WO2024031369A1

WO2024031369A1 - Harq feedback enabling and disabling in non-terrestrial network

Info

Publication number: WO2024031369A1
Application number: PCT/CN2022/111254
Authority: WO
Inventors: Pingping Wen; Jing Yuan Sun; Ping Yuan; Tao Yang
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2022-08-09
Filing date: 2022-08-09
Publication date: 2024-02-15

Abstract

Embodiments of the present disclosure relate to hybrid automatic repeat request (HARQ) feedback enabling and disabling in a non-terrestrial network (NTN). A terminal device receives, from a network device, downlink control information. The downlink control information indicates the number of transport blocks associated with uplink transmission or downlink transmission on a HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process. The terminal device obtains a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled. Moreover, the terminal device determines an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.

Description

HARQ FEEDBACK ENABLING AND DISABLING IN NON-TERRESTRIAL NETWORK

FIELD

Various example embodiments relate to the field of telecommunication and in particular, to methods, devices, apparatuses, and computer readable storage media for hybrid automatic repeat request (HARQ) feedback enabling and disabling in a non-terrestrial network (NTN) .

BACKGROUND

Third Generation Partnership Project (3GPP) has defined a new work item for Release 18 (Rel-18) on internet of things (IoT) NTN (IoT-NTN) performance enhancements in RP-212729. For IoT over a NTN, such as narrowband IoT (NB-IoT) , enhanced machine type communication (eMTC) over the NTN, etc., disabling hybrid automatic repeat request (HARQ) feedback may bring about at least the following advantages. For example, user equipment (UE) power consumption and latency can be reduced. In addition, HARQ stalling for NB-IoT due to large round trip time (RTT) in the NTN can be mitigated. Besides, uplink throughput in the NTN can be improved as more resources could be available in uplink. On the other hand, if the HARQ feedback is disabled, layer 1 (L1) reliability of the downlink transmission may degrade due to the lack of HARQ feedback. In NB-IoT, at most two HARQ processes are supported. When there is only one HARQ process configured, the solution on how to dynamically indicate HARQ feedback enabling and disabling should be considered.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for HARQ feedback enabling and disabling in an NTN.

In a first aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: receive, from a network device, downlink control information indicating the number of transport blocks associated with uplink transmission or downlink transmission on a hybrid automatic repeat request, HARQ, process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process; obtain a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled; and determine an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.

In a second aspect, there is provided a network device. The network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: determine a threshold for determining whether hybrid automatic repeat request, HARQ, feedback for a HARQ process is disabled or enabled; determine an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold; and transmit, to a terminal device, downlink control information for the HARQ process, the downlink control information indicating the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.

In a third aspect, there is provided a method implemented at a terminal device. The method comprises receiving, from a network device, downlink control information indicating the number of transport blocks associated with uplink transmission or downlink transmission on a hybrid automatic repeat request, HARQ, process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process; obtaining a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled; and determining an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.

In a fourth aspect, there is provided a method implemented at a network device. The method comprises determining a threshold for determining whether hybrid automatic repeat request, HARQ, feedback for a HARQ process is disabled or enabled; determining an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold; and transmitting, to a terminal device, downlink control information for the HARQ process, the downlink control information indicating the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.

In a fifth aspect, there is provided an apparatus. The apparatus comprises means for receiving, at a terminal device from a network device, downlink control information indicating the number of transport blocks associated with uplink transmission or downlink transmission on a hybrid automatic repeat request, HARQ, process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process; means for obtaining a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled; and means for determining an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.

In a sixth aspect, there is provided an apparatus. The apparatus comprises means for determining, at a network device, a threshold for determining whether hybrid automatic repeat request, HARQ, feedback for a HARQ process is disabled or enabled; means for determining an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold; and means for transmitting, to a terminal device, downlink control information for the HARQ process, the downlink control information indicating the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.

In a seventh aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method according to any one of the above third to fourth aspect.

In an eighth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to perform at least the method according to any one of the above third to fourth aspect.

In a ninth aspect, there is provided a terminal device. The terminal device comprises receiving circuitry configured to receive, from a network device, downlink control information indicating the number of transport blocks associated with uplink transmission or downlink transmission on a hybrid automatic repeat request, HARQ, process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process; obtaining circuitry configured to obtain a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled; and determining circuitry configured to determine an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.

In a tenth aspect, there is provided a network device. The network device comprises determining circuitry configured to determine a threshold for determining whether hybrid automatic repeat request, HARQ, feedback for a HARQ process is disabled or enabled; determining circuitry configured to determine an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold; and transmitting circuitry configured to transmit, to a terminal device, downlink control information for the HARQ process, the downlink control information indicating the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

FIG. 1A illustrates an example of a network environment in which some example embodiments of the present disclosure may be implemented;

FIGS. 1B-1C illustrate other examples of a network environment in which some example embodiments of the present disclosure may be implemented;

FIG. 2 illustrates a signaling flow between the terminal device and the network device according to some example embodiments of the present disclosure;

FIG. 3 illustrates an example process of determining HARQ disabling/enabling based on implicit indications according to some embodiments of the present disclosure;

FIG. 4 illustrates an example process of determining blind retransmission related information by reusing a field in the downlink control information according to some embodiments of the present disclosure;

FIG. 5 illustrates a flowchart of a method implemented at a terminal device according to some embodiments of the present disclosure;

FIG. 6 illustrates a flowchart of a method implemented at a network device according to some embodiments of the present disclosure;

FIG. 7 illustrates a simplified block diagram of a device that is suitable for implementing some example embodiments of the present disclosure; and

FIG. 8 illustrates a block diagram of an example of a computer readable medium in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or” , mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

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

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , New radio (NR) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) , Non-terrestrial network (NTN) , IoT over NTN, and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) , the future sixth generation (6G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a new radio (NR) NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , an integrated access and backhaul (IAB) node, a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (loT) device, a machine type communication (MTC) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

The propagation delay may vary with the movement of a satellite for Non-GEO scenarios and be different for various satellite orbits and elevation angles. For example, the following Table 1 shows delay values for various satellite orbits.

Table 1: Delay values for various satellite orbits

HARQ feedback enabling/disabling is used to avoid HARQ stalling due to a long RTT and guarantee the required UE throughput. With data repetitions in NB-IoT, the transmission time of available HARQ processes is extended, and it is still possible not to fill up the RTT and HARQ stalling can occurs in some cases, e.g., for large RTT and small repetition case. HARQ feedback enabling/disabling should be supported to avoid HARQ stalling due to a long RTT and guarantee the required UE throughput.

In the third Generation Partnership Project (3GPP) Release 17 (Rel-17) , disabling HARQ feedback for NTN IoT is discussed. In the 3GPP Release 18 (Rel-18) , there is a new work item (WI) for IoT-NTN performance enhancements. The work considers existing IoT-NTN as a baseline as well as Rel-17 WI outcome and further IoT-NTN performance enhancements are considered based on disabling HARQ feedback to mitigate the impact of HARQ stalling on UE data rates.

However, disabling HARQ feedback brings both advantages and disadvantages. For example, disabling HARQ feedback can benefit UE power consumption and latency. Besides, disabling HARQ feedback for downlink transmission can mitigate HARQ stalling for NB-IoT which is due to the large RTT in NTN. In addition, disabling HARQ feedback for downlink transmission can improve uplink throughput in NTN as more resources would be available in the uplink. But more uplink resources may be needed for RLC status reporting, which may partly consume uplink resources made available by disabled HARQ feedback. If HARQ feedback is disabled, the layer 1 (L1) reliability of downlink transmission may degrade due to the lack of HARQ feedback. In addition, the UE is still required to always transmit a HARQ-acknowledgement (ACK) for link adaptation aspects.

Therefore, both disabling and enabling of HARQ feedback should be supported. However, in NB-IoT, at most two HARQ processes are supported. When there is only one HARQ process configured, how the network dynamically indicates that HARQ feedback is disabled or enabled to the UE is still an important issue to be solved.

According to embodiments of the present disclosure, there is providing a scheme for HARQ feedback enabling and disabling in an NTN. With this scheme, a terminal device receives, from a network device, downlink control information (DCI) . The DCI indicates the number of transport blocks (TBs) associated with uplink transmission or downlink transmission on a HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process. The terminal device obtains a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled. Moreover, the terminal device determines an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number. The repetition number (N _Rep) is determined by the repetition number field (I _Rep) in the corresponding DCI, the number of subframes (N _SF) is determined by the resource assignment field (I _SF) in the corresponding DCI, the number of transport blocks (TBs) is determined by the Number of scheduled TB for Unicast field in the corresponding DCI when npdsch-MultiTB-Config is enabled.

In this way, HARQ feedback disabling and enabling can be flexibly and dynamically determined and indicated. This scheme can avoid HARQ stalling and guarantee the required UE throughput by implicitly indicating enabling or disabling of HARQ feedback. The indication of HARQ feedback enabling or disabling is fully dynamic and does not require a radio resource control (RRC) reconfiguration, as the HARQ behavior can be changed for each transmitted transport block. Besides, due to the use of an implicit indication in the DCI, there is no need to introduce additional bits/fields in the DCI, thus additional signaling overhead can be avoided. As such, it is possible to improve communication efficiency. Principle and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

Reference is first made to FIG. 1A, which illustrates an example of a network environment 100 in which some example embodiments of the present disclosure may be implemented. The network environment 100 may include a terminal device 110 and a network device 120. In some example embodiments, the environment 100 may be implemented as an NTN, and the network device 120 may include a communication satellite.

For example, as shown in FIG. 1B, the network device 120 includes the communication satellite 120-1, and the communication satellite 120-1 may operate as a gNB, or in other words, the gNB (on board) may locate in the communication satellite 120-1. As shown in FIG. 1B, the terminal device 110 may be located within a coverage 130 of the communication satellite 120-1, for example, the coverage 130 may be called as an NTN cell. Although it is not shown in FIG. 1B, the communication satellite 120-1 may communicate with a gateway device associated with a 5G core network (CN) .

For example, as shown in FIG. 1C, the communication satellite 120-1 may operate as a passive or transparent network relay node between the terminal device 110 and a network device 120-2 on the ground. In some embodiments, the satellite 120-1 may communicate with the terminal device 110 via a service link or a wireless interface, and communicate with the network device 120-2 on the ground via a feeder link or a wireless interface.

In some embodiments, the satellite 120-1 may include a GEO satellite, LEO satellite, or another type of satellite. In some embodiments, the satellite 120-1 may pertain to one or more satellite systems or architectures, such as a global navigation satellite system (GNSS) , a global positioning system (GPS) , a global navigation satellite system (GLONASS) , a BeiDou navigation satellite system (BDS) , etc.

It is to be understood that the network environment 100 shown in FIG. 1A is only for the purpose of illustration without suggesting any limitation as to the scope of the disclosure. For example, while FIG. 1B or 1C depicts the terminal device 110 as a mobile phone, the terminal device 110 may be any type of user equipment.

Communications in the network environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) , the fifth generation (5G) , and 6G, and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

It is to be understood that the number of devices (i.e., the terminal device 110, the network device 120) and their connection relationships and types as shown in FIG. 1A are only for the purpose of illustration without suggesting any limitation. The environment 100 may include any suitable number of devices adapted for implementing embodiments of the present disclosure.

FIG. 2 illustrates a signaling flow 200 between the terminal device and the network device according to some example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 200 will be described with reference to FIG. 1A.

As shown in FIG. 2, the network device 120 determines (205) a threshold for determining whether HARQ feedback for a HARQ process is disabled or enabled. In some example embodiments, the network device 120 may transmit, to the terminal device 110, information associated with the threshold by an RRC message. For example, the information associated with the threshold may comprise a plurality of thresholds corresponding to a plurality of elevation angles. In this case, the network device 120 may determine the threshold from the plurality of thresholds based on an elevation angle between the terminal device 110 and the network device 120.

As another example, the information associated with the threshold may comprise a plurality of thresholds corresponding to a plurality of distances. In this case, the network device 120 may determine the threshold from the plurality of thresholds based on a distance between the terminal device 110 and the network device 120. In some example embodiments, the information associated with the threshold may be configured per HARQ process. In this case, different HARQ processes can support different operations.

As shown in FIG. 2, the network device 120 determines (210) an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold.

For example, the network device 120 may determine HARQ feedback disabling and enabling dynamically based on the transmission time of the Narrowband physical downlink shared channel (NPDSCH) , the propagation latency, and the required UE throughput, etc. The transmission time of NPDSCH may be N consecutive NB-IoT downlink subframe (s) . The transmission time may depend on the number of scheduled transport blocks, the scheduled transport block size, and the repetition number. For example, the transmission time may be calculated as: Numberofsubframe _NPDSCH=N _TBN _RepN _SF, where N _TB is the number of scheduled transport blocks, N _Rep is the repetition number, and N _SF is the number of subframes scheduled for the transport block.

The HARQ stalling may mainly happen in the case when the transmission time of available HARQ processes cannot fill up the RTT propagation time between the terminal device 110 and the network device 120, while the HARQ stalling may not happen when the transmission time is large. Therefore a product of the number of scheduled transport blocks, the number of subframes scheduled for the transport block, and the repetition number may be associated with HARQ feedback disabling and enabling.

In some example embodiments, the network device 120 may determine the enabled state or the disabled state of the HARQ feedback based on the product of the number of transport blocks, the number of subframes for the transport block, and the repetition number. For example, if the product is smaller than the threshold, the network device 120 may determine the disabled state of the HARQ feedback. Otherwise, if the product is larger than the threshold, the network device 120 may determine the enabled state of the HARQ feedback.

It is to be understood that the enabled state or the disabled state of the HARQ feedback may be determined according to any arithmetic operation based on at least one of: the number of transport blocks, the number of subframes for the transport block, and the repetition number, and the scope of the present disclosure will not be limited in this regards. In addition, it is also to be understood that the enabled state or the disabled state of the HARQ feedback may be determined based on at least one of: the number of transport blocks, the number of subframes for the transport block, the repetition number, together with any other one or more factors either indicated in the DCI 216 or not, and the scope of the present disclosure will not be limited in this regards.

In some example embodiments, the network device 120 may determine the enabled state or the disabled state of the HARQ feedback for initial transmission of the HARQ process. That is, the determination of HARQ feedback disabling or enabling may be applied for initial HARQ transmission. For the HARQ retransmission (for example, no New Data Indicator (NDI) toggled in DCI 216 for the same HARQ) , the HARQ feedback disabling or enabling may follow the one of its initial transmission.

As shown in FIG. 2, the network device 120 transmits (215) , to the terminal device 110, DCI 216 for the HARQ process. On the receiving side, the terminal device 110 receives (220) the DCI 216 from the network device 120. The DCI 216 indicates the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.

An example format of the DCI 216 may be shown in Table 2.

Table 2: DCI format N1

The number of scheduled transport blocks N _TB may be determined based on the number of the scheduled TB field in the DCI 216. The repetition number, N _Rep, may be determined based on the repetition number field, I _Rep, in the DCI 216 according to Table 3. The number of subframes, N _SF, may be determined based on the resource assignment field, I _SF, in the DCI 216 according to Table 4.

Table 3: repetition number, N _Rep, for NPDSCH

I _Rep	N _Rep
0	1
1	2
2	4
3	8
4	16
5	32
6	64
7	128
8	192
9	256
10	384
11	512
12	768
13	1024
14	1536
15	2048

Table 4: Number of subframes, N _SF, for NPDSCH

I _SF	N _SF
0	1
1	2
2	3
3	4
4	5
5	6
6	8
7	10

In the example embodiments where the HARQ feedback is disabled, the HARQ-ACK resource field for indicating time-frequency resources for the NPUSCH carrying ACK/non-acknowledgement (NACK) response is not needed since there is no HARQ feedback. In this case, to improve the reliability, some types of blind retransmission schemes may be supported. For example, information associated with blind retransmission for the HARQ process may be indicated in the HARQ-ACK resource field in the DCI 216.

As an example, several indexes/values may be configured to indicate the blind retransmission related information, such as blind transmission with a fixed pattern, and dynamic DCI-based blind transmission. The blind retransmission with the fixed pattern refers to the resources in the frequency domain and/or time domain being fixed in a certain pattern which can be configured via semi-static signalling, for example, RRC signalling. This kind of blind retransmission can save the DCI signalling for retransmission resource indication. However, dynamic DCI-based blind transmission is flexible on resource allocation at the cost of wasting DCI signalling.

Thus, in some example embodiments, the information associated with the blind retransmission may comprise an indication (also referred to as a first indication) that the blind retransmission is based on a fixed pattern. Alternatively or in addition, the information associated with the blind retransmission may comprise another indication (also referred to as a second indication) that the blind retransmission is based on further DCI.

As an example, a value of the HARQ acknowledgement resource field may be pre-defined. Alternatively or in addition, the value of the HARQ acknowledgement resource field may be configured by an RRC message to the terminal device 110. In this case, HARQ retransmission schemes can be dynamically determined and indicated without the introduction of new bits/fields in the DCI 216, and thus extra signaling overhead can be avoided. With blind retransmission, the advantages of HARQ feedback disabling can be kept, for example, power consumption, latency reduction, and avoidance of HARQ stalling. Besides, the reliability of downlink transmission can be ensured.

In some example embodiments, the network device 120 may configure a flag to indicate determining the enabled state or the disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number. For example, a semi-static flag may be configured to indicate the HARQ feedback is enabled/disabled implicitly by the product of the number of transport blocks, the repetition number, and the number of subframes for the transport block. For example, when the flag is true, HARQ disabling/enabling may be implicitly indicated with the method. When the product of the number of transport blocks, the repetition number, and the number of subframes for the transport block is smaller than the configured threshold, HARQ disabling may be implicitly indicated. When the product of the number of transport blocks, the repetition number, and the number of subframes for the transport block is larger than the configured threshold, HARQ enabling may be implicitly indicated. Otherwise when the flag is false, this method with implicit indication HARQ disabling/enabling may not be used. In some example embodiments, the flag may be comprised in an RRC message to the terminal device 110. As an example, the flag may be configured per HARQ process. In this case, different HARQ processes can support different operations.

Then, as shown in FIG. 2, at the side of terminal device 110, it obtains (225) the threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled. In the embodiments where the information associated with the threshold is pre-defined, the terminal device 110 may determine the threshold based on the pre-configuration. Alternatively, in the embodiments where the information associated with the threshold is configured by the RRC message from the network device 120, the terminal device 110 may receive the information associated with the threshold from the network device 120. Then, the terminal device 110 may obtain the threshold based on the received information associated with the threshold.

In the embodiments where the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of elevation angles, the terminal device 110 may obtain the threshold from the plurality of thresholds based on an elevation angle between the terminal device 110 and the network device 120. Alternatively or in addition, in the embodiments where the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of distances, the terminal device 110 may obtain the threshold from the plurality of thresholds based on a distance between the terminal device 110 and the network device 120.

As shown in FIG. 2, the terminal device 110 determines (230) an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number. Similarly as described at the network device side, in some example embodiments, the terminal device 110 may determine the enabled state or the disabled state of the HARQ feedback based on a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number.

For example, if the product is smaller than the threshold, the terminal device 110 may determine the disabled state of the HARQ feedback. Otherwise, if the product is larger than the threshold, the terminal device 110 may determine the enabled state of the HARQ feedback.

Similarly as described at the network device side, in some example embodiments, the terminal device 110 may determine the enabled state or the disabled state of the HARQ feedback for initial transmission of the HARQ process. In this case, the determination of HARQ feedback disabling or enabling may be applied for initial HARQ transmission. For the HARQ retransmission (for example, no New Data Indicator (NDI) toggled in DCI 216 for the same HARQ) , the HARQ feedback disabling or enabling may follow the one of its initial transmission.

In the example embodiments where the HARQ feedback is disabled and information associated with blind retransmission for the HARQ process is indicated in a HARQ acknowledgement resource field in the DCI 216, if the information associated with the blind retransmission comprises the first indication, the terminal device 110 may determine that the blind retransmission is based on a fixed pattern. As another example, if the information associated with the blind retransmission comprises the second indication, the terminal device 110 may determine that the blind retransmission is based on further DCI. On this basis, blind retransmission may be performed to improve reliability. In the embodiments where the value of the HARQ acknowledgement resource field is pre-defined, the terminal device 110 may determine the first indication or the second indication refers to which kind of blind retransmission based on the pre-defined value of HARQ acknowledgement resource field and the HARQ acknowledgement resource field in the DCI. Alternatively or in addition, in the embodiments where the value of the HARQ acknowledgement resource field is configured by the RRC message from the network device 120, the terminal device 110 may determine the first indication or the second indication refers to which kind of blind retransmission based on the RRC configured value of HARQ acknowledgement resource field and the HARQ acknowledgement resource field in the DCI.

In the example embodiments where the flag is comprised in an RRC message from the network device 120, which indicates determining the enabled state or the disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number, the terminal device 110 may determine the enabled state or the disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number. In the embodiments where the semi-static flag is configured to indicate the HARQ feedback is enabled/disabled implicitly by the product of the number of transport blocks, the repetition number, and the number of subframes for the transport block, when the flag is true, the terminal device 110 may determine that HARQ disabling/enabling is implicitly indicated with the method. For example, the terminal device 110 may determine that HARQ disabling is implicitly indicated when the product of the number of transport blocks, the repetition number, and the number of subframes for the transport block is smaller than the configured threshold. The terminal device 110 may determine that HARQ enabling is implicitly indicated, when the product of the number of transport blocks, the repetition number, and the number of subframes for the transport block is larger than the configured threshold. Otherwise when the flag is false, the terminal device 110 may determine that this method with implicit indication HARQ disabling/enabling is not used. For example, the flag may be configured per HARQ process. In this case, different HARQ processes can support different operations.

In some example embodiments, the terminal device 110 may determine the enabled state or the disabled state of the HARQ feedback for initial transmission of the HARQ process. In this case, the determination of HARQ feedback disabling or enabling may be applied for initial HARQ transmission. For the HARQ retransmission, the HARQ feedback disabling or enabling may follow the one of its initial transmission.

FIG. 3 illustrates an example process 300 of determining HARQ disabling/enabling based on implicit indications according to some embodiments of the present disclosure. For the purpose of discussion, the process 300 will be described with reference to FIG. 1A. It would be appreciated that although the process 300 has been described in the network environment 100 of FIG. 1A, this process flow may be likewise applied to other communication scenarios. In this case, the terminal device 110 is implemented by the UE 302, and the network device 120 is implemented by the gNB 304.

In this case, for example, the orbit altitude of the LEO of 1200 km is assumed. At 305, the gNB 304 transmits an RRC message indicating a threshold of 24 ms to the UE 302. In this case, if the product of the indicated number of scheduled TB, the repetition number, and the number of subframes scheduled for transport block is smaller than the indicated threshold, HARQ disabling may be implicitly indicated for this TB.

At 310, the gNB 304 transmits DCI to the UE 302, in which the scheduled transport blocks N _TB field is “1” , the repetition number field I _Rep is “1” which corresponds to the repetition number N _Rep of “2” based on the above Table 3, and the Resource assignment field I _SF is “2” which corresponds to the number of subframes N _SF of “3” based on the above Table 4. Thus, the product of N _TB, N _Rep and N _SF is 1*2*3=6ms, which is smaller than the configured threshold. Thus, the UE 302 may know that the HARQ feedback is disabled.

At 315, the gNB 304 transmits DCI to the UE 302, in which the scheduled transport blocks N _TB field is “1” , the repetition number field I _Rep is “4” which corresponds to the repetition number N _Rep of “16” based on the above Table 3, and the Resource assignment field I _SF is “2” which corresponds to the number of subframes N _SF of “3” based on the above Table 4. Thus, the product of N _TB, N _Rep and N _SF is 1*16*3=48ms, which is larger than the configured threshold. Thus, the UE 302 may know that the HARQ feedback is enabled. Then, at 320, the UE 302 transmits HARQ ACK/NACK to the gNB 304.

All operations and features as described above with reference to FIG. 2 are likewise applicable to the process 300 and have similar effects. For the purpose of simplification, the details will be omitted.

FIG. 4 illustrates an example process 400 of determining blind retransmission related information by reusing a field in the DCI according to some embodiments of the present disclosure. For the purpose of discussion, the process 400 will be described with reference to FIG. 1A. It would be appreciated that although the process 400 has been described in the network environment 100 of FIG. 1A, this process flow may be likewise applied to other communication scenarios. In this case, the terminal device 110 is implemented by the UE 402, and the network device 120 is implemented by the gNB 404.

One or several values of the current HARQ-ACK resource field may be reserved to indicate the blind retransmission schemes. For example, the reservation of the HARQ-ACK resource field may be implemented through pre-definition or configured by the gNB 404 via an RRC message. In this case, it is assumed that the reservation of the HARQ-ACK resource field is configured by the gNB 404.

As shown in FIG. 4, at 405, the gNB 404 transmits an RRC message to the UE 402. The RRC message indicates that the values “0” and “8” of the HARQ-ACK resource field are configured to indicate the blind transmission with a fixed pattern and dynamic DCI-based blind transmission separately. That is, the contents shown in bold in Table 5 may be reused. Table 5 shows HARQ-ACK resource field corresponding to ACK/NACK subcarrier and subframe interval between the downlink scheduling DCI and scheduled NPUSCH, k ₀ with subcarrier spacing Δf=3.75 kHz.

Table 5: HARQ-ACK resource field

At 410, the gNB 304 transmits, to the UE 302, DCI with HARQ-ACK resource field of “0” . In this case, the UE determines that the blind transmission with the fixed pattern is used for this downlink transmission.

At 415, the gNB 304 transmits, to the UE 302, DCI with HARQ-ACK resource field of “8” . In this case, the UE determines that dynamic DCI-based blind transmission is used for this downlink transmission.

All operations and features as described above with reference to FIG. 2 are likewise applicable to the process 400 and have similar effects. For the purpose of simplification, the details will be omitted.

FIG. 5 illustrates a flowchart 500 of a method implemented at a terminal device 110 according to some embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the terminal device 110 with reference to FIG. 1A.

At block 510, the terminal device 110 receives, from a network device 120, downlink control information indicating the number of transport blocks associated with uplink transmission or downlink transmission on a hybrid automatic repeat request, HARQ, process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process. At block 520, the terminal device 110 obtains a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled. At block 530, the terminal device 110 determines an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.

In some example embodiments, information associated with the threshold is pre-defined or configured by a radio resource control message from the network device 120. In some example embodiments, the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of elevation angles, and the terminal device 110 obtains the threshold by obtaining the threshold from the plurality of thresholds based on an elevation angle between the terminal device 110 and the network device 120. In some example embodiments, the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of distances, and the terminal device 110 obtains the threshold by obtaining the threshold from the plurality of thresholds based on a distance between the terminal device 110 and the network device 120. In some example embodiments, the information associated with the threshold is configured per HARQ process.

In some example embodiments, the terminal device 110 determines the enabled state or the disabled state of the HARQ feedback by in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being smaller than the threshold, determining the disabled state of the HARQ feedback. In some example embodiments, information associated with blind retransmission for the HARQ process is indicated in a HARQ acknowledgement resource field in the downlink control information. In some example embodiments, the information associated with the blind retransmission comprises one of the following: a first indication that the blind retransmission is based on a fixed pattern; or a second indication that the blind retransmission is based on further downlink control information. In some example embodiments, a value of the HARQ acknowledgement resource field is pre-defined or configured by a radio resource control message from the network device 120.

In some example embodiments, the terminal device 110 determines the enabled state or the disabled state of the HARQ feedback by, in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being larger than the threshold, determining the enabled state of the HARQ feedback.

In some example embodiments, a flag is comprised in a radio resource control message from the network device 120, the flag indicating determining the enabled state or the disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number. In some example embodiments, the flag is configured per HARQ process.

In some example embodiments, the terminal device 110 to determines the enabled state or the disabled state of the HARQ feedback by determining the enabled state or the disabled state of the HARQ feedback for initial transmission of the HARQ process.

FIG. 6 illustrates a flowchart 600 of a method implemented at a network device 120 according to some embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the network device 120 with reference to FIG. 1A.

At block 610, the network device 120 determines a threshold for determining whether hybrid automatic repeat request, HARQ, feedback for a HARQ process is disabled or enabled. At block 620, the network device 120 determines an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold. At block 630, the network device 120 transmits, to a terminal device 110, downlink control information for the HARQ process, the downlink control information indicating the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.

In some example embodiments, the network device 120 further transmits, to the terminal device 110, information associated with the threshold by a radio resource control message. In some example embodiments, the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of elevation angles. In some example embodiments, the network device 120 determines the threshold by determining the threshold from the plurality of thresholds based on an elevation angle between the terminal device 110 and the network device 120. In some example embodiments, the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of distances. In some example embodiments, the network device 120 determines the threshold by determining the threshold from the plurality of thresholds based on a distance between the terminal device 110 and the network device 120. In some example embodiments, the information associated with the threshold is configured per HARQ process.

In some example embodiments, the network device 120 determines the enabled state or the disabled state of the HARQ feedback by in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being smaller than the threshold, determining the disabled state of the HARQ feedback. In some example embodiments, information associated with blind retransmission for the HARQ process is indicated in a HARQ acknowledgement resource field in the downlink control information. In some example embodiments, the information associated with the blind retransmission comprises one of the following: a first indication that the blind retransmission is based on a fixed pattern; or a second indication that the blind retransmission is based on further downlink control information. In some example embodiments, a value of the HARQ acknowledgement resource field is pre-defined or configured by a radio resource control message to the terminal device 110.

In some example embodiments, the network device 120 determines the enabled state or the disabled state of the HARQ feedback by in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being larger than the threshold, determining the enabled state of the HARQ feedback.

In some example embodiments, a flag is comprised in a radio resource control message to the terminal device 110, the flag indicating determining the enabled state or the disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number. In some example embodiments, the flag is configured per HARQ process.

In some example embodiments, the network device 120 determines the enabled state or the disabled state of the HARQ feedback by determining the enabled state or the disabled state of the HARQ feedback for initial transmission of the HARQ process.

In some example embodiments, an apparatus capable of performing the method 500 (for example, the terminal device 110) may comprise means for performing the respective steps of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for receiving, from a network device, downlink control information indicating the number of transport blocks associated with uplink transmission or downlink transmission on a hybrid automatic repeat request, HARQ, process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process; means for obtaining a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled; and means for determining an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.

In some example embodiments, information associated with the threshold is pre-defined or configured by a radio resource control message from the network device. In some example embodiments, the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of elevation angles, and the means for obtaining the threshold comprises: means for obtaining the threshold from the plurality of thresholds based on an elevation angle between the terminal device and the network device. In some example embodiments, the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of distances, and the means for obtaining the threshold comprises: means for obtaining the threshold from the plurality of thresholds based on a distance between the terminal device and the network device. In some example embodiments, the information associated with the threshold is configured per HARQ process.

In some example embodiments, the means for determining the enabled state or the disabled state of the HARQ feedback comprises: means for, in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being smaller than the threshold, determining the disabled state of the HARQ feedback. In some example embodiments, information associated with blind retransmission for the HARQ process is indicated in a HARQ acknowledgement resource field in the downlink control information. In some example embodiments, the information associated with the blind retransmission comprises one of the following: a first indication that the blind retransmission is based on a fixed pattern; or a second indication that the blind retransmission is based on further downlink control information. In some example embodiments, a value of the HARQ acknowledgement resource field is pre-defined or configured by a radio resource control message from the network device.

In some example embodiments, the means for determining the enabled state or the disabled state of the HARQ feedback comprises: means for, in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being larger than the threshold, determining the enabled state of the HARQ feedback.

In some example embodiments, a flag is comprised in a radio resource control message from the network device, the flag indicating determining the enabled state or the disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number. In some example embodiments, the flag is configured per HARQ process.

In some example embodiments, the means for determining the enabled state or the disabled state of the HARQ feedback comprises: means for determining the enabled state or the disabled state of the HARQ feedback for initial transmission of the HARQ process.

. In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 500. In some embodiments, the means comprises at least one processor and at least one memory including computer program code. The at least one memory and computer program code are configured to, with the at least one processor, cause the performance of the apparatus.

In some example embodiments, an apparatus capable of performing the method 600 (for example, the network device 120) may comprise means for performing the respective steps of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for determining a threshold for determining whether hybrid automatic repeat request, HARQ, feedback for a HARQ process is disabled or enabled; means for determining an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold; and means for transmitting, to a terminal device, downlink control information for the HARQ process, the downlink control information indicating the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.

In some example embodiments, the apparatus further comprises: means for transmitting, to the terminal device, information associated with the threshold by a radio resource control message. In some example embodiments, the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of elevation angles. In some example embodiments, the means for determining the threshold comprises: means for determining the threshold from the plurality of thresholds based on an elevation angle between the terminal device and the network device. In some example embodiments, the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of distances. In some example embodiments, the means for determining the threshold comprises: means for determining the threshold from the plurality of thresholds based on a distance between the terminal device and the network device. In some example embodiments, the information associated with the threshold is configured per HARQ process.

In some example embodiments, the means for determining the enabled state or the disabled state of the HARQ feedback comprises: means for, in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being smaller than the threshold, determining the disabled state of the HARQ feedback. In some example embodiments, information associated with blind retransmission for the HARQ process is indicated in a HARQ acknowledgement resource field in the downlink control information. In some example embodiments, the information associated with the blind retransmission comprises one of the following: a first indication that the blind retransmission is based on a fixed pattern; or a second indication that the blind retransmission is based on further downlink control information. In some example embodiments, a value of the HARQ acknowledgement resource field is pre-defined or configured by a radio resource control message to the terminal device.

In some example embodiments, a flag is comprised in a radio resource control message to the terminal device, the flag indicating determining the enabled state or the disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number. In some example embodiments, the flag is configured per HARQ process.

In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 600. In some embodiments, the means comprises at least one processor and at least one memory including computer program code. The at least one memory and computer program code are configured to, with the at least one processor, cause the performance of the apparatus.

FIG. 7 illustrates a simplified block diagram of a device 700 that is suitable for implementing some example embodiments of the present disclosure. The device 700 may be provided to implement the communication device, for example, the terminal device 110, or the network device 120 as shown in FIG. 1A. As shown, the device 700 includes one or more processors 710, one or more memories 720 coupled to the processor 710, and one or more communication modules 740 coupled to the processor 710.

The communication module 740 is for bidirectional communications. The communication module 740 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 710 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 700 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 724, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 722 and other volatile memories that will not last in the power-down duration.

A computer program 730 includes computer executable instructions that are executed by the associated processor 710. The program 730 may be stored in the ROM 724. The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 722.

The embodiments of the present disclosure may be implemented by means of the program 730 so that the device 700 may perform any process of the disclosure as discussed with reference to FIGS. 2 to 4. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 730 may be tangibly contained in a computer readable medium which may be included in the device 700 (such as in the memory 720) or other storage devices that are accessible by the device 700. The device 700 may load the program 730 from the computer readable medium to the RAM 722 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like.

FIG. 8 illustrates a block diagram of an example of a computer readable medium 800 in accordance with some example embodiments of the present disclosure. The computer readable medium 800 has the program 730 stored thereon. It is noted that although the computer readable medium 800 is depicted in form of CD or DVD in FIG. 8, the computer readable medium 800 may be in any other form suitable for carry or hold the program 730.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method as described above with reference to any of FIGS. 5-6. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term “non-transitory, ” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM) .

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A terminal device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to:

receive, from a network device, downlink control information indicating the number of transport blocks associated with uplink transmission or downlink transmission on a hybrid automatic repeat request, HARQ, process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process;

obtain a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled; and

determine an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.
The terminal device of claim 1, wherein information associated with the threshold is pre-defined or configured by a radio resource control message from the network device.
The terminal device of claim 2, wherein the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of elevation angles, and wherein the terminal device is caused to obtain the threshold by:

obtaining the threshold from the plurality of thresholds based on an elevation angle between the terminal device and the network device.
The terminal device of claim 2, wherein the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of distances, and wherein the terminal device is caused to obtain the threshold by:

obtaining the threshold from the plurality of thresholds based on a distance between the terminal device and the network device.
The terminal device of any of claims 2-4, wherein the information associated with the threshold is configured per HARQ process.
The terminal device of any of claims 1-5, wherein the terminal device is caused to determine the enabled state or the disabled state of the HARQ feedback by:

in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being smaller than the threshold, determining the disabled state of the HARQ feedback.
The terminal device of claim 6, wherein information associated with blind retransmission for the HARQ process is indicated in a HARQ acknowledgement resource field in the downlink control information.
The terminal device of claim 7, wherein the information associated with the blind retransmission comprises one of the following:

a first indication that the blind retransmission is based on a fixed pattern; or

a second indication that the blind retransmission is based on further downlink control information.
The terminal device of claim 7 or 8, wherein a value of the HARQ acknowledgement resource field is pre-defined or configured by a radio resource control message from the network device.
The terminal device of any of claims 1-9, wherein the terminal device is caused to determine the enabled state or the disabled state of the HARQ feedback by:

in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being larger than the threshold, determining the enabled state of the HARQ feedback.
The terminal device of any of claims 1-10, wherein a flag is comprised in a radio resource control message from the network device, the flag indicating determining the enabled state or the disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.
The terminal device of claim 11, wherein the flag is configured per HARQ process.
The terminal device of any of claims 1-12, wherein the terminal device is caused to determine the enabled state or the disabled state of the HARQ feedback by:

determining the enabled state or the disabled state of the HARQ feedback for initial transmission of the HARQ process.
A network device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to:

determine a threshold for determining whether hybrid automatic repeat request, HARQ, feedback for a HARQ process is disabled or enabled;

determine an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold; and

transmit, to a terminal device, downlink control information for the HARQ process, the downlink control information indicating the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.
The network device of claim 14, wherein the network device is further caused to:

transmit, to the terminal device, information associated with the threshold by a radio resource control message.
The network device of claim 15, wherein the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of elevation angles.
The network device of claim 16, wherein the network device is caused to determine the threshold by:

determining the threshold from the plurality of thresholds based on an elevation angle between the terminal device and the network device.
The network device of claim 15, wherein the information associated with the threshold comprises a plurality of thresholds corresponding to a plurality of distances.
The network device of claim 18, wherein the network device is caused to determine the threshold by:

determining the threshold from the plurality of thresholds based on a distance between the terminal device and the network device.
The network device of any of claims 15-19, wherein the information associated with the threshold is configured per HARQ process.
The network device of claim 14, wherein the network device is caused to determine the enabled state or the disabled state of the HARQ feedback by:

in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being smaller than the threshold, determining the disabled state of the HARQ feedback.
The network device of claim 21, wherein information associated with blind retransmission for the HARQ process is indicated in a HARQ acknowledgement resource field in the downlink control information.
The network device of claim 22, wherein the information associated with the blind retransmission comprises one of the following:

a first indication that the blind retransmission is based on a fixed pattern; or

a second indication that the blind retransmission is based on further downlink control information.
The network device of claim 22 or 23, wherein a value of the HARQ acknowledgement resource field is pre-defined or configured by a radio resource control message to the terminal device.
The network device of any of claims 14-24, wherein the network device is caused to determine the enabled state or the disabled state of the HARQ feedback by:

in accordance with a product of the number of transport blocks, the number of subframes for the transport block, and the repetition number being larger than the threshold, determining the enabled state of the HARQ feedback.
The network device of any of claims 14-25, wherein a flag is comprised in a radio resource control message to the terminal device, the flag indicating determining the enabled state or the disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.
The network device of claim 26, wherein the flag is configured per HARQ process.
The network device of any of claims 14-27, wherein the network device is caused to determine the enabled state or the disabled state of the HARQ feedback by:

determining the enabled state or the disabled state of the HARQ feedback for initial transmission of the HARQ process.
A method comprising:

receiving, at a terminal device from a network device, downlink control information indicating the number of transport blocks associated with uplink transmission or downlink transmission on a hybrid automatic repeat request, HARQ, process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process;

obtaining a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled; and

determining an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.
A method comprising:

determining, at a network device, a threshold for determining whether hybrid automatic repeat request, HARQ, feedback for a HARQ process is disabled or enabled;

determining an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold; and

transmitting, to a terminal device, downlink control information for the HARQ process, the downlink control information indicating the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.
An apparatus comprising:

means for receiving, at a terminal device from a network device, downlink control information indicating the number of transport blocks associated with uplink transmission or downlink transmission on a hybrid automatic repeat request, HARQ, process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process;

means for obtaining a threshold for determining whether HARQ feedback for the HARQ process is disabled or enabled; and

means for determining an enabled state or a disabled state of the HARQ feedback based on the threshold and at least one of: the number of transport blocks, the number of subframes for the transport block, or the repetition number.
An apparatus comprising:

means for determining, at a network device, a threshold for determining whether hybrid automatic repeat request, HARQ, feedback for a HARQ process is disabled or enabled;

means for determining an enabled state or a disabled state of the HARQ feedback and the number of transport blocks associated with uplink transmission or downlink transmission on the HARQ process, the number of subframes for a transport block of the transport blocks, and a repetition number for the uplink transmission or downlink transmission on the HARQ process at least based on the threshold; and

means for transmitting, to a terminal device, downlink control information for the HARQ process, the downlink control information indicating the number of transport blocks, the number of subframes for the transport block, and the repetition number for the HARQ process.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of claim 29 or 30.