shows an NTN scenario for a given time interval according to an example embodiment;

[0121] Fig. 9 Shows Figure 8 Example signaling flow for the scenario;

[0122] Fig.10 A flow chart of an example method for identifying a target satellite is shown. DETAILED DESCRIPTION

[0123] Before explaining the examples in detail, refer to Figures 1 to 3Certain general principles of wireless communication systems and mobile communication devices are briefly explained to aid understanding of the technology behind the described examples.

[0124] An example of a suitable communication system is a 5G system (5GS). The network architecture in 5GS may be similar to that of Advanced LTE. The base stations of the NR system may be referred to as Next Generation Node Bs (gNBs). Changes in the network architecture may depend on the need to support various wireless technologies and more sophisticated QoS support, as well as some on-demand requirements, such as QoS levels for supporting user-perspective QoE. In addition, network-aware services and applications, as well as service- and application-aware networks, may bring changes to the architecture. These are related to information-centric networks (ICNs), and user-centric content delivery networks (UC-CDN) approaches. NR may use multiple-input multiple-output (MIMO) antennas, more base stations or nodes than LTE (the so-called small cell concept), including macro sites that operate in cooperation with smaller base stations, and may also employ various wireless technologies to obtain better coverage and enhanced data rates.

[0125] 5G networks can take advantage of network function virtualization (NFV), which is a network architecture concept that proposes virtualizing network node functions into "building blocks" or entities that can be operationally connected or linked together to provide services. Virtualized network functions (VNFs) can include: one or more virtual machines that run computer program code using standard or common types of servers rather than custom hardware. Cloud computing or data storage can also be utilized. In wireless communications, this can mean that node operations are performed at least in part in a server, host, or node that is operably coupled to a remote wireless head. Node operations can also be distributed among multiple servers, nodes, or hosts. It should also be understood that the distribution of work between core network operations and base station operations may be different from LTE, or even non-existent.

[0126] Figure 1 A schematic diagram of a 5G system (5GS) 100 is shown. The 5GS may include: a user equipment (UE) 102 (which may also be referred to as a communication device or terminal), a 5G radio access network (5GRAN) 104, a 5G core network (5GCN) 106, one or more application functions (AFs) 108, and one or more data networks (DNs) 110.

[0127] An example 5G core network (CN) includes functional entities. The 5GCN 106 may include: one or more access and mobility management functions (AMFs) 112, one or more session management functions (SMFs) 114, an authentication server function (AUSF) 116, a unified data management (UDM) 118, one or more user plane functions (UPFs) 120, a unified data repository (UDR) 122, and / or a network exposure function (NEF) 124. The UPF is controlled by the SMF (session management function), which receives policies from the PCF (policy control function).

[0128] The CN is connected to the terminal device via a radio access network (RAN). The 5G RAN may include: one or more gNodeB distributed unit functions connected to one or more gNodeB (GNB) centralized unit functions. The RAN may include: one or more access nodes.

[0129] The UPF (User Plane Function) whose role is called PSA (Protocol Data Unit (PDU) Session Anchor) can be responsible for forwarding frames back and forth between the DN (Data Network) and the tunnel established through 5G towards (multiple) UEs to exchange services with the DN.

[0130] Now refer to Figure 2 describing in more detail possible mobile communication devices, Figure 2A schematic partial cutaway view of a communication device 200 is shown. Such a communication device is generally referred to as a user equipment (UE) or terminal. Suitable mobile communication devices can be provided by any device capable of sending and receiving wireless signals. Non-limiting examples include a mobile station (MS) or mobile device, such as a mobile phone or so-called "smart phone", a computer equipped with a wireless interface card or other wireless interface facilities (e.g., a USB dongle), a personal data assistant (PDA) or a tablet computer equipped with a wireless communication function, an IP voice (VoIP) phone, a portable computer, a desktop computer, an image capture terminal device (such as a digital camera), a game terminal device, a music storage and playback device, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop embedded device (LEE), a laptop mounted device (LME), an intelligent device, a wireless customer premises equipment (CPE), or any combination of these devices, etc. For example, a mobile communication device can provide communication for carrying data such as voice, email (email), text messages, multimedia, etc. Therefore, a user can be supplied and provided with a variety of services via his communication device. Non-limiting examples of these services include two-way or multi-way calls, data communications or multimedia services, or simply access to a data communications network system such as the Internet. Broadcast or multicast data may also be provided to the user. Non-limiting examples of content include downloads, television and radio programs, videos, advertisements, various alerts and other information.

[0131] The mobile device is typically equipped with at least one data processing entity 201, at least one memory 202, and other possible components 203 for software and hardware-assisted execution of the tasks it is designed to perform, including controlling access to and communication with access systems and other communication devices. The data processing, storage and other related control devices may be arranged on appropriate circuit boards and / or in chipsets. This feature is represented by reference numeral 204. The user can control the operation of the mobile device with the aid of a suitable user interface, such as a lower keyboard 205, voice commands, a touch-sensitive screen or touchpad, a combination thereof, etc. A display 208, a speaker and a microphone may also be provided. In addition, the mobile communication device may include appropriate connectors (wired or wireless) to other devices and / or for connecting external accessories (e.g., a hands-free device).

[0132] The mobile device 200 may receive signals over the air or wireless interface 207 via appropriate means for receiving, and may transmit signals via appropriate means for transmitting wireless signals. Figure 2 In the mobile device, the transceiver arrangement is schematically represented by block 206. The transceiver arrangement 206 may be provided, for example, by means of a radio component and an associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

[0133] Figure 3 An example of a control device 300 for a communication system is shown, for example, to be coupled to and / or used to control a station of an access system, such as a RAN node, such as a base station, eNB or gNB, a relay node, or a core network node, such as an MME or a serving gateway (S-GW) or a packet data network gateway (P-GW), or a core network function, such as an AMF / SMF, or a server or a host. The method can be implemented in a single control device or across more than one control device. The control device can be integrated with or external to the core network, or a node or module of the RAN. In some embodiments, the base station includes a separate control device unit or module. In other embodiments, the control device can be another network unit, such as a radio network controller or a spectrum controller. In some embodiments, each base station can have such a control device, as well as a control device arranged in a radio network controller. The control device 300 can be arranged to provide control of communications in a service area of ​​the system. The control device 300 includes: at least one memory 301, at least one data processing unit 302, 303, and an input / output interface 304. Via the interface, the control device can be coupled to a receiver and a transmitter of the base station. The receiver and / or the transmitter may be implemented as a wireless front end or a remote wireless head.

[0134] The following targets are defined for non-terrestrial networks (NTN) for NR and narrowband (NB) Internet of Things (IoT) / enhanced machine type communications (eMTC).

[0135] Store and forward operation has been proposed for IoT NTN. Store and forward (S&F) is a feature that enables satellite to serve IoT NTN devices even in periods or areas where the satellite is not connected to the Gateway (GW) on the ground. An eNB on-board architecture is assumed. The service link and feeder link are assumed not to operate simultaneously. The messages are stored on board until there is line of sight with the GW. Decoupled signaling procedures "UE <-> Satellite with on-board RAN node" and "Satellite with on-board RAN node <-> CN on the ground" need to be supported to achieve end-to-end functionality and dynamic connection between S-GW and eNB.

[0136] The store-and-forward operation builds on the concept of discontinuous coverage scenarios, where the UE only occasionally and temporarily has coverage from the satellite. The discontinuous coverage scenario is extended by defining that the satellite is not always connected to the core network.

[0137] The store-and-forward architecture enables low-cost deployments consisting of only a few satellites and a few ground stations. This means that the cost of connecting each device can be further reduced, but at the expense of only supporting delay-tolerant data.

[0138] The following is about the order in which satellites are connected to UE and NTN-GW respectively. This order affects whether a certain satellite (SAT) will carry relevant information of UE.

[0139] Figure 4 A scenario is illustrated where Satellite 1 (SAT1) receives data from a UE at time T=0. At T=1, SAT1 transmits the data to the core network. The data generates downlink feedback, which the core network sends to SAT2 at T=2. At T=3, SAT2 transmits the feedback to the UE. However, if SAT2 has a core network connection before T=1 or after T=3 (but not between T=1 and T=3), SAT2 may not be able to provide feedback to the UE. After T=3, SAT2 will be able to provide feedback, but it will arrive at the UE later.

[0140] In Release 17, RAN2 has agreed that the network will provide the UE with satellite assistance information (i.e., ephemeris data) about satellites that will cover the UE's area in the future. The UE can use the satellite assistance information to predict when to wake up to transmit data and / or monitor paging. This information is contained in the System Information Block (SIB) 32.

[0141] In traditional space-based communications, there are delay / disruption tolerant network protocols.

[0142] For example, Delay / Disruption Tolerant Networking (DTN) is a set of standard protocols that uses information within data streams (headers attached to data units) to enable end-to-end data delivery through network nodes. DTN enables data delivery in situations involving disconnection (e.g., end-to-end link unavailability), latency (e.g., deep space missions), and data rate mismatches (e.g., high data rate science downlinks but lower rate ground connections).

[0143] The DTN architecture is a store-and-forward communication architecture in which a source node sends a DTN packet to a destination node through the network.

[0144] The Space Packet Protocol supports path addressing, essentially the ability to forward packets on a managed end-to-end data path through the network, but this capability has never been implemented in a space system. No provisions are made to address the dispatchable nature of the connections, nor does the Space Packet Protocol support any of the DTN capabilities described above (other than simple unreliable data transfer).

[0145] The Consultative Committee for Space Data Systems (CCSDS) File Delivery Protocol (CFDP) is a file transfer protocol that provides reliable file delivery and includes its own optional application layer store-and-forward mechanism. These store-and-forward operations form the basis of DTN's reliable data transfer mechanism, but CFDP itself only supports file transfer (not messaging, streaming, or other applications).

[0146] These concepts focus on the delivery of data in packets rather than the routing of application layer feedback.

[0147] Figure 5 An example of CFDP is shown.

[0148] Figure 6 A flow chart of a method according to an example embodiment is shown. The method may be performed at a user device

[0149] In S1 , the method comprises providing data from a user equipment to a first base station, the first base station having a discontinuous connection to a core network.

[0150] In S2, the method comprises receiving first information from a first base station, the first information comprising: an indication of at least one further base station, feedback information associated with the data will be provided from the at least one further base station at a later point in time, the at least one further base station having a discontinuous connection with a core network.

[0151] The method may include receiving feedback information associated with the data from at least one further base station.

[0152] Figure 7 A flow chart of a method according to an example embodiment is shown. The method may be performed at a base station (eg, an eNB or a gNB) having a discontinuous connection with a core network.

[0153] In R1, the method comprises receiving data from a user equipment at a first base station, the first base station having a discontinuous connection with a core network.

[0154] In R2, the method includes: providing first information from a first base station to a user equipment and a core network, the first information including: an indication of at least one other base station, feedback information associated with the received data will be provided from the at least one other base station at a later point in time, and the at least one other base station has a discontinuous connection with the core network.

[0155] The first base station and the at least one further base station may comprise a mobile base station.The mobile base station may be mounted on a vehicle such as a satellite of NTN.

[0156] The first information may comprise an indication of a time at which the at least one further non-terrestrial base station will provide coverage to the user equipment.

[0157] The indication of the at least one further base station may comprise an indication of a cell or tracking area associated with the at least one further base station.

[0158] The first information may be provided to the user equipment in user equipment specific signaling or in broadcast information.

[0159] In an example embodiment, the first base station is a serving cell ( Figure 4 In the example of FIG. 1 , a serving cell receives uplink data from a user equipment and enhances the satellite assistance information with first information, the first information comprising: an indication that at least one (multiple) satellite / (multiple) cell will be able to provide feedback information associated with the data, and an indication when the feedback information is available in the area of ​​the UE (in other words, when the at least one additional base station will provide coverage for the UE). SAT1 is aware of future satellites / cells in the area of ​​the UE, and SAT1 informs the core network how to route the feedback to the correct satellite / cell.

[0160] Figure 8 It provides how to apply this method in a store-and-forward scenario.

[0161] At time T=0, UE transmits data to SAT1. SAT1 knows that UE expects feedback on the data.

[0162] SAT1 may then indicate to the UE that SAT3 will provide feedback. SAT1 may provide the time at which SAT3 will be available to the UE. If it is not 100% certain which SAT will be able to provide feedback, SAT1 may provide information about multiple satellites (and times). Alternatively or additionally, SAT1 may indicate the cell (e.g., by physical cell identity (PCI)) or tracking area(s) to carry the feedback. The indication may be in UE specific signaling, or broadcast information for the current cell or tracking area.

[0163] At time T=1, SAT1 provides data to the core network via NTN-GW1. SAT1 may inform the CN that SAT3 should provide feedback to the UE, alternatively the feedback should be sent to the (tracking) area / location of the UE.

[0164] The core network obtains data feedback information and forwards the feedback to NTN-GW2 serving SAT3

[0165] SAT3 receives feedback from NTN-GW2

[0166] At this time, the UE may transmit data to SAT2 and monitor paging, etc., but does not receive feedback on the data.

[0167] At time T=2, SAT3 transmits feedback information to the UE.

[0168] Fig. 9 1 shows a signaling flow according to an example embodiment. The signaling flow may be used in a scenario including UE, SAT1, SAT2, SAT3, and CN, as shown in FIG. Fig. 9 described.

[0169] At 901, the UE provides UL data to SAT1.

[0170] At 902, SAT1 provides an indication to the UE that SAT3 will provide feedback information. Alternatively or additionally, SAT1 may provide an indication to the UE of a minimum time until feedback.

[0171] At 903, SAT1 provides data to the CN. SAT1 may optionally provide an indication to the CN that SAT3 should provide feedback to the UE.

[0172] At 904, SAT2 passes through the UE but no feedback is provided.

[0173] At 905, the CN obtains feedback information associated with the data of the UE and determines that SAT3 can provide feedback information to the UE.

[0174] At 906, the CN provides feedback information to SAT3.

[0175] At 907, SAT3 provides feedback information to the UE.

[0176] The method may comprise providing second information to the user equipment, the second information comprising: an indication that the feedback information is postponed. The second information may comprise: an indication of a second additional base station from which the feedback information will be provided at a later point in time. The indication of the at least one second additional base station comprises: an indication of a cell or tracking area associated with the at least one second additional base station. The second information comprises: an indication of a time when the at least one second additional base station will provide coverage to the user equipment. The at least one second additional base station may comprise a mobile base station. The mobile base station may be mounted on a vehicle such as a satellite of NTN. The method may comprise: receiving the second information in user equipment specific signalling, or in broadcast information.

[0177] For example, if the prediction of which cell / satellite to provide feedback was incorrect, or the feedback was not available to the application layer / sink within the expected time, there are other aspects that can restart the UE timer to obtain feedback based on the feedback status received from the next SAT. The NW / SAT can indicate the first satellite that is potentially expected to send feedback. If the CN cannot deliver feedback to SAT3 due to other pending data, it can provide an indication via SAT3 that the feedback is deferred, potentially including which SAT will provide feedback.

[0178] SAT3 may indicate this information via paging or RRC connection so that the UE can restart the timer to obtain feedback. For example, if the feedback comes from the CN, it can be expected to arrive via the next SAT (as shown in SAT3).

[0179] The UE may utilize the feedback information to prevent (application layer) timers from expiring, thereby preventing retransmission of uplink data or application layer failure.

[0180] The UE may utilize the feedback information to adjust its cell search and / or paging monitoring mode to adapt to the situation where relevant satellites / cells (carrying feedback) are available.

[0181] A prerequisite is that the satellite serving the UE knows the timing of the serving satellite's future NTN-GW connections, the timing of upcoming satellites in the UE area, and the timing of the upcoming satellite's future NTN-GW connections.

[0182] This is necessary to determine which satellite will be able to provide feedback to the UE, and to inform the UE which satellite will be able to provide feedback and when. Specifically, the order of connections should be:

[0183] 1. Service satellite has core network connection

[0184] 2. The core network is connected to the "application receiver"

[0185] 3. The core network has connections with (multiple) future satellites

[0186] 4. The area covered by the UE by (multiple) future satellites.

[0187] Since data transmission and processing is measured in milliseconds or seconds, and the time between satellites is expected to be measured in minutes / hours, it is considered feasible for the servicing satellite to perform these predictions.

[0188] The first base station may receive at least one of location information and coverage information of the first base station and a plurality of additional base stations, and determine the at least one additional base station based on the at least one of the location information and coverage information. In an example embodiment, the core network (potentially a satellite control center) provides information about the ephemeris of other satellites and the location of the associated NTN GW to the satellite. In Release 17, the satellite in non-contiguous coverage provides the ephemeris of other satellites.

[0189] The first base station may receive location information of a gateway of the core network and determine the at least one further base station based on the location information. For example, the NTN-GW location may be shared between the CN and the RAN, i.e. the RAN-CN interface is enhanced by a container for this information. This enables the serving satellite to notify the UE of the proposed first information.

[0190] In another embodiment, a node in the CN is responsible for pre-calculating which target satellite will provide coverage for certain areas at a specific point in time, wherein the certain areas and the specific point in time are based on the ephemeris of the satellite used to receive the pre-calculated data. The determination of the target satellite is based on the above-mentioned prerequisite that the correct sequence of NTN-GW connections has occurred. In this embodiment, the first base station receives an indication of the at least one additional base station from the core network.

[0191] Table 1 illustrates how the CN node determines that the location of SAT A at time X, Y, and Z is location 1, 2, and 3, respectively. The CN node determines when SAT A has CN connection after time X, Y, and Z, namely X', Y', and Z', respectively. The CN node then determines which satellite will have CN connection after X', Y', and Z', and covers locations 1, 2, and 3 after X', Y', and Z'. Note that the CN connection must occur before the satellite arrives at the specified area, for example, the target satellite arrives at the location at time X"' after connecting with CN at time X", where X"'>X">X'>X.

[0192] The time at which the target satellite arrives at the corresponding position is given as (time) in the last column of Table 1. For example, the CN node determines that SAT B will be at position 1 at time B after X', and SAT C will be at the same position at time C.

[0193] SAT A Location Target satellite Time X 1 SAT B (Time B), SAT C (Time C) Time Y 2 SAT D (Time D) Time Z 3 SAT E (time E), SAT F (time F)

[0194] Table 1

[0195] By enabling the CN nodes to provide a pre-computed set of target satellites with reference to position and time, the SATA can inform the UE when the UE can expect feedback based on its position. If such pre-computed data is not available, the satellites can self-identify the target satellites following the same process.

[0196] Fig.10 A flow chart of the target satellite identification process described in reference Table 1 is shown.

[0197] At 1001, determine SAT A at position 1 at time X. At 1002, determine the CN connection of SAT A at time X'. At 1003, identify target satellites that provide coverage at position 1. At 1004, determine if each target satellite has a CN connection after X'. If not, then at 1005, drop the target satellite from the list. If yes, at 1006, determine if the target satellite has a CN connection before arriving at position 1. If yes, then at 1007, the satellite is added to the target list. Includes the coverage time at position 1. If no, then at 1005, drop the target satellite from the list. Fig.10 The process shown loops over the location and time instances 1000 times.

[0198] Assuming the relevant information is available in the serving satellite, the following options are proposed to ensure that the feedback is forwarded to the correct satellite(s). This is an important aspect since normally the feedback information is returned to the entity that forwarded the original application data (these options are in Figure 8 and Fig. 9 ).

[0199] When SAT1 sends UL data to CN, SAT1 also informs CN that feedback should be sent to SAT3.

[0200] SAT1 can directly inform UE of SAT3 to provide potential feedback

[0201] When SAT1 sends UL data to CN, SAT1 also informs CN that feedback should be sent to the next satellite(s) that will cover the same area as SAT1 (where it was when receiving UE data). It can also be "UE location" or "UE" (i.e., link to tracking area) instead of "same area". CN can ask the satellite control center for SAT / eNB IDs for specific areas so that data is forwarded to these satellites / eNBs

[0202] This may enable the CN to set the destination field of the IP packet to, for example, the address of SAT3. The data will then be routed through NTN-GW2 at the correct time. This requires the RAN-CN interface to be enhanced with a container of destination address / satellite / eNB ID.

[0203] If SAT1 is not 100% sure which satellite will cover the UE or is unsure if feedback is available, SAT1 may also provide information about multiple satellites that can provide feedback.

[0204] When determining the destination address, the satellite may utilize the pre-computed information of Table 1 if available.

[0205] The method may include determining the at least one additional base station based on the predicted movement of the user equipment. In other words, when performing the calculation, the movement of the UE may be taken into account by extending the position of the UE to an area. The area represents an area in which the UE may move within a certain period of time. SAT1 may provide the UE with an indication of different satellites and the time they cover the area. In addition, SAT1 may explicitly add the considered movement amount or coverage area. Alternatively, if the trajectory of the UE is known (for example, if the UE is on a ship with a known route), the trajectory of the UE may be provided.

[0206] In another embodiment, if the UE is likely to move, the serving satellite informs the UE of the time to obtain feedback in (multiple) neighboring areas / cells. To simplify the network, it may be beneficial to limit to one tracking area. If the UE is known to move, it may be beneficial to prepare paging upgrades (distribute feedback to more satellites). This action may also be performed if the UE has shared its itinerary with the network.

[0207] In another embodiment, if the UE has performed a Tracking Area Update (TAU), it should assume that there is no feedback in the new satellite where it performs the TAU. Since the new satellite will not know when feedback can be obtained, the UE should monitor paging from now on.

[0208] In one embodiment, if the UE knows the NTN-GW location, the UE can estimate which future satellite will communicate with the CN. The UE can then decide which satellite to monitor, taking into account CN processing and routing delays (i.e., some minimum time threshold).

[0209] An apparatus may include components for: providing data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network, and receiving first information from the first base station, the first information including: an indication of at least one other base station, feedback information associated with the data will be provided from the at least one other base station at a later point in time, the at least one other base station having a discontinuous connection with the core network.

[0210] Alternatively or additionally, an apparatus may include components for: receiving data from a user equipment at a first base station, the first base station having a discontinuous connection with a core network, and providing first information from the first base station to the user equipment and the core network, the first information comprising: an indication of at least one other base station, feedback information associated with the received data will be provided from the at least one other base station at a later point in time, the at least one other base station having a discontinuous connection with the core network.

[0211] It should be understood that these devices may include or be coupled to other units or modules for transmission and / or reception, such as a radio component or a wireless head. Although these devices are described as one entity, different modules and memories may be implemented in one or more physical or logical entities.

[0212] It should be noted that although some embodiments have been described with respect to 5G networks, similar principles may also be applied to other networks and communication systems. Thus, although certain embodiments are described above by way of example with reference to certain example architectures of wireless networks, technologies and standards, the embodiments may be applied to any other suitable form of communication system other than that shown and described herein.

[0213] It is also noted herein that while the above describes exemplifying embodiments, there are numerous variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

[0214] In general, various embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects of the disclosure may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device, but the disclosure is not limited thereto. Although various aspects of the disclosure may be shown and described as block diagrams, flow charts, or using some other graphical representation, it is well understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0215] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0216] (a) hardware circuit implementation only (such as implementation only in analog and / or digital circuitry) and

[0217] (b) a combination of hardware circuitry and software such as (where applicable):

[0218] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0219] (ii) any portion of hardware processor(s) (including digital signal processor(s)) with software, software and memory(s) that work together to enable a device such as a mobile phone or server to perform various functions), and

[0220] (c) Hardware circuit(s) and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), that require software (e.g., firmware) to operate, but in which case the software may not be present when not required.

[0221] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its accompanying software and / or firmware. For example, if applicable to a particular claim element, the term circuitry also includes a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0222] Embodiments of the present disclosure may 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, including software routines, applets and / or macros) may be stored in any device-readable data storage medium, and they include program instructions for performing specific tasks. A computer program product may include one or more computer executable components that are configured to perform an embodiment when the program is running. One or more computer executable components may be at least one software code or a portion thereof.

[0223] Furthermore, in this regard, it should be noted that any block of the logic flow shown in the figure can represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, boxes and functions. The software can be stored on physical media such as memory chips or memory blocks implemented in a processor, magnetic media such as hard disks or floppy disks, and optical media such as DVDs and their data variants CDs. Physical media are non-transient media.

[0224] The memory may be of any type suitable for the local technical environment and may 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 may be of any type suitable for the local technical environment and may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an FPGA, a gate-level circuit, and a processor based on a multi-core processor architecture, as non-limiting examples.

[0225] Embodiments of the present disclosure may be implemented in various components such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available to convert logic level designs into semiconductor circuit designs for etching and formation on semiconductor substrates.

[0226] The independent claims define the scope of protection sought by various embodiments of the present disclosure. Embodiments and features described in this specification that do not fall within the scope of the independent claims, if any, are to be construed as examples that aid in understanding the various embodiments of the present disclosure.

[0227] The foregoing description provides a complete and informative description of exemplary embodiments of the present disclosure by way of non-limiting examples. However, when read in conjunction with the accompanying drawings and the appended claims, various modifications and adaptations may be apparent to those skilled in the relevant art in view of the foregoing description. However, all of these and similar modifications of the teachings of the present disclosure will still fall within the scope of the present invention as defined in the appended claims. In fact, there are additional embodiments that may include a combination of one or more embodiments with any other embodiments previously discussed.

Claims

1. A device 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: providing data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network; and First information is received from the first base station, the first information comprising an indication of at least one further base station from which feedback information associated with the data will be provided at a later point in time, the at least one further base station having a discontinuous connection with the core network.

2. The apparatus according to claim 1, wherein the first information comprises: The at least one further base station will provide an indication of the time of coverage to the user equipment.

3. The apparatus according to claim 1 or 2, wherein the indication of the at least one further base station comprises: An indication of a cell or tracking area associated with the at least one further base station.

4. The apparatus according to any one of claims 1 to 3, wherein the apparatus is configured to receive the first information in user equipment specific signaling or in broadcast information.

5. The apparatus of any one of claims 1 to 4, wherein the first base station and the at least one further base station comprise mobile base stations.

6. The apparatus of claim 5, wherein the mobile base station is mounted on a non-terrestrial satellite.

7. The apparatus according to any one of claims 1 to 6, wherein the apparatus is further caused to: receive second information from the at least one further base station, the second information comprising an indication that the feedback information is deferred.

8. The apparatus of claim 7, wherein the second information comprises an indication of a second additional non-base station from which the feedback information is to be provided.

9. The apparatus according to claim 8, wherein the second information comprises: The at least one second further base station will provide an indication of the time of coverage to the user equipment.

10. The apparatus according to claim 8 or 9, wherein the indication of the at least one second further base station comprises: An indication of a cell or tracking area associated with the at least one second further base station.

11. The apparatus according to any one of claims 8 to 10, wherein the apparatus is configured to receive the second information in user equipment specific signaling or in broadcast information.

12. An 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: receiving data from a user equipment at a first base station, the first base station having a discontinuous connection with a core network; as well as First information is provided from the first base station to the user equipment and the core network, the first information comprising an indication of at least one further base station, feedback information associated with the received data will be provided from the at least one further base station at a later point in time, the at least one further base station having a discontinuous connection with the core network.

13. The apparatus according to claim 12, wherein the apparatus is caused to receive location information for a gateway of the core network and to determine the at least one further base station based on the location information.

14. An apparatus according to claim 12 or 13, wherein the apparatus is configured to: receive at least one of location information and coverage information of the first base station and multiple additional base stations, and determine the at least one additional base station based on the at least one of the location information and the coverage information.

15. An apparatus according to any one of claims 12 to 14, wherein the apparatus is caused to determine the at least one further base station based on a predicted movement of the user equipment.

16. An apparatus according to any one of claims 12 to 15, wherein the apparatus is caused to receive an indication of the at least one further base station from the core network.

17. An apparatus comprising components for: providing data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network; and First information is received from the first base station, the first information comprising an indication of at least one further base station from which feedback information associated with the data will be provided at a later point in time, the at least one further base station having a discontinuous connection with the core network.

18. An apparatus comprising components for: receiving data from a user equipment at a first base station, the first base station having a discontinuous connection with a core network; and First information is provided from the first base station to the user equipment and the core network, the first information comprising an indication of at least one further base station, feedback information associated with the received data will be provided from the at least one further base station at a later point in time, the at least one further base station having a discontinuous connection with the core network.

19. A method comprising: providing data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network; as well as First information is received from the first base station, the first information comprising an indication of at least one further base station from which feedback information associated with the data will be provided at a later point in time, the at least one further base station having a discontinuous connection with the core network.

20. A method comprising: receiving data from a user equipment at a first base station, the first base station having a discontinuous connection with a core network; as well as First information is provided from the first base station to the user equipment and the core network, the first information comprising an indication of at least one further base station, feedback information associated with the received data will be provided from the at least one further base station at a later point in time, the at least one further base station having a discontinuous connection with the core network.

21. A computer readable medium comprising program instructions, the program instructions being configured to cause an apparatus to perform at least the following: providing data from a user equipment to a first base station, the first base station having a discontinuous connection with a core network; and First information is received from the first base station, the first information comprising an indication of at least one further base station from which feedback information associated with the data will be provided at a later point in time, the at least one further base station having a discontinuous connection with the core network.

22. A computer readable medium comprising program instructions for causing an apparatus to perform at least the following: receiving data from a user equipment at a first base station, the first base station having a discontinuous connection with a core network; and First information is provided from the first base station to the user equipment and the core network, the first information comprising an indication of at least one further base station, feedback information associated with the received data will be provided from the at least one further base station at a later point in time, the at least one further base station having a discontinuous connection with the core network.

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