Methods, communications devices, and infrastructure equipment for pre-emptive retransmission and preventive scheduling in a sidelink scenario

Abstract

A method of operating a first communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface is provided. The method comprises receiving, from an infrastructure equipment of the wireless communications network, a downlink signal transmitted by the infrastructure equipment targeted to a second communications device, and decoding, at least partially, the downlink signal. Here, the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

Description

[0001] METHODS, COMMUNICATIONS DEVICES, AND INFRASTRUCTURE EQUIPMENT FOR PRE-EMPTIVE RETRANSMISSION AND PREVENTIVE SCHEDULING IN A SIDELINK SCENARIO

[0002] BACKGROUND

[0003] Field of Disclosure

[0004] The present disclosure relates to communications devices, infrastructure equipment and methods for the more efficient and effective transmission and / or reception of data by a communications device in a wireless communications network.

[0005] The present application claims the Paris Convention priority from European patent application number EP24152458.6, filed on 17 January 2024, the contents of which are hereby incorporated by reference.

[0006] Description of Related Art

[0007] The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.

[0008] Previous generation mobile telecommunication systems, such as those based on the 3GPP defined UMTS and Long Term Evolution (LTE) architecture, are able to support a wider range of services than simple voice and messaging services offered by previous generations of mobile telecommunication systems. For example, with the improved radio interface and enhanced data rates provided by LTE systems, a user is able to enjoy high data rate applications such as mobile video streaming and mobile video conferencing that would previously only have been available via a fixed line data connection. The demand to deploy such networks is therefore strong and the coverage area of these networks, i.e. geographic locations where access to the networks is possible, is expected to continue to increase rapidly.

[0009] Current and future wireless communications networks are expected to routinely and efficiently support communications with an ever-increasing range of devices associated with a wider range of data traffic profiles and types than existing systems are optimised to support. For example, it is expected future wireless communications networks will be expected to efficiently support communications with devices including reduced complexity devices, machine type communication (MTC) devices, high resolution video displays, virtual reality headsets, extended Reality (XR) and so on. Some of these different types of devices may be deployed in very large numbers, for example low complexity devices for supporting the “The Internet of Things”, and may typically be associated with the transmissions of relatively small amounts of data with relatively high latency tolerance. Other types of device, for example supporting high-definition video streaming, may be associated with transmissions of relatively large amounts of data with relatively low latency tolerance. Other types of device, for example used for autonomous vehicle communications and for other critical applications, may be characterised by data that should be transmitted through the network with low latency and high reliability. A single device type might also be associated with different traffic profiles / characteristics depending on the application(s) it is running. For example, different considerations may apply for efficiently supporting data exchange with a smartphone when it is running a video streaming application (high downlink data) as compared to when it is running an Internet browsing application (sporadic uplink and downlink data) or being used for voice communications by an emergency responder in an emergency scenario (data subject to stringent reliability and latency requirements).

[0010] In view of this there is expected to be a desire for current wireless communications networks, for example those which may be referred to as 5G or new radio (NR) systems / new radio access technology (RAT) systems, or indeed future 6G wireless communications, as well as future iterations / releases of existing systems, to efficiently support connectivity for a wide range of devices associated with different applications and different characteristic data traffic profiles and requirements.

[0011] SUMMARY OF THE DISCLOSURE

[0012] The present disclosure can help address or mitigate at least some of the issues discussed above.

[0013] Some embodiments of the present technique can provide a method of operating a first communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface. The method comprises receiving, from an infrastructure equipment of the wireless communications network, a downlink signal transmitted by the infrastructure equipment targeted to a second communications device, and decoding, at least partially, the downlink signal. Here, the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0014] Further embodiments of the present technique can provide a method of operating a first communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface. The method comprises receiving, from a second communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, and transmitting, to the infrastructure equipment, the at least partially encoded uplink signal. Here, again, the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0015] Such embodiments of the present technique, which, in addition to methods of operating communications devices, relate to methods of operating infrastructure equipment, to communications devices and infrastructure equipment, to circuitry for communications devices and infrastructure equipment, to wireless communications systems, to computer programs, and to computer-readable storage mediums, can allow for the more efficient and effective use of radio resources by a communications device operating in a wireless communications network.

[0016] Respective aspects and features of the present disclosure are defined in the appended claims.

[0017] It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the present technology. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and wherein:

[0020] Figure 1 schematically represents some aspects of an NR-type wireless telecommunications system which may be configured to operate in accordance with certain embodiments of the present disclosure; Figure 2 is a schematic block diagram of an example infrastructure equipment and communications device which may be configured to operate in accordance with certain embodiments of the present disclosure;

[0021] Figures 3A, 3B, and 3C provide examples of subnetworks in which certain embodiments of the present disclosure may be implemented;

[0022] Figure 4 illustrates an example of Physical Downlink Shared Channel (PDSCH) Hybrid Automatic Repeat Request (HARQ) transmission;

[0023] Figure 5 illustrates an example of proximity groups in a subnetwork;

[0024] Figure 6 shows an example of pre-emptive retransmission and preventive scheduling using proximity grouping;

[0025] Figure 7 shows a part schematic, part message flow diagram representation of a first wireless communications system comprising a communications device and an infrastructure equipment in accordance with embodiments of the present technique;

[0026] Figure 8 illustrates how a first (“eavesdropping”) user equipment (UE) may decode a PDSCH transmitted to another UE in accordance with embodiments of the present technique;

[0027] Figure 9 shows how an eavesdropping UE may transmit feedback in response to decoding a PDSCH transmitted to another UE in accordance with embodiments of the present technique;

[0028] Figure 10 shows how an eavesdropping UE may decode demodulation reference signals (DMRS) transmitted to another UE in accordance with embodiments of the present technique;

[0029] Figure 11 shows a part schematic, part message flow diagram representation of a second wireless communications system comprising a communications device and an infrastructure equipment in accordance with embodiments of the present technique;

[0030] Figure 12 illustrates how multiple UEs (where one UE is a “diversity” UE) may transmit the same Physical Uplink Shared Channel (PUSCH) in accordance with embodiments of the present technique; Figure 13 shows how a time window may be employed within which an eavesdropping or diversity UE may receive and decode control signals transmitted to another UE in accordance with embodiments of the present technique;

[0031] Figure 14 shows a flow diagram illustrating a first example process of communications in a communications system in accordance with embodiments of the present technique; and Figure 15 shows a flow diagram illustrating a second example process of communications in a communications system in accordance with embodiments of the present technique.

[0032] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] New Radio Access Technology (5G)

[0034] Figure 1 provides a schematic diagram illustrating an example configuration of a wireless communications network which uses some of the terminology used in NR and 5G but which may also support other radio access technologies, and which may be adapted to implement embodiments of the disclosure as described herein. Various elements of Figure 1 and certain aspects of their respective modes of operation are well-known and defined in the relevant standards administered by the 3GPP (RTM) body. It will be appreciated that operational aspects of the telecommunications networks discussed herein which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to the relevant standards and known proposed modifications and additions to the relevant standards.

[0035] In Figure 1 a plurality of transmission and reception points (TRPs) 10 are connected to distributed control units (DUs) 41, 42 by a connection interface represented as a line 16. In another example, the TRP 10 may be connected to another TRP (not shown in Figure 1) that is connected to DUs 41, 42. This connectivity can be a wireless connectivity. In this example, the TRP 10 can be a non-stationary TRP. Each of the TRPs 10 is arranged to transmit and receive signals via a wireless access interface within a radio frequency bandwidth available to the wireless communications network. Thus, within a range for performing radio communications via the wireless access interface, each of the TRPs 10, forms a coverage area (i.e. a cell) of the wireless communications network as represented by a circle 12, within which data can be communicated to and from communications devices 14. As such, wireless communications devices 14 which are within a radio communications range provided by the cells 12 can transmit and receive signals to and from the TRPs 10 via the wireless access interface. Each of the distributed units 41, 42 are connected to a central unit (CU) 40 (which may be referred to as a controlling node) via an interface 46. The central unit 40 is then connected to the core network 20 which may contain all other functions required to transmit data for communicating to and from the wireless communications devices and the core network 20 may be connected to other networks 30. The core network 20 routes data to and from communications devices 14 via the respective distributed units 41, 42 and provides functions such as authentication, mobility management, charging and so on. The core network 20 may further track the location of the communications devices 14 so that it can efficiently contact (i.e., page) the communications devices 14 for transmitting downlink data towards the communications devices 14.

[0036] The elements of the wireless access network shown in Figure 1 may operate in a similar way to corresponding elements of an LTE network, or future generation mobile communications networks. It will be appreciated that operational aspects of the telecommunications network represented in Figure 1, and of other networks discussed herein in accordance with embodiments of the disclosure, which are not specifically described (for example in relation to specific communication protocols and physical channels for communicating between different elements) may be implemented in accordance with any known techniques, for example according to currently used approaches for implementing such operational aspects of wireless telecommunications systems, e.g. in accordance with the relevant standards.

[0037] The respective central units 40 and their associated distributed units / TRPs 10 of Figure 1 may in part have base station functionality. Base stations, which are an example of network infrastructure equipment, may also be referred to as transceiver stations, nodeBs, eNodeBs, eNB, gNodeBs, gNB, Access Points (AP), master or relay user equipment (UE), and so forth. In this regard different terminology is often associated with different generations of wireless telecommunications systems for elements providing broadly comparable functionality. However, certain embodiments of the disclosure may be equally implemented in different generations of wireless telecommunications systems, and for simplicity certain terminology may be used regardless of the underlying network architecture. That is to say, the use of a specific term (such as gNodeBs or the TRPs of Figure 1) in relation to certain example implementations is not intended to indicate these implementations are limited to a certain generation of network that may be most associated with that particular terminology. The terms network infrastructure equipment / access node / access point may be used to encompass these elements and more conventional base station type elements of wireless telecommunications systems. Depending on the application at hand the responsibility for scheduling transmissions which are scheduled on the radio interface between the respective distributed units and the communications devices may lie with the controlling node / central unit and / or the distributed units / TRPs. Although each TRP / DU is shown in Figure 1 as a single entity, the skilled person will appreciate that some of the functions of the TRP / DU / base station may be carried out by disparate, inter-connected elements, such as antennas (or antennae), remote radio heads, amplifiers, etc. Collectively, one or more base stations may form a radio access network.

[0038] A communications device 14 is represented in Figure 1 within the coverage area of the first communication cell 12. This communications device 14 may thus exchange signalling with the first central unit 40 in the first communication cell 12 via one of the distributed units / TRPs 10 associated with the first communication cell 12. Communications devices 14 may also be referred to as mobile stations, user equipment (UE), user terminal, mobile radio, terminal device, and so forth.

[0039] It will further be appreciated that Figure 1 represents merely one example of a proposed architecture for a new RAT based telecommunications system in which approaches in accordance with the principles described herein may be adopted, and the functionality disclosed herein may also be applied in respect of wireless telecommunications systems having different architectures.

[0040] Thus, certain embodiments of the disclosure as discussed herein may be implemented in wireless telecommunication systems / networks according to various different architectures, such as the example architecture shown in Figure 2. It will thus be appreciated the specific wireless telecommunications architecture in any given implementation is not of primary significance to the principles described herein. In this regard, certain embodiments of the disclosure may be described generally in the context of communications between network infrastructure equipment / access nodes and a communications device, wherein the specific nature of the network infrastructure equipment / access node and the communications device will depend on the network infrastructure for the implementation at hand. For example, in some scenarios the network infrastructure equipment / access node may comprise a control unit / controlling node 40 and / or a TRP 10 of the kind shown in Figure 1 which is adapted to provide functionality in accordance with the principles described herein.

[0041] A more detailed diagram of some of the components of the network shown in Figure 1 is provided by Figure 2. In Figure 2, a TRP 10 as shown in Figure 1 comprises, as a simplified representation, a wireless transmitter 30, a wireless receiver 32 and a controller or controlling processor 34 which may operate to control the transmitter 30 and the wireless receiver 32 to transmit and receive radio signals to one or more UEs 14 within a cell 12 formed by the TRP 10. As shown in Figure 2, an example UE 14 is shown to include a corresponding transmitter 49, a receiver 48 and a controller 44 which is configured to control the transmitter 49 and the receiver 48 to transmit signals representing uplink (UL) data to the wireless communications network via the wireless access interface formed by the TRP 10 and to receive downlink (DL) data as signals transmitted by the transmitter 30 and received by the receiver 48 in accordance with the conventional operation.

[0042] The transmitters 30, 49 and the receivers 32, 48 (as well as other transmitters, receivers and transceivers described in relation to examples and embodiments of the present disclosure) may include radio frequency filters and amplifiers as well as signal processing components and devices in order to transmit and receive radio signals in accordance for example with the 5G / NR standard. The controllers 34, 44 (as well as other controllers described in relation to examples and embodiments of the present disclosure) may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc., configured to carry out instructions which are stored on a computer readable medium, such as a non-volatile memory. The processing steps described herein may be carried out by, for example, a microprocessor in conjunction with a random access memory, operating according to instructions stored on a computer readable medium. The transmitters, the receivers and the controllers are schematically shown in Figure 2 as separate elements for ease of representation. However, it will be appreciated that the functionality of these elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s). As will be appreciated the infrastructure equipment / TRP / base station as well as the UE / communications device will in general comprise various other elements associated with its operating functionality. As shown in Figure 2, the TRP 10 also includes a network interface 50 which connects to the DU 42 via a physical interface 16. The network interface 50 therefore provides a communication link for data and signalling traffic from the TRP 10 via the DU 42 and the CU 40 to the core network 20.

[0043] The interface 46 between the DU 42 and the CU 40 is known as the Fl interface which can be a physical or a logical interface. The Fl interface 46 between CU and DU may operate in accordance with specifications 3GPP TS 38.470 and 3GPP TS 38.473, and may be formed from a fibre optic or other wired or wireless high bandwidth connection. In one example the connection 16 from the TRP 10 to the DU 42 is via fibre optic. The connection between a TRP 10 and the core network 20 can be generally referred to as a backhaul, which comprises the interface 16 from the network interface 50 of the TRP 10 to the DU 42 and the Fl interface 46 from the DU 42 to the CU 40.

[0044] URLLC and eURLLC

[0045] Systems incorporating NR technology are expected to support different services (or types of services), which may be characterised by different requirements for latency, data rate and / or reliability. For example, Enhanced Mobile Broadband (eMBB) services are characterised by high capacity with a requirement to support up to 20 Gb / s. The requirements for Ultra Reliable and Eow Eatency Communications (URLLC) services are for one transmission of a 32 byte packet to be transmitted from the radio protocol layer 2 / 3 SDU ingress point to the radio protocol layer 2 / 3 SDU egress point of the radio interface within 1 ms with a reliability of 1 - 10'5(99.999 %) or higher (99.9999%) [1],

[0046] Massive Machine Type Communications (mMTC) is another example of a service which may be supported by NR-based communications networks. In addition, systems may be expected to support further enhancements related to Industrial Internet of Things (IIoT) in order to support services with new requirements of high availability, high reliability, low latency, and in some cases, high-accuracy positioning.

[0047] Enhanced URLLC (eURLLC) [2] specifies features that require high reliability and low latency, such as factory automation, transport industry, electrical power distribution, etc. in a 5G system. eURLLC is further enhanced as IIoT-URLLC [3],

[0048] Future 6G Wireless Communications

[0049] As described above, several generations of mobile communications have been standardised globally up to now, where each generation took approximately a decade from introduction before the development and introduction of another new generation. For example, generations of mobile communications have moved from the Global System for Mobile Communications (GSM) (2G) to Wideband Code Division Multiple Access (WCDMA) (3G), from WCDMA (3G) to LTE (4G), and most recently from LTE (4G) to NR (5G).

[0050] The latest generation of mobile communications is 5G, as discussed above with reference to the example configurations of Figures 1 and 2, where a significant number of additional features have been incorporated in different releases to provide new services and capabilities. Such services include eMBB, IIoT and URLLC as discussed above, but also include such services as 2-step Random Access (RACH), Unlicensed NR (NR-U), Cross-link Interference (CLI) handling for Time Division Duplexing (TDD), Positioning, Small Data Transmissions (SDT), Multicast and Broadcast Services (MBS), Reduced Capability UEs, Vehicular Communications (V2X), Integrated Access and Backhaul (IAB), UE power saving, Non Terrestrial Networks (NTN), NR operation up to 71GHz, loT over NTN, Non-public networks (NPN), extended Reality (XR) for NR, and Radio Access Network (RAN) slicing. Nevertheless, as in every decade, a new generation (e.g. 6G) is expected to be developed and deployed in the near future (around the year 2030), and will be expected to provide new services and capabilities that the current 5G cannot provide. There are discussions on technologies beyond 5G, i.e., 6G, that are expected to have significantly higher throughput, lower latency and higher reliability than 5G services, which are also expected to utilize sub-THz frequencies. One of the functionalities being considered for 6G is operation within a subnetwork.

[0051] Subnetworks

[0052] A subnetwork is a localized network of communication points. Subnetworks have the following characteristics:

[0053] • Short range (below 10 meters) low transmit power cells;

[0054] • Extreme requirements in terms of latency, reliability or data rates, i.e., below 0. 1 ms latencies, reliability with a packet error rate of 1 - 10'9(99.9999999%) reliability, and multi -Gbps data rates. A subnetwork can be defined as having any one or more of these latency, reliability, or data rate requirements;

[0055] • Consist of one or multiple access points (AP), e.g., gNBs, with edge processing capabilities; and

[0056] • May consist of a large number of low complexity or low cost communications devices, such as sensors or actuators.

[0057] The extreme reliability and latency of the subnetwork links, which can be downlink, uplink, or sidelink, make such subnetworks links suitable for replacing wires, thereby reducing the amount of wiring required in the system, which in some cases, e.g., in a car or robot, would result in a significant reduction of their weights and size. Reducing the amount of wiring required in a system or unit would also make manufacturing and installation of that system or unit easier.

[0058] Some examples of subnetworks are shown in Figures 3A to 3C. Here, as shown in the example of Figure 3 A, a car 51 can consist of a subnetwork, where cameras 53, sensors 54 (such as light detection and ranging (LIDAR), temperature, or tyre pressure sensors), and entertainment devices 55 (such as screens or speakers) that are both outside and inside the car 51 together with an AP 52 can form a subnetwork. The wireless links of the subnetwork would significantly reduce the amount of required wiring, and hence weight, in the car 51.

[0059] In other use-cases, a subnetwork can also be in a living room for the purpose of providing immersive Virtual Reality (VR) entertainment. An example of such a home entertainment based subnetwork 61 is shown in Figure 3B, where a user’s headset 63, movement sensors 64 in the user’s haptic gloves, and a fan 65 that blows wind at intensity depending on the scenario currently being experienced in the immersive VR entertainment content may together all form a subnetwork which connects to multiple APs 62.

[0060] A subnetwork can also be within a single machine, such as a robot arm 71 as shown in the example of Figure 3C. In the robot arm 71 shown in Figure 3C, the sensors, joints, and pneumatic systems used to control movements, along with one or more APs 72, may together all form a subnetwork. Like in the car 51 as shown in the example of Figure 3 A, this may significantly reduce the amount of required wiring, which in turn would allow for the robot arm 80 to be made smaller and lighter.

[0061] 5G HARQ Transmissions

[0062] In legacy systems such as 5G, a Hybrid Automatic Repeat Request (HARQ) transmission is used for the transmission of physical channels carrying data, such as Physical Downlink Shared Channels (PDSCHs) and Physical Uplink Shared Channels (PUSCHs). Here, such HARQ transmissions consist, after the initial transmission of the physical channels carrying the data, of HARQ feedback from the receiver and, if necessary, retransmissions from the transmitter. For example, an initial transmission of a physical channel may be transmitted to a receiver, and the receiver would feed back an ACK if it successfully decodes the physical channel, or otherwise it feeds back a NACK. A retransmission of the physical channel may be transmitted to the receiver if the HARQ feedback for the previous or initial transmission was a NACK, and here, the receiver would soft-combine the logarithmic likelihood ratio (LLR) soft bits of the retransmitted physical channel with all previous transmissions of the same physical channel. This would thereby increase the signal-to-noise ratio (SNR) of the transmission, and after the soft combining, the receiver then attempts to decode the transmission again. There is typically a configured maximum number of retransmissions of a physical channel before the transmission is abandoned.

[0063] An example of PDSCH HARQ transmissions in the DL is shown in Figure 4, where a DL Grant carried by downlink control information (DCI#1) is transmitted to a UE in Slot n to schedule a PDSCH#1 in Slot «+I with a corresponding PUCCH#1 (i.e. a Physical Uplink Control Channel) in sub-slot m+5 (Slot «+2) to carry the HARQ feedback for PDSCH# 1. In the example of Figure 4, the UE fails to decode PDSCH# 1 and therefore feeds back a NACK in PUCCH#1. The gNB receiving the NACK would send another DL Grant DCI#3 in Slot «+3 scheduling a retransmission of a PDSCH# 1 in the later part of Slot n+3 with a corresponding PUCCH#3 in sub-slot m+9 (Slot n+4). The UE soft-combines PDSCH# 1 received in Slot w+1 with PDSCH#1 in Slot n+3, thereby increasing the SNR of the physical channel, and here, the UE successfully decodes PDSCH# 1 and so feeds back an ACK using PUCCH#3. The total time required for the UE to successfully receive PDSCH# 1 is the time between h and tn. The HARQ Round Trip Time (RTT) is the time between the transmission of the PDSCH and its following retransmission. For example, for PDSCH# 1, the HARQ RTT is the time between time h and tn, which consists of processing time at both the UE and gNB. A Send and Wait (SAW) mechanism is employed for HARQ transmissions, where during the HARQ RTT of one HARQ process, another HARQ process can occur so that the resources can be fully utilised for data transmissions. In the example of Figure 4, during the HARQ RTT for PDSCH# 1, another HARQ process for PDSCH#2 can occur, where here, DL Grant DCI#2 in Slot w+1 schedules a PDSCH#2 in Slot n+2 with a corresponding PUCCH#2 in sub-slot m+ (Slot w+4), where PDSCH#2 occurs between the initial PDSCH#1 in Slot n+1 and the PDSCH#1 retransmission in Slot n+3. The gNB and UE keep track of the HARQ process using a HARQ Process Number (HPN), and the UE maintains a soft buffer for each HARQ process for soft combining.

[0064] HARQ transmissions in the uplink for PUSCH is similar to those in the downlink for PDSCH as described above.

[0065] The 6G subnetwork has a target of extremely high reliability and low latency as noted above, and so the legacy 5G HARQ transmission techniques may not meet such a high demand. Although the reliability may individually be reached by having a high number of retransmissions in 5G, each retransmission introduces latency due to the time required for decoding at the gNB or UE. For the PDSCH case, the HARQ feedback from the UE is issued before a retransmission can occur. Hence, there is motivation to improve the legacy HARQ transmission techniques currently employed in 5G for future use cases in 6G subnetworks.

[0066] Proximity Grouping in Subnetworks

[0067] Proximity grouping of UEs in a subnetwork was introduced in co-pending European Patent Application No . EP23181917.8 [4] , the contents of which are hereby incorporated by reference . In such proximity groups, two or more UEs that have similar radio channel conditions are grouped by the Access Point (AP) or gNB such that the AP or gNB can estimate the channel condition of the UEs in the proximity group based on known channel conditions of one or more UEs in that proximity group.

[0068] An example is shown in Figure 5, where a subnetwork consists of an AP 80 and five UEs 83-87. Here, the five UEs are divided into two proximity groups 81, 82, where the first proximity group 81 consists of UE1 83, UE2 84, and UE3 85, and the second proximity group 82 consists of UE4 86 and UE5 87. The UEs in a proximity group have similar radio conditions and, in the example of Figure 5, the UEs 83-87 are also within a small area in the subnetwork. Proximity grouping of UEs is deemed more feasible in a subnetwork with a small coverage where UEs likely have line-of-sight (LOS) with the AP than in a cellular network in an urban environment. In the example of Figure 5, the proximity groups 81, 82 are formed in such a way that UEs with similar physical positions are grouped together. However, it would be appreciated that this may not always be the case, and may only be the case in the example of Figure 5 because the AP 80 is located in a relatively central physical position to each of the UEs 83-87. In other examples to that of Figure 5, the proximity grouping may be carried out by the AP 80 on the basis of similar channel characteristics / radio conditions of UEs, or on a combination of such channel characteristics and the physical locations of those UEs.

[0069] Proximity grouping enables the gNB scheduler to perform pre-emptive retransmission and preventive scheduling. When performing pre-emptive retransmission, the gNB schedules a retransmission for a PDSCH to a UE before receiving the HARQ feedback from that UE in response to the initial transmission of that PDSCH. When performing preventive scheduling, the gNB schedules a more robust PUSCH / PDSCH (for example with repetitions, or a lower MCS, or a higher transmit power) to a UE than initially scheduled if the gNB learns in the interim that another UE in the same proximity group has experienced or is experiencing poor radio conditions, to improve likelihood of successful transmission / reception of that PUSCH / PDSCH.

[0070] An example is shown in Figure 6, where a gNB transmits two DL Grants DCI#1 and DCI#2 in Slot n to schedule PDSCH#1 and PDSCH#2 for UE1 91 and UE2 92 in Slot n and Slot w+2 respectively. UE1 91 fails to decode PDSCH# 1 and feeds back a NACK in PUCCH#1 in uplink Slot n+1. Since UE1 91 and UE2 92 belong to the same proximity group and UE1 91 fails to decode PDSCH# 1, the gNB estimates that UE2 92 is also likely to fail to decode PDSCH#2 (which has a similar MCS to PDSCH# 1). Consequently, the gNB transmits DCI#4 in Slot w+2 to schedule a pre-emptive retransmission of PDSCH#2 in Slot n+3 for UE2 92 before receiving any HARQ feedback from UE2 92. The gNB also transmits DCI#3 in Slot «+2 to schedule a retransmission for PDSCH# 1 in Slot «+4 for UE1 91. In Slot n+3, the gNB wishes to schedule PDSCH#3 to UE3 93 and, learning from the feedback from UE1 91 in Slot n+1, the gNB schedules PDSCH#3 with 2 repetitions in Slot n+3 and Slot n+4. to improve PDSCH#3 reliability. That is, the gNB performs preventive scheduling to prevent UE3 93 from having the same decoding outcome as UE1 91 did in decoding a single instance of PDSCH# 1.

[0071] A general technical issue addressed through the use of proximity grouping in subnetworks then is that latency can be reduced and more efficient resource usage can be enabled, because techniques such as those described above relating to pre-emptive retransmission and preventive scheduling allow for faster retransmissions in 6G systems, especially for such 6G subnetworks that require extreme reliability and low latency. Embodiments of the present technique seek to provide solutions to such a technical issue by further enhancing how proximity grouping within subnetworks may be utilised to allow for more efficient communication.

[0072] Collaborative UE Reception in a Subnetwork

[0073] Figure 7 shows a part schematic, part message flow diagram representation of a first wireless communications system comprising a first communications device 101 (e.g. a UE 14), an infrastructure equipment 102 (e.g. an AP such as a gNB / TRP 10), and a second communications device 103 (e.g. a UE 14) in accordance with at least some embodiments of the present technique.

[0074] The first communications device 101 may be configured to transmit signals to and / or receive signals from the wireless communications network, for example, to and from the infrastructure equipment 102. Specifically, the first communications device 101 may be configured to transmit data to and / or receive data from the wireless communications network (e.g. to / from the infrastructure equipment 102) via a wireless radio interface provided by the wireless communications network (e.g., a Uu interface between the first communications device 101 and a node of a Radio Access Network (RAN), i.e. the infrastructure equipment 102). The first communications device 101 may also be configured to transmit signals to and / or receive signals from the second communications device 103. Specifically, the first communications device 101 may be configured to transmit data to and / or receive data from the second communications device 103 via a side link interface between the first communications device 101 and the second communications device 103. The second communications device 103 may also be configured to transmit data to and / or receive data from the wireless communications network (e.g. to / from the infrastructure equipment 102) via a wireless radio interface provided by the wireless communications network (e.g., a Uu interface between the second communications device 103 and a node of the Radio Access Network (RAN), i.e. the infrastructure equipment 102).

[0075] The first communications device 101, the infrastructure equipment 102, and the second communications device 103 each comprise a transceiver (or transceiver circuitry) 101.1, 102.1, 103.1, and a controller (or controller circuitry) 101.2, 102.2, 103.2. Each of the controllers 101.2, 102.2, 103.2 may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc. The controllers 101.2, 102.2, 103.2 may also each be equipped with a memory unit (which is not shown in Figure 7).

[0076] As shown in the example of Figure 7, the transceiver circuitry 101.1 and the controller circuitry 101.2 of the first communications device 101 are configured in combination to receive 106, from the infrastructure equipment 102 of the wireless communications network, a downlink signal transmitted by the infrastructure equipment 102 and targeted 107 to the second communications device 103 (and in some cases, may be successfully decoded by the second communications device 103), and to decode 108, at least partially, the downlink signal. Here, the first communications device 101 and the second communications device 103 each form part of a proximity group of a subnetwork 104 of the wireless communications network, the subnetwork 104 comprising at least the first communications device 101, the second communications device 103, and the infrastructure equipment 102, and the proximity group may be specifically associated with the infrastructure equipment 102. Although only two communications devices 101 and 103 are shown in the example of Figure 7, those skilled in the art would appreciate that the proximity group that comprises them (and indeed any other proximity group) could contain any feasible number of communications devices / UEs. This is also true of the subnetwork 104, which might contain a plurality of proximity groups (which may each contain one or more UEs) as well as other infrastructure equipment (e.g. APs / gNBs) to the infrastructure equipment 102 shown in the example of Figure 7. Those skilled in the art would also appreciate that one or more UEs in the subnetwork may not belong to any proximity group, or may alternatively belong to more than one proximity group, while the APs / gNBs within the subnetwork may add, remove, or move UEs to, from, or between proximity groups. Here, the downlink signal may be downlink data or specifically a downlink data channel comprising a downlink packet or multiple downlink packets, and may be transmitted by the infrastructure equipment 102 using a PDSCH or an semi-persistent scheduling PDSCH (SPS-PDSCH).

[0077] Essentially then, embodiments of the present technique, as exemplified by the example wireless communications system of Figure 7 for example, propose that one or more UEs in a proximity group are able to (at least partially) perform collaborative communication between one or more other UEs in that proximity group and an AP (where this AP may be a gNB for example). Here, in arrangements of embodiments of the present technique which are specifically exemplified by the example wireless communications system of Figure 7, such collaborative communication is performed in the downlink. That is, one or more UEs in a proximity group (e.g., the first communications device 101 in the example of Figure 7) perform the collaborative communication by (at least partially) decoding the downlink packet of one or more other UEs (e.g., the second communications device 103 in the example of Figure 7). Having more than one UE in a proximity group decoding a packet can improve the reliability, and also reduce the latency of the transmission. The UE / UEs that are decoding another UE’s packet can provide receive diversity for the reception of the packet. A UE that is decoding another UE’s packet in a proximity group may be referred to as the “eavesdropping UE”.

[0078] An example is shown in Figure 8, where the subnetwork consists of five UEs 113-117 and an AP 110. UE1 113, UE2 114 and UE3 115 form a first proximity 111, whilst UE4 116 and UE5 117 form a second proximity group 112. The AP 110 transmits a PDSCH 118 to UE1 113, and in accordance with such arrangements of embodiments of the present technique, UE2 114 and UE3 115 - which both belong to the same proximity group 111 as UE1 113 - can also receive the PDSCH 118 and can at least partially decode it. Although UE1 113 and UE3 115 may have similar channel profiles, UE3 115 is closer to the AP 110 than UE1 113 and so UE3 115 may have a better received signal strength than UE1 113. UE3 115 here may therefore act as an eavesdropping UE and so may decode the PDSCH 118 scheduled for UE1 113. If UE3 115 successfully decodes the PDSCH 118, it may transmit the PDSCH 118 to UE1 113 via sidelink communications. UE1 113 may treat the PDSCH 118 from UE3 115 as a form of repetition, and so can use it to combine with the PDSCH 118 it receives directly from the AP 110 to improve the decoding outcome of the PDSCH 118.

[0079] In some arrangements of embodiments of the present technique, the said downlink packet that can be decoded by other UEs is only selected downlink packets (i.e., not all of the downlink packets). For example, the packets that can be received and decoded by an eavesdropping UE may be specified by downlink packet information that can be pre-configured, where such downlink packet information may specify that the packets that can be received and decoded by an eavesdropping UE are those downlink packets received at a given scheduled time. In other words, the first communications device at least partially decodes the downlink signal only if the downlink signal is received from the infrastructure equipment within a preconfigured set of time resources of the wireless access interface. Alternatively, or in addition, the downlink packets that can be jointly decoded may be indicated in the control channel (e.g. the DCI carried by a data control channel (e.g. a PDCCH) that schedules the downlink packet(s)). In other words, the first communications device at least partially decodes the downlink signal only upon receiving a control signal comprising an indication that the downlink signal can be decoded by other communications devices than the second communications device, wherein the control signal schedules the downlink signal. In some implementations, there may be a flag in the control channel indicating that the subsequent data shared channel (e.g. PDSCH) scheduled by that control channel (e.g. DCI) can also be decoded by other UEs.

[0080] In some arrangements of embodiments of the present technique, the said eavesdropping UE is assigned by the AP. In other words, the first communications device is configured by the infrastructure equipment to decode signals transmitted by the infrastructure equipment to the second communications device. The eavesdropping UE can be pre-configured (e.g., assigned manually), where the AP may configure one or more selected UE(s) as eavesdropping UEs or may configured all UEs within a proximity group to act as eavesdropping UEs. In another example, such a configuration may also include the association of the eavesdropping UE to another paired UE, where such an association may be reciprocal. For example, referring back to the example of Figure 8, UE1 is the eavesdropping UE of UE3 (and this may also the case vice versa) and UE2 may be the eavesdropping of UE1 (and vice versa), etc.

[0081] In some arrangements of embodiments of the present technique, the said eavesdropping UE transmits feedback to the AP regarding its decoding outcome of a downlink packet scheduled for another UE in the same proximity group. In other words, the first communications device may be configured to transmit, to the infrastructure equipment, a feedback signal indicating whether or not the first communications device successfully decoded the downlink signal. The feedback may be HARQ feedback transmitted by the UE in the form of an ACK or a NACK. This feedback can be used by the scheduler in the AP to update its link adaptation for these UEs (i.e. the targeted UE to which the downlink packet was transmitted and / or the eavesdropping UE that transmitted the feedback). For example, this might cause the AP to perform preventive scheduling, or to schedule a pre-emptive retransmission for the targeted UE. In other words, the infrastructure equipment may be configured to determine, based on receiving the feedback signal from the first communications device, one or more transmission parameters in accordance with which the infrastructure equipment will transmit future downlink signals to the first communications device and / or to the second communications device. Alternatively, or in addition, the infrastructure equipment may be configured to transmit, to the second communications device based on receiving the feedback signal from the first communications device, an indication that the infrastructure equipment is to retransmit the downlink signal to the second communications device.

[0082] It should be appreciated that for extreme reliability, such as where the target BLER is 10'9or tighter, it may take a very long time for the scheduler to determine whether a UE is hitting the BLER target, since the scheduler may need to count the number of packets received with errors over the total number of packets received in order to determine a BLER value. For example, depending on the link adaptation method employed, in the worst case, the scheduler may need to receive at least one billion packets to determine whether or not the UE has achieved the BLER target. Such procedures as those proposed by arrangements of the present technique would increase the number of packets received per UE - since a PDSCH that is targeted at one UE can also be decoded by other UEs in the same proximity group - thereby providing additional HARQ feedback to the scheduler to update its link adaptation in a quicker and more efficient manner. That is, instead of relying on a single UE to determine whether it achieves a stringent BLER target, such arrangements enable the network to determine the BLER of multiple UEs in a proximity group from the HARQ feedback received from these UEs. The eavesdropped HARQ feedback is also useful for the AP scheduler in scheduling packets for the eavesdropping UEs (in addition to the targeted UE) in the near future.

[0083] An example is shown in Figure 9, where UE1 121, UE2 122, and UE3 123 are in the same proximity group, in the same manner as UE1 113, UE2 114, and UE3 115 in the example of Figure 8. In this example, UE1 121 is the target UE and UE2 122 and UE3 123 are the eavesdropping UEs. The AP schedules PDSCH#1 to UE1 121 in Slot n and PDSCH#2 to UE2 122 in Slot w+2. Since UE2 122 and UE3 123 are in the same proximity group as UE1 121, they also attempt to decode PDSCH#1 and, as per such arrangements, they send the decoding outcome, i.e., HARQ feedback, to the AP. In this example, UE1 121 fails to decode PDSCH# 1 that the AP schedule for it, and so it feeds back a NACK in PUCCH#1 in uplink Slot n+1. UE2 122 also fails to decode PDSCH#1, and so it feeds back a NACK in PUCCH#2 in uplink Slot n+1. UE3 123, which is closer to the AP than UE1 121 or UE2 122, manages to decode PDSCH# 1, and so it feeds back an ACK in PUCCH#3 in uplink Slot n+1. The AP may then schedule a retransmission of PDSCH# 1 in Slot n+4 for UE1 121. The AP, learning that UE2 122 also failed to decode PDSCH# 1, may schedule a pre-emptive retransmission for PDSCH#2 in Slot n+3 to UE2 122. In Slot n+3, the AP schedules PDSCH#3 to UE3 123, and since it learned that UE3 123 managed to decode PDSCH#1 successfully and PDSCH#3 has similar a MCS as PDSCH#1, it schedules a single PDSCH#3 instance to UE3 123 (instead of a PDSCH with 2x repetition, as in the example in Figure 6).

[0084] In some arrangements of embodiments of the present technique, the said partially decoding is the extraction of channel characteristics based on the Demodulation Reference Signal (DMRS) by the one or more eavesdropping UEs. In other words, the at least partial decoding of the downlink signal may comprise measuring a demodulation reference signal, DMRS, within the downlink signal in order to determine one or more channel characteristics of a communications channel between the infrastructure equipment and the proximity group.

[0085] As described in the previous section, the objective of the proximity group is to be able to use a UE’s experience to estimate another UE’s future experience in decoding / transmitting a similar packet within a proximity group. The eavesdropping UE may report the measurement outcome of the DMRS to the AP; for example, it may indicate the SINR or a maximum tolerable MCS based on the DMRS to the AP. In other words, the first communications device may be configured to transmit, to the infrastructure equipment, an indication of the one or more channel characteristics, where here, the one or more channel characteristics may comprise a signal to interference and noise ratio, SINR, of the downlink signal, and / or the one or more channel characteristics may comprise a maximum modulation and coding scheme, MCS, that, if the downlink signal had been transmitted in accordance with the maximum MCS, the first communications device would have been able to successfully receive the downlink signal in accordance with a predefined error rate. Here, the indication of the maximum MCS may indicate that, if the first downlink data had been transmitted in accordance with an MCS higher than the maximum MCS, the first communications device would not have been able to successfully receive the first downlink data in accordance with the predefined error rate.

[0086] The AP may use this feedback based on the measured DMRS to determine a future packet for the UE (i.e. the eavesdropping UE and / or the targeted UE, and / or indeed another UE in the same proximity group. In other words, the infrastructure equipment may be configured to determine, based on the received indication of the one or more channel characteristics, one or more transmission parameters in accordance with which the infrastructure equipment will transmit future downlink signals to the first communications device and / or to the second communications device. Alternatively, or in addition, the AP may determine, based on the DMRS measurement outcome of the eavesdropping UE, whether that eavesdropping UE (and / or the targeted UE, and / or indeed another UE in the same proximity group) should continue to be in the proximity group or not. In other words, the infrastructure equipment may be configured to determine, based on the received indication of the one or more channel characteristics, whether or not to remove the first communications device and / or the second communications device from the proximity group.

[0087] An example is shown in Figure 10, where UE4 131 and UE5 132 belongs to the same proximity group such as the second proximity group 112 in the example of Figure 8. The AP schedules UE5 132 with PDSCH# 1 with MCS = 8, in Slot n+1, which UE5 132 successfully decodes and so transmits an ACK in PUCCH# 1 in uplink Slot n+1. As per such arrangements, UE4 131 attempts to decode the DMRS of PDSCH# 1, and it determines from the DMRS that it can tolerate a maximum MCS = 6 (as it is further away from the AP). That is, if the AP schedules a PDSCH with an MCS above 6, UE4 131 will fail to decode it. Learning from the feedback from UE4 131 and UE5 132, the AP later schedules PDSCH#2 with MCS = 8 to UE4 131 but with 2x repetitions or more, to ensure that UE4 131 can decode it successfully.

[0088] In some arrangements of embodiments of the present technique, the said partially decoding is the decoding of the downlink packet up to soft bits (LLR) by the one or more eavesdropping UEs. That is instead of completely decoding an entire PDSCH of another UE, the eavesdropping UE demodulates the PDSCH up to the soft bits. In other words, the at least partial decoding of the downlink signal may comprise decoding the downlink signal to obtain logarithmic likelihood ratios, LLRs, of each bit of the downlink signal (where, as those skilled in the art would appreciate, these LLRs indicate the likelihood of that bit being a 0 or 1).

[0089] The eavesdropping UE can then estimate whether it can successfully decode the PDSCH or not based on the soft bits, and also determines SINR or maximum tolerable MCS. In other words, the first communications device may be configured to estimate, based on the obtained LLRs, whether or not the first communications device is able to fully decode the downlink signal. Lurthermore, the first communications device may be configured to determine, based on the obtained LLRs, one or more channel characteristics of a communications channel between the infrastructure equipment and the proximity group, where here the one or more channel characteristics may comprise a signal to interference and noise ratio, SINR, of the downlink signal, and / or a maximum modulation and coding scheme, MCS, that, if the downlink signal had been transmitted in accordance with the maximum MCS, the first communications device would have been able to successfully receive the downlink signal in accordance with a predefined error rate (where again here the indication of the maximum MCS may indicate that, if the first downlink data had been transmitted in accordance with an MCS higher than the maximum MCS, the first communications device would not have been able to successfully receive the first downlink data in accordance with the predefined error rate.

[0090] This information - i.e. the extracted / measured MCS or SINR (or indeed any other extracted / measured channel characteristics), as well as the estimation of whether the eavesdropping UE can successfully decode the PDSCH or not based on the soft bits - can then be fed back by the eavesdropping UE to the AP. In other words, the first communications device may be configured to transmit, to the infrastructure equipment, an indication of the one or more channel characteristics and / or an indication of the estimation of whether or not the first communications device is able to fully decode the downlink signal.

[0091] In some arrangements of embodiments of the present technique, the one or more eavesdropping UEs transmit the at least partially decoded downlink packet to the targeted UE, i.e., the UE to which the downlink packet is scheduled. That is the eavesdropping UE may re-encode a successfully decoded PDSCH and transmit it via sidelink to the targeted UE. Alternatively or additionally, the eavesdropping UE may transmits the soft bits of a PDSCH to the targeted UE via sidelink. In other words, the first communications device may be configured to transmit, to the second communications device via a sidelink interface between the first communications device and the second communications device, the at least partially decoded downlink signal. The targeted UE may then combine the encoded PDSCH or the soft bits of a PDSCH with the received PDSCH from the AP to improve the reliability in decoding of the PDSCH.

[0092] Collaborative UE Transmission in a Subnetwork

[0093] Figure 11 shows a part schematic, part message flow diagram representation of a second wireless communications system comprising a first communications device 141 (e.g. a UE 14), an infrastructure equipment 142 (e.g. an AP such as a gNB / TRP 10), and a second communications device 143 (e.g. a UE 14) in accordance with at least some embodiments of the present technique.

[0094] The first communications device 141 may be configured to transmit signals to and / or receive signals from the wireless communications network, for example, to and from the infrastructure equipment 142. Specifically, the first communications device 141 may be configured to transmit data to and / or receive data from the wireless communications network (e.g. to / from the infrastructure equipment 142) via a wireless radio interface provided by the wireless communications network (e.g., a Uu interface between the first communications device 141 and a node of a Radio Access Network (RAN), i.e. the infrastructure equipment 142). The first communications device 141 may also be configured to transmit signals to and / or receive signals from the second communications device 143. Specifically, the first communications device 141 may be configured to transmit data to and / or receive data from the second communications device 143 via a side link interface between the first communications device 141 and the second communications device 143. The second communications device 143 may also be configured to transmit data to and / or receive data from the wireless communications network (e.g. to / from the infrastructure equipment 142) via a wireless radio interface provided by the wireless communications network (e.g., a Uu interface between the second communications device 143 and a node of the Radio Access Network (RAN), i.e. the infrastructure equipment 142).

[0095] The first communications device 141, the infrastructure equipment 142, and the second communications device 143 each comprise a transceiver (or transceiver circuitry) 141.1, 142.1, 143.1, and a controller (or controller circuitry) 141.2, 142.2, 143.2. Each of the controllers 141.2, 142.2, 143.2 may be, for example, a microprocessor, a CPU, or a dedicated chipset, etc. The controllers 141.2, 142.2, 143.2 may also each be equipped with a memory unit (which is not shown in Figure 11).

[0096] As shown in the example of Figure 11, the transceiver circuitry 141.1 and the controller circuitry 141.2 of the first communications device 141 are configured in combination to receive 146, from the second communications device 143, an at least partially encoded uplink signal that is to be transmitted 147 by the second communications device 143 to the infrastructure equipment 142, and to transmit 148, to the infrastructure equipment 142, the at least partially encoded uplink signal. Here, the first communications device 141 and the second communications device 143 each form part of a proximity group of a subnetwork 144 of the wireless communications network, the subnetwork 144 comprising at least the first communications device 141, the second communications device 143, and the infrastructure equipment 142, and the proximity group may be specifically associated with the infrastructure equipment 142. Although only two communications devices 141 and 143 are shown in the example ofFigure 11, those skilled in the art would appreciate that the proximity group that comprises them (and indeed any other proximity group) could contain any feasible number of communications devices / UEs. This is also true of the subnetwork 144, which might contain a plurality of proximity groups (which may each contain one or more UEs), as well as other infrastructure equipment (e.g. APs / gNBs) to the infrastructure equipment 142 shown in the example of Figure 11. Those skilled in the art would also appreciate that one or more UEs in the subnetwork may not belong to any proximity group, or may alternatively belong to more than one proximity group, while the APs / gNBs within the subnetwork may add, remove, or move UEs to, from, or between proximity groups. Here, the uplink signal may be uplink data comprising an uplink packet or multiple uplink packets, and may be transmitted by the first communications device 141 and / or second communications device 143 using a PUSCH or a configured grant PUSCH (CG-PUSCH). Upon receiving an uplink signal (e.g. a PUSCH) from both the first communications device 141 and second communications device 143, the infrastructure equipment 142 may combine the received PUSCHs to improve likelihood of successful decoding.

[0097] Essentially then, embodiments of the present technique, as exemplified by the example wireless communications system of Figure 11 for example, propose that one or more UEs in a proximity group are able to (at least partially) perform collaborative communication between one or more other UEs in that proximity group and an AP (where this AP may be a gNB for example). Here, in arrangements of embodiments of the present technique which are specifically exemplified by the example wireless communications system of Figure 11, such collaborative communication is performed in the uplink. That is, one or more UEs in a proximity group (e.g., the first communications device 141 in the example of Figure 11) perform the collaborative communication by transmitting the (at least partially) encoded uplink packet of one or more other UEs (e.g., the second communications device 143 in the example of Figure 11) to the AP / gNB (e.g. the infrastructure equipment 142 in the example of Figure 11). Having more than one UE in a proximity group transmitting a packet can improve the reliability, and also reduce the latency of the transmission. The UE / UEs that are transmitting another UE’s packet can provide transmit diversity for the transmission of the packet. A UE that is transmitting another UE’s packet in a proximity group may be referred to as the "diversity UE”.

[0098] An example is shown in Figure 12, where a subnetwork has five UEs 153-157 and two proximity groups 151, 152 in the same manner as the example of Figure 8. UE1 153, UE2 154, and UE3 155 form a first proximity group 151 and UE4 156 and UE5 157 form a second proximity group 152. The AP 150 schedules a PUSCH for UE1 153, and here, in addition to UE1 ’s 153 transmission 158 of the scheduled PUSCH, UE2 154 also transmits 159 the same PUSCH to the AP 150, providing transmit diversity and thereby improved reliability for that PUSCH.

[0099] In some arrangements of embodiments of the present technique, the diversity UE transmits a fully encoded uplink packet such as a PUSCH or CG-PUSCH (i.e. a configured grant PUSCH) of a targeted UE to the AP. In other words, the at least partially encoded uplink signal received from the second communications device and transmitted to the infrastructure equipment may be a fully encoded uplink signal.

[0100] In some arrangements of embodiments of the present technique, the target UE may pass the encoded PUSCH or CG-PUSCH to the one or more diversity UE via sidelink. In other words, the at least partially encoded uplink signal may be received from the second communications device via a sidelink interface between the first communications device and the second communications device.

[0101] In some arrangements of embodiments of the present technique, the application layer may pass uplink information of a target UE to one or more diversity UEs. This may be used in a subnetwork that is within a unit such as a robotic arm, where the application layer may be connected to two or more close by UEs. In other words, the first communications device may be configured to receive, from the upper layer (for example, the application layer), the at least partially encoded uplink signal that is to be transmitted to the infrastructure equipment by the second communications device. Subsequently, the target UE may request an uplink scheduling request from the AP. Then, the AP may provide an uplink resource grant to the target UE.

[0102] In some arrangements of embodiments of the present technique, the diversity UE may monitor the uplink grant indication (which may, for example, be received in a Physical Downlink Control Channel (PDCCH)). Once the diversity UE knows the target UE is allocated resources for an UL transmission, the UL allocation of the diversity UE can be assumed to be in a certain number of time units (e.g., X time-slot / sub-frames) after the transmission of the target UE uplink transmission. In other words, the first communications device may be configured to determine a first set of uplink resources of the wireless access interface in which to transmit the at least partially encoded uplink signal to the infrastructure equipment based on a second set of uplink resources resource allocated by the infrastructure equipment to the second communications device for the second communications device to transmit the uplink signal to the infrastructure equipment.

[0103] In another example, the AP may provide a dedicated uplink grant to the diversity UE, indicating that the diversity UE is to transmit the packet of the target UE in the resources scheduled by that uplink grant. In other words, the first communications device may be configured to receive, from the infrastructure equipment, an indication of a first set of uplink resources of the wireless access interface in which to transmit the at least partially encoded uplink signal to the infrastructure equipment.

[0104] In another example, AP may provide an ordinary uplink grant to the diversity UE (without specifying that the resources granted are for use by the diversity UE in transmitting the packet of another UE), and then later the diversity UE transmits the packet of the target UE using the granted resources and by indicating that the packet belongs / is associated with the target UE’s transmission. In other words, the first communications device may be configured to receive, from the infrastructure equipment, an indication of a first set of uplink resources of the wireless access interface, wherein the transmitting the at least partially encoded uplink signal to the infrastructure equipment comprises transmitting the at least partially encoded uplink signal to the infrastructure equipment in the first set of uplink resources with an indication that the at least partially encoded uplink signal is to be transmitted by the second communications device to the infrastructure equipment.

[0105] In some arrangements of embodiments of the present technique, the targeted UE may pass the soft bits of the uplink packet to the one or more diversity UE via sidelink. In other words, the at least partially encoded uplink signal received from the second communications device may comprise logarithmic likelihood ratios, LLRs, of each bit of the uplink signal. The diversity UE may then modulate the soft bits and transmit the modulated uplink packet to the AP.

[0106] In some arrangements of embodiments of the present technique, the AP may feedback the outcome of its decoding to the targeted UE and the one or more diversity UEs. In other words, the first communications device (and / or the second communications device) may be configured to receive, from the infrastructure equipment, a feedback signal indicating whether or not the infrastructure equipment successfully decoded the uplink signal.

[0107] Signalling to UEs of Collaborative UE Reception and Transmission in a Subnetwork

[0108] In some arrangements of embodiments of the present technique, a UE can be configured to be an eavesdropping UE and / or a diversity UE by the network. In other words, the first communications device is configured by the infrastructure equipment to decode signals transmitted by the infrastructure equipment to the second communications device and / or to transmit uplink signals that are to be transmitted by the second communications device to the infrastructure equipment.

[0109] The network may configure the eavesdropping UE to fully or partially decode a PDSCH, for example, it may configure one eavesdropping UE to fully decode a PDSCH and another eavesdropping UE to partially decode a PDSCH (e.g., just the DMRS or soft bits). In other words, the first communications device may be configured by the infrastructure equipment either to partially decode the downlink signal or to fully decode the downlink signal. Similarly, the AP may configure a diversity UE to transmit a fully encoded PUSCH, i.e., encoded from info bits or a partially encoded PUSCH, i.e., modulated from soft bits. In other words, the first communications device may be configured by the infrastructure equipment either to partially encode the uplink signal or to fully encode the uplink signal. The network configuration can be cell / subnetwork specific, proximity group specific, or UE specific.

[0110] In some arrangements of embodiments of the present technique, the operation of the eavesdropping or diversity UE is indicated by the AP via a control channel (PDCCH). The eavesdropping UE needs to monitor the control channel in order to determine whether it needs to decode the other UE’s PDCCH or not. In other words, the first communications device may be configured by the infrastructure equipment to decode the downlink signal and / or to transmit the uplink signal by receiving a first control signal from the infrastructure equipment, wherein the first control signal indicates that the first communications device is to decode the downlink signal and / or to transmit the uplink signal.

[0111] In some arrangements of embodiments of the present technique, a new RNTI (as part of the PDCCH) is introduced. That is, a Proximity RNTI is used to mask the CRC of the DL Grant or UL Grant, where the Proximity RNTI is read by the UEs configured for eavesdropping or diversity. This enables the eavesdropping UE or diversity UE to decode the DL Grant and UL Grant, so that they can receive or transmit the PDSCH or PUSCH respectively. The Proximity RNTI may also be used for encoding the PDSCH and PUSCH. In other words, the first control signal may comprise a radio network temporary identifier, RNTI, wherein the RNTI is for use by the first communications device in decoding a second control signal transmitted by the infrastructure equipment to the second communications device, wherein the second control signal schedules the downlink signal or the uplink signal.

[0112] In some arrangements of embodiments of the present technique, the RNTI of one or more target UE in a proximity group is broadcasted to the UEs in the proximity group, for example, using a group common DCI (GC-DCI). Eavesdropping and diversity UEs may be configured to monitor this said GC-DCI. This enables the UEs in the proximity group to read the DL Grant and / or UL Grant of one or more target UEs. In other words, the first communications device is configured by the infrastructure equipment to decode the downlink signal and / or to transmit the uplink signal by receiving at least one RNTI in a broadcast signal from the infrastructure equipment, wherein one of the RNTIs (i.e. the RNTI of the second communications device) is for use by the first communications device in decoding a control signal transmitted by the infrastructure equipment to the second communications device, wherein the control signal schedules the downlink signal or the uplink signal.

[0113] For example, an AP may group-broadcast the C-RNTI of a target UE, followed by (or together with) a DL Grant for that target UE. The UEs in the proximity group may decide to read the DL Grant and decode the corresponding PDSCH. It should be noted that this is different to the previously described arrangements in which the DL Grant and UL Grant are directly masked with a Proximity RNTI. Here, the C-RNTI of a target UE is broadcast and the eavesdropping or diversity UEs would then use that C- RNTI to decode a DL Grant and / or UL Grant that is dedicated to the target UE. Such arrangements also enable a target UE to know that it is the target UE by comparing its own C-RNTI with the C-RNTI broadcast by the AP in the said GC-DCI.

[0114] In some arrangements of embodiments of the present technique, a time window may be defined after the AP broadcasts the RNTI of the target UE to which the DL Grant and / or UL Grant will be transmitted. In other words, the broadcast signal comprises an indication of a time window in which the first communications device can use the RNTI to decode the control signal transmitted by the infrastructure equipment to the second communications device. In another example, the time window information can be pre-configured (e.g., configured by the RRC) or defined in the specifications.

[0115] An example is shown in Figure 13, where at time to, the AP transmits a GC-DCI indicating two target UEs’ RNTI; i.e., C-RNTI# 1 and C-RNTI#2. The said time window starts after the end of the GC-DCI at time ti and ends at time t«. During this time, the eavesdropping or diversity UEs can monitor for a DL Grant or UL Grant of the target UEs in addition to their individual DL / UL Grants. In this example, a DL Grant with C-RNTI#2 is transmitted in time C, which schedules a PDSCH in time t4. The eavesdropping UEs can therefore read this DL Grant and at least partially decode the PDSCH. Similarly at time an UL Grant with C-RNTI# 1 is transmitted and the diversity UEs can read this UL Grant and transmit the target UE’s data (passed via sidelink) on the scheduled PUSCH in time . In some arrangements of embodiments of the present technique, where the RNTI of the target UE is broadcast to UEs in a proximity group, the AP also indicates when the DL Grant or UL Grant of that target UE would be transmitted. In other words, the broadcast signal may comprise an indication of a set of time resources of the wireless access interface in which the infrastructure equipment is to transmit the control signal to the second communications device.

[0116] In some arrangements of embodiments of the present technique, the eavesdropping UE can be configured to pass the fully or partially decoded PDSCH to the target UE. In other words, the first communications device may be configured to receive, from the infrastructure equipment, an indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device, wherein the first communications device transmits the at least partially decoded downlink signal to the second communications device based on receiving the indication. This configuration can be configured by the RRC or indicated dynamically via a DCI.

[0117] In some arrangements of embodiments of the present technique, the eavesdropping UE can be configured to send a HARQ feedback for the PDSCH of a target UE. In other words, the first communications device may be configured to receive, from the infrastructure equipment, an indication that the first communications device is to transmit the feedback signal to the infrastructure equipment, wherein the first communications device transmits the feedback signal to the infrastructure equipment based on receiving the indication. This configuration can be configured by the RRC or indicated dynamically via a DCI.

[0118] In some arrangements of embodiments of the present technique, where the eavesdropping UE passes the fully or partially decoded PDSCH to the target UE, the target UE will expect that PDSCH in a predetermined time. The said predetermined time can be RRC configured or indicated in the DCI. In other words, the indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device may comprise an indication of a time window in which the first communications device is to transmit the at least partially decoded downlink signal to the second communications device. In some implementations, if the eavesdropping UE fails to decode the PDSCH, it may not pass the PDSCH to the target UE as it may not be beneficial to do so. In such case the target UE will blind decode for the presence of the PDSCH, e.g. by detecting the DMRS of the PDSCH.

[0119] In some arrangements of embodiments of the present technique, where the eavesdropping UE passes the fully or partially decoded PDSCH to the target UE, the eavesdropping UE transmits an indication to the target UE whether it will transmit or not transmit the PDSCH to the target UE. In other words, the first communications device may be configured to transmit to the second communications device, before transmitting the at least partially decoded downlink signal to the second communications device, an indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device. Such arrangements recognise that it may not be beneficial for the eavesdropping UE to pass the PDSCH to the target UE if the eavesdropping UE fails to decode the target UE’s PDSCH.

[0120] In some arrangements of embodiments of the present technique, the target UE reads the HARQ feedback of the eavesdropping UE. That is, the HARQ feedback indicating the decoding outcome of the target UE’s PDSCH by the eavesdropping UE acts as an indication whether the target UE should expect a PDSCH from the eavesdropping UE. Here if the eavesdropping UE fails to decode the target UE’s PDSCH, it will send a NACK to the gNB and the target UE reading the NACK will know that the eavesdropping UE may not pass the PDSCH to the target UE since it failed to decode it. On the other hand, if the eavesdropping UE sends an ACK to the gNB, the target UE reading the ACK will know that the eavesdropping UE will pass the PDSCH to the target UE since the eavesdropping UE successfully decoded the PDSCH.

[0121] Figure 14 shows a flow diagram illustrating a first example process of communications in a communications system in accordance with embodiments of the present technique. The process shown by Figure 14 is specifically a method of operating a first communications device (i.e. UE) configured to transmit signals to and / or to receive signals from a wireless communications network (i.e. to an infrastructure equipment which may be an AP such as a gNB) via a wireless access interface.

[0122] The method begins in step Si l. The method comprises, in step S12, receiving, from an infrastructure equipment of the wireless communications network, a downlink signal transmitted by the infrastructure equipment targeted to a second communications device. In step SI 3, the process comprises decoding, at least partially, the downlink signal. Here, the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment. The process ends in step S14.

[0123] Figure 15 shows a flow diagram illustrating a second example process of communications in a communications system in accordance with embodiments of the present technique. The process shown by Figure 15 is specifically a method of operating a first communications device (i.e. UE) configured to transmit signals to and / or to receive signals from a wireless communications network (i.e. to an infrastructure equipment which may be an AP such as a gNB) via a wireless access interface.

[0124] The method begins in step S21. The method comprises, in step S22, receiving, from a second communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network. In step S23, the process comprises transmitting, to the infrastructure equipment, the at least partially encoded uplink signal. Here, the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment. The process ends in step S24.

[0125] Those skilled in the art would appreciate that the methods shown by Figures 14 and 15 may be adapted in accordance with embodiments of the present technique. For example, other intermediate steps may be included in such methods, or the steps may be performed in any logical order. Though embodiments of the present technique have been described largely by way of the example communications systems shown in Figure 7 and Figure 11, and further by way of the implementation examples shown in Figure 8 to 10, 12, and 13, it would be clear to those skilled in the art that they could be equally applied to other systems to those described herein, provided that these are within the scope of the claims.

[0126] Those skilled in the art would further appreciate that such infrastructure equipment and / or communications devices as herein defined may be further defined in accordance with the various arrangements and embodiments discussed in the preceding paragraphs. It would be further appreciated by those skilled in the art that such infrastructure equipment and communications devices as herein defined and described may form part of communications systems other than those defined by the present disclosure, provided that these are within the scope of the claims. The following numbered paragraphs provide further example aspects and features of the present technique:

[0127] Paragraph 1. A method of operating a first communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, the method comprising receiving, from an infrastructure equipment of the wireless communications network, a downlink signal transmitted by the infrastructure equipment targeted to a second communications device, and decoding, at least partially, the downlink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0128] Paragraph 2. A method according to Paragraph 1, wherein the first communications device at least partially decodes the downlink signal only if the downlink signal is received from the infrastructure equipment within a preconfigured set of time resources of the wireless access interface.

[0129] Paragraph 3. A method according to Paragraph 1 or Paragraph 2, wherein the first communications device at least partially decodes the downlink signal only upon receiving a control signal comprising an indication that the downlink signal can be decoded by other communications devices than the second communications device, wherein the control signal schedules the downlink signal.

[0130] Paragraph 4. A method according to any of Paragraphs 1 to 3, wherein the first communications device is configured by the infrastructure equipment to decode signals transmitted by the infrastructure equipment to the second communications device.

[0131] Paragraph 5. A method according to Paragraph 4, wherein the first communications device is configured by the infrastructure equipment either to partially decode the downlink signal or to fully decode the downlink signal.

[0132] Paragraph 6. A method according to Paragraph 4 or Paragraph 5, wherein the first communications device is configured by the infrastructure equipment to decode the downlink signal by receiving a first control signal from the infrastructure equipment, wherein the first control signal indicates that the first communications device is to decode the downlink signal.

[0133] Paragraph 7. A method according to Paragraph 6, wherein the first control signal comprises a radio network temporary identifier, RNTI, wherein the RNTI is for use by the first communications device in decoding a second control signal transmitted by the infrastructure equipment to the second communications device, wherein the second control signal schedules the downlink signal.

[0134] Paragraph 8. A method according to any of Paragraphs 4 to 7, wherein the first communications device is configured by the infrastructure equipment to decode the downlink signal by receiving at least one RNTI in a broadcast signal from the infrastructure equipment, wherein one of the RNTIs is for use by the first communications device in decoding a control signal transmitted by the infrastructure equipment to the second communications device, wherein the control signal schedules the downlink signal.

[0135] Paragraph 9. A method according to Paragraph 8, wherein the broadcast signal comprises an indication of a time window in which the first communications device can use the RNTI to decode the control signal transmitted by the infrastructure equipment to the second communications device.

[0136] Paragraph 10. A method according to Paragraph 8 or Paragraph 9, wherein the broadcast signal comprises an indication of a set of time resources of the wireless access interface in which the infrastructure equipment is to transmit the control signal to the second communications device. Paragraph 11. A method according to any of Paragraphs 1 to 10, comprising transmitting, to the infrastructure equipment, a feedback signal indicating whether or not the first communications device successfully decoded the downlink signal.

[0137] Paragraph 12. A method according to Paragraph 11, comprising receiving, from the infrastructure equipment, an indication that the first communications device is to transmit the feedback signal to the infrastructure equipment, wherein the first communications device transmits the feedback signal to the infrastructure equipment based on receiving the indication.

[0138] Paragraph 13. A method according to any of Paragraphs 1 to 12, wherein the at least partial decoding of the downlink signal comprises measuring a demodulation reference signal, DMRS, within the downlink signal in order to determine one or more channel characteristics of a communications channel between the infrastructure equipment and the proximity group.

[0139] Paragraph 14. A method according to Paragraph 13, wherein the one or more channel characteristics comprise a signal to interference and noise ratio, SINR, of the downlink signal.

[0140] Paragraph 15. A method according to Paragraph 13 or Paragraph 14, wherein the one or more channel characteristics comprise a maximum modulation and coding scheme, MCS, that, if the downlink signal had been transmitted in accordance with the maximum MCS, the first communications device would have been able to successfully receive the downlink signal in accordance with a predefined error rate.

[0141] Paragraph 16. A method according to any of Paragraphs 13 to 15, comprising transmitting, to the infrastructure equipment, an indication of the one or more channel characteristics.

[0142] Paragraph 17. A method according to any of Paragraphs 1 to 16, wherein the at least partial decoding of the downlink signal comprises decoding the downlink signal to obtain logarithmic likelihood ratios, LLRs, of each bit of the downlink signal.

[0143] Paragraph 18. A method according to Paragraph 17, comprising determining, based on the obtained LLRs, one or more channel characteristics of a communications channel between the infrastructure equipment and the proximity group.

[0144] Paragraph 19. A method according to Paragraph 18, wherein the one or more channel characteristics comprise a signal to interference and noise ratio, SINR, of the downlink signal.

[0145] Paragraph 20. A method according to Paragraph 18 or Paragraph 19, wherein the one or more channel characteristics comprise a maximum modulation and coding scheme, MCS, that, if the downlink signal had been transmitted in accordance with the maximum MCS, the first communications device would have been able to successfully receive the downlink signal in accordance with a predefined error rate.

[0146] Paragraph 21. A method according to any of Paragraphs 18 to 20, comprising transmitting, to the infrastructure equipment, an indication of the one or more channel characteristics.

[0147] Paragraph 22. A method according to any of Paragraphs 17 to 21, comprising estimating, based on the obtained LLRs, whether or not the first communications device is able to fully decode the downlink signal.

[0148] Paragraph 23. A method according to Paragraph 22, comprising transmitting, to the infrastructure equipment, an indication of the estimation of whether or not the first communications device is able to fully decode the downlink signal.

[0149] Paragraph 24. A method according to any of Paragraphs 1 to 23, comprising transmitting, to the second communications device via a sidelink interface between the first communications device and the second communications device, the at least partially decoded downlink signal.

[0150] Paragraph 25. A method according to Paragraph 24, comprising receiving, from the infrastructure equipment, an indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device, wherein the first communications device transmits the at least partially decoded downlink signal to the second communications device based on receiving the indication.

[0151] Paragraph 26. A method according to Paragraph 25, wherein the indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device comprises an indication of a time window in which the first communications device is to transmit the at least partially decoded downlink signal to the second communications device. Paragraph 27. A method according to any of Paragraphs 24 to 26, comprising transmitting to the second communications device, before transmitting the at least partially decoded downlink signal to the second communications device, an indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device.

[0152] Paragraph 28. A first communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from an infrastructure equipment of the wireless communications network, a downlink signal transmitted by the infrastructure equipment targeted to a second communications device, and to decode, at least partially, the downlink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0153] Paragraph 29. Circuitry for a first communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from an infrastructure equipment of the wireless communications network, a downlink signal transmitted by the infrastructure equipment targeted to a second communications device, and to decode, at least partially, the downlink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0154] Paragraph 30. A method of operating an infrastructure equipment forming part of a wireless communications network configured to transmit signals to and / or to receive signals from a plurality of communications devices via a wireless access interface, the method comprising transmitting, to each of a first and a second of the plurality of communications devices, a downlink signal targeted at the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0155] Paragraph 31. A method according to Paragraph 30, comprising configuring the first communications device either to partially decode the downlink signal or to fully decode the downlink signal.

[0156] Paragraph 32. A method according to Paragraph 30 or Paragraph 31, comprising transmitting a first control signal to the first communications device, wherein the first control signal indicates that the communications device is to decode the downlink signal.

[0157] Paragraph 33. A method according to Paragraph 32, wherein the first control signal comprises a radio network temporary identifier, RNTI, wherein the RNTI is for use by the first communications device in decoding a second control signal transmitted by the infrastructure equipment to the second communications device, wherein the second control signal schedules the downlink signal.

[0158] Paragraph 34. A method according to any of Paragraphs 30 to 33, comprising broadcasting a broadcast signal comprising at least one RNTI, wherein the first communications device is configured by the infrastructure equipment to decode the downlink signal by receiving the broadcast signal, wherein one of the RNTIs is for use by the first communications device in decoding a control signal transmitted by the infrastructure equipment to the second communications device, wherein the control signal schedules the downlink signal.

[0159] Paragraph 35. A method according to Paragraph 34, wherein the broadcast signal comprises an indication of a time window in which the first communications device can use the RNTI to decode the control signal transmitted by the infrastructure equipment to the second communications device. Paragraph 36. A method according to Paragraph 34 or Paragraph 35, wherein the broadcast signal comprises an indication of a set of time resources of the wireless access interface in which the infrastructure equipment is to transmit the control signal to the second communications device.

[0160] Paragraph 37. A method according to any of Paragraphs 30 to 36, comprising receiving, from the first communications device, a feedback signal indicating whether or not the first communications device successfully decoded the downlink signal.

[0161] Paragraph 38. A method according to Paragraph 37, comprising transmitting, to the first communications device, an indication that the first communications device is to transmit the feedback signal to the infrastructure equipment, wherein the infrastructure equipment receives the feedback signal from the first communications device based on transmitting the indication.

[0162] Paragraph 39. A method according to Paragraph 37 or Paragraph 38, comprising transmitting, to the second communications device based on receiving the feedback signal from the first communications device, an indication that the infrastructure equipment is to retransmit the downlink signal to the second communications device.

[0163] Paragraph 40. A method according to any of Paragraphs 30 to 39, comprising transmitting, to the infrastructure equipment, an indication of one or more channel characteristics determined by the first communications device by at least partially decoding the downlink signal. Paragraph 41. A method according to Paragraph 40, wherein the one or more channel characteristics comprise a signal to interference and noise ratio, SINR, of the downlink signal.

[0164] Paragraph 42. A method according to Paragraph 40 or Paragraph 41, wherein the one or more channel characteristics comprise a maximum modulation and coding scheme, MCS, that, if the downlink signal had been transmitted in accordance with the maximum MCS, the first communications device would have been able to successfully receive the downlink signal in accordance with a predefined error rate.

[0165] Paragraph 43. A method according to any of Paragraphs 40 to 42, comprising determining, based on the received indication of the one or more channel characteristics, one or more transmission parameters in accordance with which the infrastructure equipment will transmit future downlink signals to the first communications device and / or to the second communications device. Paragraph 44. A method according to any of Paragraphs 40 to 43, comprising determining, based on the received indication of the one or more channel characteristics, whether or not to remove the first communications device and / or the second communications device from the proximity group.

[0166] Paragraph 45. A method according to any of Paragraphs 30 to 44, comprising receiving, from the first communications device, an indication of an estimation of whether or not the first communications device is able to fully decode the downlink signal.

[0167] Paragraph 46. A method according to any of Paragraphs 30 to 45, comprising transmitting, to the first communications device, an indication that the first communications device is to transmit, after at least partially decoding the downlink signal, the at least partially decoded downlink signal to the second communications device via a sidelink interface between the first communications device and the second communications device. Paragraph 47. A method according to Paragraph 46, wherein the indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device comprises an indication of a time window in which the first communications device is to transmit the at least partially decoded downlink signal to the second communications device. Paragraph 48. An infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a plurality of communications devices via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to transmit to each of a first and a second of the plurality of communications devices, a downlink signal targeted at the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0168] Paragraph 49. Circuitry for an infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a plurality of communications devices via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to transmit to each of a first and a second of the plurality of communications devices, a downlink signal targeted at the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0169] Paragraph 50. A method of operating a second communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, the method comprising receiving, from a first communications device via a sidelink interface between the first communications device and the second communications device, a downlink signal that has been at least partially decoded by the first communications device, wherein the downlink signal was transmitted by an infrastructure equipment of the wireless communications network targeted to the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0170] Paragraph 51. A method according to Paragraph 50, comprising receiving the downlink signal from the infrastructure equipment.

[0171] Paragraph 52. A method according to Paragraph 50 or Paragraph 51, comprising receiving the at least partially decoded downlink signal from the first communications device within a specified time window.

[0172] Paragraph 53. A method according to any of Paragraphs 50 to 52, comprising receiving, from the first communications device, before receiving the at least partially decoded downlink signal from the first communications device, an indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device. Paragraph 54. A method according to any of Paragraphs 50 to 53, comprising receiving, from the infrastructure equipment, an indication that the infrastructure equipment is to retransmit the downlink signal to the second communications device before the second communications device sends a feedback signal to the infrastructure equipment indicating that the second communications device had failed to decode the downlink signal.

[0173] Paragraph 55. A method according to any of Paragraphs 50 to 54, comprising receiving an indication of a feedback signal transmitted by the first communications device to the infrastructure equipment, the feedback signal indicating whether or not the first communications device successfully decoded the downlink signal.

[0174] Paragraph 56. A second communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a first communications device via a sidelink interface between the first communications device and the second communications device, a downlink signal that has been at least partially decoded by the first communications device, wherein the downlink signal was transmitted by an infrastructure equipment of the wireless communications network targeted to the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0175] Paragraph 57. Circuitry for a second communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a first communications device via a sidelink interface between the first communications device and the second communications device, a downlink signal that has been at least partially decoded by the first communications device, wherein the downlink signal was transmitted by an infrastructure equipment of the wireless communications network targeted to the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0176] Paragraph 58. A wireless communications system comprising a first communications device according to Paragraph 28 and an infrastructure equipment according to Paragraph 48.

[0177] Paragraph 59 A wireless communications system according to Paragraph 58, further comprising a second communications device according to Paragraph 56.

[0178] Paragraph 60. A method of operating a first communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, the method comprising receiving, from a second communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, and transmitting, to the infrastructure equipment, the at least partially encoded uplink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment. Paragraph 61. A method according to Paragraph 60, wherein the at least partially encoded uplink signal received from the second communications device and transmitted to the infrastructure equipment is a fully encoded uplink signal.

[0179] Paragraph 62. A method according to Paragraph 60 or Paragraph 61, wherein the at least partially encoded uplink signal is received from the second communications device via a sidelink interface between the first communications device and the second communications device.

[0180] Paragraph 63. A method according to any of Paragraphs 60 to 62, wherein the at least partially encoded uplink signal received from the second communications device comprises logarithmic likelihood ratios, LLRs, of each bit of the uplink signal.

[0181] Paragraph 64. A method according to any of Paragraphs 60 to 63, comprising receiving the at least partially encoded uplink signal from an upper layer.

[0182] Paragraph 65. A method according to any of Paragraphs 60 to 64, comprising determining a first set of uplink resources of the wireless access interface in which to transmit the at least partially encoded uplink signal to the infrastructure equipment based on a second set of uplink resources resource allocated by the infrastructure equipment to the second communications device for the second communications device to transmit the uplink signal to the infrastructure equipment.

[0183] Paragraph 66. A method according to any of Paragraphs 60 to 65, comprising receiving, from the infrastructure equipment, an indication of a first set of uplink resources of the wireless access interface in which to transmit the at least partially encoded uplink signal to the infrastructure equipment.

[0184] Paragraph 67. A method according to any of Paragraphs 60 to 66, comprising receiving, from the infrastructure equipment, an indication of a first set of uplink resources of the wireless access interface, wherein the transmitting the at least partially encoded uplink signal to the infrastructure equipment comprises transmitting the at least partially encoded uplink signal to the infrastructure equipment in the first set of uplink resources with an indication that the at least partially encoded uplink signal is to be transmitted by the second communications device to the infrastructure equipment. Paragraph 68. A method according to any of Paragraphs 60 to 67, comprising receiving, from the infrastructure equipment, a feedback signal indicating whether or not the infrastructure equipment successfully decoded the uplink signal.

[0185] Paragraph 69. A method according to any of Paragraphs 60 to 68, wherein the first communications device is configured by the infrastructure equipment to transmit uplink signals that are to be transmitted by the second communications device to the infrastructure equipment.

[0186] Paragraph 70. A method according to Paragraph 69, wherein the first communications device is configured by the infrastructure equipment either to partially encode the uplink signal or to fully encode the uplink signal.

[0187] Paragraph 71. A method according to Paragraph 69 or Paragraph 70, wherein the first communications device is configured by the infrastructure equipment to transmit the uplink signal by receiving a first control signal from the infrastructure equipment, wherein the first control signal indicates that the first communications device is to transmit the uplink signal.

[0188] Paragraph 72. A method according to Paragraph 71, wherein the first control signal comprises a radio network temporary identifier, RNTI, wherein the RNTI is for use by the first communications device in decoding a second control signal transmitted by the infrastructure equipment to the second communications device, wherein the second control signal schedules the uplink signal.

[0189] Paragraph 73. A method according to any of Paragraphs 69 to 72, wherein the first communications device is configured by the infrastructure equipment to transmit the uplink signal by receiving at least one RNTI in a broadcast signal from the infrastructure equipment, wherein one of the RNTIs is for use by the first communications device in decoding a control signal transmitted by the infrastructure equipment to the second communications device, wherein the control signal schedules the uplink signal. Paragraph 74. A method according to Paragraph 73, wherein the broadcast signal comprises an indication of a time window in which the first communications device can use the RNTI to decode the control signal transmitted by the infrastructure equipment to the second communications device. Paragraph 75. A method according to Paragraph 73 or Paragraph 74, wherein the broadcast signal comprises an indication of a set of time resources of the wireless access interface in which the infrastructure equipment is to transmit the control signal to the second communications device.

[0190] Paragraph 76. A first communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a second communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, and to transmit, to the infrastructure equipment, the at least partially encoded uplink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0191] Paragraph 77. Circuitry for a first communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a second communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, and to transmit, to the infrastructure equipment, the at least partially encoded uplink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0192] Paragraph 78. A method of operating an infrastructure equipment forming part of a wireless communications network configured to transmit signals to and / or to receive signals from a communications device via a wireless access interface, the method comprising receiving, from a first of the plurality of communications devices, an at least partially encoded uplink signal, wherein the uplink signal is targeted to the infrastructure equipment by a second of the plurality of communications devices, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0193] Paragraph 79. A method according to Paragraph 78, wherein the at least partially encoded uplink signal received from the first communications device is a fully encoded uplink signal.

[0194] Paragraph 80. A method according to Paragraph 78 or Paragraph 79, wherein the at least partially encoded uplink signal received from the first communications device and / or the second communications device is received from an upper layer at the first communications device and / or the second communications device.

[0195] Paragraph 81. A method according to any of Paragraphs 78 to 80, comprising transmiting, to the first communications device, an indication of a first set of uplink resources of the wireless access interface in which the first communications device is to transmit the at least partially encoded uplink signal to the infrastructure equipment.

[0196] Paragraph 82. A method according to any of Paragraphs 78 to 81, comprising transmiting, to the first communications device, a feedback signal indicating whether or not the infrastructure equipment successfully decoded the uplink signal.

[0197] Paragraph 83. A method according to any of Paragraphs 78 to 82, comprising configuring the first communications device to transmit uplink signals that are to be transmited by the second communications device to the infrastructure equipment.

[0198] Paragraph 84. A method according to any of Paragraphs 78 to 83, comprising configuring the first communications device either to partially encode the uplink signal or to fully encode the uplink signal.

[0199] Paragraph 85. A method according to any of Paragraphs 78 to 84, comprising transmiting a first control signal to the first communications device, wherein the first control signal indicates that the first communications device is to transmit the uplink signal.

[0200] Paragraph 86. A method according to Paragraph 85, wherein the first control signal comprises a radio network temporary identifier, RNTI, wherein the RNTI is for use by the first communications device in decoding a second control signal transmited by the infrastructure equipment to the second communications device, wherein the second control signal schedules the uplink signal.

[0201] Paragraph 87. A method according to any of Paragraphs 78 to 86, comprising broadcasting a broadcast signal comprising at least one RNTI, wherein the first communications device is configured by the infrastructure equipment to transmit the uplink signal by receiving the broadcast signal, wherein one of the RNTIs is for use by the first communications device in decoding a control signal transmited by the infrastructure equipment to the second communications device, wherein the control signal schedules the uplink signal.

[0202] Paragraph 88. A method according to Paragraph 87, wherein the broadcast signal comprises an indication of a time window in which the first communications device can use the RNTI to decode the control signal transmited by the infrastructure equipment to the second communications device. Paragraph 89. A method according to Paragraph 87 or Paragraph 88, wherein the broadcast signal comprises an indication of a set of time resources of the wireless access interface in which the infrastructure equipment is to transmit the control signal to the second communications device. Paragraph 90. An infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a communications device via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a first of the plurality of communications devices, an at least partially encoded uplink signal, wherein the uplink signal is targeted to the infrastructure equipment by a second of the plurality of communications devices, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0203] Paragraph 91. Circuitry for an infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a communications device via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a first of the plurality of communications devices, an at least partially encoded uplink signal, wherein the uplink signal is targeted to the infrastructure equipment by a second of the plurality of communications devices, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0204] Paragraph 92. A method of operating a second communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, the method comprising transmitting, to a first communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, wherein the at least partially encoded uplink signal is transmitted to the first communications device so that the first communications device can also transmit the at least partially encoded uplink signal to the infrastructure equipment, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0205] Paragraph 93. A method according to Paragraph 92, wherein the at least partially encoded uplink signal transmitted to the first communications device is a fully encoded uplink signal.

[0206] Paragraph 94. A method according to Paragraph 92 or Paragraph 93, wherein the at least partially encoded uplink signal is transmitted to the first communications device via a sidelink interface between the first communications device and the second communications device.

[0207] Paragraph 95. A method according to any of Paragraphs 92 to 94, wherein the at least partially encoded uplink signal transmitted to the first communications device comprises logarithmic likelihood ratios, LLRs, of each bit of the uplink signal.

[0208] Paragraph 96. A second communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to transmit, to a first communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, wherein the at least partially encoded uplink signal is transmitted to the first communications device so that the first communications device can also transmit the at least partially encoded uplink signal to the infrastructure equipment, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0209] Paragraph 97. Circuitry for a second communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to transmit, to a first communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, wherein the at least partially encoded uplink signal is transmitted to the first communications device so that the first communications device can also transmit the at least partially encoded uplink signal to the infrastructure equipment, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

[0210] Paragraph 98. A wireless communications system comprising a first communications device according to Paragraph 76 and an infrastructure equipment according to Paragraph 90.

[0211] Paragraph 99 A wireless communications system according to Paragraph 98, further comprising a second communications device according to Paragraph 96.

[0212] Paragraph 100. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform a method according to any of Paragraphs 1 to 27, Paragraphs 30 to 47, Paragraphs 50 to 55, Paragraphs 60 to 75, Paragraphs 78 to 89, or Paragraphs 92 to 94.

[0213] Paragraph 101. A non-transitory computer-readable storage medium storing a computer program according to Paragraph 100.

[0214] It will be appreciated that the above description for clarity has described embodiments with reference to different functional units, circuitry and / or processors. However, it will be apparent that any suitable distribution of functionality between different functional units, circuitry and / or processors may be used without detracting from the embodiments.

[0215] Described embodiments may be implemented in any suitable form including hardware, software, firmware or any combination of these. Described embodiments may optionally be implemented at least partly as computer software running on one or more data processors and / or digital signal processors. The elements and components of any embodiment may be physically, functionally and logically implemented in any suitable way. Indeed, the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units. As such, the disclosed embodiments may be implemented in a single unit or may be physically and functionally distributed between different units, circuitry and / or processors.

[0216] Although the present disclosure has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Additionally, although a feature may appear to be described in connection with particular embodiments, one skilled in the art would recognise that various features of the described embodiments may be combined in any manner suitable to implement the technique.

[0217] References

[0218] [1] TR 38.913, “Study on Scenarios and Requirements for Next Generation Access Technologies (Release 14)”, third Generation Partnership Project, vl4.3.0, August 2017.

[0219] [2] RP- 190726, “Physical layer enhancements for NR ultra-reliable and low latency communication (URLLC)”, Huawei, HiSilicon, RAN#83, March 2019.

[0220] [3] RP-201310, “Revised WID: Enhanced Industrial Internet of Things (loT) and ultra-reliable and low latency communication (URLLC) support for NR,” Nokia, Nokia Shanghai Bell, RAN#88e, July 2020.

[0221] [4] European Patent Application No . EP23181917.8.

Claims

CLAIMSWhat is claimed is:

1. A method of operating a first communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, the method comprising receiving, from an infrastructure equipment of the wireless communications network, a downlink signal transmitted by the infrastructure equipment targeted to a second communications device, and decoding, at least partially, the downlink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

2. A method according to Claim 1, wherein the first communications device at least partially decodes the downlink signal only if the downlink signal is received from the infrastructure equipment within a preconfigured set of time resources of the wireless access interface.

3. A method according to Claim 1, wherein the first communications device at least partially decodes the downlink signal only upon receiving a control signal comprising an indication that the downlink signal can be decoded by other communications devices than the second communications device, wherein the control signal schedules the downlink signal.

4. A method according to Claim 1, wherein the first communications device is configured by the infrastructure equipment to decode signals transmitted by the infrastructure equipment to the second communications device.

5. A method according to Claim 4, wherein the first communications device is configured by the infrastructure equipment either to partially decode the downlink signal or to fully decode the downlink signal.

6. A method according to Claim 4, wherein the first communications device is configured by the infrastructure equipment to decode the downlink signal by receiving a first control signal from the infrastructure equipment, wherein the first control signal indicates that the first communications device is to decode the downlink signal.

7. A method according to Claim 6, wherein the first control signal comprises a radio network temporary identifier, RNTI, wherein the RNTI is for use by the first communications device in decoding a second control signal transmitted by the infrastructure equipment to the second communications device, wherein the second control signal schedules the downlink signal.

8. A method according to Claim 4, wherein the first communications device is configured by the infrastructure equipment to decode the downlink signal by receiving at least one RNTI in a broadcast signal from the infrastructure equipment, wherein one of the RNTIs is for use by the first communications device in decoding a control signal transmitted by the infrastructure equipment to the second communications device, wherein the control signal schedules the downlink signal.

9. A method according to Claim 8, wherein the broadcast signal comprises an indication of a time window in which the first communications device can use the RNTI to decode the control signal transmitted by the infrastructure equipment to the second communications device.

10. A method according to Claim 8, wherein the broadcast signal comprises an indication of a set of time resources of the wireless access interface in which the infrastructure equipment is to transmit the control signal to the second communications device.

11. A method according to Claim 1, comprising transmitting, to the infrastructure equipment, a feedback signal indicating whether or not the first communications device successfully decoded the downlink signal.

12. A method according to Claim 11, comprising receiving, from the infrastructure equipment, an indication that the first communications device is to transmit the feedback signal to the infrastructure equipment, wherein the first communications device transmits the feedback signal to the infrastructure equipment based on receiving the indication.

13. A method according to Claim 1, wherein the at least partial decoding of the downlink signal comprises measuring a demodulation reference signal, DMRS, within the downlink signal in order to determine one or more channel characteristics of a communications channel between the infrastructure equipment and the proximity group.

14. A method according to Claim 13, wherein the one or more channel characteristics comprise a signal to interference and noise ratio, SINR, of the downlink signal.

15. A method according to Claim 13, wherein the one or more channel characteristics comprise a maximum modulation and coding scheme, MCS, that, if the downlink signal had been transmitted in accordance with the maximum MCS, the first communications device would have been able to successfully receive the downlink signal in accordance with a predefined error rate.

16. A method according to Claim 13, comprising transmitting, to the infrastructure equipment, an indication of the one or more channel characteristics.

17. A method according to Claim 1, wherein the at least partial decoding of the downlink signal comprises decoding the downlink signal to obtain logarithmic likelihood ratios, LLRs, of each bit of the downlink signal.

18. A method according to Claim 17, comprising determining, based on the obtained LLRs, one or more channel characteristics of a communications channel between the infrastructure equipment and the proximity group.

19. A method according to Claim 18, wherein the one or more channel characteristics comprise a signal to interference and noise ratio, SINR, of the downlink signal.

20. A method according to Claim 18, wherein the one or more channel characteristics comprise a maximum modulation and coding scheme, MCS, that, if the downlink signal had been transmitted in accordance with the maximum MCS, the first communications device would have been able to successfully receive the downlink signal in accordance with a predefined error rate.

21. A method according to Claim 18, comprising transmitting, to the infrastructure equipment, an indication of the one or more channel characteristics.

22. A method according to Claim 17, comprising estimating, based on the obtained LLRs, whether or not the first communications device is able to fully decode the downlink signal.

23. A method according to Claim 22, comprising transmitting, to the infrastructure equipment, an indication of the estimation of whether or not the first communications device is able to fully decode the downlink signal.

24. A method according to Claim 1, comprising transmitting, to the second communications device via a sidelink interface between the first communications device and the second communications device, the at least partially decoded downlink signal.

25. A method according to Claim 24, comprising receiving, from the infrastructure equipment, an indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device, wherein the first communications device transmits the at least partially decoded downlink signal to the second communications device based on receiving the indication.

26. A method according to Claim 25, wherein the indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device comprises an indication of a time window in which the first communications device is to transmit the at least partially decoded downlink signal to the second communications device.

27. A method according to Claim 24, comprising transmitting to the second communications device, before transmitting the at least partially decoded downlink signal to the second communications device, an indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device.

28. A first communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from an infrastructure equipment of the wireless communications network, a downlink signal transmitted by the infrastructure equipment targeted to a second communications device, and to decode, at least partially, the downlink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

29. Circuitry for a first communications device comprisingtransceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from an infrastructure equipment of the wireless communications network, a downlink signal transmitted by the infrastructure equipment targeted to a second communications device, and to decode, at least partially, the downlink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

30. A method of operating an infrastructure equipment forming part of a wireless communications network configured to transmit signals to and / or to receive signals from a plurality of communications devices via a wireless access interface, the method comprising transmitting, to each of a first and a second of the plurality of communications devices, a downlink signal targeted at the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

31. A method according to Claim 30, comprising configuring the first communications device either to partially decode the downlink signal or to fully decode the downlink signal.

32. A method according to Claim 30, comprising transmitting a first control signal to the first communications device, wherein the first control signal indicates that the communications device is to decode the downlink signal.

33. A method according to Claim 32, wherein the first control signal comprises a radio network temporary identifier, RNTI, wherein the RNTI is for use by the first communications device in decoding a second control signal transmitted by the infrastructure equipment to the second communications device, wherein the second control signal schedules the downlink signal.

34. A method according to Claim 30, comprising broadcasting a broadcast signal comprising at least one RNTI, wherein the first communications device is configured by the infrastructure equipment to decode the downlink signal by receiving the broadcast signal, wherein one of the RNTIs is for use by the first communications device in decoding a control signal transmitted by the infrastructure equipment to the second communications device, wherein the control signal schedules the downlink signal.

35. A method according to Claim 34, wherein the broadcast signal comprises an indication of a time window in which the first communications device can use the RNTI to decode the control signal transmitted by the infrastructure equipment to the second communications device.

36. A method according to Claim 34, wherein the broadcast signal comprises an indication of a set of time resources of the wireless access interface in which the infrastructure equipment is to transmit the control signal to the second communications device.

37. A method according to Claim 30, comprising receiving, from the first communications device, a feedback signal indicating whether or not the first communications device successfully decoded the downlink signal.

38. A method according to Claim 37, comprising transmitting, to the first communications device, an indication that the first communications device is to transmit the feedback signal to the infrastructure equipment, wherein the infrastructure equipment receives the feedback signal from the first communications device based on transmitting the indication.

39. A method according to Claim 37, comprising transmitting, to the second communications device based on receiving the feedback signal from the first communications device, an indication that the infrastructure equipment is to retransmit the downlink signal to the second communications device.

40. A method according to Claim 30, comprising transmitting, to the infrastructure equipment, an indication of one or more channel characteristics determined by the first communications device by at least partially decoding the downlink signal.

41. A method according to Claim 40, wherein the one or more channel characteristics comprise a signal to interference and noise ratio, SINR, of the downlink signal.

42. A method according to Claim 40, wherein the one or more channel characteristics comprise a maximum modulation and coding scheme, MCS, that, if the downlink signal had been transmitted in accordance with the maximum MCS, the first communications device would have been able to successfully receive the downlink signal in accordance with a predefined error rate.

43. A method according to Claim 40, comprising determining, based on the received indication of the one or more channel characteristics, one or more transmission parameters in accordance with which the infrastructure equipment will transmit future downlink signals to the first communications device and / or to the second communications device.

44. A method according to Claim 40, comprising determining, based on the received indication of the one or more channel characteristics, whether or not to remove the first communications device and / or the second communications device from the proximity group.

45. A method according to Claim 30, comprising receiving, from the first communications device, an indication of an estimation of whether or not the first communications device is able to fully decode the downlink signal.

46. A method according to Claim 30, comprising transmitting, to the first communications device, an indication that the first communications device is to transmit, after at least partially decoding the downlink signal, the at least partially decoded downlink signal to the second communications device via a sidelink interface between the first communications device and the second communications device.

47. A method according to Claim 46, wherein the indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device comprisesan indication of a time window in which the first communications device is to transmit the at least partially decoded downlink signal to the second communications device.

48. An infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a plurality of communications devices via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to transmit to each of a first and a second of the plurality of communications devices, a downlink signal targeted at the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

49. Circuitry for an infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a plurality of communications devices via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to transmit to each of a first and a second of the plurality of communications devices, a downlink signal targeted at the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

50. A method of operating a second communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, the method comprising receiving, from a first communications device via a sidelink interface between the first communications device and the second communications device, a downlink signal that has been at least partially decoded by the first communications device, wherein the downlink signal was transmitted by an infrastructure equipment of the wireless communications network targeted to the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

51. A method according to Claim 50, comprising receiving the downlink signal from the infrastructure equipment.

52. A method according to Claim 50, comprising receiving the at least partially decoded downlink signal from the first communications device within a specified time window.

53. A method according to Claim 50, comprisingreceiving, from the first communications device, before receiving the at least partially decoded downlink signal from the first communications device, an indication that the first communications device is to transmit the at least partially decoded downlink signal to the second communications device.

54. A method according to Claim 50, comprising receiving, from the infrastructure equipment, an indication that the infrastructure equipment is to retransmit the downlink signal to the second communications device before the second communications device sends a feedback signal to the infrastructure equipment indicating that the second communications device had failed to decode the downlink signal.

55. A method according to Claim 50, comprising receiving an indication of a feedback signal transmitted by the first communications device to the infrastructure equipment, the feedback signal indicating whether or not the first communications device successfully decoded the downlink signal.

56. A second communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a first communications device via a sidelink interface between the first communications device and the second communications device, a downlink signal that has been at least partially decoded by the first communications device, wherein the downlink signal was transmitted by an infrastructure equipment of the wireless communications network targeted to the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

57. Circuitry for a second communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a first communications device via a sidelink interface between the first communications device and the second communications device, a downlink signal that has been at least partially decoded by the first communications device, wherein the downlink signal was transmitted by an infrastructure equipment of the wireless communications network targeted to the second communications device, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

58. A wireless communications system comprising a first communications device according to Claim 28 and an infrastructure equipment according to Claim 48.59 A wireless communications system according to Claim 58, further comprising a second communications device according to Claim 56.

60. A method of operating a first communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, the method comprising receiving, from a second communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, and transmitting, to the infrastructure equipment, the at least partially encoded uplink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

61. A method according to Claim 60, wherein the at least partially encoded uplink signal received from the second communications device and transmitted to the infrastructure equipment is a fully encoded uplink signal.

62. A method according to Claim 60, wherein the at least partially encoded uplink signal is received from the second communications device via a sidelink interface between the first communications device and the second communications device.

63. A method according to Claim 60, wherein the at least partially encoded uplink signal received from the second communications device comprises logarithmic likelihood ratios, LLRs, of each bit of the uplink signal.

64. A method according to Claim 60, comprising receiving the at least partially encoded uplink signal from an upper layer.

65. A method according to Claim 60, comprising determining a first set of uplink resources of the wireless access interface in which to transmit the at least partially encoded uplink signal to the infrastructure equipment based on a second set of uplink resources resource allocated by the infrastructure equipment to the second communications device for the second communications device to transmit the uplink signal to the infrastructure equipment.

66. A method according to Claim 60, comprising receiving, from the infrastructure equipment, an indication of a first set of uplink resources of the wireless access interface in which to transmit the at least partially encoded uplink signal to the infrastructure equipment.

67. A method according to Claim 60, comprising receiving, from the infrastructure equipment, an indication of a first set of uplink resources of the wireless access interface, wherein the transmitting the at least partially encoded uplink signal to the infrastructure equipment comprises transmitting the at least partially encoded uplink signal to the infrastructure equipment in the first set of uplink resources with an indication that the at least partially encoded uplink signal is to be transmitted by the second communications device to the infrastructure equipment.

68. A method according to Claim 60, comprising receiving, from the infrastructure equipment, a feedback signal indicating whether or not the infrastructure equipment successfully decoded the uplink signal.

69. A method according to Claim 60, wherein the first communications device is configured by the infrastructure equipment to transmit uplink signals that are to be transmitted by the second communications device to the infrastructure equipment.

70. A method according to Claim 69, wherein the first communications device is configured by the infrastructure equipment either to partially encode the uplink signal or to fully encode the uplink signal.

71. A method according to Claim 69, wherein the first communications device is configured by the infrastructure equipment to transmit the uplink signal by receiving a first control signal from the infrastructure equipment, wherein the first control signal indicates that the first communications device is to transmit the uplink signal.

72. A method according to Claim 71, wherein the first control signal comprises a radio network temporary identifier, RNTI, wherein the RNTI is for use by the first communications device in decoding a second control signal transmitted by the infrastructure equipment to the second communications device, wherein the second control signal schedules the uplink signal.

73. A method according to Claim 69, wherein the first communications device is configured by the infrastructure equipment to transmit the uplink signal by receiving at least one RNTI in a broadcast signal from the infrastructure equipment, wherein one of the RNTIs is for use by the first communications device in decoding a control signal transmitted by the infrastructure equipment to the second communications device, wherein the control signal schedules the uplink signal.

74. A method according to Claim 73, wherein the broadcast signal comprises an indication of a time window in which the first communications device can use the RNTI to decode the control signal transmitted by the infrastructure equipment to the second communications device.

75. A method according to Claim 73, wherein the broadcast signal comprises an indication of a set of time resources of the wireless access interface in which the infrastructure equipment is to transmit the control signal to the second communications device.

76. A first communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a second communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, and to transmit, to the infrastructure equipment, the at least partially encoded uplink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

77. Circuitry for a first communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitryto receive, from a second communications device, an at least partially encoded uplink signal that is to be transmitted by the second communications device to an infrastructure equipment of the wireless communications network, and to transmit, to the infrastructure equipment, the at least partially encoded uplink signal, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

78. A method of operating an infrastructure equipment forming part of a wireless communications network configured to transmit signals to and / or to receive signals from a communications device via a wireless access interface, the method comprising receiving, from a first of the plurality of communications devices, an at least partially encoded uplink signal, wherein the uplink signal is targeted to the infrastructure equipment by a second of the plurality of communications devices, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

79. A method according to Claim 78, wherein the at least partially encoded uplink signal received from the first communications device is a fully encoded uplink signal.

80. A method according to Claim 78, wherein the at least partially encoded uplink signal received from the first communications device and / or the second communications device is received from an upper layer at the first communications device and / or the second communications device.

81. A method according to Claim 78, comprising transmitting, to the first communications device, an indication of a first set of uplink resources of the wireless access interface in which the first communications device is to transmit the at least partially encoded uplink signal to the infrastructure equipment.

82. A method according to Claim 78, comprising transmitting, to the first communications device, a feedback signal indicating whether or not the infrastructure equipment successfully decoded the uplink signal.

83. A method according to Claim 78, comprising configuring the first communications device to transmit uplink signals that are to be transmitted by the second communications device to the infrastructure equipment.

84. A method according to Claim 78, comprising configuring the first communications device either to partially encode the uplink signal or to fully encode the uplink signal.

85. A method according to Claim 78, comprising transmitting a first control signal to the first communications device, wherein the first control signal indicates that the first communications device is to transmit the uplink signal.

86. A method according to Claim 85, wherein the first control signal comprises a radio network temporary identifier, RNTI, wherein the RNTI is for use by the first communications device in decoding a second control signal transmitted by the infrastructure equipment to the second communications device, wherein the second control signal schedules the uplink signal.

87. A method according to Claim 78, comprising broadcasting a broadcast signal comprising at least one RNTI, wherein the first communications device is configured by the infrastructure equipment to transmit the uplink signal by receiving the broadcast signal, wherein one of the RNTIs is for use by the first communications device in decoding a control signal transmitted by the infrastructure equipment to the second communications device, wherein the control signal schedules the uplink signal.

88. A method according to Claim 87, wherein the broadcast signal comprises an indication of a time window in which the first communications device can use the RNTI to decode the control signal transmitted by the infrastructure equipment to the second communications device.

89. A method according to Claim 87, wherein the broadcast signal comprises an indication of a set of time resources of the wireless access interface in which the infrastructure equipment is to transmit the control signal to the second communications device.

90. An infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a communications device via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a first of the plurality of communications devices, an at least partially encoded uplink signal, wherein the uplink signal is targeted to the infrastructure equipment by a second of the plurality of communications devices, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

91. Circuitry for an infrastructure equipment forming part of a wireless communications network, the infrastructure equipment comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a communications device via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to receive, from a first of the plurality of communications devices, an at least partially encoded uplink signal, wherein the uplink signal is targeted to the infrastructure equipment by a second of the plurality of communications devices, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

92. A method of operating a second communications device configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, the method comprisingtransmiting, to a first communications device, an at least partially encoded uplink signal that is to be transmited by the second communications device to an infrastructure equipment of the wireless communications network, wherein the at least partially encoded uplink signal is transmited to the first communications device so that the first communications device can also transmit the at least partially encoded uplink signal to the infrastructure equipment, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

93. A method according to Claim 92, wherein the at least partially encoded uplink signal transmited to the first communications device is a fully encoded uplink signal.

94. A method according to Claim 92, wherein the at least partially encoded uplink signal is transmited to the first communications device via a sidelink interface between the first communications device and the second communications device.

95. A method according to Claim 92, wherein the at least partially encoded uplink signal transmited to the first communications device comprises logarithmic likelihood ratios, LLRs, of each bit of the uplink signal.

96. A second communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to transmit, to a first communications device, an at least partially encoded uplink signal that is to be transmited by the second communications device to an infrastructure equipment of the wireless communications network, wherein the at least partially encoded uplink signal is transmited to the first communications device so that the first communications device can also transmit the at least partially encoded uplink signal to the infrastructure equipment, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

97. Circuitry for a second communications device comprising transceiver circuitry configured to transmit signals to and / or to receive signals from a wireless communications network via a wireless access interface, and controller circuitry configured in combination with the transceiver circuitry to transmit, to a first communications device, an at least partially encoded uplink signal that is to be transmited by the second communications device to an infrastructure equipment of the wireless communications network, wherein the at least partially encoded uplink signal is transmited to the first communications device so that the first communications device can also transmit the at least partially encoded uplink signal to the infrastructure equipment, wherein the first communications device and the second communications device each form part of a proximity group of a subnetwork of the wireless communications network, the subnetwork comprising at least the first communications device, the second communications device, and the infrastructure equipment.

98. A wireless communications system comprising a first communications device according to Claim 76 and an infrastructure equipment according to Claim 90.99 A wireless communications system according to Claim 98, further comprising a second communications device according to Claim 96.

100. A computer program comprising instructions which, when loaded onto a computer, cause the computer to perform a method according to any of Claim 1, Claim 30, Claim 50, Claim 60, Claim 78, or Claim 92.

101. A non-transitory computer-readable storage medium storing a computer program according to Claim 100.

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