Method, user equipment, and network node

Abstract

The present disclosure relates to a method for a user equipment (UE) (3), the method including receiving first information including an indication for a HARQ process, and determining, based on the first information, whether feedback for the HARQ process is enabled.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system operating according to 3rd Generation Partnership Project (3GPP) (registered trademark) standards or their equivalents or derivatives, and devices thereof. The present disclosure has a particular, but not exclusive, relevance to improvements in Hybrid Automatic Repeat Request (HARQ) feedback.

Background Art

[0002] Under 3GPP standards, a NodeB (or "eNB" in LTE, "gNB" in 5G) is a base station for a communication device (user equipment, i.e., "UE") to connect to a core network and communicate with other communication devices or remote servers. End-user communication devices are generally called User Equipment (UE) and can be operated by humans or equipped with automated devices. Such communication devices may be, for example, mobile communication devices such as mobile phones, smartphones, smartwatches, personal digital assistants, laptop / tablet computers, web browsers, e-book readers, connected vehicles, etc. Such mobile (or more generally fixed) devices are usually operated by users (thus, they are often collectively referred to as user equipment "UE"), but it is also possible to connect Internet of Things (IoT) devices and similar Machine Type Communication (MTC) devices to the network. For simplicity, in this application, the term base station is used to refer to any such base station, and the terms mobile device or UE are used to refer to such communication devices.

[0003] The latest development in 3GPP standards is the so-called "5G" or "New Radio" (NR) standard, which refers to an evolving communication technology expected to support a variety of applications and services such as MTC, IoT / Industrial IoT (IIoT) communications, satellite communications or aircraft communications, autonomous vehicles, high-definition video streaming, and smart city services. 3GPP intends to support 5G through the so-called 3GPP Next Generation (NextGen) radio access network (RAN) / radio access technology (RAT) and 3GPP NGC (NextGen core) networks. Various details of 5G networks are described, for example, in the "NGMN 5G White Paper" V1.0 by the Next Generation Mobile Networks (NGMN) Alliance, which can be obtained from https: / / www.ngmn.org / 5g-white-paper.html.

[0004] 3GPP is also working on designating integrated satellite and terrestrial network infrastructure in the context of 4G and 5G. The term Non-Terrestrial Network (NTN) refers to a network or segment of a network that uses aircraft or spacecraft for transmission. Satellites refer to Geostationary Earth Orbits (GEO) or Non-Geostationary Earth Orbits (NGEO), such as Low Earth Orbits (LEO), Medium Earth Orbits (MEO), and Highly Elliptical Orbits (HEO). Aircraft refer to High Altitude Platforms (HAP), which include Unmanned Aircraft Systems (UAS), tethered UAS, lighter-than-air UAS, and heavier-than-air UAS, all of which typically operate in a quasi-steady state at altitudes of 8-50 km.

[0005] 3GPP Technical Report (TR) 38.811 V15.4.0 is a study on New Radio supporting such non-terrestrial networks. This study includes, in particular, NTN deployment scenarios and related system parameters (e.g., architecture, altitude, orbit, etc.), and a description of the adaptation of the 3GPP channel model to non-terrestrial networks (propagation conditions, mobility, etc.). 3GPP TR 38.821 V16.1.0 provides further details on NTN.

[0006] Non-terrestrial networks are To upgrade the performance of terrestrial networks, it will help to promote the deployment of 5G services in areas where service is not available or is insufficiently available. -Enhance service reliability by providing service continuity to user equipment or mobile platforms (e.g., passenger cars, aircraft, ships, high-speed trains, buses). - To enhance service availability everywhere, especially for critical communications, and future rail / maritime / air communications, - Enables 5G network scalability by providing efficient multicast / broadcast resources for data distribution to the network edge or directly to user devices. It is hoped that...

[0007] NTN access typically features the following elements (in particular): -NTN terminal: May refer to a 3GPP UE or terminal specific to a satellite system when the satellite does not directly provide services to a 3GPP UE. - A service link referring to a wireless link between user equipment and a spatial / airborne platform (which may be added to the wireless link with the ground-based RAN). - A space or aerial platform (e.g., a satellite). - A gateway ("NTN Gateway") connecting a satellite or air access network to the core network. It will be understood that gateways are most likely to be located in the same place as base stations. Alternatively, gateways and base stations may be located separately. In one alternative, some or all of the functions of a base station may be provided instead by a satellite (or another non-terrestrial node). - A feeder link refers to the wireless link between the gateway and the spatial / airborne platform. A satellite or aircraft may generate several beams over a given area to supply to each NTN cell. These beams typically have an elliptical footprint on the Earth's surface.

[0008] 3GPP intends to support the following three types of NTN beams or cells: - Earth-fixed cells (e.g., GEO satellites and HAPS) featuring (one or more) beams that always cover the same geographical area, - Quasi-Earth-fixed cells (e.g., NGEO satellites that generate steerable beams) featuring (one or more) beams that cover one geographical region over a finite period and different geographical regions over different periods, and - A mobile Earth cell (e.g., an NGEO satellite generating a fixed beam or a non-steering beam) featuring (one or more) beams that cover one geographical region at one moment and a different geographical region at another moment.

[0009] For a satellite or aircraft that maintains a fixed position with respect to a given point on Earth, such as a GEO and UAS, the beam footprint is fixed to the Earth.

[0010] For satellites orbiting the Earth (e.g., LEO) or in elliptical orbits around the Earth (e.g., HEO), the beam footprint may move across the Earth along with the movement of the satellite or aircraft in its orbit. Alternatively, the beam footprint may be temporarily fixed to the Earth (or quasi-Earth), in which case an appropriate beam pointing mechanism (mechanical or electronic steering) may be used to compensate for the movement of the satellite or aircraft. [Prior art documents] [Non-patent literature]

[0011] [Non-Patent Document 1] NGMN Alliance "NGMN 5G White Paper" V1.0 (https: / / www.ngmn.org / 5g-white-paper.html) [Non-Patent Document 2] 3GPP TR 38.811 V15.4.0 [Non-Patent Document 3] 3GPP TR 38.821 V16.1.0 [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] LEO satellites may have steerable beams, in which case the beams are temporarily directed to a substantially fixed footprint on Earth. In other words, beam footprints (representing NTN cells) remain stationary on the ground for a certain period of time before changing their focal area to another NTN cell (due to the satellite's movement in orbit). From a cell coverage / UE perspective, even when these beams service the same terrestrial area (having the same footprint), a different Physical Cell Identity (PCI) and / or Synchronization Signal / Physical Broadcast Channel (PBCH) block (SSB) must be assigned after each service link change, resulting in cell changes occurring regularly at discrete intervals. LEO satellites without steerable beams produce beams (cells) that constantly sweep across the ground as the satellite moves along its orbit, and as with steerable beams, service link changes and consequently cell changes occur regularly at discrete intervals. Similar to service link changes, feeder link changes also occur at regular intervals due to the satellite's movement in orbit. Changes to both service links and feeder links can be made between different base stations / gateways (which may be called “inter-gNB radio link switches”) or within the same base station / gateway (“intra-gNB radio link switches”).

[0013] In wireless communication links, some transmitted packets may be lost or may suffer errors introduced by noise or interference. Such packet loss and errors can be mitigated by using HARQ procedures to retransmit (or selectively retransmit) data packets. For example, a UE may receive a transmission from a base station containing erroneous or missing packets. The UE may attempt to correct the errors in the received transmission where possible, and may provide feedback to the base station regarding the received transmission, for example, including an acknowledgment (ACK) or negative acknowledgment (NACK). Based on the feedback, the base station may retransmit some or all of the original transmission. HARQ procedures may include several simultaneous HARQ processes, each used for each part of a transmission. Therefore, while the base station is awaiting feedback from a UE corresponding to a particular HARQ process (and thus a particular part of a transmission), the base station can continue transmitting data for other HARQ processes.

[0014] In non-terrestrial networks, the round-trip time between user equipment and base stations is greater than in terrestrial networks due to propagation delays in service links and / or feeder links. Therefore, since the HARQ procedure involves sending feedback and retransmitting data, implementing the HARQ procedure in non-terrestrial networks can lead to a significant decrease in overall transmission throughput due to delays caused by the increased round-trip time between the UE and base station, potentially resulting in a so-called "HARQ stall." However, disabling the HARQ procedure reduces the reliability of transmissions due to the lack of feedback. Thus, it is difficult to ensure reliable transmissions in non-terrestrial networks while also ensuring that excessive delays are not introduced. The feedback procedure also needs to be compatible with the low complexity, low cost, low power consumption, and low throughput requirements of IoT services (including extended coverage, latency-tolerant and low-frequency data transmission, and support for large-scale communications), making this issue particularly challenging when transmissions occur between IoT devices and base stations.

[0015] This disclosure aims to provide a method and related apparatus for solving (at least some of) the above-mentioned problems, or at least mitigating them. [Means for solving the problem]

[0016] In a first aspect, the Disclosure provides a method for a user device (UE) which includes receiving first information including instructions for a HARQ process and determining, based on the first information, whether feedback for the HARQ process is enabled.

[0017] The first information may include feedback configuration information for a HARQ process supported by a UE, and the feedback configuration information indicates that HARQ feedback is disabled for the HARQ process. Determining may include enabling the feedback of the HARQ process when the downlink transmission is a specific type of downlink transmission.

[0018] The first information may include downlink control information for a HARQ process. Determining may include determining whether the downlink control information includes an indication as to whether the feedback of the HARQ process should be enabled or disabled for the downlink transmission.

[0019] The method may further include determining that the downlink control information includes an indication when the downlink transmission is for transmission in a cell of a non-terrestrial network portion.

[0020] Determining whether the downlink control information includes an indication may be based on system information broadcast in the cell.

[0021] The method may further include receiving control signaling including an indication as to whether the downlink control information is adapted to include an indication, and determining whether the downlink control information includes an indication based on the control signaling.

[0022] The method may further include receiving cell-specific feedback instructions from a network node indicating whether HARQ feedback should be enabled or disabled for downlink transmissions in the cell, receiving the first information may include receiving UE-specific feedback instructions from the network indicating whether HARQ process feedback should be enabled for downlink transmissions, and determining may include determining whether HARQ process feedback should be enabled based on UE-specific feedback instructions, regardless of cell-specific feedback instructions.

[0023] Receiving may include receiving configuration information from a network node for HARQ process feedback, and the method may include using the configuration information to configure HARQ process feedback for a procedure in which the UE transmits data to the network node while in a radio resource control (RRC) idle state.

[0024] Data transmission to network nodes can use preconfigured uplink resources (PURs).

[0025] HARQ feedback configuration information can be received from network nodes when the UE is in an RRC connected state.

[0026] HARQ feedback configuration information can be received from network nodes when the UE is in an RRC idle state.

[0027] The method may further include receiving HARQ feedback configuration information from a network node in a PUR configuration message, or receiving a PUR configuration message indicating that downlink control information transmitted by a network node includes HARQ feedback configuration information.

[0028] In a second aspect, the Disclosure provides a method for a network node, the method comprising transmitting to a user device (UE) first information including instructions for at least one HARQ process, wherein the first information causes the UE to determine, based on the first information, whether feedback for at least one HARQ process is enabled.

[0029] The first information may include control information for the UE, the control information indicating that feedback for at least one HARQ process is disabled, and the method may further include sending a downlink transmission to the UE and receiving feedback for at least one HARQ process if the downlink transmission is a particular type of downlink transmission.

[0030] The method may further include sending instructions to the UE that feedback should be enabled for at least one HARQ process if the downlink transmission is of a particular type of downlink transmission.

[0031] Certain types of downlink transmission may be Physical Downlink Shared Channel (PDSCH) transmission carrying RRC messages, or medium access control element (MAC CE).

[0032] The first information may include downlink control information for the UE, which includes instructions indicating that feedback for at least one HARQ process should be enabled or disabled for downlink transmission.

[0033] Downlink transmission may be scheduled by downlink control information.

[0034] The instructions may be included in the bits of the downlink control information.

[0035] The method may further include deciding to include a bit in the downlink control information indicating whether feedback for at least one HARQ process should be enabled, when the downlink control information is transmitted in a cell provided using a non-terrestrial network portion.

[0036] Downlink control information may indicate whether feedback for all HARQ processes in the UE should be enabled for at least one downlink transmission.

[0037] Downlink control information may indicate whether feedback from at least one specific HARQ process of the UE should be enabled for downlink transmission.

[0038] The method may further include transmitting a control signaling to indicate whether the downlink control information includes instructions.

[0039] Control signaling may include RRC signaling.

[0040] The control signaling may be UE-specific control signaling.

[0041] The control signaling may include a number of bits to indicate whether the downlink control information includes instructions on whether feedback should be enabled for at least one HARQ process, each bit indicating whether the downlink control information includes instructions on whether feedback should be enabled for at least one of the HARQ processes.

[0042] The method may further include transmitting system information for the UE indicating whether the downlink control information includes instructions.

[0043] The downlink control information may further include instructions for configuration information for at least one HARQ process.

[0044] The downlink control information may, using information related to the modulation coding scheme (MCS) contained within the downlink control information, indicate whether feedback from at least one HARQ process should be enabled for the transmission of a particular transport block, data packet, or control element.

[0045] The first piece of information may include cell-specific or UE-specific feedback instructions indicating whether feedback for at least one HARQ process should be enabled for downlink transmission.

[0046] Feedback instructions may be included in the system information (SI) transmitted within the cell.

[0047] Feedback instructions may include information indicating whether HARQ feedback should be enabled or disabled for all or some of the HARQ processes within the cells of the non-terrestrial network portion.

[0048] The feedback instruction may include a bitmap having multiple bits, each bit of which indicates whether HARQ feedback should be enabled for each HARQ process within a cell in the non-terrestrial network portion.

[0049] In a third aspect, the Disclosure provides a method performed by a network node in a network including a non-terrestrial network portion, the method comprising selecting a HARQ process from among a plurality of HARQ processes supported by the UE that is configured to have feedback enabled, in order to provide feedback of the HARQ process regarding downlink transmissions to be transmitted to a user equipment (UE) using the non-terrestrial network portion.

[0050] In a fourth aspect, the disclosure provides a user device comprising means for receiving first information including instructions for a HARQ process, and means for determining whether feedback for the HARQ process is enabled based on the first information.

[0051] In a fifth aspect, the Disclosure provides a network node comprising means for transmitting to a user device (UE) first information including instructions for at least one HARQ process, wherein the first information causes the UE to determine, based on the first information, whether feedback for at least one HARQ process is enabled.

[0052] In a sixth aspect, the disclosure provides a network node in a network including a non-terrestrial network portion, the network node comprising means for selecting a HARQ process from among a plurality of HARQ processes supported by the UE that is configured to have feedback enabled, in order to provide feedback on the HARQ process relating to downlink transmissions to be transmitted to a user equipment (UE) using the non-terrestrial network portion.

[0053] A method performed by a network node is also disclosed, which includes transmitting control information for a user device (UE) to a HARQ process, wherein the control information instructs the HARQ process that feedback is disabled, and transmitting a downlink transmission to the UE, and receiving HARQ feedback if the downlink transmission is of a particular type.

[0054] A method performed by a network node is also disclosed, which includes transmitting downlink control information for a user equipment (UE) to the HARQ process, the downlink control information including instructions on whether HARQ feedback should be enabled or disabled for downlink transmissions.

[0055] Furthermore, a method performed by a network node is disclosed, which includes sending cell-specific or user equipment (UE)-specific feedback instructions indicating whether HARQ feedback should be enabled for downlink transmissions.

[0056] Furthermore, a method performed by a user device (UE) is disclosed, which includes obtaining feedback configuration information for a UE-supported HARQ process indicating that HARQ feedback is disabled for the HARQ process; receiving a downlink transmission; enabling feedback for the HARQ process if the downlink transmission is a first type of downlink transmission; and not enabling feedback for the HARQ process if the downlink transmission is a second type of downlink transmission.

[0057] Also disclosed is a method performed by a user equipment (UE), which includes receiving downlink control information for the HARQ process from a network node in the network, including a non-terrestrial network portion, and determining whether the downlink control information includes instructions on whether HARQ feedback should be enabled for downlink transmissions.

[0058] A method performed by a user device (UE) is also disclosed, which includes receiving a cell-specific feedback instruction from a network node indicating whether HARQ feedback should be enabled for downlink transmissions in cells of the non-terrestrial network portion; receiving a UE-specific feedback instruction from the network indicating whether HARQ feedback should be enabled for downlink transmissions received by the UE; and determining whether HARQ feedback should be enabled based on the UE-specific feedback instruction, regardless of the cell-specific feedback instruction.

[0059] A method performed by a user device (UE) is also disclosed, which includes receiving HARQ feedback configuration information from a network node, storing the HARQ feedback configuration information, and using the HARQ feedback configuration information to configure HARQ feedback for a procedure in which the UE sends a message to the network node in an RRC idle state.

[0060] Also disclosed is a user device (UE) comprising means for receiving first information including instructions for the HARQ process, and means for determining whether or not feedback for the HARQ process is enabled based on the first information.

[0061] Also disclosed is a network node comprising means for transmitting control information for a user equipment (UE) to a HARQ process, wherein the control information instructs the HARQ process that feedback is disabled and transmits a downlink transmission to the UE, and means for receiving HARQ feedback if the downlink transmission is of a particular type.

[0062] Also disclosed is a network node in a network that includes a non-terrestrial network portion, which has means for selecting a HARQ process from among several HARQ processes supported by the UE that is configured with feedback enabled, in order to provide feedback regarding downlink transmissions to be transmitted to the UE using the non-terrestrial network portion.

[0063] Also disclosed is a network node having means for transmitting downlink control information for a user equipment (UE) to the HARQ process, wherein the downlink control information includes instructions on whether HARQ feedback should be enabled or disabled for downlink transmission.

[0064] Also disclosed are network nodes that have means for transmitting cell-specific or user equipment (UE)-specific feedback instructions indicating whether or not HARQ feedback should be enabled for downlink transmissions.

[0065] Aspects of this disclosure extend to computer program products, such as computer-readable storage media storing corresponding systems, devices, and instructions, which are operable to program a programmable processor to perform the methods described in each aspect and possible methods described above or in the claims, and / or to program a computer appropriately adapted to provide the device described in any of the claims.

[0066] Each feature disclosed herein (this term includes the claims) and / or each feature shown in the drawings may be incorporated into this disclosure independently of (or in combination with) any other disclosed and / or illustrated features. In particular, any feature of a claim dependent on a particular independent claim may be introduced into that independent claim in any combination or individually.

[0067] Herein, embodiments of the present disclosure will be described with reference to the attached drawings as an example. [Brief explanation of the drawing]

[0068] [Figure 1] This figure schematically illustrates a mobile (cellular or wireless) telecommunications system to which embodiments of the present disclosure may be applied. [Figure 2] This is a schematic block diagram of a mobile device. [Figure 3] This is a schematic block diagram of an access network node (e.g., a base station). [Figure 4] This diagram shows the procedure for sending HARQ feedback by the user device (UE). [Figure 5] This diagram shows the procedure for sending downlink control information to the UE. [Figure 6]This diagram shows the procedure for sending control signaling to the UE. [Figure 7] This diagram shows the procedure for sending downlink control information to multiple UEs. [Figure 8] This figure shows the further procedure for sending downlink control information to multiple UEs. [Figure 9] This diagram shows the PUR configuration request and PUR configuration procedure. [Figure 10] This diagram shows the procedure, including transmission using PUR. [Figure 11] This diagram shows the procedure, including sending HARQ feedback after the UE receives an RRCConnectionRelease message. [Figure 12] This diagram shows the further steps involved, including sending HARQ feedback, after the UE receives the RRCConnectionRelease message. [Figure 13] This diagram shows the further steps involved, including sending HARQ feedback, after the UE receives the RRCConnectionRelease message. [Figure 14] This diagram schematically illustrates several exemplary architectural options for providing NTN features. [Modes for carrying out the invention]

[0069] Figure 1 schematically illustrates a mobile (cellular or wireless) telecommunications system 1 to which embodiments of the present disclosure may be applied.

[0070] In this system 1, users of mobile devices 3 (UEs) can communicate with each other and with other users via the satellites 5 and / or base stations 6 of each access network node, as well as the data network 7, using appropriate 3GPP RATs, such as Evolved Universal Terrestrial Radio Access (E-UTRA) and / or 5G RATs. As those skilled in the art will understand, Figure 1 shows two mobile devices 3, one satellite 5, and one base station 6 for illustrative purposes, but the system, when implemented, will typically include other satellite / UAS platforms, base station / RAN nodes, and mobile devices (UEs). Some or all of the UEs may be IoT devices and similar MTC devices.

[0071] It will be understood that several base stations 6 form a (radio) access network, i.e., (R)AN, and several NTN nodes 5 (satellite and / or UAS platforms) form NTN. Each NTN node 5 is connected to a suitable gateway (located in the same place as the base station 6 in this case) using a so-called feeder link, and then connected to its respective UE3 via a corresponding service link. Thus, when serviced by an NTN node 5, the mobile device 3 communicates data to the base station 6 via the NTN node 5 using the appropriate service link (between the mobile device 3 and the NTN node 5) and the feeder link (between the NTN node 5 and the gateway / base station 6). In other words, NTN forms part of the (R)AN but may also provide satellite communication services independently of E-UTRA (i.e., "4G") and / or New Radio (i.e., "5G") communication services.

[0072] Although not shown in Figure 1, adjacent base stations 6 are connected to each other via appropriate inter-base station interfaces (e.g., so-called "X2" interfaces, "Xn" interfaces, etc.). Base stations 6 are also connected to data network nodes via appropriate interfaces (e.g., so-called "S1", "NG-C", "NG-U" interfaces, etc.).

[0073] The data (or core) network 7 (e.g., EPC in the case of LTE or NGC in the case of NR / 5G) typically includes logical nodes (or "functions") for supporting communications in the telecommunications system 1, particularly for subscriber management, mobility management, billing, security, and call / session management. For example, the data network 7 in a "Next Generation" / 5G system includes user plane entities and control plane entities, such as one or more control plane functions (CPFs) and one or more user plane functions (UPFs). The so-called Access and Mobility Management Function (AMF) in 5G or Mobility Management Entity (MME) in 4G is responsible for handling the connection and mobility management tasks of the mobile device 3. The data network 7 also connects to other data networks, such as the Internet and similar Internet Protocol (IP) based networks (not shown in Figure 1).

[0074] Each NTN node 5 controls several directional beams that may be provided through the associated NTN cells. Specifically, each beam has an associated footprint on the Earth's surface corresponding to an NTN cell. Each NTN cell (beam) has an associated PCI and / or beam identification information. The beam footprint may move as the NTN node 5 moves along its orbit. Alternatively, the beam footprint may be fixed to the Earth, in which case an appropriate beam pointing mechanism (mechanical or electronic steering) may be used to compensate for the movement of the NTN node 5.

[0075] When UE3 first establishes an RRC connection with base station 6 via a cell, UE3 registers with the appropriate AMF9 (or MME). UE3 is in a so-called RRC connected state, and the associated UE context is maintained by the network. When UE3 is serviced via NTN node 5, UE3 sends and receives data via one of NTN node 5's beams (NTN cells). When UE3 is in a so-called RRC idle or RRC inactive state, UE3 still needs to select an appropriate cell for camp-on so that the network knows UE3's approximate location (though not necessarily at the cell level).

[0076] The system illustrated in Figure 1 includes a ground-based gNB / TRP6b, but some or all of the functions of gNB6b may be provided on the serving satellite. For example, all of the functions of gNB6b may be provided on satellite 5, and gateway 6a may be directly located between satellite 5 and data network 7.

[0077] Satellite 5 may be configured to implement a transparent payload or a regenerative payload. In the case of a transparent payload, satellite 5 performs radio frequency filtering, frequency conversion, and amplification, and the signal received by satellite 5 is simply repeated for transmission to the ground gateway 6a. In other words, the waveform signal repeated by satellite 5 is substantially immutable. An exemplary control plane protocol stack for a transparent payload (for a transparent satellite) is described, for example, in Technical Specification (TS) 38.821.

[0078] For a regenerative payload, satellite 5 may be configured to perform radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. In other words, some or all of the functions of gNB6b are provided on satellite 5. If only some of the functions of gNB6b are provided on the satellite (for example, in the system shown in Figure 2), the ground-based gNB6b may have a central unit (gNB-CU) including higher-layer functions (e.g., PDCP, RRC), and the functions of gNB6b on satellite 5 may have a distributed unit (gNB-DU) including lower-layer functions (e.g., PHY, MAC, RLC). In other words, the functions of gNB6b are divided between the non-terrestrial node (satellite 5) and the ground-based node. If all of the functions of gNB6b are provided on satellite 5, the ground-based gNB6b may be completely omitted, as shown in Figure 3. An exemplary control plane protocol stack for a regenerative payload is described, for example, in TS 38.821.

[0079] User Equipment (UE) Figure 2 is a block diagram illustrating the main components of the mobile device (UE) 3 shown in Figure 1. As shown in the figure, the UE 3 includes a transceiver circuit 31 capable of transmitting signals to and receiving signals from one or more nodes connected via one or more antennas 33. Although not necessarily shown in Figure 5, the UE 3 naturally has all the usual functions of a conventional mobile device (such as a user interface 35) as needed, which can be provided by any one or any combination of hardware, software, and firmware. The control unit 37 controls the operation of the UE 3 according to software stored in memory 39. The software may be pre-installed in memory 39 and / or downloaded, for example, via a telecommunications network 1 or from a removable data storage device (RMD). The software includes, in particular, an operating system 41, a communication control module 43, and a HARQ module 45.

[0080] The communication control module 43 is responsible for processing (generating / transmitting / receiving) signaling messages and uplink / downlink data packets between UE3 and other nodes, including NTN node 5, (R)AN node 6, and core network nodes. Signaling may include control signaling (such as RRC signaling) related to configuring and assisting cell reselection by UE3.

[0081] The HARQ module 45 is responsible for controlling the transmission of HARQ feedback in HARQ procedures. For example, UE3 may receive HARQ control information from the network (e.g., from gNB6b via NTN gateway 6a and satellite 5) and control the transmission of HARQ feedback based on the received HARQ control information. It will be understood that the HARQ module 45 may be configured to control the transmission of HARQ feedback in any of the HARQ procedures described later.

[0082] Base station / gateway (access network node) Figure 3 is a block diagram illustrating the main components of the gateway / base station 6 (base station (gNB) or similar access network node; the base station does not necessarily have to be a gNB6) shown in Figure 1. As shown in the figure, the gateway / base station 6 includes transceiver circuitry 71 that can operate to transmit signals to and receive signals from connected (one or more) UE3s via one or more antennas 73, and to transmit signals to and receive signals from other network nodes (directly or indirectly) via network interface 75. Signals may be transmitted to and received from (one or more) UE3s directly and / or via NTN node 5, as needed. Network interface 75 typically includes appropriate inter-base station interfaces (such as X2 / Xn) and appropriate base station-core network interfaces (such as S1 / NG-C / NG-U). Control unit 77 controls the operation of base station 6 according to software stored in memory 79. The software may be pre-installed in memory 79 and / or downloaded, for example, via telecommunications network 1 or from a removable data storage device (RMD). The software includes, in particular, an operating system 81, a communication control module 83, and a HARQ module 85.

[0083] The communication control module 83 is responsible for processing (generating / transmitting / receiving) signaling between the base station 6 and other nodes such as the UE3, NTN node 5, and core network nodes. The signaling may include control signaling (such as RRC signaling) related to configuring and assisting cell reselection by the UE3.

[0084] The HARQ module 85 is responsible for controlling transmissions related to HARQ procedures. More generally, the HARQ module 85 may be configured to perform any of the HARQ procedures described below, including generating or modifying downlink control information, control signaling, or other transmissions related to HARQ procedures.

[0085] HARQ Feedback Procedure Figure 4 illustrates the procedure by which HARQ feedback is sent by the UE. In this example, UE3 is initially configured to enable HARQ feedback. In step S41, a downlink transmission from base station 6 is received by UE3. After receiving the downlink transmission, UE3 performs the HARQ procedure and, in step S42, sends HARQ feedback to base station 6. Based on the feedback received from UE3 in step S42, the base station may retransmit part or all of the original data transmission.

[0086] Some IoT devices support a relatively small number of HARQ processes, and some narrowband IoT UEs may support only a single HARQ process. Given the limited coverage of IoT devices, HARQ feedback may be necessary for some downlink transmissions. If the HARQ process is always enabled, data transmission throughput may be reduced (for example, due to large NTN round-trip times). Furthermore, when HARQ feedback is enabled, the entire resources available for uplink transmission are reused. In the case of HD-FDDs, HARQ feedback, when always enabled, affects downlink scheduling and resource allocation in the time domain, impacting downlink throughput / data rate, especially in the case of large coupling losses on uplinks requiring many iterations. However, if the HARQ process is always disabled, system performance and reliability may be reduced. Figure 5 shows the procedure for sending downlink control information to UE3 to enable HARQ feedback.

[0087] In this example, UE3 may initially be configured to disable HARQ feedback. For example, UE3 may disable HARQ feedback in response to a signaling response broadcast to all UE3s in a cell within base station 6's cell. However, advantageously, downlink control information is used to enable HARQ feedback for downlink transmission. Alternatively, UE3 may initially be configured to enable HARQ feedback, and advantageously, downlink control information can be used to disable HARQ feedback for downlink transmission. In a further alternative, UE3 may not store any information at all about whether HARQ feedback should be disabled or enabled, and advantageously, downlink control information can be used to enable / disable HARQ feedback for downlink transmission.

[0088] In step S51, downlink control information is transmitted from base station 6 to UE3. The downlink control information includes instructions on whether HARQ feedback should be enabled or disabled for the HARQ process. If HARQ feedback should be enabled, in response to receiving the downlink control information, UE3 enables HARQ feedback for the HARQ process. In step S52, UE receives a downlink transmission from base station 6. In step S52, UE transmits HARQ feedback to base station 6. Advantageously, base station 6 can allow HARQ feedback to be transmitted by UE3 even if it is initially disabled. Thus, in this example, UE3 can be initially configured to disable HARQ feedback (advantageously reducing UE3's power consumption) and then enable HARQ feedback in response to signaling received from base station 6. For example, base station 6 may decide to transmit downlink control information to enable HARQ feedback if the communication link between base station 6 and UE3 is particularly unreliable.

[0089] The downlink control information in step S51 may enable / disable HARQ feedback for a specific downlink transmission or set of downlink transmissions. In one example, base station 6 may enable / disable HARQ feedback for a specific type of transmission from base station 6 to UE3 using downlink control information. of It may transmit. For example, base station 6 may transmit downlink control information to enable HARQ feedback for important or essential messages to be sent to UE3 (and therefore feedback is desirable to increase the likelihood that the message will be successfully received by the UE). For example, base station 6 may transmit downlink control information to enable HARQ feedback for PDSCH transmissions carrying RRC messages, or for downlink transmissions including MAC CEs. MAC CEs may be for Buffer Status Reports (BSRs) or timing advance commands, etc.

[0090] Advantageously, the example illustrated with reference to Figure 5 allows for more flexible scheduling and activation / deactivation of HARQ feedback. In other words, HARQ feedback can be enabled / disabled in specific scenarios, regardless of the initial configuration of HARQ feedback in the corresponding HARQ process. Furthermore, since instructions on whether HARQ feedback should be enabled or disabled are received in downlink control information (DCI), excessive RRC signaling between UE3 and base station 6 is advantageously avoided.

[0091] For example, UE3 may support multiple HARQ processes, with at least one of the HARQ processes configured with feedback enabled and the other HARQ processes of UE3 configured with feedback disabled. Advantageously, this allows feedback to be used for specific downlink transmissions while reducing overall power consumption and retransmissions by disabling feedback for some of the HARQ processes. Advantageously, the HARQ processes (one or more) with feedback enabled can be selected by the network to be used for high-priority (e.g., critical or essential) downlink transmissions. For example, a node in the network may determine the priority or class of downlink transmissions and select HARQ processes based on that priority or class.

[0092] For IoT devices, especially narrowband (NB) IoT devices, data transmission may be infrequent, and the number of HARQ processes may be relatively limited. Advantageously, downlink control information sent to the UE3 can be used to enable HARQ feedback in a more flexible way by indicating the HARQ feedback configuration for the transmission of a specific PDSCH, transport block, or data packet.

[0093] DCI may include (one or more) dedicated bits to indicate whether HARQ feedback should be enabled (or disabled) for the HARQ process. For NB-IoT, DCI can be in format N1. For eMTC (BL UE, UE in CE), DCI can be in DCI format 6-1A / B.

[0094] DCI may include bits to explicitly indicate whether HARQ feedback should be enabled or disabled. For example, DCI may include bits to explicitly indicate whether HARQ feedback for the corresponding PDSCH should be enabled (or disabled). For example, a value of "1" may indicate that HARQ feedback should be enabled, or a value of "0" may indicate that HARQ feedback should be disabled.

[0095] Figure 6 illustrates the procedure by which control signaling is sent to UE3. Advantageously, in this example, the control signaling is used to indicate to UE3 whether the downlink control information includes instructions on whether HARQ feedback should be enabled or disabled. UE3 may first store information indicating that HARQ feedback is enabled, or information indicating that HARQ feedback is disabled, or alternatively, it may not first store HARQ information indicating whether HARQ feedback is enabled or disabled.

[0096] In step S61, a control signaling is transmitted from base station 6 to UE3. In this example, the control signaling indicates whether the downlink control information includes instructions on whether HARQ feedback should be enabled or disabled. In this example, the DCI includes instructions on whether HARQ feedback should be enabled or disabled, and therefore the control signaling indicates that the DCI includes instructions.

[0097] In step S62, DCI is transmitted from base station 6 to UE3. Based on the DCI, UE3 determines whether HARQ feedback should be enabled or disabled.

[0098] In step S63, UE3 receives a downlink transmission from base station 6.

[0099] In step S64, if the DCI indicates that feedback should be enabled, the UE sends HARQ feedback for downlink transmission in accordance with the instructions received by the DCI in step S61. Otherwise, if the DCI indicates that feedback should be disabled, the UE 3 does not send HARQ feedback to the base station 6. If the DCI indicates that feedback should be disabled, the UE 3 may send a NACK to the base station corresponding to the HARQ process with disabled feedback, regardless of the decoding result of the corresponding PDSCH.

[0100] Advantageously, UE3 can determine, based on the control signaling received in step 62, that the downlink control information includes instructions on whether or not HARQ feedback should be enabled or disabled.

[0101] Alternatively, instead of UE3 determining whether the DCI contains instructions on whether HARQ feedback should be enabled or disabled based on control signaling, UE3 may determine that instructions exist in the DCI based on implicit instructions. For example, UE3 may determine that instructions exist in the DCI when UE3 is in a cell provided by a non-terrestrial network. UE3 may also determine that instructions exist in the DCI based on NTN-specific SIB broadcasts in an NTN cell. UE3 may also determine that a cell is an NTN cell based on system information, for example, that an NTN-specific SIB is scheduled, and therefore the DCI contains instructions on whether HARQ feedback should be enabled or disabled.

[0102] The instructions provided in the DCI may indicate that HARQ feedback should be enabled or disabled for a specific HARQ process configured (or supported) for the UE, or for a set of HARQ processes configured (or supported) for the UE, or for all HARQ processes configured (or supported) for the UE. The DCI may include a bitmap, where each bit indicates whether HARQ feedback should be enabled for the respective HARQ process. Bits indicating the HARQ feedback configuration in the DCI may be placed after bits indicating the HARQ process ID. Thus, the UE can decide whether to consider or ignore these bits after decoding the HARQ process ID (for example, based on the RRC configuration).

[0103] The presence of a bit in the DCI indicating the HARQ feedback configuration (i.e., whether HARQ feedback should be enabled or not) may depend on the HARQ process ID. The bit indicating the HARQ feedback configuration in the DCI may appear after the bit indicating the HARQ process ID to facilitate UE decoding and reduce the UE's processing load. Alternatively, if the bit exists before the HARQ process ID field, it may be reserved or used for other purposes when it is not used for the HARQ feedback configuration. For example, this bit could be reused to indicate an extended repetition count. In either case, after decoding the HARQ process ID, the UE can decide whether to ignore or consider the bit based on the RRC configuration. Furthermore, the UE assumes (for decoding) that the bit is always present in the DCI. The DCI size may be instructed to the UE (e.g., by base station 6).

[0104] Existing bits or bit fields within the DCI may be used to indicate the HARQ configuration. Advantageously, this reduces the DCI size and increases uplink coverage. Since transmissions without HARQ feedback are expected to occur with better MCS values ​​or more transmissions, the MCS field or the repetition count field itself can be used to indicate whether HARQ feedback is enabled or not. For example, for a subset of values ​​in the MCS field and / or repetition count (which may be fixed or RRC configured values), the UE may determine that HARQ feedback is not required, while for other values ​​in the MCS field and / or repetition count, the UE may determine that HARQ feedback is required. In other examples, less HARQ feedback per UE means fewer HARQ feedback resources are required for NTN with the same cell bandwidth (and therefore fewer HARQ feedback bits). Thus, how the HARQ feedback field is interpreted may also depend on whether the cell is of NTN type. For example, a UE may interpret the HARQ feedback field in different ways based on the RRC configuration or cell type. In one case, the UE may use the same mapping as that present in legacy LTE NBIoT, while in a second case, the first bit of the HARQ feedback field may indicate whether HARQ feedback is present, and the remaining bits may indicate the HARQ feedback resource. If the presence of this field in the DCI is based on the HARQ process ID, the UE may decode the HARQ process ID field first before decoding the HARQ feedback field. The HARQ feedback field may be interpreted by the UE based on the result of decoding the HARQ feedback configuration bits.For example, if the HARQ feedback configuration bit indicates that HARQ feedback is not required, the HARQ feedback field can be used for another purpose (e.g., an extended HARQ process ID, MCS value, or iteration count indication).

[0105] The control signaling in step S62 may be RRC signaling. The control signaling can be UE-specific signaling that indicates to a particular UE whether the DCI contains instructions on whether HARQ feedback should be enabled or disabled. For example, UE3 may be configured to use instructions in the DCI on whether HARQ feedback should be enabled or disabled only if it receives a control signaling that indicates the presence of such instructions in the DCI.

[0106] Figure 7 illustrates the procedure for sending a DCI to multiple UEs (alternatively, the DCI may be sent to a specific UE). In this example, HARQ feedback is initially disabled for each UE. Alternatively, in this example, HARQ feedback may not be configured for each UE. In other words, a UE may not have received the HARQ configuration and may not remember information about whether HARQ feedback should be enabled or disabled.

[0107] In step S71, UE-specific control signaling is sent to UE3b, which is one of several UEs. The control signaling includes an instruction that the DCI should include instructions on whether or not HARQ feedback should be enabled / disabled.

[0108] In step S72, the DCI is sent to multiple UE3a,3b (e.g., all UE3 in a cell; alternatively, the DCI may be sent to a specific UE). The DCI contains instructions on whether HARQ feedback should be enabled or disabled. In this example, the DCI indicates that HARQ feedback should be enabled (e.g., for a specific HARQ process). UE3b reads the instructions provided in the DCI and determines that HARQ feedback should be enabled (alternatively, UE3b reads the instructions provided in the DCI and determines that HARQ feedback should be enabled or disabled as indicated in the DCI).

[0109] In step S73, the downlink transmission from base station 6 is received by UE3b.

[0110] In step S74, if HARQ feedback is enabled for the corresponding HARQ process, UE3b sends HARQ feedback to the base station responsible for downlink transmission.

[0111] Alternatively, UE3b will not send HARQ feedback to the base station responsible for the downlink transmission if HARQ feedback is disabled for the corresponding HARQ process. Alternatively, UE3b may send a HARQ NACK to the base station responsible for the downlink transmission regardless of the PDSCH decoding result if HARQ feedback is disabled for the corresponding HARQ process.

[0112] Advantageously, as illustrated in Figure 7, HARQ feedback can be enabled for a specific UE using UE-specific signaling. For example, base station 6 may use signaling to override the HARQ feedback configuration in UE3 that is configured with previous DCI or control information. Alternatively, UE3 may not have a HARQ feedback configuration initially.

[0113] Figure 8 shows a modified example of Figure 7 where HARQ feedback is initially enabled for each of UE3a and 3b. Alternatively, in this example, HARQ feedback does not need to be configured for each of the UEs. In other words, a UE may not have received the HARQ configuration and may not remember information on whether HARQ feedback should be enabled or disabled.

[0114] In step S81, UE-specific control signaling is sent to UE3b, which is one of several UEs. The control signaling includes an instruction that DCI should include instructions on whether or not HARQ feedback should be enabled.

[0115] In step S82, DCI is sent to multiple UE3a,3b (e.g., all UE3 in a cell). DCI contains instructions on whether HARQ feedback should be enabled or disabled. In this example, DCI indicates that HARQ feedback should be disabled (e.g., for a specific HARQ process). UE3b reads the instructions provided in DCI and determines that HARQ feedback should be disabled.

[0116] In step S83, UE3b receives a downlink transmission from the base station. Since UE3b has received instructions in DCI that HARQ feedback should be disabled, UE3b does not send HARQ feedback to base station 6. Thus, advantageously, HARQ feedback can be disabled (for example, for a specific downlink transmission) even if it is initially enabled (for example, by default, for all UEs in the cell).

[0117] In the examples illustrated in Figures 5 to 8, the instruction on whether HARQ feedback should be enabled or disabled is included in the DCI, but the instruction may also be included in any other appropriate transmission sent to the UE by the network. For example, the instruction on whether HARQ feedback should be enabled or disabled may be provided in system information transmitted at the cell (which may be UE-specific or cell-specific system information).

[0118] Enable / disable HARQ feedback per cell At NTN, enabling and / or disabling HARQ feedback for downlink transmission may be configured per HARQ process via UE-specific signaling. However, the network may alternatively (or additionally) send instructions to multiple devices (e.g., devices sharing similar or the same quality requirements) regarding whether HARQ feedback should be enabled / disabled.

[0119] For example, HARQ feedback can be enabled / disabled on a per-cell basis. For instance, if there are several IoT devices within a cell receiving the same or similar services with the same or similar requirements (e.g., quality requirements), configuring HARQ feedback on a per-cell basis simplifies network implementation.

[0120] The network may instruct a group of UE3s in a cell that HARQ feedback should be enabled or disabled for all or some of the HARQ processes. The instruction may be provided in system information transmitted by base station 6 (e.g., by broadcast). For example, the instruction may be provided in master information block (MIB)(-NB), system information block 1 (SIB1)(-NB), or NTN-specific SIB(-NB). The instruction may be used to indicate that HARQ feedback should be enabled or disabled for some or all of the HARQ processes. For example, one bit may be used to indicate whether feedback should be enabled or disabled for all HARQ processes, or one or more bitmaps may be used to indicate whether feedback should be enabled or disabled for each set of HARQ processes. For example, the bitmap may contain multiple bits, where a first bit indicates whether a first HARQ process should be configured with feedback enabled, a second bit indicates whether a second HARQ process should be configured with feedback enabled, and so on. Instructions regarding whether HARQ feedback should be enabled or disabled may be either explicit or implicit.

[0121] In other examples, HARQ feedback is enabled per HARQ process, per UE. For example, a network (e.g., any appropriate node in the network) may decide to override the HARQ feedback configuration for a particular UE3 (or a particular group of UE3s). The network may decide to override the HARQ feedback configuration for, for example, relatively low radio link quality, higher quality of service requirements, or based on any other appropriate type of determination. The HARQ feedback configuration may be transmitted to (one or more) UE3s using, for example, dedicated RRC signaling, MAC CE, or DCI (as described above). When a UE3 receives UE-specific signaling, the UE3 applies the HARQ feedback configuration provided in the signaling and ignores or overrides any previous cell-specific configurations for HARQ feedback.

[0122] HARQ Feedback for PUR In the case of uplink transmissions using PUR, after the UE sends an uplink transmission to the network, the UE may receive a downlink transmission, such as N / MPDSCH. However, if the UE receives a HARQ feedback configuration while in an RRC connection state, there is a problem in that the UE releases the HARQ feedback configuration when it enters an RRC idle state (for example, after receiving an RRCConnectionRelease message). Therefore, the UE may not be able to determine which HARQ feedback configuration to use for procedures involving PUR.

[0123] Figure 9 shows an exemplary PUR configuration request and PUR configuration procedure. As shown in Figure 9, the UE is initially RRC_CONNECTED, and PUR is enabled in the cell. This procedure is described in more detail in TS 36.300.

[0124] In any step 1, a PURConfigurationRequest message may be sent from UE3 to (ng-)eNB (however, any other suitable base station may be used). (ng-)eNB may consider the above request when moving the UE to RRC_IDLE mode. In step 2, an RRCConnectionRelease is sent from (ng-)eNB to UE3. If (ng-)eNB decides to configure the PUR for the UE, a PURConfiguration IE is sent in the RRCConnectionRelease.

[0125] Figure 10 shows an example of a transmission using PUR for control plane CIoT EPS / 5GS optimization. This procedure is described in more detail in TS 36.300.

[0126] In step 0, the UE has a valid PUR resource.

[0127] In step 1, the UE sends an RRCE EarlyDataRequest message to the (ng-)eNB. After the RRCE EarlyDataRequest message is received by the (ng-)eNB, the MO-EDT procedure for control plane CIOT EPS / 5GS optimization is performed between the (ng-)eNB, MME or AMF and the S-GW or SMF / UPF.

[0128] In step 7a, a Layer 1 Ack is sent from (ng-)eNB to eNB.

[0129] In step 7b, MAC CE is sent from (ng-)eNB to eNB.

[0130] In step 7c, the RRCEarlyDataComplete message is sent from (ng-)eNB to eNB.

[0131] In step 8, the S1 / AN release procedure is performed.

[0132] Here, we describe a favorable way to provide the UE with HARQ feedback configurations that can be used as part of the PUR procedure.

[0133] Figure 11 shows the procedure, including sending HARQ feedback after the UE receives the RRCConnectionRelease message.

[0134] In step S111, UE3 receives HARQ feedback configuration information from base station 6. The HARQ feedback configuration information indicates the HARQ feedback configuration that UE3 should use (for example, whether HARQ feedback should be enabled / disabled for the HARQ process).

[0135] In any step S112, the UE sends a PUR configuration request to base station 6. After base station 6 receives the PUR configuration request, base station 6 sends an RRCConnectionRelease message S113 to UE3, and the UE enters RRC idle mode. However, advantageously, the UE continues to store the HARQ feedback configuration information received in step S111.

[0136] In step S114, UE3 transmits an uplink transmission to base station 6.

[0137] In step S115, UE3 receives a downlink transmission from base station 6.

[0138] In step S116, UE3 sends HARQ feedback corresponding to downlink transmission to UE3 based on the HARQ feedback configuration information received in step S111.

[0139] Advantageously, in this example, the UE stores the HARQ feedback configuration received / applied while the UE is in an RRC connected state and reuses the configuration during the UL transmission procedure in the PUR. Thus, the UE can determine the HARQ feedback configuration to use in the PUR procedure.

[0140] If the UE re-enters the RRC connection state and / or receives further HARQ configuration information, the UE may apply the new HARQ configuration.

[0141] Alternatively, the network may instruct the UE to provide a HARQ feedback configuration during the PUR procedure (for example, included in the PURConfiguration illustrated in Figure 9). The HARQ feedback configuration may indicate whether HARQ feedback should be enabled / disabled, or whether HARQ feedback should be enabled if the corresponding information element (IE) is configured. The HARQ feedback configuration may be instructed, for example, per HARQ process and / or per UE. Alternatively, similar to the method illustrated in Figure 6, the information provided in the PUR configuration may indicate that the downlink control information sent to (or to be sent to) the UE contains information for configuring HARQ feedback.

[0142] Figure 12 shows further procedures, including sending HARQ feedback after the UE receives the RRCConnectionRelease message. In this example, DCI is used to show the HARQ feedback configuration for use as part of the PUR procedure.

[0143] Steps S121-S124 and S126-S127 are the same as steps S111-S116 described with reference to Figure 11, and therefore will not be repeated here except that UE3 may release (e.g., overwrite or lose) the HARQ feedback configuration information received in step S121.

[0144] In step S125, a DCI is transmitted from base station 6 to UE3. The DCI contains HARQ feedback configuration information for configuring the UE's HARQ process (e.g., an instruction on whether HARQ feedback should be enabled / disabled for the HARQ process). A DCI that schedules the corresponding PDSCH or NPDSCH / MPDSCH may be used to include the HARQ feedback configuration instruction. The instruction may be provided in the DCI as described above, see 5-7 (e.g., using bits to explicitly indicate whether HARQ feedback should be enabled or disabled). Alternatively, for example, if (N) PUCCH resources are not specified, the HARQ feedback configuration may be implicitly specified.

[0145] Figure 13 shows a modified example of Figure 12 in which system information is used to indicate whether HARQ feedback should be enabled or disabled. Steps 131-S133 and S135-S137 are the same as steps S121-S123 and S125-S127, respectively, and are therefore not repeated here. UE3 may release (e.g., overwrite or lose) the HARQ feedback configuration information received in step S131.

[0146] In step 134, system information is transmitted by base station 6 and received as UE3. The system information includes instructions on whether HARQ feedback should be enabled or disabled (for example, as described above). The system information may also be broadcast in the cell of base station 6, and therefore, in this example, the instructions on whether HARQ feedback should be enabled or disabled are cell-specific instructions. Advantageously, the instructions on whether HARQ feedback should be enabled or disabled can therefore be efficiently broadcast to multiple UE3.

[0147] Examples of modifications and alternatives Detailed embodiments have been described above. As those skilled in the art will understand, several modifications and substitutions can be made to the embodiments described above, while still benefiting from the disclosure embodied in the embodiments described above. Some of these substitutions and modifications are described here only as examples.

[0148] The above examples illustrate networks that include non-terrestrial network elements, but this is not necessarily required. Nevertheless, the benefits of this disclosure can also be achieved when implemented in terrestrial networks. For example, the method for transmitting HARQ feedback configurations in this disclosure enables efficient and reliable signaling of HARQ configuration information, even when implemented in terrestrial networks.

[0149] While the above examples illustrate HARQ feedback for downlink transmission, it should be understood that some of the above examples can also be applied to feedback for uplink transmission.

[0150] While the above example primarily illustrates transmission between UE3 and base station 6, it should be understood that signaling could alternatively occur between UE3 and any other suitable node in the network.

[0151] It will be understood that the above examples can be applied to any suitable NTN, including (but not limited to) any suitable type of non-terrestrial node. Examples of satellites (GEO, MEO, LEO, etc.) that can be used to perform measurements to estimate the position of UE3 include: [Table 1]

[0152] Base stations for 5G / NR communication systems are generally called New Radio Base Stations ("NR-BS") or "gNBs," but it will be understood that they may also be referred to using the term "eNB" (or 5G / NR eNB), which is more typically associated with Long Term Evolution (LTE) base stations (commonly also called "4G" base stations). 3GPP TS 38.300 V16.7.0 and TS 37.340 V16.7.0 define the following nodes in particular: A node that provides protocol termination for the NR user plane and control plane toward the gNB:UE and is connected to the 5G core network (5GC) via the NG interface. A node that provides protocol termination for the E-UTRA user plane and control plane toward ng-eNB:UE, and is connected to 5GC via the NG interface. A node that provides protocol termination for the NR user plane and control plane toward En-gNB:UE, and functions as a secondary node in E-UTRA-NR Dual Connectivity (EN-DC). NG-RAN node: Either gNB or ng-eNB.

[0153] It will be understood that the above embodiments may apply to both 5G New Radio systems and LTE systems (E-UTRAN). Base stations (gateways) that support the E-UTRAN / 4G protocol may be called "eNBs," and base stations that support the NextGeneration / 5G protocol may be called "gNBs." It will be understood that some base stations may be configured to support both 4G and 5G protocols, and / or any other 3GPP or non-3GPP communication protocols.

[0154] It will be understood that there are various architectural options for implementing NTN in 5G systems, some of which are schematically illustrated in Figure 14. The first option shown in the figure is an NTN that serves the UE and features a satellite / air-based access network with a vent-pipe type payload and a ground-based gNB (satellite hub or gateway level). The second option is an NTN that serves the UE and features a satellite / air-based access network equipped with a gNB. The third option is an NTN that serves the relay nodes and features a satellite / air-based access network with a vent-pipe type payload. The fourth option is an NTN that serves the relay nodes and features a satellite / air-based access network with a gNB. It will be understood that other architectural options, such as combinations of two or more of the above options, may also be used. Alternatively, the relay nodes may be equipped with satellites / UASs. Similar architectural options may be used in 4G / LTE systems, but it will be understood that eNBs are used instead of gNBs, EPCs are used instead of NGCs, and appropriate LTE interfaces are used instead of the NG interfaces shown in Figure 19.

[0155] Each cell has an associated "NR Cell Global Identifier" (NCGI) to identify the cell globally. The NCGI is constructed from the Public Land Mobile Network (PLMN) identity (ID) to which the cell belongs and the cell's NR Cell Identity (NCI). The PLMN ID included in the NCGI is the first PLMN ID in the set of PLMN IDs associated with the NR cell identification information in System Information Block Type 1 (SIB1). The "gNB Identifier" (gNB ID) is used to identify a specific gNB within the PLMN. The gNB ID is included in the cell's NCI. The "Global gNB ID" is used to identify a gNB globally and is constructed from the PLMN identification information to which the gNB belongs and the gNB ID. The Mobile Country Code (MCC) and Mobile Network Code (MNC) are the same as those included in the NCGI.

[0156] In the above description, the UE and access network nodes (base stations) are described as having several separate modules (such as communication control modules) for ease of understanding. These modules may be provided in this way in certain applications, for example, where an existing system is modified to implement the present disclosure, but in other applications, for example, systems designed from the outset with the features of the present invention in mind, these modules may be incorporated into the overall operating system or code, and therefore these modules may not be identifiable as separate entities. These modules may be implemented in software, hardware, firmware, or a combination thereof.

[0157] Each control unit may include, for example (but not limited to), one or more hardware-implemented computer processors, microprocessors, central processing units (CPUs), arithmetic logic units (ALUs), input / output (IO) circuits, internal memory / cache (programs and / or data), processing registers, communication buses (e.g., control buses, data buses and / or address buses), direct memory access (DMA) functions, hardware or software-implemented counters, pointers and / or timers, and any other suitable form of processing circuitry.

[0158] In the embodiments described above, several software modules were explained. As those skilled in the art will understand, the software modules may be provided in compiled or uncompiled form and supplied to the UE, NTN nodes, and access network nodes (base stations) via a computer network or as signals on a recording medium. Furthermore, the functions performed by some or all of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred because it facilitates the updating of the UE, NTN nodes, and access network nodes (base stations) to update their functions.

[0159] The embodiments described above are also applicable to “non-mobile” or generally fixed user devices. The mobile devices (UEs) described above may include MTC / IoT devices, low-power UEs, and the like. Various other modifications are obvious to those skilled in the art and will not be described in further detail here.

[0160] For example, all or part of the exemplary embodiments disclosed above may be described as follows, but are not limited thereto. (Note 1) A method for user equipment (UE), Receiving first information including instructions for the HARQ process, Based on the first piece of information, determine whether or not feedback for the HARQ process is enabled. Methods that include... (Note 2) The first piece of information includes feedback configuration information for the HARQ process supported by the UE, where the feedback configuration information indicates that HARQ feedback is disabled for the HARQ process. Determining whether a downlink transmission is of a specific type of downlink transmission includes enabling feedback in the HARQ process. The method described in Appendix 1. (Note 3) The first piece of information includes downlink control information for the HARQ process, The determination includes determining whether the downlink control information includes instructions indicating whether HARQ process feedback should be enabled or disabled for downlink transmission. The method described in Appendix 1. (Note 4) If the downlink transmission is for transmission within a cell in the non-terrestrial network portion, determine that the downlink control information includes instructions. The method described in Appendix 3, further including the method described in Appendix 3. (Note 5) The determination of whether the downlink control information includes instructions is made using the method described in Appendix 3 or 4, based on the system information broadcast in the cell. (Note 6) Receiving control signaling that includes instructions on whether the downlink control information is adapted to include instructions, Based on control signaling, determine whether the downlink control information includes instructions. The method described in any one of the appendices 3 to 5, further including the method described in any one of the appendices 3 to 5. (Note 7) The network node further includes receiving cell-specific feedback instructions indicating whether HARQ process feedback should be enabled or disabled for downlink transmissions in the cell, Receiving the first information includes receiving UE-specific feedback instructions from the network indicating whether HARQ process feedback should be enabled for downlink transmissions, The determination includes determining whether feedback in the HARQ process should be enabled based on UE-specific feedback instructions, regardless of cell-specific feedback instructions. The method described in Appendix 1. (Note 8) Receiving means receiving configuration information from network nodes for feedback on the HARQ process, This includes configuring feedback for the HARQ process for the procedure in which the UE sends data to network nodes while RRC idle, using configuration information. The method described in Appendix 1. (Note 9) Data transmission to network nodes is performed using PUR, as described in Appendix 8. (Note 10) Configuration information is received from the network node when the UE is in an RRC connection state, as described in Appendix 8 or 9. (Note 11) Configuration information is received from the network node when the UE is in an RRC idle state, as described in Appendix 8 or 9. (Note 12) Receiving configuration information from a network node via a PUR configuration message, or Receiving a PUR configuration message indicating that downlink control information sent by a network node includes configuration information. The method described in Appendix 8, further including the method described in Appendix 8. (Note 13) A method for network nodes, This includes transmitting first information to a user device (UE) that includes instructions for at least one HARQ process, The first piece of information prompts the UE to determine, based on the first piece of information, whether feedback for at least one HARQ process is enabled. method. (Note 14) The first piece of information includes control information for the UE, where the control information indicates that feedback for at least one HARQ process is disabled, and the method is: Sending downlink transmission to the UE, Receiving feedback from at least one HARQ process when the downlink transmission is of a specific type of downlink transmission Further including, The method described in Appendix 13. (Note 15) Sending instructions to the UE that feedback for at least one HARQ process should be enabled when the downlink transmission is of a specific type. The method described in Appendix 14, further including the method described in Appendix 14. (Note 16) The method described in Appendix 15, wherein a specific type of downlink transmission is a PDSCH transmission or MAC CE carrying an RRC message. (Note 17) The first piece of information includes downlink control information for the UE, which includes instructions indicating that feedback from at least one HARQ process should be enabled or disabled for downlink transmission. The method described in Appendix 13. (Note 18) Downlink transmission is scheduled by downlink control information, as described in Appendix 17. (Note 19) The instructions are as described in Appendix 17, as included in the bits of the downlink control information. (Note 20) When downlink control information is transmitted in a cell provided using a non-terrestrial network portion, it is decided to include a bit in the downlink control information indicating whether feedback for at least one HARQ process should be enabled. The method described in any one of the appendices 17 to 19, further including the method described in any one of the appendices 17 to 19. (Note 21) Downlink control information is the method described in any one of the appendices 17 to 20, indicating whether feedback for all HARQ processes of the UE should be enabled for at least one downlink transmission. (Note 22) Downlink control information is the method described in any one of Annexes 17 to 21, indicating whether feedback for at least one specific HARQ process of the UE should be enabled for downlink transmission. (Note 23) To transmit control signaling to indicate whether or not downlink control information includes instructions. The method described in any one of the appendices 17 to 22, further including the method described in any one of the appendices 17 to 22. (Note 24) Control signaling is the method described in Appendix 23, including RRC signaling. (Note 25) Control signaling is UE-specific control signaling, as described in Appendix 23 or 24. (Note 26) The control signaling includes multiple bits to indicate whether the downlink control information includes instructions on whether feedback should be enabled for at least one HARQ process, with each bit indicating whether the downlink control information includes instructions on whether feedback should be enabled for at least one of the HARQ processes. The method described in any one of the appendices 23 to 25. (Note 27) To transmit system information for the UE indicating whether or not downlink control information includes instructions. The method described in any one of the appendices 17 to 26, further including the method described in any one of the appendices 17 to 26. (Note 28) The downlink control information is as described in any one of the appendices 17 to 27, further including instructions for configuration information for at least one HARQ process. (Note 29) The method described in any one of the appendices 17 to 28, wherein downlink control information, using MCS-related information contained in the downlink control information, indicates whether feedback from at least one HARQ process should be enabled for the transmission of a particular transport block, data packet, or control element. (Note 30) The first piece of information includes cell-specific or UE-specific feedback instructions indicating whether feedback for at least one HARQ process should be enabled for downlink transmission. The method described in Appendix 13. (Note 31) The feedback instructions are as described in Appendix 30, included in the SI transmitted in the cell. (Note 32) The method according to Appendix 30 or 31, wherein the feedback instructions include information indicating whether HARQ feedback should be enabled or disabled for all or some of the HARQ processes in the cells of the non-terrestrial network portion. (Note 33) The method according to any one of the appendices 30 to 32, wherein the feedback instruction includes a bitmap having multiple bits, each bit of the bitmap indicating whether or not HARQ feedback should be enabled for each HARQ process in a cell of the non-terrestrial network portion. (Note 34) A method performed by a network node in a network that includes a non-terrestrial network portion, To provide feedback on the HARQ process for downlink transmissions to be transmitted to user equipment (UE) using the non-terrestrial network portion, the UE selects one of several HARQ processes that is configured with feedback enabled. A method that includes this. (Note 35) Means for receiving first information including instructions for the HARQ process, Based on the first piece of information, a means for determining whether or not feedback for the HARQ process is enabled. User equipment equipped with the following features. (Note 36) The system includes means for transmitting first information to a user device (UE) that includes instructions for at least one HARQ process, The first piece of information prompts the UE to determine, based on the first piece of information, whether feedback for at least one HARQ process is enabled. Network node. (Note 37) A means for selecting an HARQ process from among several HARQ processes supported by the UE that are configured with feedback enabled, in order to provide feedback on the HARQ process for downlink transmissions to be transmitted to the user equipment (UE) using the non-terrestrial network portion. A network node in a network that includes a non-terrestrial network portion.

[0161] This application claims priority under UK Patent Application No. 2206252.5, filed on 28 April 2022, the disclosure of which is incorporated herein by reference in its entirety. [Explanation of Symbols]

[0162] 1. Telecommunications Systems 3 Mobile devices 5 Non-terrestrial network nodes 6 base station 7. Data Network 31 Transceiver Circuit 33 Antennas 35 User Interface 37 Control Unit 39 memory 41 Operating Systems 43 Communication control module 45 HARQ modules 71 Transceiver Circuit 73 Antenna 75 Network Interfaces 77 Control Unit 79 memory 81 Operating Systems 83 Communication control module 85 HARQ Modules

Claims

1. Means for receiving radio resource control (RRC) messages that include information indicating whether downlink control information includes instructions on whether HARQ feedback for a Hybrid Automatic Repeat Request (HARQ) process is enabled, If the information contained in the RRC message indicates that the downlink control information includes the instruction, a predetermined field contained in the downlink control information is determined to be first information including the instruction, and a means for determining whether the HARQ feedback of the HARQ process is enabled based on the first information and the information contained in the RRC message, If the predetermined field included in the downlink control information is not used as the first information, means for determining that the predetermined field is information different from the first information, User Equipment (UE), including user equipment.

2. The first information includes downlink control information for each Transport block (TB) and / or data packet for the HARQ process, The means for making the determination determines whether the HARQ feedback of the HARQ process is enabled for each TB and / or data packet based on the information. The user device according to claim 1.

3. If the downlink transmission for the HARQ process is for transmission in a cell of a non-terrestrial network, the first information includes the indication of whether the HARQ feedback for the HARQ process is enabled for each TB and / or data packet. The determination means performs the determination for each TB and / or data packet if the first information includes an instruction on whether the HARQ feedback of the HARQ process is enabled for each TB and / or data packet. The user device according to claim 1 or 2.

4. The UE is an NB (narrowband) IoT (Internet of Things) device, The information included in the RRC message is information for the NB IoT device, The format of the downlink control information is format N1. The user device according to claim 1 or 2.

5. Means for transmitting a radio resource control (RRC) message to User Equipment (UE) that includes information indicating whether downlink control information includes instructions on whether HARQ feedback for the Hybrid Automatic Repeat Request (HARQ) process is enabled, If the information contained in the RRC message indicates that the downlink control information includes the instruction, means for setting a predetermined field contained in the downlink control information as first information including the instruction, and transmitting the downlink control information to the UE, If the predetermined field included in the downlink control information is not used as the first information, the means for setting the predetermined field as information different from the first information and transmitting the downlink control information to the UE, The first information causes the UE to determine, based on the first information and the information contained in the RRC message, whether or not the HARQ feedback for at least one HARQ process is enabled. Network node.

6. The UE is an NB (narrowband) IoT (Internet of Things) device, The information included in the RRC message is information for the NB IoT device, The format of the downlink control information is format N1. The network node according to claim 5.

7. Receiving a radio resource control (RRC) message that includes information indicating whether or not downlink control information contains instructions on whether or not HARQ feedback for the Hybrid Automatic Repeat Request (HARQ) process is enabled, If the information contained in the RRC message indicates that the downlink control information includes the instruction, a predetermined field contained in the downlink control information is determined to be the first information containing the instruction, and based on the first information and the information contained in the RRC message, it is determined whether or not the HARQ feedback of the HARQ process is enabled. A method in User Equipment (UE) comprising determining that the predetermined field included in the downlink control information is different from the first information if the predetermined field is not used as the first information.

8. The UE is an NB (narrowband) IoT (Internet of Things) device, The information included in the RRC message is information for the NB IoT device, The format of the downlink control information is format N1. The method according to claim 7.

9. To send a radio resource control (RRC) message to the user equipment (UE) that includes information indicating whether or not downlink control information contains instructions on whether or not HARQ feedback for the Hybrid Automatic Repeat Request (HARQ) process is enabled, If the information contained in the RRC message indicates that the downlink control information includes the instruction, a predetermined field contained in the downlink control information is set as the first information including the instruction, and the downlink control information is transmitted to the UE. If the predetermined field included in the downlink control information is not used as the first information, the predetermined field is set as information different from the first information, and the downlink control information is transmitted to the UE. Includes, The first information causes the UE to determine, based on the first information and the information contained in the RRC message, whether or not the HARQ feedback for at least one HARQ process is enabled. A method in network nodes.

10. The UE is an NB (narrowband) IoT (Internet of Things) device, The information included in the RRC message is information for the NB IoT device, The format of the downlink control information is format N1. The method in a network node according to claim 9.

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