WO2020191625A9

WO2020191625A9 - Service-based harq enabling mechanism

Info

Publication number: WO2020191625A9
Application number: PCT/CN2019/079725
Authority: WO
Inventors: Pingping Wen
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2019-03-26
Filing date: 2019-03-26
Publication date: 2021-09-10
Also published as: CN113748625B; CN113748625A; WO2020191625A1

Abstract

Embodiments of the present disclosure relate to service-based HARQ enabling mechanism. According to embodiments of the present disclosure, a service-based HARQ disabling/enabling mechanism in uplink is proposed. The HARQ is dynamically disabled/enabled based on service types. The terminal device determines whether the HARQ is enabled for the data packet. In this way, the disabling/enabling of HARQ is controlled dynamically considering the practical status of the system.

Description

SERVICE-BASED HARQ ENABLING MECHANISM

FIELD

Embodiments of the present disclosure generally relate to the field of communications, especially in non-terrestrial network and in particular, to a method, device, apparatus and computer readable storage medium for service-based HARQ enabling mechanism.

BACKGROUND

3GPP has initiated a study item to extend the applicability to non-terrestrial network (NTN) , more specifically being able to use the 5G radio access for satellite links, where the long round trip delay will have impact on HARQ design. HARQ is a combination of high-rate forward error-correcting coding and ARQ error-control.

With HARQ, a transmitter needs to wait for the feedback from the receiver before sending new data. In case of a negative acknowledgement (NACK) , the transmitter may need to resend the data packet. Otherwise, it may send new data. This stop-and-wait (SAW) procedure introduces inherent latency to the communication protocol, which may reduce the link throughput. To alleviate this issue, existing HARQ procedure allows activating multiple HARQ processes at the transmitter. That is, the transmitter may initiate multiple transmissions in parallel without having to wait for a HARQ completion. The data transmission becomes more reliable and efficient with the introduction of HARQ.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for service-based HARQ enabling mechanisms in uplink for NTN system.

In a first aspect, there is provided a terminal device. The terminal device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to obtain a configuration of a radio bearer for data to be transmitted from the terminal device to a network device. The terminal device is also caused to determine whether Hybrid Automatic Repeat Request (HARQ) is enabled/disabled for a logical channel to which the radio bearer is mapped based on the configuration of the radio bearer. The terminal device is further caused to determine, based on the determination, enable/disable setting of HARQ for a data packet comprising the data from the logical channel. The terminal device is yet caused to transmit the data packet to the network device.

In a second aspect, there is provided a network device. The device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the network device to transmit, to a terminal device, a configuration of a radio bearer for data, the configuration indicating whether HARQ is enabled/disabled for a logical channel to which the radio bearer is mapped. The network device is also caused to transmit an indication as to whether HARQ is enabled for a data packet comprising the data from the logical channel. The network device is further caused to receive the data packet from the network device.

In a third aspect, there is provided a method implemented at a terminal device. The method comprises obtaining a configuration of a radio bearer for data to be transmitted from a terminal device to a network device. The method also comprises determining whether Hybrid Automatic Repeat Request (HARQ) is enabled/disabled for a logical channel to which the radio bearer is mapped based on the configuration of the radio bearer. The method further comprises configuring, based on the determination, enable/disable setting of HARQ for a data packet comprising the data from the logical channel. The method yet comprises transmitting the data packet to the network device.

In a fourth aspect, there is provided a method implemented at a network device. The method comprises transmitting, to a terminal device, a configuration of a radio bearer for data. The configuration indicates whether HARQ is enabled for a logical channel to which the radio bearer is mapped. The method further comprises transmitting an indication as to whether HARQ is enabled for a data packet comprising the data from the logical channel. The method also comprises receiving the data packet from the network device.

In a fifth aspect, there is provided an apparatus comprising means for obtaining a configuration of a radio bearer for data to be transmitted from a terminal device to a network device; means for determining whether Hybrid Automatic Repeat Request (HARQ) is enabled/disabled for a logical channel to which the radio bearer is mapped based on the configuration of the radio bearer; means for determining, based on the determination, enable/disable setting of HARQ for a data packet comprising the data from the logical channel; and means for transmitting the data packet to the network device.

In an sixth aspect, there is provided an apparatus comprising means for means for transmitting, to a terminal device, a configuration of a radio bearer for data, the configuration indicating whether HARQ is enabled/disabled for a logical channel to which the radio bearer is mapped; means for transmitting an indication as to whether HARQ is enabled for a data packet comprising the data from the logical channel; and means for receiving the data packet from the network device.

In a seven 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 and fourth aspects.

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. 1 illustrates an example communication network in which embodiments of the present disclosure may be implemented;

Fig. 2 illustrates a schematic diagram of interactions among communication devices according to some embodiments of the present disclosure;

Figs. 3A and 3B illustrates a schematic diagram of uplink medium access control (MAC) protocol data unit (PDU) according to some embodiments of the present disclosure;

Fig. 4 illustrates a flowchart of a method implemented at a terminal device 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 embodiments of the present disclosure; and

Fig 8 illustrates a block diagram of an example computer readable medium in accordance with some 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 embodirnents 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 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) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) , New Radio (NR) , Non-terrestrial network (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 future fifth generation (5G) 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 NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , 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-prernises equipment (CPE) , an Internet of Things (loT) 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.

Recently, the 3rd Generation Partnership Project (3GPP) has initiated a study item to extend the applicability to non-terrestrial network (NTN) , more specifically being able to use the 5G radio access for satellite links, where the long round trip delay will have impact on HARQ design. The HARQ disabling mechanism should be studied in NTN in 3GPP.

The HARQ issue has been discussed and the problem of HARQ in NTN is that large propagation delays force an increase in the amount of HARQ-processes which seems to be impractical due to the extreme buffer size requirement for the receivers’s oft buffer and large signaling requirement on indicating the HARQ process number. The following two principles are captured for further study: enhancing existing HARQ operation and limiting HARQ capabilities and/or disabling HARQ.

The dynamic HARQ enabling mechanism can decide whether to disable the HARQ operation with retransmission packet by packet. In addition, service data and signaling as well as the different services have different QoS requirements, the HARQ enabling/disabling can be based on data types. The control signaling and the service with high Block Error Ratio (BLER) requirement can support the HARQ transmission and the service with low BLER requirement can disable the HARQ function. This can be implemented by dynamic scheduling. However, for uplink, due to the service packet is generated at the UE and the gNB cannot get timely information on the status of service packet through the buffer report due to the long propagation delay. For example, the gNB allocate the resources to the UE considering different kinds of service pending for transmission based on the latest received buffer status report (BSR) , if the service packet is generated after the previous buffer status report, even if the new buffer status report is triggered, the gNB on the satellite cannot receive the new buffer status report and the HARQ disabling can only depend on the received buffer status report.

There are some proposed HARQ disabling/enabling mechanisms For example, a HARQ process ID which is greater than the set of HARQ processes is used to indicate that HARQ ACK/NACK feedback is not to be sent. Different C-RNTIs may be used as UE identifiers, one C-RNTI identifier refers to the UE with normal HARQ operation, when another C-RNTI identifier refers to the same UE, but indicates that HARQ ACK/NACK feedback is not to be transmitted.

In addition, there are proposals to support differentiated HARQ operations for services with different reliability requirement in one UE and consider to selectively turn off HARQ. But how to support the selectively turning off HARQ as well as differentiated HARQ operations are not given. Especially, with consideration of the special issue in uplink system that the gNB will not know the timely information of UE side due to the long propagation delay, the uplink solution should be specially considered, but there is no uplink specific solution currently.

According to embodiments of the present disclosure, a service-based HARQ disabling/enabling mechanism in uplink is proposed. The HARQ is dynamically disabled/enabled based on service types. The terminal device determines whether the HARQ is enabled for the data packet. In this way, the disabling/enabling of HARQ is controlled dynamically considering the practical status of the system.

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. 1, which illustrates an example communication system 100 in which embodiments of the present disclosure may be implemented.

Fig. 1 illustrates a schematic diagram of a communication system 100 in which embodiments of the present disclosure can be implemented. The communication system 100, which is a part of a communication network, comprises terminal devices 110-1, 110-2, ..., ll0-N (collectively referred to as “terminal device (s) 110” where N is an integer number) . The communication system 100 comprises a network device 120. It should be understood that the communication system 100 may also comprise other elements which are omitted for the purpose of clarity. It is to be understood that the numbers of terminal devices and network devices shown in Fig. 1 are given for the purpose of illustration without suggesting any limitations. The network device 120 may communicate with the terminal devices 110.

It is to be understood that the number of network devices and terminal devices is only for the purpose of illustration without suggesting any limitations. The system 100 may include any suitable number of network devices and terminal devices adapted for implementing embodiments of the present disclosure. Although not shown, it would be appreciated that one or more terminal devices may be located in the cell 101 or 102.

Communications in the communication system 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) and the fifth generation (5G) 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.

Fig. 2 illustrates a schematic diagram of interactions 200 in accordance with embodiments of the present disclosure. The interactions 200 may be implemented at any suitable devices. Only for the purpose of illustrations, the interactions 200 are described to be implemented at the terminal device 110-1 and the network device 120.

The HARQ enable/disable can be individually supported for different types of services, for example, radio bearer. The network device 120 transmits 205 configurations of radio bearers to the terminal device 110-1. The configurations may be transmitted in downlink signalling, for example, Radio Resource Control (RRC) .

The HARQ for each radio bearer may be set into two states: “HARQ enabled” or “HARQ disabled. ” Table 1 below shows RadioBearerConfig information element of defining HARQ states for radio bearers.

Table 1

In this way, user plane data and control plane data as well as different kinds of service can be configured with different HARQ states. For example, the HARQ state of Signalling Radio Bearer (SRB) for control plane data may be configured with “HARQ enabled” and the Dedicated Radio Bearer (DRB) with high BLER requirement may also be configured with “HARQ enabled” , but the DRB with low BLER requirement may be configured with “HARQ disabled. ”

The HARQ for uplink may be dynamically disabled packet by packet. In some embodiments, the network device 120 may transmit an indication to the terminal device 110-1. The indication may indicate whether the network device 120 determine to disable the HARQ for the data packet. The network device 120 may determine the HARQ disabling during scheduling process. The indication may be transmitted in resource grant command, for example, downlink control information (DCI) .

The network device 120 may determine whether the HARQ is enabled for the data packet based on one of Buffer Status Report (BSR) , power headroom report (PHR) power and channel information between the terminal device 110-1 and the network device 120. Alternatively, the network device 120 may receive a Buffer Status Report (BSR) of some data from the terminal device 110-1.

In some embodiments, the network device 120 may transmit a default HARQ state (for example, “HARQ enabled” or “HARQ disabled” ) to the terminal device 110-1 through the RRC signalling. Alternatively, the default HARQ state may be preconfigured.

The terminal device 110-1 may generate 215 data. In some embodiments, the terminal device 110-1 may construct the Medium Access Control (MAC) Protocol Data Unit (PDU) based on the legacy Logical Channel Prioritization (LCP) procedure. The terminal device 110-1 determines 220 whether the HARQ is enabled/disabled for the logical channel on which the radio bearer is mapped to. In some embodiments, the terminal device 110-1 may check the radio bearers from which the Radio Link Control (RLC) PDU is put in the MAC PDU.

The terminal device 110-1 determines 230 enable/disable setting of HARQ for the data packet. The data packet comprises the data. In some embodiments, if the HARQ is enabled for the logical channel to which the radio bearer is mapped, the terminal device 110-1 may set that the HARQ is enabled for the data packet. If the HARQ is disabled for the logical channel to which the radio bearer is mapped, the terminal device 110-1 may determine whether the HARQ is enabled for other logical channels. If the HARQ is enabled for any one of the other logical channels, the terminal device 110-1 may set that the HARQ is enabled for the data packet. In some embodiments, if the HARQ is disabled for all logical channels in the data packet, the terminal device 110-1 may set that the HARQ is disabled for the data packet. In this way, the HARQ for the data packet can be disabled/enabled with latest information.

By way of an example, if the RLC PDU from any radio bearers which is configured with “HARQ enabled” is included in the MAC PDU, the terminal device 110-1 may set the setting of the MAC PDU to be “HARQ enabled. ” If the RLC PDUs from all the radio bearers which are configured with “HARQ disabled” is included in the MAC PDU, the terminal device 110-1 may set the setting of the MAC PDU to be “HARQ disabled. ”

For example, as shown in Fig. 3A, the MAC PDU may comprise the data packets from three logical channels. The SRB is mapped to logical channel 310. The DRB 1 and DRB2 are mapped to logical channel 320 and logical channel 330 respectively. The SRB and the DRB1 are configured with “HARQ enabled” and the DRB2 is configured with “HARQ disabled. ” In this example, since the SRB and the DRB1 are configured with “HARQ enabled” , the HARQ is also enabled for the MAD PDU 3010.

As another example, as shown in Fig. 3B, the MAC PDU may comprise the data from two logical channels (logical channel 340 and logical channel 350) . The DRB2 and DRB3 are mapped to logical channel 340 and logical channel 350, respectively. In this case, the DRB2 and DRB3 are both configured with “HARQ disabled. ” Thus, the HARQ is also disabled for the MAD PDU 3020.

In some embodiments, the terminal device 110-1 may determine the HARQ state further based on the buffer status and power consumption on the terminal device 110-1 side. For example, if the available buffer of the terminal device 110-1 is blow a threshold amount, the terminal device 110-1 may enable the HARQ for the data packet. If the amount of power consumption of the terminal device is above a threshold amount, the terminal device 110-1 may enable the HARQ for the data packet. Moreover, terminal device 110-1 may also determine the HARQ state based on the MAC control element (CE) type (or with/without MAC CE) in the MAC PDU. If the there is MAC CE in the data packet, the terminal device 110-1 may enable the HARQ for the data packet.

The terminal device 110-1 transmits 235 the data packet to the network device 120. In some embodiments, as mentioned above, the network device 120 may transmit the indication regarding whether the HARQ is enabled for the data packet. The terminal device 110-1 may compare 240 the indication with the determination regarding whether the HARQ is enabled for the data packet.

If the indication may indicate that the HARQ is disabled for the data packet and the terminal device 110-1 may also determine the HARQ is disabled for the data packet, the terminal device 110-1 may not transmit any information to the network device 120 regarding the HARQ. Similarly, if the indication may indicate that the HARQ is enabled for the data packet and the terminal device 110-1 may also determine the HARQ is enabled for the data packet, the terminal device 110-1 may not transmit any information to the network device 120 regarding the HARQ.

In some embodiments, the terminal device 110-1 may transmit 245 a request to enable/disable HARQ for the data packet. The request may be transmitted in uplink control information (UCI) . There may be a new indication bit introduced to indicate the request. Alternatively, the scheduling request may be reused to indicate the HARQ enable/disable request, which is different the conventional scheduling request. Since scheduling request is used to request the scheduling grant for buffer status report when there is no Physical Uplink Shared Channel (PUSCH) . And when the PUSCH is allocated resource, the scheduling request is not used. Therefore, it can define when the PUSCH is allocated resource, and the scheduling request can be used to indicate the HARQ enabling. With this solution, the new indication in UCI is not needed, it is simple with only new definition of the UE procedure. Then the network device will make corresponding HARQ operation based on the received HARQ enabling/disabling request.

If the indication may indicate that the HARQ is disabled for the data packet and the terminal device 110-1 may determine the HARQ is enabled for the data packet, the terminal device 110-1 may transmit a request to the network device 120 to enable the HARQ for the data packet.

If the indication may indicate that the HARQ is enabled for the data packet and the terminal device 110-1 may determine the HARQ is disabled for the data packet, the terminal device 110-1 may transmit a request to the network device 120 to disable the HARQ for the data packet.

In some embodiments, the terminal device 110-1 may obtain a default configuration indicating HARQ state. The terminal device 110-1 may transmit the request to enable/disable the HARQ function at the network device 120 regardless of the default HARQ state. Alternatively, ifthe terminal device 110-1 may determine that the HARQ is enabled for the data packet which is different from the default HARQ state, the terminal device 110-1 may transmit the request to enable the HARQ. If the terminal device 110-1 may determine that the HARQ is disabled for the data packet which is different from the default HARQ state, the terminal device 110-1 may transmit the request to disable the HARQ.

Alternatively, the terminal device 110-1 may not obtain any indication regarding the HARQ state or default HARQ state. The terminal device 110-1 may transmit the request to enable the HARQ to the network device 120 if the terminal device 110-1 determines that the HARQ is enabled for the data packet. The terminal device 110-1 may transmit the request to disable the HARQ to the network device 120 if the terminal device 110-1 determines that the HARQ is disabled for the data packet.

In some embodiments, the terminal device 110-1 may transmit BSR which includes the data amount for logical channel at time t1, the buffer status includes the data amount for logical channel 340 and logical channel 350. The DRB3 and DRB4 are mapped to logical channel 340 and logical channel 350, respectively. The DRB3 and DRB4 are both configured with “HARQ disabled. ” The network device 120 may receive the BSR at time t2 and allocate resources as well as disable the HARQ operation for the terminal device 110-1 based on the BSR at time t3. The terminal device 110-1 may receive the scheduling grant at time t4. In the duration between tl and t4, the new data of DRB1 is generated and DRB1 is configured with “HARQ enabled. ” Based on the LCP, the data of DRB1 is included in the MAC PDU, then the terminal device 110-1 may determine to enable the HARQ and transmit the request to the network device 120 to enable the HARQ. The network device 120 may turn on the HARQ function for this packet based on the received HARQ enabling request.

Fig. 4 shows a flowchart of an example method 400 implemented at a terminal device in accordance with some embodiments of the present disclosure. For the purpose of discussion, the method 300 will be described from the perspective of the terminal device 120 with reference to Fig. 1.

At block 410, the terminal device 110-1 obtains the HARQ configuration for the radio bearer the data to be transmitted from the terminal device to a network device. In some embodiments, the terminal device 110-1 may receive configurations of radio bearers. The configurations may be transmitted in downlink signaling, for example, Radio Resource Control (RRC) . The HARQ for each radio bearer may be set into two states “HARQ enabled” or “HARQ disabled. ”

The HARQ for uplink may be dynamically disabled packet by packet. In some embodiments, the terminal device 110-1 may receive an indication from the network device 120. The indication may indicate whether the network device 120 determine to disable the HARQ for the data packet. The indication may be transmitted in resource grant command, for example, downlink control information (DCI) .

At block 420, the terminal device 110-1 determines whether the HARQ is enabled/disabled for the a logical channel to which the radio bearer is mapped based on the configuration of the radio bearer. In some embodiments, the terminal device 110-1 may check the radio bearers from which the Radio Link Control (RLC) PDU is put in the MAC PDU.

At block 430, the terminal device 110-1 determines the enable/disable setting of the HARQ for the data packet from the logical channel based on the determination. By way of an example, if the RLC PDU from any radio bearers which is configured with “HARQ enabled” is included in the MAC PDU, the terminal device 110-1 may set the setting of the MAC PDU to be “HARQ enabled. ” If the RLC PDUs from all the radio bearers which are configured with “HARQ disabled” is included in the MAC PDU, the terminal device 110-1 may set the setting of the MAC PDU to be “HARQ disabled. ”

Fig. 5 illustrates a flow char of a method of configuring the setting of the HARQ according to some embodiments of the present disclosure. It should be noted that the method shown in Fig. 5 is only an example.

At block 510, the terminal device 110-1 may determine whether the HARQ is enabled/disabled for the logical channel. If the HARQ is enabled for the logical channel, the terminal device 110-1 may set, at block 540, that the HARQ is enabled for the data packet. If the HARQ is disabled for the logical channel, the terminal device 110-1 may determine, at block 520, whether the HARQ is enabled for other logical channels.

If the HARQ is enabled for any one of the other logical channels, the terminal device 110-1 may set, at block 540, that the HARQ is enabled for the data packet.

If the HARQ is disabled for all other logical channels, the terminal device 110-1 may set, at block 530, that the HARQ is disabled for the data packet. In this way, the HARQ for the data packet can be disabled/enabled with latest information.

Referring back to Fig. 4. At block 440, the terminal device 110-1 transmits the data packet to the network device 120. In some embodiments, as mentioned above, the network device 120 may transmit the indication regarding whether the HARQ is enabled for the data packet. The terminal device 110-1 may compare the indication with the determination regarding whether the HARQ is enabled for the data packet.

In some embodiments, the terminal device 110-1 may transmit a request to enable/disable HARQ for the data packet. The request may be transmitted in uplink control information (UCI) . There may be a new indication bit introduced to indicate the request. Alternatively, the scheduling request may be used to indicate the HARQ enable/disable request. Since scheduling request is used to request the scheduling grant for buffer status report when there is no Physical Uplink Shared Channel (PUSCH) . And when the PUSCH is allocated resource, the scheduling request is not used. Therefore, it can define when the PUSCH is allocated resource, and the scheduling request can be used to indicate the HARQ enabling. With this solution, the new indication in UCI is not needed, it is simple with only new definition of the UE procedure. Then the network device will make corresponding HARQ operation based on the received HARQ enabling/disabling request.

In some embodiments, the terminal device 110-1 may obtain a default configuration indicating whether HARQ is enabled/disabled for the data packet. The terminal device 110-1 may transmit the request to enable/disable the HARQ function at the network device 120 despite of the default HARQ state. Alternatively, if the terminal device 110-1 may determine that the HARQ is enabled for the data packet which is different from the default HARQ state, the terminal device 110-1 may transmit the request to enable the HARQ. If the terminal device 110-1 may determine that the HARQ is disabled for the data packet which is different from the default HARQ state, the terminal device 110-1 may transmit the request to disable the HARQ.

In some embodiments, the terminal device 110-1 may transmit, at time tl, BSR which includes the data amount for logical channel the buffer status includes the data amount for logical channel 340 and logical channel 350. The DRB3 and DRB4 are mapped to logical channel 340 and logical channel 350, respectively. The DRB3 and DRB4 are both configured with “HARQ disabled. ” The network device 120 may receive the BSR at time t2 and allocate resources as well as disable the HARQ operation for the terminal device 110-1 based on the BSR at time t3. The terminal device 110-1 may receive the scheduling grant at time t4. In the duration between t1 and t4, the new data of DRB1 is generated and DRB1 is configured with “HARQ enabled. ” Based on the LCP, the data of DRB1 is included in the MAC PDU, then the terminal device 110-1 may determine to enable the HARQ and transmit the request to the network device 120 to enable the HARQ. The network device 120 may turn on the HARQ function for this packet based on the received HARQ enabling request.

In this way, the service based dynamic HARQ enabling/disabling for uplink in non-terrestrial network (NTN) can be supported. The HARQ can be dynamically disabled considering the practical status of the system such as the dynamic status of the UE buffer status, power consumption as well as the real data type in the packet, thus the QoS such as the latency, jitter as well as the reliability can be guaranteed.

In some embodiments, an apparatus for performing the methods 400 and 500 (for example, the terminal device 110-1) may comprise respective means for performing the corresponding steps in the

methods

400 and 500. These means may be implemented in any suitable manners. For example, it can be implemented by circuitry or software modules.

In some embodiments, the apparatus comprises means for obtaining a configuration of a radio bearer for data to be transmitted from a terminal device to a network device; means for determining whether Hybrid Automatic Repeat Request (HARQ) is enabled/disabled for a logical channel to which the radio bearer is mapped based on the configuration of the radio bearer; means for determining, based on the determination, enable/disable setting of HARQ for a data packet comprising the data from the logical channel; and means for transmitting the data packet to the network device.

In some embodiments, the means for determining whether HARQ is enabled for the logical channel comprises: means for receiving the configuration of the radio bearer from the network device, the configuration comprising an indication as to whether the HARQ is enabled/disabled for the radio bearer; and means for determining whether the HARQ is enabled/disabled for the logical channel to which the radio bearer is mapped based on the indication.

In some embodiments, the means for determining enable/disable setting of HARQ for the data packet comprises: means for in response to a determination that the HARQ is enabled for the logical channel, enabling the HARQ for the data packet comprising the data from the logical channel.

In some embodiments, the apparatus further comprises: means for in response to a determination that the HARQ is disabled for each of further logical channels, disabling the HARQ for the data packet comprising further data from the further logical channels.

In some embodiments, the apparatus further comprises: mans for receiving, from the network device, a further indication as to whether HARQ is enabled/disabled for the data packet; and means for in response to the indication that the HARQ is enabled for the data packet, transmitting a request to disable HARQ for the data packet.

In some embodiments, the apparatus further comprises: means for determining a default configuration indicating whether HARQ is enabled/disabled for the data packet; and means for in response to the default configuration indicating the HARQ is enabled for the data packet, transmitting a request to disable the HARQ for the data packet.

In some embodiments, the apparatus further comprises: means for transmitting a request to disable HARQ for the data packet.

In some embodiments, the apparatus further comprises: means for receiving, from the network device, a further indication as to whether HARQ is enabled/disabled for the data packet; and means for in response to the indication that the HARQ is disabled for the data packet, transmitting a request to enable HARQ for the data packet.

In some embodiments, the apparatus further comprises: means for transmitting a request to enable HARQ for the data packet.

In some embodiments, the means for configuring enable/disable setting of HARQ for the data packet comprises: means for enabling the HARQ for the data packet, in response to one of: the available buffer of the terminal device being above a threshold amount, the amount of power consumption of the terminal device being above a threshold amount, or an occurrence of a control element in the data packet.

In some embodiments, the apparatus further comprises: means for determining a default configuration indicating whether HARQ is enabled/disabled for the data packet; and means for in response to the default configuration indicating the HARQ is disabled for the data packet, transmitting a request to enable the HARQ for the data packet.

In some embodiments, the request to enable the HARQ for the data packet is transmitted in uplink control information (UCI) or scheduling request.

In some embodiments, the request to disable the HARQ for the data packet is transmitted in uplink control information (UCI) or scheduling request.

Fig. 6 shows a flowchart of an example method 600 implemented at a terminal device in accordance with some embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described frorn the perspective of the terminal device 110-1 with reference to Fig. 1.

At block 610, the network device 120 transmits the configurations of radio bearers to the terminal device 110-1. The configuration indicates whether HARQ is enabled/disabled for a logical channel to which the radio bearer is mapped. The configurations may be transmitted in downlink signalling, for example, Radio Resource Control (RRC) . The HARQ for each radio bearer may be set into two states: “HARQ enabled” or “HARQ disabled. ”

At block 620, the network device 120 may transmit the indication as to whether the HARQ is enabled/disabled for the data packet. The data packet comprises data from the logical channel. In some embodiments, the network device 120 may transmit a default HARQ state.

In some embodiments, the network device 120 may determine whether the HARQ is enabled for the data packet based on one of: the available buffer of the terminal device, the power headroom report of the terminal device, or channel information between the terminal device and the network device.

At block 630, the network device 120 receives the data packet from the terminal device 110-1. In some embodiments, the network device 120 may receive the request to enable/disable the HARQ function at the network device 120.

In some embodiments, an apparatus for performing the method 600 (for example, the terminal device 120) may comprise respective means for performing the corresponding steps in the method 600. These means may be implemented in any suitable manners. For example, it can be implemented by circuitry or software modules.

In some embodiments, the apparatus comprises: means for transmitting, to a terminal device, a configuration of a radio bearer for data, the configuration indicating whether HARQ is enabled/disabled for the a logical channel to which the radio bearer is mapped; means for transmitting an indication as to whether HARQ is enabled for a data packet comprising the data from the logical channel;; and means for receiving the data packet from the network device.

In some embodiments, the means for determining whether the HARQ is enabled for the data packet based on one of: the available buffer of the terminal device, a buffer status report from the terminal device, a power headroom report fiom the terminal device, or channel information between the terminal device and the network device.

In some embodiments, the apparatus comprises means for receiving a request to enable HARQ for the data packet in uplink control information (UCI) or scheduling request.

In some embodiments, the apparatus comprises means for receiving a request to disable HARQ for the data packet in uplink control information (UCI) or scheduling request.

FIG. 7 is a simplified block diagram of a device 700 that is suitable for implementing embodiments of the present disclosure. The device 700 may be provided to implement the communication device, for example the network device 120 or the terminal device 110-1 as shown in Fig. 1. 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 module (for example, transmitters and/or receivers (TX/RX) ) 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 6. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some 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 shows an example of the computer readable medium 800 in form of CD or DVD. The computer readable medium has the program 730 stored thereon.

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 600 as described above with reference to Figs. 2-6. 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.

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 including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the terminal device to:

obtain a configuration of a radio bearer for data to be transmitted from the terminal device to a network device;

determine whether Hybrid Automatic Repeat Request (HARQ) is enabled/disabled for a logical channel to which the radio bearer is mapped based on the configuration of the radio bearer;

determine, based on the determination, enable/disable setting of HARQ for a data packet comprising the data from the logical channel; and

transmit the data packet to the network device.
The terminal device of claim 1, wherein the terminal device is caused to determine whether HARQ is enabled for the logical channel by:

receiving the configuration of the radio bearer from the network device, the configuration comprising an indication as to whether the HARQ is enabled/disabled for the radio bearer; and

determining whether the HARQ is enabled/disabled for the logical channel to which the radio bearer is mapped based on the indication.
The terminal device of claim 1, wherein the terminal device is caused to determine enable/disable setting of HARQ for the data packet by:

in response to a determination that the HARQ is enabled for the logical channel, enabling the HARQ for the data packet comprising the data from the logical channel.
The terminal device of claim 1, wherein the terminal device is caused to determine enable/disable setting of HARQ for the data packet by:

in response to a determination that the HARQ is disabled for each of further logical channels, disabling the HARQ for the data packet comprising further data from the further logical channels.
The terminal device of claim 4, wherein the terminal device is further caused to:

receive, from the network device, a further indication as to whether HARQ is enabled/disabled for the data packet; and

in response to the indication that the HARQ is enabled for the data packet, transmit a request to disable HARQ for the data packet.
The terminal device of claim 4, wherein the terminal device is further caused to:

transmit a request to disable HARQ for the data packet.
The terminal device of claim 4, wherein the terminal device is further caused to:

determine a default configuration indicating whether HARQ is enabled/disabled for the data packet; and

in response to the default configuration indicating the HARQ is enabled for the data packet, transmit a request to disable the HARQ for the data packet.
The terminal device of any one of claims 5-7, wherein the request to disable the HARQ for the data packet is transmitted in uplink control information (UCI) or scheduling request.
The terminal device of claim 3, wherein the terminal device is further caused to:

receive, from the network device, a further indication as to whether HARQ is enabled/disabled for the data packet; and

in response to the indication that the HARQ is disabled for the data packet, transmit a request to enable HARQ for the data packet.
The terminal device of claim 3, wherein the terminal device is further caused to:

transmit a request to enable HARQ for the data packet.
The terminal device of claim 3, wherein the terminal device is further caused to:

determine a default configuration indicating whether HARQ is enabled/disabled for the data packet; and

in response to the default configuration indicating the HARQ is disabled for the data packet, transmit a request to enable the HARQ for the data packet.
The terminal device of any one of claims 9-11, wherein the request to enable the HARQ for the data packet is transmitted in uplink control information (UCI) or scheduling request.
The terminal device of claim 1, wherein the terminal device is caused to configure enable/disable setting of HARQ for the data packet by:

enabling the HARQ for the data packet, in response to one of:

available buffer of the terminal device being above a threshold amount,

the amount of power consumption of the terminal device being above a threshold amount, or

an occurrence of a control element in the data packet.
A network device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the network device to:

transmit, to a terminal device, a configuration of a radio bearer for data, the configuration indicating whether HARQ is enabled/disabled for a logical channel to which the radio bearer is mapped;

transmit an indication as to whether HARQ is enabled for a data packet comprising the data from the logical channel; and

receive the data packet from the network device.
The network device of claim 14, wherein the network device is caused to transmit the indication as to whether HARQ is enabled for the data packet by:

determining whether the HARQ is enabled for the data packet based on one of:

available buffer of the terminal device,

a buffer status report from the terminal device,

a power headroom report from the terminal device, or

channel information between the terminal device and the network device.
The network device of claim 14, wherein the network device is further caused to:

receive a request to enable HARQ for the data packet in uplink control information (UCI) or scheduling request.
The network device of claim 14, wherein the network device is further caused to:

receive a request to disable HARQ for the data packet in uplink control information (UCI) or scheduling request.
A method comprising:

obtaining a configuration of a radio bearer for data to be transmitted from a terminal device to a network device;

determining whether Hybrid Automatic Repeat Request (HARQ) is enabled/disabled for a logical channel to which the radio bearer is mapped based on the configuration of the radio bearer;

determining, based on the determination, enable/disable setting of HARQ for a data packet comprising the data from the logical channel; and

transmitting the data packet to the network device.
The method of claim 18, wherein determining whether HARQ is enabled for the logical channel comprises:

receiving the configuration of the radio bearer from the network device, the configuration comprising an indication as to whether the HARQ is enabled/disabled for the radio bearer; and

determining whether the HARQ is enabled/disabled for the logical channel to which the radio bearer is mapped based on the indication.
The method of claim 18, wherein configuring enable/disable setting of HARQ for the data packet comprises:

in response to a determination that the HARQ is enabled for the logical channel, enabling the HARQ for the data packet comprising the data from the logical channel.
The method of claim 18, wherein determining enable/disable setting of HARQ for the data packet comprises:

in response to a determination that the HARQ is disabled for each of further logical channels, disabling the HARQ for the data packet comprising further data from the further logical channels.
The method of claim 21, further comprising:

receiving, from the network device, a further indication as to whether HARQ is enabled/disabled for the data packet; and

in response to the indication that the HARQ is enabled for the data packet, transmitting a request to disable HARQ for the data packet.
The method of claim 21, further comprising:

transmitting a request to disable HARQ for the data packet.
The method of claim 21, further comprising:

determining a default configuration indicating whether HARQ is enabled/disabled for the data packet; and

in response to the default configuration indicating the HARQ is enabled for the data packet, transmitting a request to disable the HARQ for the data packet.
The method of any one of claims 22-24, wherein the request to disable the HARQ for the data packet is transmitted in uplink control information (UCI) or scheduling request.
The method of claim 20, further comprising:

receiving, from the network device, a further indication as to whether HARQ is enabled/disabled for the data packet; and

in response to the indication that the HARQ is disabled for the data packet, transmitting a request to enable HARQ for the data packet.
The method of claim 20, further comprising:

transmitting a request to enable HARQ for the data packet.
The method of claim 20, further comprising:

determining a default configuration indicating whether HARQ is enabled/disabled for the data packet; and

in response to the default configuration indicating the HARQ is disabled for the data packet, transmitting a request to enable the HARQ for the data packet.
The method of any one of claims 26-28, wherein the request to enable the HARQ for the data packet is transmitted in uplink control information (UCI) or scheduling request.
The method of claim 18, wherein configuring enable/disable setting of HARQ for the data packet comprises:

enabling the HARQ for the data packet, in response to one of:

available buffer of the terminal device being above a threshold amount,

the amount of power consumption of the terminal device being above a threshold amount, or

an occurrence of a control element in the data packet.
A method comprising:

transmitting, to a terminal device, a configuration of a radio bearer for data, the configuration indicating whether HARQ is enabled/disabled for a logical channel to which the radio bearer is mapped;

transmitting an indication as to whether HARQ is enabled for a data packet comprising the data from the logical channel; and

receiving the data packet from the network device.
The method of claim 31, wherein transmitting the indication as to whether HARQ is enabled for the data packet comprises:

determining whether the HARQ is enabled for the data packet based on one of:

available buffer of the terminal device,

a buffer status report from the terminal device,

a power headroom report from the terminal device, or

channel information between the terminal device and the network device.
The method of claim 31, further comprising:

receiving a request to enable HARQ for the data packet in uplink control information (UCI) or scheduling request.
The method of claim 31, further comprising:

receiving a request to disable HARQ for the data packet in uplink control information (UCI) or scheduling request.
An apparatus, comprising:

means for obtaining a configuration of a radio bearer for data to be transmitted from a terminal device to a network device;

means for determining whether Hybrid Automatic Repeat Request (HARQ) is enabled/disabled for a logical channel to which the radio bearer is mapped based on the configuration of the radio bearer;

means for determining, based on the determination, enable/disable setting of HARQ for a data packet comprising the data from the logical channel; and

means for transmitting the data packet to the network device.
An apparatus, comprising:

means for transmitting, to a terminal device, a configuration of a radio bearer for data, the configuration indicating whether HARQ is enabled/disabled for a logical channel to which the radio bearer is mapped;

means for transmitting an indication as to whether HARQ is enabled for a data packet comprising the data from the logical channel; and

means for receiving the data packet from the network device.
A computer readable medium storing instructions thereon, the instructions, when executed by at least one processing unit of a machine, causing the machine to perform the method according to any one of claims 18-34.