WO2022222062A1

WO2022222062A1 - Sidelink assistance mechanism

Info

Publication number: WO2022222062A1
Application number: PCT/CN2021/088695
Authority: WO
Inventors: Dong Li; Saeed Reza KHOSRAVIRAD; Tao Tao; Yong Liu
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2021-04-21
Filing date: 2021-04-21
Publication date: 2022-10-27
Also published as: CN117356063A

Abstract

Example embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable storage media of sidelink assistance transmission. The method comprises: transmitting, to a second device, a message indicating quality of a channel between first and second devices; receiving first control information in connection with a data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and at least one of a group of third devices, the first control information is configurable to be transmitted, based on the quality of the channel, either directly from the second device to the first device, or from the second device to the first device via the at least one of the group of third devices; and communicating the data transmission with the second device via the at least one sidelink channel based on the first control information.

Description

SIDELINK ASSISTANCE MECHANISM

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to devices, methods, apparatus and computer readable storage media of sidelink assistance mechanism.

BACKGROUND

In the 5G New Radio (NR) system, Industrial Internet of Things (IIoT) is one of the important vertical domains for triggering and enabling the industrial 4.0 revolution. There are generally stringent requirements in reliability and latency for end-to-end transmissions, especially for the wireless transmissions over the air interface. For example, for factory automation and motion control applications, 6 to 8 nines of service availability are required within the one-way latency budget of 0.5 to 2.0ms.

In the IIoT scenarios, a base station (e.g., gNB) may transmit critical command messages to the actuator devices to implement the actions of the command, meanwhile in uplink, some devices, e.g. sensor device may transmit measurement results to the serving gNB. In the typical IIoT environments which usually have various metallic clutters, some of the devices (e.g., UEs) may occasionally experience poor radio channel conditions due to channel fading, shadowing, blocking and etc. As a result, when directly communicating with the serving gNB, they may have very low signal noise ratio (SNR) temporally. Under such poor channel conditions, very low spectral efficiency transmission formats are used to satisfy the reliability requirements. In other words, the network may have to allocate an excessive amount of time/frequency resources for the low SNR transmissions. In practical application, the excessive resource allocation is often prohibitive.

SUMMARY

In general, example embodiments of the present disclosure provide a solution of sidelink assistance mechanism.

In a first aspect, there is provided a first device. The first 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 first device at least to: transmit, to a second device, a message indicating quality of a channel between the first device and the second device; receive first control information in connection with a data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and at least one of a group of third devices, wherein the first control information is configurable to be transmitted, based on the quality of the channel, either directly from the second device to the first device, or from the second device to the first device via the at least one of the group of third devices; and communicate the data transmission with the second device via the at least one sidelink channel based on the first control information.

In a second aspect, there is provided a second device. The second 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 second device at least to: receive, from a first device, a message indicating quality of a first channel between the first device and the second device; transmit to at least one of a group of third devices, based on the quality of the first channel, an indication for assisting in communicating a data transmission between the first device and the second device; transmit first control information and second control information for the data transmission, wherein the first control information is in connection with the data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and the at least one of the group of third devices, and the second control information is in connection with a second channel between the second device and the at least one of the group of third devices for the data transmission; and communicate the data transmission with the first device via the at least one sidelink channel based at least on the first control information.

In a third aspect, there is provided a third device. The third 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 third device at least to: receive, from a second device, an indication for assisting in communicating a data transmission between a first device and the second device; receive, from the second device, first control information and second control information, wherein the first control information is in connection with a data transmission to be communicated between the first device and the second device via a sidelink channel between the first device and the third device, the second control information is in connection with a channel between the second device and the third device for the data transmission; and support the data transmission between the first device and the second device by using the sidelink channel based at least on the first control information.

In a fourth aspect, there is provided a method. The method comprises: transmitting, at a first device and to a second device, a message indicating quality of a channel between the first device and the second device; receiving first control information in connection with a data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and at least one of a group of third devices, wherein the first control information is configurable to be transmitted, based on the quality of the channel, either directly from the second device to the first device, or from the second device to the first device via the at least one of the group of third devices; and communicating the data transmission with the second device via the at least one sidelink channel based on the first control information.

In a fifth aspect, there is provided a method. The method comprises: receiving, at a second device and from a first device, a message indicating quality of a first channel between the first device and the second device; transmitting to at least one of a group of third devices, based on the quality of the first channel, an indication for assisting in communicating a data transmission between the first device and the second device; transmitting first control information and second control information for the data transmission, wherein the first control information is in connection with the data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and the at least one of the group of third devices, and the second control information is in connection with a second channel between the second device and the at least one of the group of third devices for the data transmission; and communicating the data transmission with the first device via the at least one sidelink channel based at least on the first control information.

In a sixth aspect, there is provided a method. The method comprises: receiving, at a third device and from a second device, an indication for assisting in communicating a data transmission between a first device and the second device; receiving, from the second device, first control information and second control information, wherein the first control information is in connection with a data transmission to be communicated between the first device and the second device via a sidelink channel between the first device and the third device, the second control information is in connection with a channel between the second device and the third device for the data transmission; and supporting the data transmission between the first device and the second device by using the sidelink channel based at least on the first control information.

In a seventh aspect, there is provided a first apparatus comprising: means for transmitting, to a second device, a message indicating quality of a channel between the first apparatus and the second device; means for receiving first control information in connection with a data transmission to be communicated between the first apparatus and the second device using at least one sidelink channel between the first apparatus and at least one of a group of third devices, wherein the first control information is configurable to be transmitted, based on the quality of the channel, either directly from the second device to the first apparatus, or from the second device to the first apparatus via the at least one of the group of third devices; and means for communicating the data transmission with the second device via the at least one sidelink channel based on the first control information.

In an eighth aspect, there is provided a second apparatus comprising: means for receiving, from a first device, a message indicating quality of a first channel between the first device and the second apparatus; means for transmitting to at least one of a group of third devices, based on the quality of the first channel, an indication for assisting in communicating a data transmission between the first device and the second apparatus; means for transmitting first control information and second control information for the data transmission, wherein the first control information is in connection with the data transmission to be communicated between the first device and the second apparatus using at least one sidelink channel between the first device and the at least one of the group of third devices, and the second control information is in connection with a second channel between the second apparatus and the at least one of the group of third devices for the data transmission; and means for communicating the data transmission with the first device via the at least one sidelink channel based at least on the first control information.

In a ninth aspect, there is provided a third apparatus comprising: means for receiving, from a second device, an indication for assisting in communicating a data transmission between a first device and the second device; means for receiving, from the second device, first control information and second control information, wherein the first control information is in connection with a data transmission to be communicated between the first device and the second device via a sidelink channel between the first device and the third apparatus, the second control information is in connection with a channel between the second device and the third apparatus for the data transmission; and means for supporting the data transmission between the first device and the second device by using the sidelink channel based at least on the first control information.

In a tenth aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the fourth aspect.

In a eleventh aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the fifth aspect.

In a twelfth aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the sixth aspect.

Other features and advantages of the embodiments of the present disclosure will also be apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure are presented in the sense of examples and their advantages are explained in greater detail below, with reference to the accompanying drawings, where

FIG. 1A shows a schematic diagram of an example deployment of UE-to-network relay in a communication architecture;

FIG. 1B shows a schematic diagram of layer 3 user plane protocol stack for relaying the terminal device to the network in the communication architecture;

FIG. 1C shows a schematic diagram of layer 2 user plane protocol stack for relaying the terminal device to the network in the communication architecture;

FIG. 2 shows an example environment in which example embodiments of the present disclosure can be implemented;

FIG. 3 shows a schematic diagram of layer 1 protocol stack for sidelink assistance mechanism according to some example embodiments of the present disclosure;

FIG. 4 shows a signaling chart illustrating a sidelink assistance transmission procedure according to some example embodiments of the present disclosure;

FIG. 5 shows a schematic diagram of a control resource set (CORESET) allocated for the sidelink assistance transmission according to some example embodiments of the present disclosure;

FIG. 6A shows a schematic diagram of the CORESET and a common search space (CSS) allocated for the downlink sidelink assistance transmission according to some example embodiments of the present disclosure;

FIG. 6B shows a schematic diagram of the CORESET and a common search space (CSS) allocated for the uplink sidelink assistance transmission according to some example embodiments of the present disclosure;

FIG. 7 shows a flowchart of an example method for sidelink assistance transmission according to some example embodiments of the present disclosure;

FIG. 8 shows a flowchart of an example method for sidelink assistance transmission according to some example embodiments of the present disclosure;

FIG. 9 shows a flowchart of an example method for sidelink assistance transmission according to some example embodiments of the present disclosure;

Fig. 10 illustrates a simplified block diagram of an apparatus that is suitable for implementing embodiments of the present disclosure; and

FIG. 11 shows 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 example 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 functionalities of various elements. 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 fifth generation (5G) systems, 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) 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) new radio (NR) 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 Next Generation NodeB (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 network device is allowed to be defined as part of a gNB such as for example in CU/DU split in which case the network device is defined to be either a gNB-CU or a gNB-DU.

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 (IoT) 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. The terminal device may also correspond to Mobile Termination (MT) part of the integrated access and backhaul (IAB) node (a.k.a. a relay node) . In the following description, the terms “terminal device” , “communication device” , “terminal” , “end device” , “stations” , “STA” , “user equipment” and “UE” may be used interchangeably.

In the legacy communication architecture, such as, in a LTE system, UE-to-network relaying may be implemented for assisting remote UEs or weak UEs which have poor or no direct connectivity to the network in communicating with the base station. FIG. 1A shows a schematic diagram of an example deployment of UE-to-network relay in a communication architecture 100. As shown in FIG. 1A, the remote UE 110 suffers from poor radio channel conditions, the relay UE 130 has relatively good radio channel conditions, and the eNB 120 is a network device that serves the remote UE 110 and the relay UE 130. The eNB 120 is connected to the evolved packet core (EPC) 140.

In order to improve the communication quality of the remote UE 110, the relay UE 130 may support downlink (DL) and uplink (UL) transmissions for the remote UE 110 via the device-to-device (D2D) sidelink interface. For example, in downlink data transmissions, the relay UE 130 may receive and decode data from the eNB 120 and then forward the data to remote UE 110 over a sidelink channel. In uplink data transmissions, the relay UE 130 may firstly decode the data transmitted by the remote UE 110 over the sidelink channel and then relay the data to the eNB 120 over uplink interface. In this way, the D2D relaying can be effectively implemented and thus enhance a reliability of weak UEs in a low latency budget.

Typically, the UE-to-network relaying is based on Layer 3 protocol stack and mainly for public safety usage. By UE-to-network relaying, the network coverage is extended. Additionally or alternatively, the power consumption for the remote UEs (e.g. the wearable devices) may be reduced by connecting to the network through relay UEs, such as mobile phones. FIG. 1B shows a schematic diagram of Layer 3 user plane protocol stack for relaying the terminal device to the network device in the communication architecture. As shown in FIG. 1B, the relay UE receives DL data from the eNB and decode the DL data in L1 Uu interface. The relay UE then processes and delivers the data from Medium Access Control (MAC) , Radio Link Control (RLC) to Packet Data Convergence Protocol (PDCP) sublayer until to the IP layer. Subsequently, a generally inverse processing procedure has to be conducted from the PDCP sublayer to L1 via the PC5 interface before forwarding to the remote UE over the sidelink.

The cumbersome relaying operations in the above UE-to-network relaying mechanism may lead to additional latency which is particularly undesirable in latency sensitive scenarios, such as, the Ultra-Reliable Low Latency Communication (URLLC) or IIoT scenario. In addition, such a layer 2 and /or layer 3 relaying mechanism may be difficult to cooperatively implement among multiple relay UEs with reasonable efficiency. For example, the multiple relay nodes need to use orthogonalized sidelink resources, which may increase latency and reduce resource utilization efficiency.

In 3GPP NR Rel-17, layer 2 and /or layer 3 based UE-to-network relaying and UE-to-UE relaying mechanisms are developed for providing enhanced functionalities and flexibility. FIG. 1C shows a schematic diagram of layer 2 user plane protocol stack for relaying the terminal device to the network in the communication architecture. As shown in the FIG. 1C, the relaying protocol structure is implemented at the RLC sublayer, which causes similar technical issues to the L3 based UE-to-network relaying mechanism as discussed above for the potential usage in the latency sensitive URLLC/IIoT scenarios.

In order to solve the above and other potential problems, embodiments of the present disclosure provide a sidelink assistance transmission mechanism. In general, the sidelink assistance transmission mechanism is implemented at layer 1, and the base station can transmit first control information and second control information in a flexible and bundled manner. The first control information is in connection with the data transmission to be communicated between the weak UE or remote UE and the base station by using at least one sidelink channel between the weak UE or remote UE and at least one relay UE, and the second control information is in connection with a second channel between the base station and the at least one relay UE. As such, control information can be transmitted with a relatively low overhead, while the requirement of latency and reliability in various scenarios can be met.

FIG. 2 shows an example environment 200 in which example embodiments of the present disclosure can be implemented. As shown in FIG. 2, the network system 200 includes a first device 210, a second device 220 and a group of third devices 230-1 and 230-2, which may be collectively referred to as third device 230. Further, there is an obstacle 202 which degrades the radio channel condition of the first device 210. It should be understood that although obstacle 202 is illustrated as a physical block, it is given as an example of the factors resulting in the channel fading, shadowing or blocking, without suggesting any limitations. The obstacle 202 may be other factors than a physical block.

The first device 210 and the group of third devices 230-1 and 230-2 may be terminal devices, such as, UEs, sensors, and so on. The first device 210 and the third device 230 are served by the second device 220. However, due to the obstacle 202, the quality of the channel 204 between the first device 210 and the second device may be poor, while the quality of channels 206 and 208 between the third devices 230-1 and 230-2 and the second device 220 may be good and stable.

Further, the first device 210 and the third device 230 may communicate with each other over

sidelink channels

212 and 214. The

sidelink channels

212 and 214 may be physical sidelink shared channel (PSSCH) and/or physical sidelink control channel (PSCCH) .

The first device 210 and the third device 230 may monitor the quality of respective channels 204 to 208. Once monitoring an emergency event that may threaten the reliability of data transmission, a corresponding one or more of the first device 210 and the third device 230 may notify the second device 220 of the emergency event. For example, the first device 210 may monitor the poor channel condition, and thus need the sidelink assistance provided by the group of third devices 230-1 and 230-2. As such, the group of third devices 230-1 and 230-2 may act as relay devices for supporting the data transmission between the first device 210 and the second device 220, which will be discussed in details below.

The sidelink assistance mechanism implemented among the first device 210, the second device 220 and the third device 230 may be supported at layer 1. FIG. 3 shows a schematic diagram of layer 1 protocol stack for sidelink assistance mechanism according to some example embodiments of the present disclosure. As shown in FIG. 3, the relay procedure is entirely implemented at layer 1 without the cumbersome operations for delivery the data transmission at layer 2 or layer 3.

The sidelink assistance mechanism may be triggered in either an explicit manner or an implicit manner. Specifically, the first device 210 may transmit a message indicating quality of the channel 204 to the second device 220. The message may include, but not limited to, a channel quality indicator feedback indicating the quality of the channel 204 being below a channel quality threshold or indicating the quality level of the channel 204, an acknowledgement (ACK) feedback, a non-acknowledgement (NACK) feedback for triggering an emergency event related to the quality of the channel 204, a sidelink assistance request for communicating the data transmission via the

sidelink channel

212 and 214 due to the quality of the channel 204, and so on.

The second device 220 may be a network device of the RAN, for example, the gNB, and provide radio coverage for the

terminal devices

210 and 230. The second device 220 may transmit control information or data transmission to the first device 210 and the third device 230 in downlink channel, such as, physical downlink control channel (PDCCH) or physical downlink shared channel (PDSCH) . The second device 220 may also receive data transmission from the first device 210 and the third device 230 in uplink channel, such as, physical uplink shared channel (PUSCH) .

A channel such as the channel 204 may comprise a downlink communication link established from the second device 220 to the first device 210 and/or an uplink communication link established from the first device 210 to the second device 220. The first device 210 may derive the quality of the channel 204 from downlink signal (s) received in the downlink communication link of the channel 204. The first device 210 may report the quality of the channel 204 in the message to the second device 220. The second device 220 may determine or derive the quality of the channel 204 based at least in part on the channel quality indicator feedback reported from the first device 210. In an example embodiment, the quality of the channel 204 may indicate how good/bad the quality of the downlink communication/link of the channel 204 is. For example, the quality of the channel 204 may indicate a suitable downlink transmission data rate in the downlink communication link of the channel 204. In an example embodiment, the quality of the channel 204 may indicate how good/bad the quality of the uplink communication link of the channel 204 is. For example, the second device 220 may determine, based on the quality of the channel 204 reported from the first device 210, the quality of the uplink communication link of the channel 204 according to a channel reciprocity property between the downlink and uplink communication links of the channel 204.

The second device 220 may transmit control information (e.g., downlink control information (DCI) ) for DL assignment or UL grant for downlink or uplink transmission by means of sidelink assistance mechanism. The control information may include first control information that is in connection with the data transmission to be communicated between the first device 210 and the second device 220 using at least one sidelink channel between the first device 210 and the at least one of the group of third devices 230-1 and 230-2. The control information may further include second control information that is in connection with a second channel between the second device 220 and the at least one of the group of third devices 230-1 and 230-2 for the data transmission. In the example as shown in FIG. 2, the second channel may be at least one of the channels 206 and 208.

The second device 220 may configure a control resource set (CORESET) and a corresponding common search space (CSS) set for the control information. In some example embodiments, the second device 220 may transmit sidelink assistance configuration information comprising the control resource set and/or the search space set. The control resource set and the search space set may be transmitted together or separately, and the scope of the present disclosure is not limited in this regard.

For example, the control resource set may include

physical resource blocks (PRBs) in frequency domain and

(e.g., 1, 2 or 3) symbols in time domain, which constitute

number of control channel elements (CCEs) in an interleaved or non-interleaved manner. The control resource set may be a common CORESET shared by the first device 210 and the group of third device 230.

The CSS set is associated with the CORESET, and includes a set of candidate resources for PDCCH for the first device 210 and the group of third devices 230-1 and 230-2 to monitor. By way of example, in an NR system, the CSS set may be a Type3-PDCCH CSS set. The CSS set may be defined as in NR system including indications of the periodicity and offset of the PDCCH search space set, the candidate PDCCH occasions within each period, the supported aggregation level (AL) and an associated number of candidate resources on PDCCH and a potential supported downlink control information formats.

In some example embodiments, the CSS set may be deactivated by default. The second device 220 may activate the CSS for the first and

third devices

210 and 230 via dynamic signaling, such as, MAC Control Element (CE) . From the perspective of the weak UEs that have or soon to have very poor channel quality or fail to decode data packets in a transmission cycle thus in survival time mode, they may assume that the CSS set is activated after a certain period of time of the emergency event.

In some example embodiments, upon receipt of the message indicating the quality of the channel 204 form the first device 210, the second device 220 may select a group of relay devices, e.g., the group of third devices 230-1 and 230-2. The second device 220 may then transmit an indication to the group of third devices 230-1 and 230-2 for providing sidelink assistance to the first device 210.

Although in the context of the present disclosure, the first device 210 is described to be the “weak UE” that suffers from a poor channel condition, and the group of the third device 230 is described to be the relay UE, in some cases, the roles of the weak UE and the relay UE can be interchangeable. For example, when the channel condition experienced by the first device 210 is improved, while the channel condition experienced by the third device 230 becomes worse, the first device 120 may act as the relay UE and the third device 230 may be the “weak UE” . In these cases, the first device 210 may support the data transmission between the third device 230 and the second device 220 via the

sidelink channel

212 or 214.

It is to be understood that the number of terminal devices and network device shown in FIG. 2 is given for the purpose of illustration without suggesting any limitations. The network architecture 200 may include any suitable number of terminal devices, network devices and additional devices adapted for implementing implementations of the present disclosure. Although illustrated as mobile phones and base station, the first device 210, the third device 230 and the second device 220 may be other device than mobile phones, base station, or a part of the same.

Depending on the communication technologies, the network architecture 200 may be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Address (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency-Division Multiple Access (OFDMA) network, a Single Carrier-Frequency Division Multiple Access (SC-FDMA) network or any others. Communications discussed in the network 100 may conform to any suitable standards including, but not limited to, New Radio Access (NR) , Long Term Evolution (LTE) , LTE-Evolution, LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , Code Division Multiple Access (CDMA) , cdma2000, and Global System for Mobile Communications (GSM) and the like. Furthermore, the communications may be performed according to any generation of communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, 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) communication protocols. The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, certain aspects of the techniques are described below for LTE, and LTE terminology is used in much of the description below.

Principle and implementations of the present disclosure will be described in detail below with reference to FIGs. 4 to 9. FIG. 4 shows a schematic diagram of layer 1 protocol stack for sidelink assistance transmission according to some example embodiments of the present disclosure. For the purpose of discussion, the process 400 will be described with reference to FIG. 2. The process 400 may involve the first device 210, the second device 220 and the third device 230.

The second device 220 transmits 405, to the first device 210, sidelink assistance configuration information. The sidelink assistance configuration information may include the CORESET and/or a CSS set for control information for downlink and/or uplink transmission with sidelink assistance. Likewise, the second device 220 transmits 410 the sidelink assistance configuration information to the third device 230. The CORESET and the CSS set are shared by the first device 210 and the third device 230.

In some example embodiments, the CORESET may be allocated by the second device 220 for the sidelink assisted transmission. By way of example, under the NR Rel-15 framework, assuming the CORESET includes 96 PRBs over two OFDM symbols, i.e. there are totally 32 CCEs with logical indexes from 0 to 31. Furthermore, the CSS set on PDCCH is configured to be associated with the CORESET. Table 1 shows an example aggregation level (AL) and the associated number of candidate resources on PDCCH per aggregation level.

Table 1. the supported AL and associated number of candidate resources on PDCCH

AL (L)	Number of candidates (M)
2	8
4	4
8	4
16	2

FIG. 5 shows a schematic diagram of the CORESET configured for the sidelink assisted transmission according to some example embodiments of the present disclosure.

The first device 210 may monitor the quality of the channel 204, and transmit 415 a message indicating quality of the channel 204 between the first device 210 and the second device 220. For example, once monitoring an emergency event that may threaten reliability of the data transmission between the first device 210 and the second device 220, the first device 210 may notify the second device 220 of the emergency event.

For another example, the first device 210 may transmit regular feedback to the second device 220, such as, channel quality indicator (CQI) . The CQI feedback may be lower than a predetermined threshold.

Alternatively, the first device 210 may transmit ACK/NACK feedback to the second device 220. The NACK feedback may trigger the emergency event. Note that the NACK may imply that the first device 210 is in emergent survival time mode in some application scenarios, e.g., consecutive errors may lead to service unavailability.

For still another example, the first device 210 may transmit a sidelink assistance request for communicating the data transmission via the

sidelink channels

212 and 214 due to the quality of the channel 204. The degradation of the quality of the channel 204 may already occur or may be estimated to occur soon, for example, based on machine learning prediction. The sidelink assistance request may trigger the emergency event.

In response to the message, the second device 220 selects a group of relay devices for providing sidelink assistance, that is, the group of third devices 230-1 and 230-2. The selection of relay devices may be based on prior information on locations, device grouping, etc. The second device 220 transmits 420 an indication to the group of third device 230 for indicating providing sidelink assistance to the data transmission between the first device 210 and the second device220. For example, the indication may include the Radio Network Temporary Identity (RNTI) of the first device 210 and optionally additional information related to the relaying operations or semi-persistent scheduling. The indication may be transmitted via dynamic signaling, e.g. MAC CE with or without the data payload of the third device 230.

The second device 220 transmits control information (e.g., DCI) to the first device 210 and the group of third device 230. The control information may include first control information that is in connection with the data transmission to be communicated between the first device 210 and the second device 220 by using at least one

sidelink channel

212 and 214 between the first device 210 and the at least one of the group of third devices 230-1 and 230-2. The control information may further include second control information that is in connection with a second channel 206 or 208 between the second device 220 and the at least one of the group of third devices 230-1 and 230-2 for the data transmission.

The first control information may be configurable to be transmitted based on the quality of the channel 204. In other words, the first control information may be transmitted directly from the second device 220 to the first device 210, or alternatively from the second device 220 to the first device 210 via the at least one of the group of third devices 230-1 and 230-2.

In some example embodiments, the first control information may be transmitted after or at the same time with a transmission of the second control information. In some other example embodiments, the first control information may be transmitted before or at the same time with a transmission of the second control information. In a case where the first control information is transmitted not later than the second control information, the interface-irrelevant control information can be transmitted only in the first control information on first PDCCH, and there is no need to transmit the interface-irrelevant control information in the second control information on second PDCCH. The interface-irrelevant control information may be referred to the information that is needed for decoding transport blocks but not relevant to the Uu or sidelink interface.

In the former case where the first control information is transmitted directly from the second device 220 to the first device 210, the second device 220 may transmit 425 the first control information on a first downlink control channel (e.g., the first PDCCH) and transmit 430 the second control information on a second downlink control channel (e.g., the second PDCCH) that is different from the first PDCCH. In this case, the AL of the first PDCCH is higher than or equal to the AL of the second PDCCH.

The first PDCCH may be monitored by the first device 210 and the at least one of the group of third devices 230-1 and 230-2, and the second PDCCH may be monitored by the at least one of the group of third devices 230-1 and 230-2. In other words, the first device 210 may receive the first control information, while the third device 230 may receive both the first control information and the second control information.

In the above case, the second device 220 may further transmit information indicating a bundling relation between the first PDCCH and the second PDCCH on at least one of the first and second PDCCHs. The information may include at least one of an occasion position of the first PDCCH in the CSS set, an occasion position of the second PDCCH in the CSS set, the AL of the first PDCCH, the AL of the second PDCCH, a Hybrid Automatic Repeat request, HARQ, process identification value for the first PDCCH, a HARQ process identification value for the second PDCCH and so on.

FIG. 6A shows a schematic diagram of the CORESET and the CSS allocated for the downlink sidelink assistance transmission according to some example embodiments of the present disclosure. As shown in FIG. 6A, the transmission of the second control information on the second PDCCH is before the transmission of the first control information on the first PDCCH. Alternatively, the transmissions of the first and second control information may occur at the same time. The AL of first PDCCH is not less than that of the second PDCCH. Information relevant to the associated first PDCCH is also transmitted on the second PDCCH, such as, information related to the location of the first PDCCH. For example, the information indicating the bundling relation may include a 2-bit indicator for an interval of the bundled PDCCHs, such as, ‘01’ means the bundled first PDCCH is located in the next monitored occasion, as shown in Figure 6A by arrow 601. The information may also include a 2-bit indicator for AL difference of the bundled PDCCHs, such as, ‘01’ means that the first PDCCH is one level higher than the second PDCCH in AL, e.g. AL2 for the second PDCCH and AL4 for the first PDCCH.

FIG. 6B shows a schematic diagram of the CORESET and the CSS allocated for the uplink sidelink assistance transmission according to some example embodiments of the present disclosure. As shown in FIG. 6B, for UL data transmission, the transmission of the first control information on the first PDCCH is before the transmission of the second control information on the second PDCCH. Alternatively, the transmissions of the first and second control information may occur at the same time. Additionally, the AL of first PDCCH is not less than the AL of the second PDCCH. As such, the same information fields described above can be provided by the first PDCCH.

In the latter case where the first control information is transmitted from the second device 220 to the first device 210 via the at least one of the group of third devices 230-1 and 230-2, the second device 220 may transmit 435 the first control information and the second control information on a same PDCCH between the second device 220 and the third device 230. In this case, upon receipt of the first and second control information, the third device 230 may transmit 440, to the first device 210, the first control information on at least one

sidelink channel

212 or 214.

As mentioned above, the first control information may be configurable to be transmitted based on the quality of the channel 204. In some example embodiments, if the quality of the channel 204 is greater than a first threshold and lower than a second threshold, where the first threshold is less than the second threshold, the first control information may be transmitted on the first PDCCH, while the second control information may be transmitted on the second PDCCH.

In some other example embodiments, if the quality of the channel 204 is lower than the first threshold, the first control information is transmitted with the second control information on the same PDCCH. In this case, the PDCCH channel from the second device 220 to the first device 210 may be too poor to transmit DCI, and thus the first control information is barely to be decoded even with relatively large AL.

In still other example embodiments, if the quality of the channel 204 is greater than the second threshold, the second device 220 may determine that the quality of the channel 204 is good and thus there is no need to trigger the sidelink assistance mechanism.

From the perspective of the first device 210, it may not be aware of whether the first control information is transmitted on the first PDCCH or on the

sidelink channel

212 or 214. In some example embodiments, the first device 210 may monitor the first PDCCH based on the CORESET and the associated CSS set. If the first control information is not detected on the first PDCCH, the first device 210 may monitor the

sidelink channel

212 or 214 to detect the first control information.

Steps 445 to 460 illustrate a downlink transmission between the first device 210 and the second device 220 by means of sidelink assistance supported by the group of third devices 230-1 and 230-2.

The second device 220 transmits 445 the data transmission to the at least one of the group of third device 230 based on the second control information.

Upon receipt of the data transmission, the third device 230 may decode 450 the data transmission, and then encode 455 into a sidelink transmission. The third device 230 transmits 460 the sidelink transmission on the sidelink channel 212 and/or 214 based on the first control information. The first device 210 then receives the sidelink transmission on the at least one sidelink channel 212 and/or 214 based on the first control information.

Steps 465 to 480 illustrate an uplink transmission between the first device 210 and the second device 220 by means of sidelink assistance supported by the group of third devices 230-1 and 230-2. The first device 210 transmits 465, to the at least one of the group of third device 230, a sidelink transmission on the at least one sidelink channel 212 and/or 214 based on the first control information.

The corresponding third device 230 receives the sidelink transmission based on the first control information. The third device 230 decodes 470 the sidelink transmission, and then encodes 475 the decoded sidelink transmission into the data transmission. The third device 230 transmits 480, to the second device 220, the data transmission based on the second control information.

According to the example embodiments of the present disclosure, there is provided a sidelink assistance transmission mechanism which is implemented at layer 1 of the network architecture. With the bundled PDCCH structure, the two PDCCHs that schedule the transmissions over different interface (e.g., Uu and sidelink interfaces) are associated together. It is also beneficial to reduce the blind decoding for PDCCHs at the receiver.

Further, the network device (e.g., gNB) is capable of transmitting control information for sidelink assistance transmission among the terminal devices on a bundled control channel. In this way, the control information can be reliably received by the terminal devices that may suffer from a poor channel condition, and the control information has a reasonable size and thus the robustness would not be impacted.

FIG. 7 shows a flowchart of an example method 700 for sidelink assistance transmission according to some example embodiments of the present disclosure. The method 700 can be implemented at a terminal device, e.g., the first device 210 described with reference to FIG. 2.

At 710, the first device 210 transmits, to the second device 220, a message indicating quality of a channel 204 between the first device 210 and the second device 220. The message may include at least one of a channel quality indicator feedback indicating the quality of the channel 204 being below a channel quality threshold or indicating the quality level of the channel 204, an acknowledgement feedback, a non-acknowledgement feedback for triggering an emergency event related to the quality of the channel 204 and a sidelink assistance request for communicating the data transmission via the sidelink channel 212 and/or 214 due to the quality of the channel 204.

At 720, the first device 210 receives first control information in connection with a data transmission to be communicated between the first device 210 and the second device 220 using at least one

sidelink channel

212 or 214 between the first device 210 and at least one of a group of third devices 230. The first control information may be configurable to be transmitted, based on the quality of the channel 204, either directly from the second device 220 to the first device 210, or from the second device 220 to the first device 210 via the at least one of the group of third devices 230.

In some example embodiments, the first device 210 may receive the first control information either directly from the second device 220, or from the second device 220 via the at least one of the group of third devices 230.

At 730, the first device 210 communicates the data transmission with the second device 220 via the at least one

sidelink channel

212 or 214 based on the first control information.

In some example embodiments of downlink transmission, the first device 210 may receive, from the at least one of the group of third devices 230, a sidelink transmission on the at least one

sidelink channel

212 or 214 based on the first control information. The sidelink transmission may be generated by the at least one of the group of third devices 230 by decoding the data transmission based on second control information that is transmitted from the second device 220 to the at least one of the group of third devices 230.

In some example embodiments of uplink transmission, the first device 210 may transmit, to the at least one of the group of third devices 230, a sidelink transmission on the at least one

sidelink channel

212 or 214 based on the first control information. The sidelink transmission may be encoded to the data transmission by the at least one of the group of third devices 230 based on second control information that is transmitted from the second device 220 to the at least one of the group of third devices 230.

In some example embodiments, the first device 210 may receive, from the second device 220, sidelink assistance configuration information comprising a control resource set and/or a search space set. The control resource set and search space may correspond to the first control information, and the search space is shared by the group of third devices 230 and the first device 210.

According to the example embodiments of the present disclosure, there is provided a sidelink assistance transmission mechanism which is implemented at layer 1 of the network architecture. With the improved mechanism, the data transmission, such as, URLLC communications can be supported by relaying terminal devices without introducing much latency or reducing resource utilization efficiency by cumbersome operations at layer 2 or layer 3. As such, the downlink and uplink data transmission can be implemented and the requirements of reliability and latency can be met by means of sidelink assistance.

FIG. 8 shows a flowchart of an example method 800 for sidelink assistance transmission according to some example embodiments of the present disclosure. The method 800 can be implemented at a network device of the RAN, e.g., the second device 220 described with reference to FIG. 2.

At 810, the second device 220 receives, from the first device 210, a message indicating quality of a first channel 204 between the first device 210 and the second device 220. The message may include at least one of a channel quality indicator feedback indicating the quality of the first channel 204 being below a channel quality threshold or indicating the quality level of the first channel 204, an acknowledgement feedback, a non-acknowledgement feedback for triggering an emergency event related to the quality of the first channel 204, and a sidelink assistance request for performing the data transmission via the at least one

sidelink channel

212 or 214 due to the quality of the first channel 204.

At 820, the second device 220 transmits to at least one of a group of third devices 230, based on the quality of the first channel 204, an indication for assisting in communicating a data transmission between the first device 210 and the second device 220.

At 830, the second device 220 transmits first control information and second control information for the data transmission. The first control information may be in connection with the data transmission to be communicated between the first device 210 and the second device 220 using at least one

sidelink channel

212 or 214 between the first device 210 and the at least one of the group of third devices 230. The second control information may be in connection with a second channel between the second device 220 and the at least one of the group of third devices 230 for the data transmission.

In some example embodiments, the second device 220 may transmit the first control information based on the quality of the first channel 204, either directly from the second device 220 to the first device 210 and the at least one of the group of third devices 230, or alternatively from the second device 220 to the first device 210 via the at least one of the group of third devices 230. The second device 220 may also transmit the second control information to the at least one of the group of third devices 230.

In some example embodiments, a first channel quality condition may indicate that the quality of the first channel 204 exceeds a first channel quality threshold and not exceeds a second channel quality threshold, and the second channel quality threshold may be larger than the first channel quality threshold.

In the above embodiments, the second device 220 may transmit the first control information on a first downlink control channel, and the first downlink control channel is monitored by the first device 210 and the at least one of the group of third devices 230. The second device 220 may also transmit the second control information on a second downlink control channel that is different from the first downlink control channel, and the second downlink control channel is monitored by the at least one of the group of third devices 230. The aggregation level of the first downlink control channel may be higher than or equal to the aggregation level of the second downlink control channel.

In some example embodiments, the second device 220 may transmit the first control information after or at the same time with a transmission of the second control information.

In some other example embodiments, the second device 220 may transmit the first control information before or at the same time with a transmission of the second control information.

In some example embodiments, the second device 220 may further transmit, to the at least one of the group of third device 230, information indicating a bundling relation between the first downlink control channel and the second downlink control channel on at least one of the first and second downlink control channels. The information may include at least one of an occasion position of the first downlink control channels in a search space set, an occasion position of the second downlink control channels in a search space set, the aggregation level of the first downlink control channels, the aggregation level of the second downlink control channels, a Hybrid Automatic Repeat request, HARQ, process identification value for the first downlink control channel; and a HARQ process identification value for the second downlink control channel.

In some example embodiments, the second device 220 may transmit the first control information and the second control information to the at least one of the group of third devices 230 on a downlink control channel between the second device 220 and the at least one of the group of third devices 230. The first control information may be forwarded by the at least of the group of third devices 230 to the first device 210 on at least one

sidelink channel

212 or 214 between the first device 210 and the at least one of the group of third devices 230.

At 840, the second device 220 communicates the data transmission with the first device 210 via the at least one

sidelink channel

212 or 214 based at least on the first control information.

In some example embodiments of downlink transmission, the second device 220 may transmit the data transmission to the at least one of the group of third devices 230 based on the second control information. The data transmission may be decoded by the at least one of the group of third devices 230, and encoded into a sidelink transmission to the first device 210 based on the first control information.

In some example embodiments of uplink transmission, the second device 220 may receive the data transmission from the at least one of the group of third devices 230 based on the second control information. The data transmission may be generated by the at least one of the group of third devices 230, from a sidelink transmission from the first device 210 based on the first control information.

In some example embodiments, the second device 220 may transmit, to the first device 210 and the at least one of the group of third devices 230, sidelink assistance configuration information comprising a control resource set and/or a search space set. The control resource set and the search space may correspond to the first control information, and the search space is shared by the group of third devices 230 and the first device 210.

According to the example embodiments of the present disclosure, there is provided a sidelink assistance transmission mechanism which is implemented at layer 1 of the network architecture. With the improved mechanism, the network device (e.g., gNB) is capable of transmitting control information for sidelink assistance transmission among the terminal devices on a bundled control channel. In this way, the control information can be reliably received by the terminal devices that may suffer from a poor channel condition. Further, the control information has a reasonable size and thus the robustness would not be impacted.

FIG. 9 shows a flowchart of an example method 900 for sidelink assistance transmission according to some example embodiments of the present disclosure. The method 900 can be implemented at a terminal device, e.g., the third device 230 described with reference to FIG. 2.

At 910, the third device 230 receives, from the second device 220, an indication for assisting in communicating a data transmission between the first device 210 and the second device 220.

At 920, the third device 230 receives first control information and second control information from the second device 220. The first control information may be in connection with a data transmission to be communicated between the first device 210 and the second device 220 via a

sidelink channel

212 or 214 between the first device 210 and the third device 230. The second control information may be in connection with a channel between the second device 220 and the third device 230 for the data transmission.

In some example embodiments, the third device 230 may receive the first control information on a first downlink control channel, and the first downlink control channel is monitored by the first device 210 and the third device 230. The third device 230 may also receive the second control information on a second downlink control channel that is different from the first downlink control channel, and the second downlink control channel may be monitored by the third device 230. The aggregation level of the first downlink control channel may be higher than or equal to the aggregation level of the second downlink control channel.

In some example embodiments, the third device 230 may receive the first control information after or at the same time with a receipt of the second control information.

In some other example embodiments, the third device 230 may receive the first control information before or at the same time with a receipt of the second control information.

In some other example embodiments, the third device 230 may further receive, from the second device 220, information indicating a bundling relation between the first downlink control channel and the second downlink control channel on at least one of the first and second downlink control channels. The information may be at least one of an occasion position of the first downlink control channels in a search space set, an occasion position of the second downlink control channels in a search space set, the aggregation level of the first downlink control channels, the aggregation level of the second downlink control channels, a Hybrid Automatic Repeat request, HARQ, process identification value for the first downlink control channels; and a HARQ process identification value for the second downlink control channels.

In some other example embodiments, the first control information and the second control information may be received on a downlink control channel between the second device 220 and the third device 230.

In some other example embodiments, the third device 230 may further transmit, to the first device 210, the first control information on at least one

sidelink channel

212 or 214 between the first device 210 and the third device 230.

At 930, the third device 230 supports the data transmission between the first device 210 and the second device 220 by using the sidelink channel 212 and/or 214 based at least on the first control information.

In some example embodiments, the third device 230 may receive, from the second device 220, the data transmission based on the second control information. The third device 230 may decode the data transmission and then encode the decoded data transmission into a sidelink transmission. The third device 230 may transmit the sidelink transmission to the first device 210 based on the first control information.

In some example embodiments, the third device 230 may receive, from the first device 210, a sidelink transmission based on the first control information. The third device 230 may decode the sidelink transmission and then encode the decoded sidelink transmission into a data transmission. The third device 230 may transmit the data transmission to the second device 220 based on the second control information.

In some example embodiments, the third device 230 may receive, from the second device 220, sidelink assistance configuration information comprising a control resource set and/or a search space set. The control resource set and the search space may correspond to the first control information, and the search space is shared by a plurality of devices including the third device 230 and the first device 210.

According to the example embodiments of the present disclosure, there is provided a sidelink assistance transmission mechanism which is implemented at layer 1 of the network architecture. With the improved mechanism, the terminal devices that experience relatively good and stable channel condition are capable of supporting downlink or uplink data transmission between a terminal device that suffers from poor channel condition and the network device by D2D relaying. Further, control information for the sidelink assistance transmission has a reasonable size and thus the robustness would not be impacted. In this way, the requirements of reliability, latency, and communication quality can be improved, which is beneficial to the latency sensitive URLLC/IIoT scenarios.

In some example embodiments, a first apparatus capable of performing the method 700 (for example, the first device 210) may comprise means for performing the respective steps of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first device 210. In some embodiments, the means may comprise 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 performance of the first apparatus.

In some example embodiments, the first apparatus comprises: means for transmitting, to a second device, a message indicating quality of a channel between the first apparatus and the second device; means for receiving first control information in connection with a data transmission to be communicated between the first apparatus and the second device using at least one sidelink channel between the first apparatus and at least one of a group of third devices, wherein the first control information is configurable to be transmitted, based on the quality of the channel, either directly from the second device to the first apparatus or from the second device to the first apparatus via the at least one of the group of third devices; and means for communicating the data transmission with the second device via the at least one sidelink channel based on the first control information.

In some example embodiments, the message comprises at least one of the following: a channel quality indicator feedback indicating the quality of the first channel being below a channel quality threshold or indicating the quality level of the first channel; an acknowledgement feedback; a non-acknowledgement feedback for triggering an emergency event related to the quality of the first channel; and a sidelink assistance request for performing the data transmission via the at least one sidelink channel due to the quality of the first channel.

In some example embodiments, the means for receiving the first control information comprises: means for receiving the first control information either directly from the second device, or from the second device via the at least one of the group of third devices.

In some example embodiments, the means for communicating the data transmission comprises: means for receiving, from the at least one of the group of third devices, a sidelink transmission on the at least one sidelink channel based on the first control information, wherein the sidelink transmission is generated by the at least one of the group of third devices by decoding the data transmission based on second control information that is transmitted from the second device to the at least one of the group of third devices.

In some example embodiments, the means for communicating the data transmission comprises: means for transmitting, to the at least one of the group of third devices, a sidelink transmission on the at least one sidelink channel based on the first control information, wherein the sidelink transmission is to be encoded to the data transmission by the at least one of the group of third devices based on second control information that is transmitted from the second device to the at least one of the group of third devices.

In some example embodiments, the first apparatus further comprises: means for receiving, from the second device, sidelink assistance configuration information comprising a control resource set and/or a search space set, wherein the control resource set and search space correspond to the first control information, and the search space is shared by the group of third devices and the first apparatus.

In some example embodiments, the first apparatus comprises a terminal device, the second device comprises a network deice, and the group of third devices comprises a group of further terminal devices.

In some example embodiments, a second apparatus capable of performing the method 800 (for example, the second device 220) may comprise means for performing the respective steps of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second device 220. In some embodiments, the means may comprise 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 performance of the second apparatus.

In some example embodiments, the second apparatus comprises: means for receiving, from a first device, a message indicating quality of a first channel between the first device and the second apparatus; means for transmitting to at least one of a group of third devices, based on the quality of the first channel, an indication for assisting in communicating a data transmission between the first device and the second apparatus; means for transmitting first control information and second control information for the data transmission, wherein the first control information is in connection with the data transmission to be communicated between the first device and the second apparatus using at least one sidelink channel between the first device and the at least one of the group of third devices, and the second control information is in connection with a second channel between the second apparatus and the at least one of the group of third devices for the data transmission; and means for communicating the data transmission with the first device via the at least one sidelink channel based at least on the first control information.

In some example embodiments, the means for transmitting the first control information and the second control information comprises: means for transmitting the first control information based on the quality of the first channel, either directly from the second apparatus to the first device and the at least one of the group of third devices, or from the second apparatus to the first device via the at least one of the group of third devices; and means for transmitting the second control information to the at least one of the group of third devices.

In some example embodiments, a first channel quality condition indicates that the quality of the first channel exceeds a first channel quality threshold and not exceeds a second channel quality threshold, the second channel quality threshold is larger than the first channel quality threshold, and the means for transmitting the first control information and the second control information by: means for transmitting the first control information on a first downlink control channel, wherein the first downlink control channel is monitored by the first device and the at least one of the group of third devices; and means for transmitting the second control information on a second downlink control channel that is different from the first downlink control channel, wherein the second downlink control channel is monitored by the at least one of the group of third devices.

In some example embodiments, an aggregation level of the first downlink control channel is higher than or equal to an aggregation level of the second downlink control channel.

In some example embodiments, the means for transmitting the first control information and the second control information comprises: means for transmitting the first control information after or at the same time with a transmission of the second control information.

In some example embodiments, the means for transmitting the first control information and the second control information comprises: means for transmitting the first control information before or at the same time with a transmission of the second control information.

In some example embodiments, the second apparatus further comprises: means for transmitting, to the at least one of the group of third device, information indicating a bundling relation between the first downlink control channel and the second downlink control channel on at least one of the first and second downlink control channels, the information comprising at least one of the following: an occasion position of the first downlink control channels in a search space set; an occasion position of the second downlink control channels in a search space set; the aggregation level of the first downlink control channels; the aggregation level of the second downlink control channels; a Hybrid Automatic Repeat request, HARQ, process identification value for the first downlink control channel; and a HARQ process identification value for the second downlink control channel.

In some example embodiments, a first channel quality condition indicates that the quality of the first channel is below a first channel quality threshold, and the means for transmitting first control information and second control information comprises: means for transmitting the first control information and the second control information to the at least one of the group of third devices on a downlink control channel between the second apparatus and the at least one of the group of third devices, wherein the first control information is forwarded by the at least of the group of third devices to the first device on at least one sidelink channel between the first device and the at least one of the group of third devices.

In some example embodiments, the means for communicating the data transmission comprises: means for transmitting the data transmission to the at least one of the group of third devices based on the second control information, wherein the data transmission is decoded by the at least one of the group of third devices, and encoded into a sidelink transmission to the first device based on the first control information.

the means for communicating the data transmission comprises: means for receiving the data transmission from the at least one of the group of third devices based on the second control information, wherein the data transmission is generated by the at least one of the group of third devices, from a sidelink transmission from the first device based on the first control information.

In some example embodiments, the second apparatus further comprises: means for transmitting, to the first device and the at least one of the group of third devices, sidelink assistance configuration information comprising a control resource set and/or a search space set, wherein the control resource set and the search space correspond to the first control information, and the search space is shared by the group of third devices and the first device.

In some example embodiments, the first device comprises a terminal device, the second apparatus comprises a network deice, and the group of third devices comprises a group of further terminal devices.

In some example embodiments, a third apparatus capable of performing the method 900 (for example, the third device 230) may comprise means for performing the respective steps of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the third device 230. In some embodiments, the means may comprise 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 performance of the third apparatus.

In some example embodiments, the third apparatus comprises: means for receiving, from a second device, an indication for assisting in communicating a data transmission between a first device and the second device; means for receiving, from the second device, first control information and second control information, wherein the first control information is in connection with a data transmission to be communicated between the first device and the second device via a sidelink channel between the first device and the third apparatus, the second control information is in connection with a channel between the second device and the third apparatus for the data transmission; and means for supporting the data transmission between the first device and the second device by using the sidelink channel based at least on the first control information.

In some example embodiments, the means for receiving the first control information and the second control information comprises: means for receiving the first control information on a first downlink control channel, wherein the first downlink control channel is monitored by the first device and the third apparatus; and means for receiving the second control information on a second downlink control channel that is different from the first downlink control channel, wherein the second downlink control channel is monitored by the third apparatus.

In some example embodiments, the means for receiving the first control information and the second control information comprises: means for receiving the first control information after or at the same time with a receipt of the second control information.

In some example embodiments, the means for receiving the first control information and the second control information comprises: means for receiving the first control information before or at the same time with a receipt of the second control information.

In some example embodiments, the third apparatus further comprises: means for receiving, from the second device, information indicating a bundling relation between the first downlink control channel and the second downlink control channel on at least one of the first and second downlink control channels, the information comprising at least one of the following: an occasion position of the first downlink control channels in a search space set; an occasion position of the second downlink control channels in a search space set; the aggregation level of the first downlink control channels; the aggregation level of the second downlink control channels; a Hybrid Automatic Repeat request, HARQ, process identification value for the first downlink control channels; and a HARQ process identification value for the second downlink control channels.

In some example embodiments, the first control information and the second control information are received on a downlink control channel between the second device and the third apparatus.

In some example embodiments, the third apparatus further comprises: means for transmitting, to the first device, the first control information on at least one sidelink channel between the first device and the third apparatus.

In some example embodiments, the means for supporting the data transmission comprises: means for receiving, from the second device, the data transmission based on the second control information; means for decoding the data transmission; means for encoding the decoded data transmission into a sidelink transmission; and means for transmitting, to the first device, the sidelink transmission, based on the first control information.

In some example embodiments, the means for supporting the data transmission comprises: means for receiving, from the first device, a sidelink transmission based on the first control information; means for decoding the sidelink transmission; means for encoding the decoded sidelink transmission into the data transmission; and means for transmitting, to the second device, the data transmission on based on the second control information.

In some example embodiments, the third apparatus further comprises: means for receiving, from the second device, sidelink assistance configuration information comprising a control resource set and/or a search space set, wherein the control resource set and the search space correspond to the first control information, and the search space is shared by a plurality of devices including the third apparatus and the first device.

In some example embodiments, the first device comprises a terminal device, the second device comprises a network deice, and the third apparatus comprises a further terminal device.

FIG. 10 is a simplified block diagram of a device 1000 that is suitable for implementing embodiments of the present disclosure. The device 1000 may be provided to implement the communication device, for example the first device 210, the second device 220 or the third device 230 as shown in FIG. 2. As shown, the device 1000 includes one or more processors 1010, one or more memories 1020 coupled to the processor 1010, and one or more transmitters and receivers (TX/RX) 1040 coupled to the processor 1010.

The TX/RX 1040 is for bidirectional communications. The TX/RX 1040 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 1010 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 1000 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 1020 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) 1024, 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) 1022 and other volatile memories that will not last in the power-down duration.

A computer program 1030 includes computer executable instructions that are executed by the associated processor 1010. The program 1030 may be stored in the ROM 1020. The processor 1010 may perform any suitable actions and processing by loading the program 1030 into the RAM 1020.

The embodiments of the present disclosure may be implemented by means of the program 1030 so that the device 1000 may perform any process of the disclosure as discussed with reference to FIGs. 7-9. 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 1030 may be tangibly contained in a computer readable medium which may be included in the device 1000 (such as in the memory 1020) or other storage devices that are accessible by the device 1000. The device 1000 may load the program 1030 from the computer readable medium to the RAM 1022 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. 11 shows an example of the computer readable medium 1100 in form of CD or DVD. The computer readable medium has the program 1030 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, device, 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

methods

700, 800, and 900 as described above with reference to FIGs. 7-9. 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 device, 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, device 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, device, 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 first device comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to:

transmit, to a second device, a message indicating quality of a channel between the first device and the second device;

receive first control information in connection with a data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and at least one of a group of third devices, wherein the first control information is configurable to be transmitted, based on the quality of the channel, either directly from the second device to the first device, or from the second device to the first device via the at least one of the group of third devices; and

communicate the data transmission with the second device via the at least one sidelink channel based on the first control information.
The first device of Claim 1, wherein the message comprises at least one of the following:

a channel quality indicator feedback indicating the quality of the channel being below a channel quality threshold;

an acknowledgement feedback;

a non-acknowledgement feedback for triggering an emergency event related to the quality of the channel; and

a sidelink assistance request for communicating the data transmission via the sidelink channel due to the quality of the channel.
The first device of Claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to receive the first control information by:

receiving the first control information either directly from the second device, or from the second device via the at least one of the group of third devices.
The first device of Claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to communicate the data transmission by:

receiving, from the at least one of the group of third devices, a sidelink transmission on the at least one sidelink channel based on the first control information, wherein the sidelink transmission is generated by the at least one of the group of third devices by decoding the data transmission based on second control information that is transmitted from the second device to the at least one of the group of third devices.
The first device of Claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the first device to communicate the data transmission by:

transmitting, to the at least one of the group of third devices, a sidelink transmission on the at least one sidelink channel based on the first control information, wherein the sidelink transmission is to be encoded to the data transmission by the at least one of the group of third devices based on second control information that is transmitted from the second device to the at least one of the group of third devices.
The first device of Claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the first device to:

receive, from the second device, sidelink assistance configuration information comprising a control resource set and/or a search space set, wherein the control resource set and search space correspond to the first control information, and the search space is shared by the group of third devices and the first device.
The first device of Claim 1, wherein the first device comprises a terminal device, the second device comprises a network deice, and the group of third devices comprises a group of further terminal devices.
A second device comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to:

receive, from a first device, a message indicating quality of a first channel between the first device and the second device;

transmit to at least one of a group of third devices, based on the quality of the first channel, an indication for assisting in communicating a data transmission between the first device and the second device;

transmit first control information and second control information for the data transmission, wherein the first control information is in connection with the data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and the at least one of the group of third devices, and the second control information is in connection with a second channel between the second device and the at least one of the group of third devices for the data transmission; and

communicate the data transmission with the first device via the at least one sidelink channel based at least on the first control information.
The second device of Claim 8, wherein the message comprises at least one of the following:

a channel quality indicator feedback indicating the quality of the first channel being below a channel quality threshold;

an acknowledgement feedback;

a non-acknowledgement feedback for triggering an emergency event related to the quality of the first channel; and

a sidelink assistance request for performing the data transmission via the at least one sidelink channel due to the quality of the first channel.
The second device of Claim 8, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to transmit the first control information and the second control information by:

transmitting the first control information based on the quality of the first channel, either directly from the second device to the first device and the at least one of the group of third devices, or from the second device to the first device via the at least one of the group of third devices; and

transmitting the second control information to the at least one of the group of third devices.
The second device of Claim 10, wherein a first channel quality condition indicates that the quality of the first channel exceeds a first channel quality threshold and not exceeds a second channel quality threshold, the second channel quality threshold is larger than the first channel quality threshold, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to transmit the first control information and the second control information by:

transmitting the first control information on a first downlink control channel, wherein the first downlink control channel is monitored by the first device and the at least one of the group of third devices; and

transmitting the second control information on a second downlink control channel that is different from the first downlink control channel, wherein the second downlink control channel is monitored by the at least one of the group of third devices.
The second device of Claim 11, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to transmit the first control information and the second control information by:

transmitting the first control information after or at the same time with a transmission of the second control information.
The second device of Claim 11, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to transmit the first control information and the second control information by:

transmitting the first control information before or at the same time with a transmission of the second control information.
The second device of Claim 11, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the second device to:

transmit, to the at least one of the group of third device, information indicating a bundling relation between the first downlink control channel and the second downlink control channel on at least one of the first and second downlink control channels, the information comprising at least one of the following:

an occasion position of the first downlink control channels in a search space set;

an occasion position of the second downlink control channels in a search space set;

an aggregation level of the first downlink control channels;

an aggregation level of the second downlink control channels;

a Hybrid Automatic Repeat request, HARQ, process identification value for the first downlink control channel; and

a HARQ process identification value for the second downlink control channel.
The second device of Claim 11, wherein an aggregation level of the first downlink control channel is higher than or equal to an aggregation level of the second downlink control channel.
The second device of Claim 10, wherein a first channel quality condition indicates that the quality of the first channel is below a first channel quality threshold, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to transmit first control information and second control information by:

transmitting the first control information and the second control information to the at least one of the group of third devices on a downlink control channel between the second device and the at least one of the group of third devices, wherein the first control information is forwarded by the at least of the group of third devices to the first device on at least one sidelink channel between the first device and the at least one of the group of third devices.
The second device of claim 8, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to communicate the data transmission by:

transmitting the data transmission to the at least one of the group of third devices based on the second control information, wherein the data transmission is decoded by the at least one of the group of third devices, and encoded into a sidelink transmission to the first device based on the first control information.
The second device of claim 8, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the second device to communicate the data transmission by:

receiving the data transmission from the at least one of the group of third devices based on the second control information, wherein the data transmission is generated by the at least one of the group of third devices, from a sidelink transmission from the first device based on the first control information.
The second device of Claim 8, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the second device to:

transmit, to the first device and the at least one of the group of third devices, sidelink assistance configuration information comprising a control resource set and/or a search space set, wherein the control resource set and the search space correspond to the first control information, and the search space is shared by the group of third devices and the first device.
The second device of Claim 8, wherein the first device comprises a terminal device, the second device comprises a network deice, and the group of third devices comprises a group of further terminal devices.
A third device comprising:

at least one processor; and

at least one memory including computer program code;

wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to:

receive, from a second device, an indication for assisting in communicating a data transmission between a first device and the second device;

receive, from the second device, first control information and second control information, wherein the first control information is in connection with a data transmission to be communicated between the first device and the second device via a sidelink channel between the first device and the third device, the second control information is in connection with a channel between the second device and the third device for the data transmission; and

support the data transmission between the first device and the second device by using the sidelink channel based at least on the first control information.
The third device of Claim 21, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to receive the first control information and the second control information by:

receiving the first control information on a first downlink control channel, wherein the first downlink control channel is monitored by the first device and the third device; and

receiving the second control information on a second downlink control channel that is different from the first downlink control channel, wherein the second downlink control channel is monitored by the third device.
The third device of Claim 22, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to receive the first control information and the second control information by:

receiving the first control information after or at the same time with a receipt of the second control information.
The third device of Claim 22, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to receive the first control information and the second control information by:

receiving the first control information before or at the same time with a receipt of the second control information.
The third device of Claim 22, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the third device to:

receive, from the second device, information indicating a bundling relation between the first downlink control channel and the second downlink control channel on at least one of the first and second downlink control channels, the information comprising at least one of the following:

an occasion position of the first downlink control channels in a search space set;

an occasion position of the second downlink control channels in a search space set;

an aggregation level of the first downlink control channels;

an aggregation level of the second downlink control channels;

a Hybrid Automatic Repeat request, HARQ, process identification value for the first downlink control channels; and

a HARQ process identification value for the second downlink control channels.
The third device of Claim 22, wherein an aggregation level of the first downlink control channel is higher than or equal to an aggregation level of the second downlink control channel.
The third device of Claim 21, wherein the first control information and the second control information are received on a downlink control channel between the second device and the third device.
The third device of Claim 27, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the third device to:

transmit, to the first device, the first control information on at least one sidelink channel between the first device and the third device.
The third device of any of Claims 21 to 28, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to support the data transmission by:

receiving, from the second device, the data transmission based on the second control information;

decoding the data transmission;

encoding the decoded data transmission into a sidelink transmission; and

transmitting, to the first device, the sidelink transmission, based on the first control information.
The third device of any of Claims 21 to 28, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the third device to support the data transmission by:

receiving, from the first device, a sidelink transmission based on the first control information;

decoding the sidelink transmission;

encoding the decoded sidelink transmission into the data transmission; and

transmitting, to the second device, the data transmission based on the second control information.
The third device of Claim 21, wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the third device to:

receive, from the second device, sidelink assistance configuration information comprising a control resource set and/or a search space set, wherein the control resource set and the search space correspond to the first control information, and the search space is shared by a plurality of devices including the third device and the first device.
The third device of Claim 21, wherein the first device comprises a terminal device, the second device comprises a network deice, and the third device comprises a further terminal device.
A method comprising:

transmitting, at a first device and to a second device, a message indicating quality of a channel between the first device and the second device;

receiving first control information in connection with a data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and at least one of a group of third devices, wherein the first control information is configurable to be transmitted, based on the quality of the channel, either directly from the second device to the first device, or from the second device to the first device via the at least one of the group of third devices; and

communicating the data transmission with the second device via the at least one sidelink channel based on the first control information.
A method comprising:

receiving, at a second device and from a first device, a message indicating quality of a first channel between the first device and the second device;

transmitting to at least one of a group of third devices, based on the quality of the first channel, an indication for assisting in communicating a data transmission between the first device and the second device;

transmitting first control information and second control information for the data transmission, wherein the first control information is in connection with the data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and the at least one of the group of third devices, and the second control information is in connection with a second channel between the second device and the at least one of the group of third devices for the data transmission; and

communicating the data transmission with the first device via the at least one sidelink channel based at least on the first control information.
A method comprising:

receiving, at a third device and from a second device, an indication for assisting in communicating a data transmission between a first device and the second device;

receiving, from the second device, first control information and second control information, wherein the first control information is in connection with a data transmission to be communicated between the first device and the second device via a sidelink channel between the first device and the third device, the second control information is in connection with a channel between the second device and the third device for the data transmission; and

supporting the data transmission between the first device and the second device by using the sidelink channel based at least on the first control information.
A first apparatus comprising:

means for transmitting, to a second device, a message indicating quality of a channel between the first device and the second device;

means for receiving first control information in connection with a data transmission to be communicated between the first device and the second device using at least one sidelink channel between the first device and at least one of a group of third devices, wherein the first control information is configurable to be transmitted, based on the quality of the channel, either directly from the second device to the first apparatus, or from the second device to the first apparatus via the at least one of the group of third devices; and

means for communicating the data transmission with the second device via the at least one sidelink channel based on the first control information.
A second apparatus comprising:

means for receiving, from a first device, a message indicating quality of a first channel between the first device and the second apparatus;

means for transmitting to at least one of a group of third devices, based on the quality of the first channel, an indication for assisting in communicating a data transmission between the first device and the second apparatus;

means for transmitting first control information and second control information for the data transmission, wherein the first control information is in connection with the data transmission to be communicated between the first device and the second apparatus using at least one sidelink channel between the first device and the at least one of the group of third devices, and the second control information is in connection with a second channel between the second apparatus and the at least one of the group of third devices for the data transmission; and

means for communicating the data transmission with the first device via the at least one sidelink channel based at least on the first control information.
A third apparatus comprising:

means for receiving, from a second device, an indication for assisting in communicating a data transmission between a first device and the second device;

means for receiving, from the second device, first control information and second control information, wherein the first control information is in connection with a data transmission to be communicated between the first device and the second device via a sidelink channel between the first device and the third apparatus, the second control information is in connection with a channel between the second device and the third apparatus for the data transmission; and

means for supporting the data transmission between the first device and the second device by using the sidelink channel based at least on the first control information.
A computer readable medium comprising program instructions for causing an apparatus to perform at least the method of Claim 33, 34 or 35.