Systems and methods for supporting multicast broadcast service (MBS) services in non-terrestrial networks (NTN)

Abstract

The present disclosure relates to systems and methods for supporting multicast broadcast service (MBS) services in non-terrestrial networks (NTN). In some aspects, a user equipment (UE) device can include at least one antenna, at least one radio configured to perform wireless communication utilizing at least one radio access technology, and one or more processors coupled to the at least one radio, wherein the at least one radio and the one or more processors are configured to receive multicast broadcast service (MBS) data, wherein the one or more processors are configured to cause the UE device to receive, from a network device, a timing offset indicating a slot offset for hybrid automatic repeat request (HARQ) feedback transmission, and determine, based on the timing offset, a transmission timing for the HARQ feedback transmission for the MBS data.

Description

TECHNICAL FIELD

[0001] This application relates generally to wireless communication systems, including support for multicast broadcast service (MBS) services in non-terrestrial networks (NTNs). BACKGROUND

[0002] Wireless mobile communication technology uses various standards and protocols to transmit data between base stations and wireless communication devices. Wireless communication system standards and protocols can include, for example, the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) (such as 4G), 3GPP New Radio (NR) (such as 5G), and IEEE 802.11 standards (commonly referred to as Wi-Fi® within the industry organization) for wireless local area networks (WLANs).

[0003] As contemplated by 3GPP, different wireless communication system standards and protocols can use various radio access networks (RANs) to enable base stations of the RAN (which can also be referred to at times as a RAN node, network node, or simply a node) to communicate with wireless communication devices referred to as user equipment (UE). 3GPP RANs can include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN can use one or more radio access technologies (RATs) for communication between base stations and UEs. For example, GERAN implements GSM and / or EDGE RAT, UTRAN implements Universal Mobile Telecommunications System (UMTS) RAT or other 3GPP RAT, E-UTRAN implements LTE RAT (which is sometimes simply referred to as LTE), and NG-RAN implements NR RAT (which is sometimes also referred to herein as 5G RAT, 5G NR RAT, or simply NR). In certain deployments, E-UTRAN can also implement NR RAT. In certain deployments, NG-RAN can also implement LTE RAT.

[0005] A base station used by a RAN can correspond to that RAN. One example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly denoted as an Evolved Node B, Enhanced Node B, eNodeB, or eNB). One example of an NG-RAN base station is a Next Generation Node B (sometimes also referred to as a gNodeB or gNB).

[0006] ​The RAN, through its connection with a core network (CN), together with the external entities, provides communication services to users. For example, an E-UTRAN can utilize an Evolved Packet Core (EPC), while a NG-RAN can utilize a 5G Core (5GC).

[0007] In some cases, a wireless communications system can include one or more satellites that can relay signals or act as base stations, such as in a non-terrestrial network (NTN). On the other hand, it has been proposed that NR support multicast broadcast service (MBS) services. Accordingly, techniques for supporting MBS services in an NTN are needed. SUMMARY

[0008] In some aspects, a user equipment (UE) device can include at least one antenna; at least one radio configured to perform wireless communication utilizing at least one radio access technology; and one or more processors coupled to the at least one radio, wherein the at least one radio and the one or more processors are configured to receive multicast broadcast service (MBS) data, wherein the one or more processors are configured to cause the UE device to: receive, from a network device, a timing offset indicating a slot offset for hybrid automatic repeat request (HARQ) feedback transmission; and determine, based on the timing offset, a transmission timing for HARQ feedback transmission for the MBS data.

[0009] In some aspects, a non-transitory computer-readable memory medium can store program instructions executable by one or more processors to cause a user equipment (UE) device to: receive, from a network device, a timing offset indicating a slot offset for hybrid automatic repeat request (HARQ) feedback transmission; and determine, based on the timing offset, a transmission timing for HARQ feedback transmission for the MBS data.

[0010] In some aspects, a method can include: receiving, from a network device, a timing offset indicating a slot offset for hybrid automatic repeat request (HARQ) feedback transmission; and determining, based on the timing offset, a transmission timing for HARQ feedback transmission for the MBS data.

[0011] In some aspects, a computer program product includes a computer program that, when executed by a processor of a user equipment (UE) device, causes the UE device to: receive, from a network device, a timing offset indicating a slot offset for hybrid automatic repeat request (HARQ) feedback transmission; and determine, based on the timing offset, a transmission timing for HARQ feedback transmission for the MBS data.

[0012] According to some embodiments, the HARQ feedback transmission for the MBS data is a negative acknowledgement (NACK) only based HARQ feedback.

[0013] According to some embodiments, the timing offset is a cell-specific timing offset and is carried in system information from the network device.

[0014] According to some embodiments, the timing offset is a group-specific timing offset that is smaller than a cell-specific timing offset, the group comprising a plurality of UE devices that receive the MBS data and are not located at a cell edge.

[0015] According to some embodiments, the UE device can forgo the HARQ feedback transmission for the MBS data when the group-specific timing offset is smaller than a UE-specific timing offset.

[0016] According to some embodiments, the group-specific timing offset is signaled via at least one of: a medium access control (MAC) channel element (CE); a group common downlink control information (DCI) with a cyclic redundancy check (CRC) scrambled by a group radio network temporary identifier (G-RNTI); an RRC configuration; or the RRC configuration updated by the MAC CE or the group common DCI.

[0017] According to some embodiments, the timing offset is selected from a set of timing offsets received from the network device based on a UE-specific timing offset.

[0018] According to some embodiments, the timing offset is selected to be a smallest one of the set of timing offsets that is greater than or equal to the UE-specific timing offset.

[0019] According to some embodiments, the UE device can determine a cell-specific timing offset as the timing offset when the group-specific timing offset is not configured, and determine the group-specific timing offset as the timing offset when the group-specific timing offset is configured.

[0020] According to some embodiments, the UE device can determine a cell-specific timing offset as the timing offset when the set of timing offsets is not configured, and select the timing offset from the set of timing offsets when the set of timing offsets is configured.

[0021] According to some embodiments, the UE device can stop the HARQ feedback transmission for the MBS data based on determining that the UE device is more than a threshold away from a serving satellite.

[0022] According to some embodiments, the UE device can make the determination when a UE-specific timing advance (TA) or a UE full TA is greater than a TA threshold configured per MBS session.

[0023] According to some embodiments, the UE device can make the determination when a UE-specific timing advance (TA) or a UE full TA is greater than a TA threshold configured per MBS session.

[0024] According to some embodiments, the UE device can receive a frequency compensation amount via group common downlink control information (DCI) from the network device.

[0025] The techniques described herein can be implemented in and / or performed by a number of different types of devices, including but not limited to cellular base stations, cellular telephones, tablet computers, wearable computing devices, portable media players, and various other computing devices.

[0026] This summary is intended to provide a brief overview of some of the subject matter described in this document. Accordingly, it will be appreciated that the above-described features are merely examples and should not be construed to narrow the scope or spirit of the subject matter described herein. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following DETAILED DESCRIPTION, Figures, and Claims. BRIEF DESCRIPTION OF DRAWINGS

[0027] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number are often reproduced in the reference number itself.

[0028] Figure 1 An exemplary architecture of a wireless communication system is shown in accordance with the embodiments disclosed herein.

[0029] Figure 2 A system for performing signaling between a wireless device and a network device is shown in accordance with the embodiments disclosed herein.

[0030] Figure 3 An example of slot timing to support MBS services in an NTN is shown in accordance with the embodiments disclosed herein.

[0031] Figure 4 is a flowchart illustrating an exemplary method for determining, by a UE device, a transmission timing for transmission of HARQ feedback for MBS data in accordance with the embodiments disclosed herein.

[0032] Figure 5is a flow diagram illustrating another exemplary method for determining, by a UE device, a transmission timing for transmission of HARQ feedback for MBS data, in accordance with embodiments disclosed herein.

[0033] Figure 6 is a flow diagram illustrating an exemplary method for determining, by a UE device, whether to disable transmission of HARQ feedback for MBS data, in accordance with embodiments disclosed herein.

[0034] While the features described herein can be susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the disclosure to the particular form disclosed but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the subject matter defined by the appended claims. DETAILED DESCRIPTION

[0035] Embodiments are described in terms of a UE. However, references to a UE are provided for illustrative purposes only. Exemplary embodiments can be used with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Thus, a UE as described herein is used to represent any appropriate electronic component. Examples of a UE can include a mobile device, a personal digital assistant (PDA), a tablet computer, a laptop computer, a personal computer, an Internet of Things (IoT) device, or a machine type communication (MTC) device, among others, which can be implemented in various objects such as an appliance or a vehicle, a meter, etc.

[0036] Figure 1 An exemplary architecture of a wireless communication system 100, in accordance with embodiments disclosed herein, is shown. The description provided below is directed to an exemplary wireless communication system 100 that operates in conjunction with LTE system standards and / or 5G or NR system standards provided by 3GPP Technical Specifications.

[0037] As shown in Figure 1 Wireless communication system 100 includes a satellite 101, UEs 102 and 104 (although any number of UEs can be used), and a base station 112. In this example, UE 102 is illustrated as a smart phone (e.g., a handheld touchscreen mobile computing device connected to one or more cellular networks), and UE 104 is illustrated as a vehicle, but can also include any mobile or non-mobile computing device configured for wireless communication.

[0038] The UEs 102 and 104 can be configured to communicate using the cellular communication bands and can be configured to communicate using one or more other communication protocols. For example, the UEs 102 and 104 can exchange data directly when in proximity to one another by way of a direct wireless connection, such as a Bluetooth connection, a near-field communication (NFC) connection, a local wireless connection, etc. In this example, the UE 104 is shown to be configured to access an access point (shown as AP 118) via connection 120. For example, the connection 120 can comprise a local wireless connection, such as a connection consistent with an IEEE 802.11 protocol, a Bluetooth protocol (e.g., a connection using a Bluetooth low energy technology), a code division multiple access (CDMA) network, a global system for mobile communications (GSM) network, a long-term evolution (LTE) network, a wideband code division multiple access (WCDMA) network, a 5G network, or the like, and can be based on an orthogonal frequency division multiplexing (OFDM) technology, a code division multiple access (CDMA) technology, a wideband CDMA (WCDMA) technology, a global system for mobile communication (GSM) technology, a wideband code division multiple access (WCDMA) technology, a 5G technology, or the like.

[0039] In this example, the connections 108 and 110 are air interfaces that employ one or more wireless communication technologies to communicate with the RAN 106. The connections 108 and 110 can be configured to transmit and receive radio frequency signals according to the RAT(s) used by the RAN 106, such as, for example, LTE and / or NR.

[0040] In some embodiments, the UEs 102 and 104 can also exchange communication data directly via a sidelink interface. The UE 104 is shown to be configured to access an access point (shown as AP 118) via connection 120. For example, the connection 120 can include a local wireless connection, such as a connection consistent with an IEEE 802.11 protocol, a Bluetooth protocol (e.g., a connection using a Bluetooth low energy technology), a code division multiple access (CDMA) network, a global system for mobile communications (GSM) network, a long-term evolution (LTE) network, a wideband code division multiple access (WCDMA) network, a 5G network, or the like, and can be based on an orthogonal frequency division multiplexing (OFDM) technology, a code division multiple access (CDMA) technology, a wideband CDMA (WCDMA) technology, a global system for mobile communication (GSM) technology, a wideband code division multiple access (WCDMA) technology, a 5G technology, or the like. In this example, the AP 118 can connect to another network (e.g., the Internet) without going through the CN 124.

[0041] In embodiments, the UEs 102 and 104 can be configured to communicate using various communication technologies, such as, but not limited to, orthogonal frequency division multiplexing (OFDM) communication techniques (e.g., for downlink communications) or single-carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or sidelink communications), using orthogonal frequency division multiplexing (OFDM) communication signals to communicate with one another or with the base stations 112 over a multicarrier communication channel, although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise orthogonal subcarriers. In some embodiments, all or part of the base stations 112 can be implemented as one or more software entities running on a server computer as part of a virtual network.

[0042] The RAN 106 is shown to be communicatively coupled to a CN 124. The CN 124 can include one or more network elements 126, which are configured to provide various data and telecommunications services to customers / subscribers (e.g., users of the UEs 102 and 104) who are connected to the CN 124 via the RAN 106. The components of the CN 124 can be implemented in one physical device or separate physical devices, including components to read and execute instructions from a machine- or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0043] In embodiments, the CN 124 can be an EPC and the RAN 106 can be connected with the CN 124 via an S1 interface 128. In embodiments, the S1 interface 128 can be split into two parts, an S1 user plane (S1-U) interface, which carries traffic data between the base stations 112 and the serving gateway (S-GW), and the S1-MME interface, which is a signaling interface between the base stations 112 and mobility management entities (MMEs).

[0044] In embodiments, the CN 124 can be a 5GC and the RAN 106 can be connected with the CN 124 via an NG interface 128. In embodiments, the NG interface 128 can be split into two parts: the NG user plane (NG-U) interface, which carries traffic data between the base stations 112 and user plane functions (UPFs), and the S1 control plane (NG-C) interface, which is a signaling interface between the base stations 112 and access and mobility management functions (AMFs).

[0045] Generally, the application server 130 can be an element of a system that provides applications, e.g., packet- switched data services, using Internet Protocol (IP) bearer resources with the CN 124. The application server 130 can also be configured to support one or more communication services, e.g., VoIP sessions, group communication sessions, etc., for UEs 102 and 104 via the CN 124. The application server 130 can communicate with the CN 124 through an IP communications interface 132.

[0046] In embodiments, the satellite 101 can communicate with the base stations 112 and the UEs 102 and 104. The satellite 101 can be any suitable type of communication satellite configured to relay communications between different end nodes in a wireless communication system. The satellite 101 can be an example of a space satellite, a balloon, a dirigible, an airplane, a drone, an unmanned aerial vehicle, etc. In some examples, the satellite 101 can be in a geosynchronous or geostationary Earth orbit, a low Earth orbit, or a medium Earth orbit. The satellite 101 can be a multi-beam satellite configured to serve a plurality of serving beam coverage areas in a predefined geographic service area. The satellite 101 can be any distance away from the Earth’s surface.

[0047] In embodiments, the satellite 101 can perform the functions of a base station 112, act as a bend pipe satellite, or can act as a regenerative satellite, or a combination thereof. In other cases, the satellite 112 can be an example of a smart satellite or a satellite with intelligence. For example, a smart satellite can be configured to perform more functions than a regenerative satellite. A bend pipe satellite can be configured to receive signals from a ground station and transmit those signals to a different ground station. A regenerative satellite can be configured to relay signals as a bend pipe satellite, but can also use on-board processing to perform other functions. In the case of a regenerative satellite, the satellite can function as a base station for wireless communications.

[0048] Figure 2 A system 200 for performing signaling 234 between a wireless device 202 and a network device 218 is shown in accordance with the embodiments disclosed herein. The system 200 can be part of a wireless communication system as described herein. The wireless device 202 can be, for example, a UE of the wireless communication system. The network device 218 can be, for example, a satellite or a base station (e.g., an eNB or gNB) of the wireless communication system.

[0049] The wireless device 202 can include one or more processors 204. The processor(s) 204 can execute instructions to perform various operations of the wireless device 202 as described herein. The processor(s) 204 can include one or more baseband processors configured to perform the operations described herein using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof.

[0050] The wireless device 202 can include a memory 206. The memory 206 can be a non-transitory computer-readable storage medium that stores instructions 208 (which can include, for example, instructions for execution by the processor(s) 204). The instructions 208 can also be referred to as program code or a computer program. The memory 206 can also store data used by the processor(s) 204 and results of operations computed by the processor(s).

[0051] The wireless device 202 can include one or more transceivers 210, which can include radio frequency (RF) transmitter and / or receiver circuits that use an antenna 212 of the wireless device 202 to facilitate signaling (e.g., the signaling 234) to and / or from the wireless device 202 with other devices (e.g., the network device 218) in accordance with a respective RAT.

[0052] The wireless device 202 can include one or more antennas 212 (e.g., one, two, four, or more). For embodiments with multiple antennas 212, the wireless device 202 can take full advantage of the spatial diversity of these multiple antennas 212 to send and / or receive multiple different data streams over the same time and frequency resources. This approach can be referred to as, for example, a multiple-input multiple-output (MIMO) approach (referring to the multiple antennas used in this regard at the transmitting device and receiving device sides, respectively). MIMO transmissions by the wireless device 202 can be implemented according to precoding (or digital beamforming) applied to the wireless device 202, which multiplexes data streams among the antennas 212 such that each data stream is received at an appropriate signal strength relative to the other streams, and at a desired location in space (e.g., the location of the receiver associated with that data stream). Certain embodiments can use a single-user MIMO (SU-MIMO) approach (where data streams are all directed to a single receiver) and / or a multi-user MIMO (MU-MIMO) approach (where individual data streams can be directed to individual (different) receivers at different locations in space).

[0053] In certain embodiments with multiple antennas, the wireless device 202 can implement an analog beamforming technique, whereby the phase of the signals transmitted by the antennas 212 are adjusted relatively so that the (joint) transmission by the antennas 212 can be directed (this is sometimes referred to as beam steering).

[0054] The wireless device 202 can include one or more interfaces 214. The interfaces 214 can be used for providing input to or output from the wireless device 202. For example, a wireless device 202 that is a UE can include interfaces 214 such as a microphone, speaker, display, button, etc. to allow a user of the UE to input to and / or output from the UE. Other interfaces of such a UE can be made up of transmitters, receivers, and other circuitry (e.g., in addition to the transceiver 210 / antennas 212 already described) that allow the UE to communicate with other devices, and can operate according to known protocols (e.g., Bluetooth®, Bluetooth Low Energy, Zigbee®, Wi-Fi, etc.).

[0055] The network device 218 can include one or more processors 220. The processors 220 can execute instructions to perform various operations of the network device 218 as described herein. The processors 204 can include one or more baseband processors configured to perform the operations described herein using, for example, CPUs, DSPs, ASICs, controllers, FPGA devices, another hardware devices, firmware devices, or any combination thereof.

[0056] ​The network device 218 can include a memory 222. The memory 222 can be a non-transitory computer-readable medium that stores instructions 224 (which can include, for example, instructions for execution by the processor 220). The instructions 224 can also be referred to as program code or a computer program. The memory 222 can also store data used by the processor 220 and results of computations performed by that processor.

[0057] The network device 218 can include one or more transceivers 226, which can include RF transmitter and / or receiver circuits that use the antennas 228 of the network device 218 to facilitate signaling (e.g., signaling 234) to and / or from the network device 218 with other devices (e.g., the wireless device 202) in accordance with a respective RAT.

[0058] The network device 218 can include one or more antennas 228 (e.g., one, two, four, or more). In embodiments with multiple antennas 228, the network device 218 can perform MIMO, digital beamforming, analog beamforming, beam direction, etc., as previously described.

[0059] The network device 218 can include one or more interfaces 230. The interface 230 can be used for providing input to or output from the network device 218. For example, the network device 218 as a base station can include an interface 230 made up of transmitters, receivers, and other circuitry (e.g., in addition to the transceivers 226 / antennas 228 already described) that enable the base station to communicate with other equipment in the core network and / or to communicate with external networks, computers, databases etc. for the purposes of operation, management, and maintenance of the base station or other equipment with which the base station is operatively connected.

[0060] When a UE receives physical downlink shared channel (PDSCH) data transmitted by a network device, the UE needs to send hybrid automatic repeat request (HARQ) feedback to the network device.

[0061] In example cases where the satellite 101 acts as a network device 218 in an NTN, the network device 218 and the UE can be thousands of kilometers apart, and electromagnetic waves can take some time to propagate over the distance between the UE and the satellite 101. Propagation delays for non-terrestrial networks can be orders of magnitude larger than for terrestrial networks. Moreover, the high speed of non-geostationary satellites, such as the satellite 101, can promote variations in the propagation delay. Thus, the UE can experience variations in uplink and downlink timing synchronization with the satellite 101.

[0062] To provide synchronized uplink and downlink timing at satellite 101, communication with and from the satellite can be performed based on a satellite timing reference. The UE can adjust the timing of uplink communication to the satellite so that it receives uplink communication at the desired time at the satellite.

[0063] Timing offset K offset Introduced in the 3GPP protocol on NTN, this allows sufficient time for the UE to adjust the timing between receiving PDSCH data and sending HARQ feedback. Timing offset K offset Timing relationships can be enhanced in several ways, including the transmission timing of the Physical Uplink Shared Channel (PUSCH) scheduled by Downlink Control Information (DCI), the transmission timing of the PUSCH scheduled by Random Access Response (RAR) (Back-off RAR) grants, the transmission timing of the first transmission opportunity of the PUSCH in the configured grant type 2, the transmission timing of the aperiodic sounding reference signal (SRS), the transmission timing of HARQ-ACK on the PUCCH, the transmission timing of HARQ acknowledgment (ACK) on the PUCCH for Msg4 / MsgB, the timing of Channel State Information (CSI) reference resources, and the timing of Time Ahead (TA) command activation, etc. offset Updates can be made after the initial connection.

[0064] For K used in the initial access offset K offset The information is carried in the system information from the network device to the UE. When the UE is not provided with K signaling transmitted in the system information... offset K other than the value offset When the value is displayed, the K signaling transmitted in the system information... offset The value was used for all cases where K was required. offset Enhanced timing relationships. K signaling transmission in system information. offset The values ​​are always used for the transmission timing of PUSCH for RAR / Rollback RAR grant scheduling, the transmission timing of Msg3 retransmissions scheduled with DCI format 0_0 scrambled with cyclic redundancy check (CRC) scrambled by Temporary Cell Radio Network Temporary Identifier (TC-RNTI), the transmission timing of HARQ-ACK on PUCCH to the contention-resolving Physical Downlink Shared Channel (PDSCH) scheduled with DCI format 1_0 scrambled with CRC scrambled by TC-RNTI, and the transmission timing of HARQ-ACK on PUCCH to MsgB scheduled with DCI format 1_0 scrambled with CRC scrambled by MsgB-RNTI.

[0065] NR has been proposed to support multicast and broadcast services (MBS), in which a network device can transmit a message to multiple UEs via one transmission. Various RAN basic functions for broadcast / multicast of UEs in RRC_CONNECTED state have been specified. Some required changes have been specified to improve reliability of broadcast / multicast services, e.g., through UL feedback. The level of reliability should be based on the requirements of the provided application / service.

[0066] For example, it is proposed that for RRC_CONNECTED UEs receiving multicast, a NACK-only based HARQ-ACK feedback is supported to save uplink resources. In addition, for NACK-only based HARQ-ACK feedback for multicast, PUCCH format 0 and format 1 are supported. Thus, the PUCCH resources for NACK-only can be shared by UEs transmitting NACK-only based HARQ-ACK feedback.

[0067] This disclosure will describe techniques for supporting MBS services in NTN. The following will first discuss techniques for determining HARQ feedback transmission timing for MBS data.

[0068] Different UEs have different UE-specific K offset values. However, in NACK-only feedback for MBS data, HARQ-NACKs from all UEs need to be received at the gNB, i.e., the satellite, at the same time. That is, the same HARQ resource is shared by all UEs. In ACK / NACK-based feedback, HARQs from all UEs are preferably received at the gNB (satellite) at approximately the same time. Embodiments for determining HARQ feedback transmission timing will be explained with reference to Figure 3

[0069] Figure 3 An example of slot timing for supporting MBS services in NTN according to embodiments disclosed herein is shown. In some examples, Figure 3 Slot timing of can be implemented by a UE 102 or 104 for estimating and determining uplink timing in non-terrestrial networks, as described with reference to Figure 1 and Figure 2 Although Figure 3 only two UEs, i.e., UE1 and UE2, are shown, one skilled in the art will understand that this number of UEs is not limited to two, but can be any number that can be configured to receive MBS services for implementing the techniques disclosed herein.

[0070] In this example, gNB DL timing 305 can have multiple slots. The gNB can schedule a UE to transmit in slot n+K1+K offset ​The uplink transmission is transmitted in the middle, where n is the time slot for receiving the PDSCH, K1 is indicated in the DCI, and K offset This is a timing offset indicating the slot offset used for HARQ feedback transmission. Figure 3 In the example, n is exemplified as 0, K1 is exemplified as 2, and K offset It is exemplified as 11. Therefore, the gNB can schedule the UE to transmit uplink transmissions in time slot 13.

[0071] UE1 DL timing 310 may lag gNB DL timing 305 by the amount of propagation delay between UE1 and gNB, which is illustrated as 4 time slots in this example. To provide uplink communication received at gNB, UE1 UL timing 315 may have a timing lead (TA) preceding UE1 DL timing 310, which is illustrated as 8 time slots in this example. Based on the timing lead and propagation delay, UE1 may determine the UL timing for HARQ feedback, i.e., time slot 13 in UE1 UL timing 315.

[0072] Similarly, UE2 DL timing 320 can lag gNB DL timing 305 by the amount of propagation delay between UE2 and gNB, which is illustrated as 6 time slots in this example. To provide uplink communication received at gNB, UE2 UL timing 325 can have a timing advance (TA) preceding UE2 DL timing 320, which is illustrated as 12 time slots in this example. Based on timing advance and propagation delay, UE2 can determine the UL timing for HARQ feedback, i.e., time slot 13 in UE2 UL timing 325. K applied to UE2... offset It is very small compared to its TA value, and this limits the processing time at UE2.

[0073] Since UE1 and UE2 share the PUCCH resource in the NTN used for HARQ feedback for MBS service, the gNB receives HARQ feedback from all UEs at gNB UL timing 330.

[0074] In some implementations, the UE uses K offset It can be community-specific, and it is broadcast as system information.

[0075] In some implementations, the UE uses K offset It can be group-specific. Specifically, if a group of UEs receiving MBS service does not include cell-edge UEs, then the group-based K... offset Can be assigned. K in group mode. offset Generally less than the specific K of the community offset Each UE applies a group-based K-axis when determining the HARQ feedback timing. offset If the group method Koffset K < K offset , then this means that the UE is out of the range of the MBS service. In this case, the UE does not feedback HARQ for MBS. K offset may be assigned via various signaling, including but not limited to medium access control (MAC) channel element (CE), group common downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by group radio network temporary identifier (G-RNTI), RRC configuration, or a combination thereof, e.g., RRC configuration updated by MAC CE or group common DCI.

[0076] In some embodiments, there can be multiple PUCCH resources for NACK only feedback. In this case, each UE can determine the corresponding K offset based on the UE-specific K offset . Specifically, a set of K offset values can be configured for the MBS service, which satisfies K offset,g1 < K offset,g2 <... < K offset,gn . Each UE can determine the corresponding K offset (i = 1,..., n) from the set of K offset values based on the UE-specific K offset,gi . For example, K offset,gi is the smallest value in the set of K offset values that is greater than or equal to the UE-specific K offset .

[0077] In some embodiments, the cell-specific K offset and the group-specific K offset or the set of specific K offset values can be combined for determining the timing of HARQ feedback. For example, if the group-specific K offset or the set of group-specific K offset values is not configured, the cell-specific K offset is used. Otherwise, the group-specific K offset or the set of specific K offset values is used.

[0078] Figure 4 is a flowchart illustrating an exemplary method for determining transmission timing of HARQ feedback transmission for MBS data according to embodiments disclosed herein. Figure 4Aspects of the methods of FIGS. 1-3 can be implemented by a wireless device such as the UEs 102 or 104 shown in the figures herein, and / or more generally can be implemented in accordance with any of the computer circuitry, systems, devices, elements, or components shown in the above figures, as desired. For example, a processor (and / or other hardware) of such a device can be configured to cause the device to perform any combination of the method elements shown and / or other method elements.

[0079] In various embodiments, some of the elements of the methods shown can be performed simultaneously, in a different order than shown, can be omitted, or can be replaced or augmented by other method elements, as desired. Additional elements can also be performed as desired. For example, Figure 4 The method of FIG. 4 can operate as follows.

[0080] At 401, the UE device can receive, from a network device, a timing offset K offset for a slot offset for hybrid automatic repeat request (HARQ) feedback transmission.

[0081] In one example, the timing offset can be a cell-specific timing offset K offset and is carried in system information from the network device.

[0082] In another example, the timing offset can be a group-specific timing offset K offset that is smaller than a cell-specific timing offset K offset . The group can include a plurality of UE devices that receive the MBS data and are not located at a cell edge.

[0083] The group-specific timing offset K offset may be signaled via at least one of: a medium access control (MAC) channel element (CE); a group common downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by a group radio network temporary identifier (G-RNTI); RRC configuration; or the RRC configuration updated by the MAC CE or the group common DCI.

[0084] In yet another example, the UE can receive, from a network device, a set of timing offsets K offset,g1 , K offset,g2 ,..., K offset,gn . Operation of the UE in this case will be described below with reference to FIG. 5. Figure 5

[0085] At 402, the UE device can determine, based on the received or determined timing offset, a transmission timing for a HARQ NACK transmission for the MBS data.

[0086] ​In case the timing offset is a cell-specific timing offset K offset , UE1 can determine the UL timing for HARQ feedback in slot n + K1 + cell-specific K Figure 3 offset , i.e. in slot 13 in UE1 UL timing 315.

[0087] In case the timing offset is a group-specific timing offset K offset , the UE device can also determine the UL timing for HARQ feedback in slot n + K1 + group-specific K offset in combination with the timing advance. The group-specific K offset is generally smaller than the cell-specific K offset , but larger than the UE-specific K offset . If the group-specific K offset is smaller than the UE-specific K offset , the UE device can drop the HARQ NACK transmission for MBS data.

[0088] The operation of the UE device in case the UE device receives a set of timing offsets from the network device will be described with reference to Figure 5 .

[0089] At 501, the UE device can receive a set of K offset values for MBS services from the network device, which satisfy K offset,g1 < K offset,g2 <... < K offset,gn .

[0090] At 502, the UE device can receive a UE-specific K offset for its unicast transmission.

[0091] At 503, the UE device can determine corresponding K offset (i = 1,..., n) from the set of K offset values based on the UE-specific K offset,gi . For example, K offset,gi may be the smallest value in the set of K offset values that is larger than or equal to the UE-specific K offset .

[0092] At 504, the UE device can determine a transmission timing for HARQ feedback transmission for the MBS data based on the determined timing offset. In this step, the UE device can determine the UL timing for HARQ feedback in slot n + K1 + the determined K offset in combination with the timing advance and the propagation delay.

[0093] ​The UE device can use a cell-specific K offset and a group-specific K offset or the set of group-specific K offset values to determine the timing of HARQ feedback. For example, if a group-specific K offset or the set of group-specific K offset values is not configured, a cell-specific K offset is used. Otherwise, a group-specific K offset or the set of specific K offset values is used.

[0094] The enabling / disabling feature on HARQ feedback for MBS data will be described below Figure 6 with reference to FIGs. 6-8.

[0095] HARQ feedback can be configured to be disabled in NTN. In NTN for unicast service, the enabling / disabling of HARQ feedback for downlink transmission should be configurable per HARQ process via UE-specific RRC signaling. However, in NTN for MBS service, the enabling / disabling on HARQ feedback should be configurable per MBS session via RRC signaling. That is, all HARQ processes corresponding to a MBS session should have the same feedback enabling / disabling feature. For example, a MBS session can be configured with MBS HARQ process IDs #3 and #4. The enabling / disabling of HARQ feedback is configured for this MBS session, which means that the MBS HARQ processes with IDs #3 and #4 have the same feedback enabling / disabling feature. Regarding the HARQ-ACK codebook for feedback disabled MBS session, the DCI fields of downlink assignment index (DAI) (T-DAI and C-DAI) can be reserved for HARQ processes corresponding to MBS sessions with feedback disabled feature.

[0096] In some embodiments, the UE device can disable HARQ feedback for MBS data based on determining that the UE device is more than a threshold away from the serving satellite. There are various ways to determine whether the UE device is more than a threshold away from the serving satellite. For example, the UE device can use a threshold related to TA or K offset .

[0097] Figure 6 An example method for determining whether to disable HARQ feedback transmission for MBS data by using a threshold related to TA is illustrated.

[0098] At 601, the UE device can receive a configuration of a MBS session. The configuration can include at least a TA threshold for HARQ disabling.

[0099] At 602, the UE device can compare its TA to a TA threshold. The UE can maintain the TA through closed loop and open loop control. The TA can be the full TA from the UE to the timing reference point or the UE-specific TA from the UE to the satellite.

[0100] At 603, if the UE-specific TA is greater than the TA threshold, the UE device can stop HARQ feedback transmission. Otherwise, the UE device can perform HARQ feedback transmission.

[0101] Using the TA threshold can be suitable for the NACK-only HARQ feedback case, as the gNB typically does not know the UE-specific TA.

[0102] In another example, the UE device can use a threshold related to K offset . The operation of the UE device using the K offset threshold is similar to those using the TA threshold. In particular, the UE device can receive a K offset threshold for HARQ disabling. Then, the UE device can compare its K offset to the K offset threshold. If the UE-specific K offset is greater than the K offset threshold, the UE device can stop HARQ feedback transmission. Otherwise, the UE device can perform HARQ feedback transmission.

[0103] Using the K offset threshold can be suitable for both NACK-only HARQ feedback or ACK-NACK HARQ feedback, as both the gNB and the UE know the UE-specific K offset .

[0104] The threshold can be dynamically indicated in group common DCI and can be configured per MBS session.

[0105] According to some aspects, in NTN, the communication between the satellite and the UE is referred to as the service link, and the communication between the satellite and the ground gateway is referred to as the feeder link. If DL frequency compensation for service link Doppler is applied, the indication of the amount of frequency compensation is necessary.

[0106] In DL broadcast, the amount of frequency compensation can be indicated in system information. In DL unicast, the amount of frequency compensation can be configured and indicated via UE-specific RRC signaling.

[0107] In NTN for MBS service, the amount of frequency compensation can be indicated via group common DCI.

[0108] Embodiments contemplated herein include one or more non-transitory computer- readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of the above method. The non-transitory computer-readable medium can be, for example, a memory of a UE (such as the memory 206 of the wireless device 202 of the UE, as described herein).

[0109] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry to perform one or more elements of the above method. The apparatus can be, for example, an apparatus of a UE (such as the wireless device 202 of the UE, as described herein).

[0110] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions to cause the one or more processors, upon execution of the instructions, to perform one or more elements of the above method. The apparatus can be, for example, an apparatus of a UE (such as the wireless device 202 of the UE, as described herein).

[0111] Embodiments contemplated herein include a signal as described in or related to one or more elements of the above method.

[0112] Embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processor is to cause the processor to perform one or more elements of the above method. The processor can be a processor of a UE (such as the processor 204 of the wireless device 202 of the UE, as described herein). The instructions can be, for example, located within the processor and / or on a memory of the UE (such as the memory 206 of the wireless device 202 of the UE, as described herein).

[0113] For one or more embodiments, at least one of the components shown in one or more of the preceding figures can be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described herein in connection with one or more of the preceding figures can be configured to operate in accordance with one or more of the examples described herein. As another example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures can be configured to operate in accordance with one or more of the examples shown herein.

[0114] Unless otherwise expressly stated, any of the foregoing embodiments can be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more implementations provides functionality and / or technical advantages, but do not limit the implementations to the precise form described. Modifications and alterations, or alternative implementations, can be made to the implementations disclosed herein as readily apparent to those having average skill in the art, and the implementations of the present disclosure are not to be limited to the specific illustrative implementations described.

[0115] Embodiments and implementations of the systems and methods described herein can include various operations, which can be embodied in machine-executable instructions to be executed by a computer system. The computer system can include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system can include hardware components, including specific logic for performing the operations, or can include a combination of hardware, software, and / or firmware.

[0116] It will be recognized that the systems described herein include descriptions of specific embodiments. These embodiments can be combined into a single system, incorporated into other systems, divided into multiple systems, or otherwise divided or combined. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment can be used in another embodiment. For clarity, these parameters, attributes, aspects, etc. are only described in one or more embodiments, and it will be recognized that these parameters, attributes, aspects, etc. can be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless specifically stated otherwise herein.

[0117] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled in a way to minimize risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

[0118] Although the foregoing has been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications can be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatuses described herein. Accordingly, the embodiments of the application are to be considered illustrative and not restrictive, and the description is not to be limited to the details given herein, but can be modified within the scope and equivalents of the appended claims.

Claims

1. A user equipment (UE) device, comprising: At least one antenna; At least one radio component, the at least one radio component being configured to perform wireless communication using at least one radio access technology; as well as One or more processors coupled to the at least one radio component, wherein the at least one radio component and the one or more processors are configured to receive multicast broadcast service (MBS) data. The one or more processors are configured to cause the UE device to: Receive from network devices a timing offset indicating a slot offset for Hybrid Automatic Repeat Request (HARQ) feedback transmission, wherein the timing offset is a group-specific timing offset that is less than a cell-specific timing offset, and the group includes multiple UE devices that receive the MBS data and are not located at the cell edge. The transmission timing for HARQ feedback transmission of the MBS data is determined based on the timing offset; as well as When the timing offset specific to the group is less than the timing offset specific to the UE, the HARQ feedback transmission for the MBS data is abandoned.

2. The UE device of claim 1, wherein the HARQ feedback transmission for the MBS data is based on negative-only acknowledgment (NACK) HARQ feedback.

3. The UE device of claim 1, wherein the group-specific timing offset is signaled via at least one of: Media Access Control (MAC) Channel Element (CE); Group common downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by the group radio network temporary identifier (G-RNTI); RRC configuration; or The RRC configuration updated by the MAC CE or the group public DCI.

4. The UE device according to claim 1, wherein the timing offset is selected from a set of timing offsets received from the network device based on the UE-specific timing offset.

5. The UE device of claim 4, wherein the timing offset is selected as the smallest of the set of timing offsets that is greater than or equal to the UE-specific timing offset.

6. The UE device of claim 1, wherein the one or more processors are further configured to cause the UE device to: When the group-specific timing offset is not configured, the cell-specific timing offset is determined as the timing offset; and When the group-specific timing offset is configured, the group-specific timing offset is determined as the timing offset.

7. The UE device of claim 4, wherein the one or more processors are further configured to cause the UE device to: When the set of timing offsets is not configured, the cell-specific timing offset is determined as the timing offset; and When the set of timing offsets is configured, the timing offset is selected from the set of timing offsets.

8. The UE device of claim 1, wherein the one or more processors are further configured to cause the UE device to: The HARQ feedback transmission for the MBS data is stopped based on the determination that the UE device is too far from the serving satellite to exceed a threshold.

9. The UE device of claim 8, wherein the one or more processors are further configured to cause the UE device to: The determination is made if the UE-specific timing advance (TA) or the UE-wide TA is greater than the TA threshold configured per MBS session.

10. The UE device of claim 8, wherein the one or more processors are further configured to cause the UE device to: The determination is made if the timing offset specific to the UE is greater than the timing offset threshold configured per MBS session.

11. The UE device of claim 1, wherein the one or more processors are further configured to cause the UE device to: Frequency compensation is received via Group Common Downlink Control Information (DCI) from the network device.

12. A non-transitory computer-readable storage medium storing program instructions executable by one or more processors to cause a user equipment (UE) device to: Receive from network devices a timing offset indicating a slot offset for Hybrid Automatic Repeat Request (HARQ) feedback transmission, wherein the timing offset is a group-specific timing offset that is less than a cell-specific timing offset, and the group includes multiple UE devices that receive multicast broadcast service (MBS) data and are not located at the cell edge. The transmission timing for HARQ feedback transmission of the MBS data is determined based on the timing offset; as well as When the timing offset specific to the group is less than the timing offset specific to the UE, the HARQ feedback transmission for the MBS data is abandoned.

13. The non-transitory computer-readable storage medium of claim 12, wherein the HARQ feedback transmission for the MBS data is based on negative-only acknowledgment (NACK) HARQ feedback.

14. The non-transitory computer-readable storage medium of claim 12, wherein the timing offset is selected from a set of timing offsets received from the network device based on a UE-specific timing offset.

15. The non-transitory computer-readable storage medium of claim 12, wherein the program instructions are executable by the one or more processors to further cause the UE device to: The HARQ feedback transmission for the MBS data is stopped based on the determination that the UE device is farther away from the serving satellite than a threshold. The determination is made if the UE-specific timing advance (TA) or the UE-wide TA is greater than the TA threshold configured per MBS session, or if the UE-specific timing offset is greater than the timing offset threshold configured per MBS session.

16. A method for wireless communication, comprising: Receive from network devices a timing offset indicating a slot offset for Hybrid Automatic Repeat Request (HARQ) feedback transmission, wherein the timing offset is a group-specific timing offset that is less than a cell-specific timing offset, and the group includes multiple user equipment (UE) devices that receive multicast broadcast service (MBS) data and are not located at the cell edge. The transmission timing for HARQ feedback transmission of the MBS data is determined based on the timing offset; as well as When the timing offset specific to the group is less than the timing offset specific to the UE, the HARQ feedback transmission for the MBS data is abandoned.

17. The method of claim 16, wherein the HARQ feedback transmission for the MBS data is based on negative-only acknowledgment (NACK) HARQ feedback.

18. The method of claim 16, wherein the timing offset is selected from a set of timing offsets received from the network device based on the UE-specific timing offset.

19. The method of claim 16, further comprising: The HARQ feedback transmission for the MBS data is stopped based on the determination that the UE device is farther away from the serving satellite than a threshold. The determination is made if the UE-specific timing advance (TA) or the UE-wide TA is greater than the TA threshold configured per MBS session, or if the UE-specific timing offset is greater than the timing offset threshold configured per MBS session.

20. A computer program product comprising a computer program that, when executed by a processor of a user equipment (UE) device, causes the UE device to: Receive from network devices a timing offset indicating a slot offset for Hybrid Automatic Repeat Request (HARQ) feedback transmission, wherein the timing offset is a group-specific timing offset that is less than a cell-specific timing offset, and the group includes multiple UE devices that receive multicast broadcast service (MBS) data and are not located at the cell edge. The transmission timing for HARQ feedback transmission of the MBS data is determined based on the timing offset; as well as When the timing offset specific to the group is less than the timing offset specific to the UE, the HARQ feedback transmission for the MBS data is abandoned.

Images