WO2023033703A1 - Enhanced network controlled sidelink communications - Google Patents

Abstract

A method (1100) by a user equipment, UE (512, 600), for network controlled sidelink communications includes receiving (1102) control information (102, 202, 302, 402) for establishing a sidelink communication session with at least one other UE (512, 600). The UE transmits (1104), to a network node (510, 700), first feedback (414a, 414b) in response to a reception of a transmission associated with the sidelink communication session.

Description

ENHANCED NETWORK CONTROLLED SIDELINK COMMUNICATIONS

TECHNICAL FIELD

The present disclosure relates, in general, to wireless communications and, more particularly, systems and methods for enhanced network-controlled sidelink communications.

BACKGROUND

Third Generation Partnership Project (3GPP) specified support in Long Term Evolution (LTE) for proximity services (ProSe) in Releases 12 and 13, targeting public safety use cases (e.g., first responders) as well as a small subset of commercial use cases (e.g., discovery). The main novelty of ProSe was the introduction of device-to-device (D2D) communications using the sidelink (SL) interface. During Rel-14 and Rel-15 in 3GPP, major changes were introduced to the LTE SL framework with the aim of supporting Vehicle-to-Anything/Vehicle-to-Everything (V2X) communications, where V2X collectively denotes communication between vehicle to any other endpoint (e.g., a vehicle, a pedestrian, etc.). The feature targeted mostly basic V2X use cases such as day-1 safety, etc.

During Rel-16, 3GPP worked on specifying the SL interface for the 5^th Generation (5G) New Radio (NR). The NR sidelink in Rel-16 mainly targets advanced V2X services, which can be categorized into four use case groups: vehicles platooning, extended sensors, advanced driving and remote driving. The advanced V2X services require a new SL in order to meet the stringent requirements in terms of latency and reliability. The NR SL is designed to provide higher system capacity and better coverage, and to allow for an easy extension to support the future development of further advanced V2X services and other related services.

Given the targeted V2X services by NR SL, it is commonly recognized that groupcast/multicast and unicast transmissions are desired, in which the intended receiver of a message consists of only a subset of the vehicles in proximity to the transmitter (groupcast) or of a single vehicle (unicast). For example, in the platooning service, there are certain messages that are only of interest to the members of the platoon, making the members of the platoon a natural groupcast. In another example, the see-through use case most likely involves only a pair of vehicles, for which unicast transmissions naturally fit. Therefore, NR sidelink not only supports broadcast as in LTE sidelink, but also groupcast and unicast transmissions. Like in LTE sidelink, the NR sidelink is designed in such a way that its operation is possible with and without network coverage and with varying degrees of interaction between the user equipments (UEs) and the network), including support for standalone, network-less operation.

In Rel- 17, 3GPP is working on multiple enhancements for the SL with the aim of extending the support for V2X and to cover other use cases (UCs) such as public safety (see RP- 193231). Among these, improving the performance of power limited UEs (e.g., pedestrian UEs, first responder UEs, etc.) and improving the performance using resource coordination are considered critical.

For Rel- 18, high level discussions regarding non-V2X vertical use cases for SL have just begun. While the details are too early to discuss, some examples of use cases that involve SL or some form of direct-link between devices are: in-vehicle communications, Industrial loT, personal loT such as wearables, drones and SL in unlicensed spectrum.

Resource allocation for sidelink transmissions

Like in LTE SL, there are two resource allocation modes for NR SL:

• Network-based resource allocation, in which the network selects the resources and other transmit parameters used by SL UEs. In some cases, the network may control every single transmission parameter. In other cases, the network may select the resources used for transmission but may give the transmitter the freedom to select some of the transmission parameters, possibly with some restrictions. In the context of NR SL, 3GPP refers to this resource allocation mode as Mode 1 (also termed network-controlled mode). o Similar to NR Uu, NR SL Mode 1 supports two types of resource grants that a gNodeB (gNB) can give to a UE: dynamic grant (DG) and configured grant (CG). With DG, the UE needs to request for SL resources for the transmission of every transport block (TB). In contrast, with CG, the network can allocate (periodic) resources for the transmission of multiple transport blocks (TBs). The CG typically consists of a set of parameters such as the CG index, the time-frequency allocation and the periodicity of the allocated SL resources. The time-frequency allocation indicates the slot(s) and sub-channel(s) assigned periodically to the UE in a CG. A UE can be allocated up to three SL resources during each period of the CG. The UE can only transmit one new TB in each CG period and can retransmit a TB initially transmitted in the same or in a previous CG period. • Autonomous resource allocation, in which the UEs autonomously select the resources and other transmit parameters. In this mode, there may be no intervention by the network (e.g., out of coverage, unlicensed carriers without a network deployment, etc.) or very minimal intervention by the network (e.g., configuration of pools of resources, etc.). In the context of NR SL, 3GPP refers to this resource allocation mode as Mode 2 (also termed autonomous transmission mode).

Physical sidelink channels

In NR SL, different physical sidelink channels are defined.

• Physical sidelink control channel (PSCCH): This is used to carry (part of) SL control information (SCI), which is also referred to as the l^st-stage SCI or SQL The l^st-stage SCI carries the resource allocation information which is essential to decode for performing sensing-based resource allocation (i.e. mode-2).

• Physical sidelink shared channel (PSSCH): This is used to carry actual data transmission. Also, a part of SCI, often referred to as the 2^nd-stage SCI or SCI2, is carried over the PSSCH.

• Physical sidelink feedback channel (PSFCH): This is used to carry the Hybrid Automatic Repeat Request (HARQ) feedback information such as positive acknowledgement feedback (HARQ-ACK) or negative- acknowledgement feedback (HARQ-NACK). In Rel. 16, only sequence-based PSFCH is supported.

• Physical sidelink broadcast channel (PSBCH): This is used to carry the system information which is used to perform SL transmissions.

SCI formats

In NR SL, the SCI is divided into two different stages. The first stage (denoted in the specification as SCI format 1-A, often referred to as SCI1) is included in the PSCCH and the second stage (which two different formats are denoted in the specifications as SCL2A and SCL 2B, often commonly referred to as SCI2) is carried by PSSCH. The format of each of the stages is defined in Section 8.3 and 8.4 of 3GPP TS 38.212.

The first stage SCI carries some key information such as time and frequency domain resource allocation, Modulation and Coding Scheme (MCS), as well as the indication of the second stage SCI format. This first stage SCI is decodable by all the UEs supporting SL as it is intended for resource reservation and sensing. The second stage SCI further provides additional information such as HARQ process number, New Data Indicator (NDI), Redundance Value (RV), and source and destination identifiers (IDs). To be able to receive PSSCH correctly, the Receiving UE (Rx UE) needs to successfully receives both the first stage and the corresponding second stage SCIs correctly.

Groupcast modes

In case of groupcast, NR supports two types of HARQ mechanisms:

• Option 1 : When only NACK is transmitted in case of failed PSSCH decoding.

• Option 2: When ACK is transmitted if PSSCH is successfully decoded or NACK is transmitted in case of failed PSSCH decoding.

Option 1 has the issue that there is no way for a transmitter UE to distinguish between failed PSCCH and successful data transmission. However, in this case, it is reasonable that the Transmitting UE (TX UE) assumes that the PSSCH has been successfully decoded if no NACK is received. Option 1 is particularly useful to limit unnecessary transmissions and hence the congestion in the network. It is to be noted that the use of each option in NR is made (pre- )configurable and depends on the scenario.

Related to the groupcast modes and included in the SCI content as Cast Type Indicator, the different unicast, groupcast, and broadcast types are indicated as shown in Table 1, which corresponds to Table 8.4.1.1-1 of 3GPP TS 38.212:

Table 1

Configuration, pre-configuration, and predefinition of parameters

To operate SL different parameters are used. These parameters may be provided to a UE in different ways:

• The parameters may be configured by a network node (e.g., a gNB). Configuration may be received using dedicated or broadcast signaling such as, for example, using a System Information Block (SIB) or Radio Resource Control (RRC) signaling. This is typically used when the UE is in coverage of a gNB for a given frequency. • The parameters may be preconfigured in the UE. In this case, the pre-configuration is stored in the UE, typically in the SIM card. This is typically used when the UE is not in coverage for a given frequency.

• The parameters may be predefined or defined in a specification.

Herein, the term (pre-)configuration includes any of configuration and pre-configuration.

CSI report over SL

Currently, SL CSI consists of Channel Quality Indicator (CQI) and Rank Indicator (RI), where the CQI and RI are always reported together. The SL CSI is computed based on sidelink Channel State Information-Reference Signal (CSLRS) transmitted from Tx UE.

The SL CSI report is sent in Medium Access Control-Control Element (MAC CE) and only transmitted to Tx UE. The SL CSI reporting is performed in an aperiodic manner, i.e., only when triggered by the CSI request field in the SCI format 2- A.

Industrial Internet-of-Things (IIoT) and Ultra-reliable low latency communication (URLLC)

3GPP NR is capable of fulfilling the requirements of ultra-reliable low latency communication (URLLC). Enhancements for URLLC and Industrial Internet of things (IIoT) were introduced in NR Rel-16 and further enhanced as part of current Rel-17 3GPP discussions in work item RP-201310, NR_IIOT_URLLC_enh. Several features for reaching low latencies and high reliability of transmission had been introduced. Furthermore, support of 5G NR for time sensitive networking (TSN) had been introduced.

Meeting URLLC reliability and low latency delay simultaneously

URLLC requirements specified for NR by the 3 GPP are intended to handle a variety of new demanding wireless use cases. Such use cases appear in the automotive safety field, in factory automation, as well as when augmented and virtual reality functionality with tactile feedback are run over NR. The performance requirements are then enhanced, from 4G mobile broadband capacity/spectral efficiency requirements, to include also stringent requirements on round trip latency and reliability. Typically, the latency requirements reach sub-millisecond figures and the reliability requirements reach packet loss probabilities as low as 10’⁶ -10’⁴. This may require redesign, as compared to previous mobile broadband focused systems.

First, focusing on the reliability figures, it is noted that the mobile broadband transmission system is optimized for operation at a block-error rate of 1-10%, meaning that error rates of perhaps 10’² are achievable without re-transmission. There is no easy realizable way to improve this figure since the measurement of the statistics to achieve, say a block-error rate of 10’⁶ , would require data collection over k(10’⁶)^-1 = k 10⁶ transmission time intervals, where k may be of the order of 100. With a TTI of 1 millisecond, this adds up to 3 hours which is clearly infeasible as compared to the radio channel variation rate.

To solve this issue, one may, for example, write 10’⁶ = (IO^-2)³. This relation hints to a solution by means of transmission of the URLLC data over three independent wireless interfaces, i.e., towards running URLLC using some kind of multi-point transmission. The requirements also hint towards a need for at least three multi-path connections, which may be based on dual connectivity or repetitions.

Reliability tools

The problem is that there are no existing retransmission schemes with purpose to optimize both spectrum efficiency and latency at higher protocol layer.

To meet application layer reliability requirements, there are many existing tools in different layers. One of the most commonly used tools on different protocol layers are retransmissions, for examples retransmissions on Transmission Control Protocol (TCP), Packet Data Convergence Protocol (PDCP), Radio Link Control (RLC), and MAC layer. These retransmission schemes in different protocol layers are performed when the transmission feedback indicates that the transmission has failed. For example, a MAC layer failure resulting from failed HARQ (retransmissions in MAC layer will trigger a retransmission of a RLC packet; multiple RLC retransmission failures will result in a failed transmission of PDCP packet and, thus, a PDCP retransmission will be triggered. At the TCP layer, if TCP acknowledge is not received, a retransmission of TCP packet will be triggered.

These schemes are on demand based on transmission feedback and optimized for resource utilization efficiency. For example, if a transmission failed, a retransmission is triggered, and the extra resources are consumed only if a retransmission occurs. However, since any retransmission loop will require at least a round trip time delay to receive the feedback information, they are not optimized to minimize latency and transmission delay.

It is a challenge especially for guaranteed delay critical Guaranteed Bit Rate (GBR). For example, for a 5G Quality of Service Indicator (5QI) of 85 smart grid service in large Mobile Network Operator (MNO) network, with required packet error rate below 10’⁵ and with packet delay budget= 3ms in Radio Access Network (RAN), retransmissions that potentially are required for reliability purpose in different layers are not affordable due to the latency constraint.

• Repetitions/duplications It is possible to have reliability improvement with latency optimized solution that multiple simultaneous replicated/repeated packets transmitted in multiple independent paths, including both time, frequency, spatial resources, may improve reliability with relaxed Block Error Rate (BLER) target at individual transmission path.

One example in previous techniques is PDCP duplication, which includes duplicating PDCP packets in different carriers or bands based on dual connectivity (DC) and carrier aggregation (CA) scheme. Maximally 4 copies are supported. The number of replications is RRC configured and can be activated through MAC CE or RRC configuration. FIGURE 1 illustrates an example configuration with DC and CA in both Master Cell Group (MCG) and Secondary Cell Group (SCG) with 4 configured RLC entities for PDCP data duplication and only 4 activated RLC entities activated.

There currently exist certain challenges, however. For example, in the current SL design, in both autonomous transmission mode and network-controlled mode, the Rx UE needs to decode the scheduling information (i.e., the SCI) sent by the Tx UE in order to decode the corresponding data packet. However, SCI transmission from a UE is generally not as reliable as DCI transmission from a gNB. This may be due to higher interference in the SL, lower transmit power, and/or less beam-forming capability of the UE. Therefore, for IIoT, to achieve ultra-high reliable SL transmission, SCI reliability can be an issue.

One potential solution to improve the reliability of control information for SL is to allow the network to control both Tx UE and Rx UE if both UEs are under network coverage. Such a scenario can be considered reasonable in IIoT settings and has been considered in the context of feedback for SL, though no details have been disclosed regarding the signaling of the scheduling information as well as how to evolve the current NR SL design to support such a scenario.

As another example, some issues with the current NR SL design when applying to IIoT are the HARQ feedback and the CSI acquisition and reporting mechanisms in the network-controlled SL transmission mode (Mode 1). Specifically, SL HARQ feedback is first sent from the Rx UE to the Tx UE via SL before the SL HARQ feedback is reported by the Tx UE to the gNB. In case of CSI reports, the Rx UE sends the reports to the Tx UE over the SL and the Tx UE makes use of the information such as, for example, for adapting the MCS, without the network’s participation. While this design is the only option in some cases such as for example, when only the Tx UE has connection to the gNB, it is not optimal in terms of latency and reliability when the Rx UE also has connection to the gNB. This is because transmissions in the SL are typically more susceptible to interference and collisions than in the uplink/downlink and having two hops from the Rx UE to the gNB is latency-disadvantageous. Not to mention that having separate entities for the scheduling (gNB) and link adaptation (Tx UE) might not be an efficient design.

SUMMARY

Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. For example, methods and systems are disclosed for providing control information needed for SL transmission more reliably. As another example, methods and systems are provided that propose different solutions related to how HARQ-ACK feedback and CSI feedback is performed at the Rx UE in response to data reception via SL.

According to certain embodiments, a method by a UE for network controlled sidelink communications includes receiving control information for establishing a sidelink communication session with at least one other UE. The UE transmits, to a network node, first feedback in response to a reception of a transmission associated with the sidelink communication session.

According to certain embodiments, a UE is provided for network controlled sidelink communications. The UE includes processing circuitry adapted to receive control information for establishing a sidelink communication session with at least one other UE and transmit, to a network node, first feedback in response to a reception of a transmission associated with the sidelink communication session.

According to certain embodiments, a method by a network node for network controlled sidelink communications includes receiving, from a UE, a first feedback associated with a reception of a transmission associated with a sidelink communication session between the UE and at least one other UE.

According to certain embodiments, a network node is provided for network controlled sidelink communications. The network node includes processing circuitry adapted to receive, from a UE, a first feedback associated with a reception of a transmission associated with a sidelink communication session between the UE and at least one other UE.

Certain embodiments may provide one or more of the following technical advantage(s). For example, certain embodiments may provide a technical advantage of improving reliability of control information transmission for SL communication which in turn can improve reliability of the data transmission on SL. As another example, certain embodiments may provide a technical advantage of providing benefits in terms of reducing overhead of SL transmission, which can lead to improved reliability and/or data rate of the data channel since, for example, the resources of the reduced control overhead can be used for the data channel. As yet another example, certain embodiments may provide a technical advantage of improving reliability and latency of the HARQ-ACK feedback transmission in response to SL data transmission. Thus, certain embodiments may improve reliability and latency of the overall transmission on SL in general.

As still another example certain embodiments enable HARQ-ACK feedback to be transmitted directly to gNB and can also provide a technical advantage of improving resource efficiency in the sense that if positive acknowledgement feedback is received early at gNB, then the gNB can make use of resources already reserved for SL retransmission for some other purposes.

As yet another example, certain embodiments relating to sidelink CSI reporting may provide a technical advantage of improving CSI transmission reliability. Additionally or alternatively, certain embodiments may enable more efficient SL scheduling and link adaptation when gNB can schedule both Tx UE and Rx UE.

Other advantages may be readily apparent to one having skill in the art. Certain embodiments may have none, some, or all of the recited advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the disclosed embodiments and their features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 illustrates an example configuration with DC and CA in both Master Cell Group (MCG) and Secondary Cell Group (SCG) with 4 configured RLC entities for PDCP data duplication and only 4 activated RLC entities activated;

FIGURE 2 illustrates such a solution where the gNB controls both Tx UE and Rx UE for SL communication;

FIGURE 3 illustrates an example where the DCI sent to the Rx UE contains partial SA and the SCI contains full SA, according to certain embodiments;

FIGURE 4 illustrates an example where DCI sent to Rx UE contains full SA and SCI contains partial SA, according to certain embodiments;

FIGURE 5 illustrates an example wherein both DCI and SCI sent to Rx UE contain partial SA, according to certain embodiments;

FIGURE 6 illustrates an example where the gNB controls both the Tx UE and the Rx UE for SL communication, according to certain embodiments; FIGURE 7 illustrates an example communication system, according to certain embodiments;

FIGURE 8 illustrates an example UE, according to certain embodiments;

FIGURE 9 illustrates an example network node, according to certain embodiments;

FIGURE 10 illustrates a block diagram of a host, according to certain embodiments;

FIGURE 11 illustrates a virtualization environment in which functions implemented by some embodiments may be virtualized, according to certain embodiments;

FIGURE 12 illustrates a host communicating via a network node with a UE over a partially wireless connection, according to certain embodiments;

FIGURE 13 illustrates a method by a UE for network controlled sidelink communications, according to certain embodiments; and

FIGURE 14 illustrates a method by a network node for network controlled sidelink communications, according to certain embodiments.

DETAILED DESCRIPTION

Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

For example, according to certain embodiments, methods and systems are disclosed for providing control information needed for SL transmission more reliably. For example, according to certain particular embodiments, different combinations of SCI may be sent from Tx UE to Rx UE. Additionally or alternatively, different combinations of DCI may be sent from the gNB to the Rx UE. Each combination has its own technical advantages in improving the reliability of control information (and of data packet) of the SL communications. Also, resource-efficient signaling methods for the gNB to schedule both Tx UE and Rx UE are also disclosed.

According to certain particular embodiments, for example, methods and systems are disclosed that include complementing and/or replacing SCI transmission from TX UE to Rx UE with a DCI transmission from gNB to the Rx UE. Different variants on the contents of SCI and DCI are proposed. Similar solutions for configured grant activation and deactivation based on DCI are also described.

In addition, new solutions to closely related procedures are proposed, including a resourceefficient method of sending a common DCI to both Tx UE and Rx UE and signaling methods for SL configured grants. According to certain particular embodiments, methods and systems are provided that propose different solutions related to how HARQ-ACK feedback transmission is performed at the Rx UE in response to data reception via SL. The methods, systems, and solutions include having HARQ-ACK feedback transmitted to Tx UE and/or gNB depending on some conditions. Moreover, certain embodiments are provided for how the retransmission can be scheduled based on different feedback transmissions.

In addition to HARQ-ACK feedback, certain embodiments additionally or alternatively propose solutions for SL CSI acquisition and reporting, where the SL CSI may be reported to Tx UE and/or gNB based on specific configuration or explicit indication.

Currently a SL transmission is solely scheduled by the SCI sent from the Tx UE to the Rx UE, and that can be a reliability bottleneck for URLLC applications in IIoT. One viable solution to this problem is allowing the gNB to schedule both the Tx UE and the Rx UE of a SL communication when both of them are under network coverage. FIGURE 2 illustrates such a solution where the gNB controls both Tx UE and Rx UE for SL communication, according to certain embodiments. In so doing, the reliability of the scheduling (control) information received at the Rx UE can be improved. Such a scenario is plausible in the context of IIoT and is considered herein. Note that the scenario is discussed in U.S. Patent Publication No. 2020/0295887A1, which is incorporated by reference in its entirety.

According to certain embodiments, SL communication can happen according to the following steps:

• Step 1: gNB determines the transmitting UE (Tx UE) and receiving UE (Rx UE) of a desired SL communication session o This step may include Tx UE sending assistance information to gNB (e.g., information about the desired Rx UE)

• Step 2: Sending control information: o 2a: gNB sends control information via downlink (DL) to Tx UE and Rx UE o 2b: Tx UE sends control information via SL to Rx UE

• Step 3 : Tx UE sends data to Rx UE.

The focus of certain embodiments described herein is on details of Step 2. It may be noted that:

• Step 2b may or may not be included, depending on the signaling option covered by the embodiments described herein.

• Step 2b can happen in the same TTI with Step 3. • An assumption is that the gNB is aware of both the Tx UE and the Rx UE of the SL communication (e.g., after Step 1), which can include at least one or more of the following types of information:

The identifier (ID) of the Tx UE involved in SL communication with the Rx UE.

The ID of the Rx UE involved in SL communication with the Tx UE.

The ID of the SL link between the Tx UE and the Rx UE.

How the gNB obtains the above information is outlined below.

Note that the control information in FIGURE 2 can be sent in the physical layer (e.g., an SCI in the sidelink or a DCI in the downlink) or in higher layer (e.g., the RRC signal). Both methods of signaling are discussed below.

Herein, the term transmitting includes the transmission of signals, messages, data, etc. whether or not the transmissions are successfully received. Stated differently, a transmission step described herein includes any attempt at transmission by a device regardless of whether the transmission is received by a recipient device.

DCI + SCI variants

Herein, the term scheduling assignment (SA) is used to denote the information necessary for the Rx UE to decode a (data) SL transmission from the Tx UE, i.e., the information equivalent to the SCI (SCH+SCI2) of the current NR SL design. To differentiate different options in our solutions, the term hill SAis used to denote the complete content of the SA and partial SA to denote some parts of the content of the SA.

One of the main design questions when the gNB schedules both Tx UE and Rx UE is how the SA is delivered to the Rx UE. It may be noted that the Tx UE can be controlled in a similar way as in the existing SL design, i.e., NR SL Mode 1, with possibly some differences in terms of the contents of the DCI. Certain of the various embodiments presented herein address this question.

According to certain embodiments, a solution is provided to split the contents of the SA into two parts, which could be but are not necessarily overlapping. One part is sent in the SL and one part is sent in the DL. Different variants of the split are presented, taking into account the current SCI design of NR SL and potential reliability improvements can be achieved.

FIGURE 3 illustrates an example 100 where the DCI 102 sent to the Rx UE 104 contains partial SA and the SCI 106 contains full SA, according to certain embodiments. Specifically, as illustrated in FIGURE 3, full SA is sent via SL (in an SCI 106) from Tx UE 108 and partial SA is sent via the DL (in a DCI) from gNB 110 to the Rx UE 104. In this way, the SA diversity can help improve the reliability of SA reception at the Rx UE 104. Furthermore, the SA sent in the SL ensures the sensing process for resource selection at other SL UEs as in the current NR SL design, hence facilitating the coexistence of SL UEs in different releases in the same resource pool.

In a first particular embodiment, the DCI 102 including the partial SA that is sent via the downlink contains the contents of the SCI1 of NR SL Rel-16. It may be understood that how to utilize the SA from the two links (SL and DL) can be left to Rx UE’ s implementation. For example, the Rx UE 104 can first decode the DCI 102 from the downlink, and if decoding is successful, the Rx UE 104 decodes the SCI2 and the PSSCH sent in the SL without the need to decode the SCI1 in the SL. Only in the case Rx UE 104 fails the DCI decoding, the Rx UE 104 tries to decode the SCI1 106 in the SL. Note that since DCI is typically more reliable than SCI, this latter case is not expected to happen very often.

In a second particular embodiment, the partial SA 102 sent via the downlink contains some fields of SCI1, which, after decoded at the Rx UE 104, can improve the decodability of the SCI1 sent in the SL. For example, consider a field that is present in both partial SA and full SA and that the same value is expected. Assume that the Rx UE 104 first decodes the partial SA and obtains a value for the field. The obtained value may be used by the Rx UE 104 to decode other fields in the full SA. If the full SA is encoded using a polar code, then the decoded value for the field may be assumed as known by the decoder (i.e., its bit values may be frozen in the decoder).

In a third particular embodiment, the partial SA sent via the downlink contains only the resource allocation (i.e., the time and frequency allocation) of the SCI1 in the SL. The Rx UE 104 can use that information to decode the SCI1 in the SL directly, without the need for blind decoding. This approach also has an advantage of smaller DCI size which can improve the DCI reliability.

FIGURE 4 illustrates an example 200 where the DCI 202 sent to the Rx UE 204 contains full SA and the SCI 206 sent to the Rx UE 204 contains partial SA, according to certain embodiments. Thus, full SA is sent via DL (in DCI 202) from gNB 210 and partial SA is sent via SL (in an SCI 206) from TX UE 208 to the Rx UE 204. This approach also creates diversity for SA and hence improve the reliability of SA reception at the Rx UE 204. In a first particular embodiment, the DCI 206 containing the partial SA consists of only the SCI1 of NR SL Rel-16. Thus, the SCI2 is only sent via the DCI 202. In this way, the reliability of the SCI1 is improved and the sensing process for resource selection at other SL UEs is not affected because only SCI1 is needed for sensing. This also means that there’s no big problem with coexistence of SL UEs in different releases in the same resource pool. Another advantage is that, since the SCI2 is sharing the same resources with the data in the PSSCH in the current NR design, removing SCI2 in the SL will either improve the reliability or the data rate of the data channel. It may be understood that how to utilize the received SA parts at the Rx UE 204 can be left to UE implementation. In one example, the Rx UE 204 decodes the SA in the DCI 202, and if this decoding is successful, the UE then decodes the PSSCH without decoding the SCI1 sent in the SL.

In a second particular embodiment, the DCI 206 containing the partial SA consists of only the resource assignment of the SL transmission. For example, the DCI 206 may include only the time and frequency resource assignment of the SL transmission and potential reserved resources for future transmissions. This is different from the above-described embodiment in which the partial SA carries the SCI1 of NR SL Rel-16 because, besides resource assignment, the SCI1 also contains some information about the transport format of the SCI2. In this particular embodiment, such information is not needed because the full SA is sent in the DCI 202. The advantage of this embodiment is that the partial SA still contains essential information for resource sensing at other UEs, but the size of the SCI is reduced. Thus, the SCI can be sent with more robust transport format, thereby improving reliability, or more resources can be used to send data in the SL.

FIGURE 5 illustrates an example 300 wherein both DCI 302 and SCI 306 sent to Rx UE 304 contain partial SA, according to certain embodiments. Thus, as illustrated, partial SA is sent in both the SL from Tx UE 308 and the DL from gNB 310. The contents of the two partial SA’s can be partially overlapping or non-overlapping, in various embodiments. For example, in a particular embodiment, SCI1 is sent in the SL via SCI 306 while SCI2 is sent in the DL via DCI 302. In so doing, the resource sensing and selection at other SL UEs, which depends on SCI1 only, are not affected. At the same time, it allows for a robust transmission of SCI2 through PDCCH from gNB 310 such as, for example, with improved beamforming gain and higher transmit power. Thus, higher reliability and/or improved data rate of the SL data channel may be achieved without taking resources used for the data channel in the SL. This is in contrast to the NR Rel-16 SL design where SCI2 shares resources with the SL data channel.

According to still other particular embodiments, full SA is sent via DL (in a DCI 302) and no SA content is sent via SL. This approach has an advantage of maintaining high reliability for SL. This is in thanks to the general high reliability of DCI. However, the approach also completely removes the control information overhead in the SL, which can lead to higher reliability and/or higher data rate for the data channel (since the resources of the control overhead can be used for data transmission). It also removes the complexity related to encoding and decoding the SCI in the SL.

According to still other particular embodiments, full SA is sent via both SL and DL. This approach provides highest SA diversity and hence reliability of the SA. According to still other particular embodiments, when there are overlapping or equivalent fields in the SCI 306 and the DCI 302, a field in the SCI 306 can override the corresponding/equivalent field in the DCI if their respective values are different, or conversely a field in the DCI 302 can override the corresponding/equivalent field in the SCI 306. The rule to determine the which control information source (SCI 306 or DCI 302) can override the other can be (pre)defined such as, for example, by assigning priority for each of the sources. For example, the SCI 306 can be (pre)configured to have higher priority than the DCI 302, or vice versa. This overriding mechanism can be used, for example, to perform intra- UE pre-emption. In an example, the 302 DCI schedules a first transport block (TB1) to the Rx UE 304, but right before the TB1 is to be transmitted, there is a higher priority I more urgent transport block (TB2) arrives at the Tx UE 308. In this case, the Tx UE 308 can use the SCI 306 to schedule the TB2 and the SCI 306 will override the DCI 302 at the Rx UE 304. That means the Tx UE 308 uses SCI 306 to pre-empt TB1 for transmitting TB2.

According to still other particular embodiments, when there are overlapping or equivalent fields in the SCI 306 and the DCI 302, the Rx UE 304 is not expected to decode the SL transmission if the value of one or more fields in the SCI 306 is different from the value of the corresponding I equivalent field in the DCI 302. In so doing, the error detection rate for control information at the Rx UE 304 can be improved.

Higher layer + PHY signaling

According to certain embodiments, a variation of the embodiments disclosed above includes a scenario where one of the two SAs (one in DL and one in SL) is provided using higher layer (i.e., above physical layer in the protocol stack) signaling and the other SA is provided using physical layer signaling.

In a first example particular embodiment, the gNB 110, 210, 310 uses RRC signaling to configure a SL grant for reception at the Rx UE 104, 204, 304. This grant includes SA information. The Tx UE 108, 208, 308 uses physical layer (PHY) signaling (e.g., the PSCCH channel) to transmit the SCI 106, 206, 306 carrying SA information to the Rx UE 104, 204, 304.

In a second example particular embodiment, the Tx UE 108, 208, 308 uses higher layer (e.g., PC5-RRC) signaling to configure a SL grant for reception at the Rx UE 104, 204, 304. This grant includes SA information. The gNB uses physical layer (PHY) signaling (e.g., the PDCCH channel) to transmit the DCI 102, 202, 302 carrying SA information to the Rx UE 104, 204, 304.

In a third example particular embodiment, the gNB 110, 210, 310 uses RRC signaling to configure a SL grant for reception at the Rx UE 104, 204, 304. This grant includes SA information for multiple SL receptions at the Rx UE 104, 204, 304. The Tx UE 108, 208, 308 uses physical layer (PHY) signaling (e.g., the PSCCH channel) to transmit an SCI 106, 206, 306 to the Rx UE 104, 204, 304 to activate the grant configured by the gNB, and/or the Tx UE 108, 208, 308 uses physical layer (PHY) signaling (e.g., the PSCCH channel) to transmit an SCI 106, 206, 306 to the Rx UE 104, 204, 304 to deactivate an active grant configured by the gNB 110, 210, 310.

In principle, each of the two parts may be a full and/or partial SA as described earlier and so the earlier embodiments are also applicable here.

Providing a grant over RRC (or PC5-RRC) is typically a semi-static operation. That is, grants provided using higher layer signaling are for a periodic or recurrent instance of the resources. In contrast, PHY signaling is typically used in a much more dynamic way. Grants provided with PHY signaling are often for a single transmission or for a small number of transmissions of a TB. In this regard, examples 1 and 2 are two variants of which entity (gNB 110, 210, 310 or TX UE 108, 208, 308) is given dynamic means to provide SA and which one is given semi-static means only.

Given the difference in timing and operation of conveying SA information using higher layer or PHY layer, the use of prioritization described in the embodiment described above is very relevant. Typically, dynamic SA information (i.e., conveyed using PHY signaling) would override semi-static information (i.e., conveyed using higher layer signaling).

In a fourth example particular embodiment, the gNB 110, 210, 310 uses RRC signaling to configure a SL grant for reception at the Rx UE 104, 204, 304. This includes a value XI for a field Y in the SA. Occasionally, the Tx UE 108, 208, 308 uses physical layer (PHY) signaling (e.g., the PSSCH channel) to transmit the SCI carrying SA information to the Rx UE 104, 204, 304. This includes a different value X2 for a field Y in the SA.

If the Rx UE 104, 204, 304 succeeds in decoding the SCI 106, 206, 306, then the Rx UE 104, 204, 304 uses the value X2 for the field Y. If not, the Rx UE 104, 204, 304 uses the default value XI for the field Y.

Some aspects of DCI signaling (e.g. Common DCI format for both Tx UE and Rx UE)

In scenarios discussed above, gNB 110, 210, 310 transmits DCIs to both Tx UE 108, 208, 308 and Rx UE 104, 204, 304. To save downlink control resources at gNB 110, 210, 310, it is beneficial to send a single DCI scheduling SL unicast transmission to both Tx UE 108, 208, 308 and Rx UE 104, 204, 304 (instead of sending two separates DCI, one to Tx UE 108, 208, 308 and one to Rx UE 104, 204, 304). In a particular embodiment, two UEs are instructed to monitor the same DL control resources and are assigned with the same RNTI, e.g., PAIR-SL-RNTI. The RNTI is used to scramble a CRC which is appended to the common DCI. In each pair of Tx and Rx UEs, each UE has a corresponding identity number, e.g., 0 and 1, which, for example, can be exchanged between the UEs during the connection establishment phase. In the DCI there is a bit-field (e.g., link direction field), indicating which UE is a Tx UE 108, 208, 308 (assigned for SL transmission), while another UE in a pair automatically becomes an Rx UE 104, 204, 304 in a pair if the bit-field does not match with its identity number of the SL pair. For example, if the bit-field in DCI is “0”, UE with ID “0” is a Tx UE 108, 208, 308 and UE with ID “1” is an Rx UE 104, 204, 304. For SL transmission in the opposite direction, the bit-field in DCI should be set to “1”, thus, UE with ID “1” is interpreted as a Tx UE 108, 208, 308 and UE with ID “0” is interpreted as an Rx UE 104, 204, 304.

In a further particular embodiment, the previous embodiment can be extended to a case of three and more UEs in a group. In this case, the link direction bit-field needs to be extended for coding different directions of transmission. For example, if only unicast transmissions are of interest, three UEs in a group will require 6 options to signal: UE1 to UE2; UE1 to UE3; UE2 to UE1; UE2 to UE3; UE3 to UE1 and UE3 to UE2. Thus, a 3-bit field is required. In addition, there may be cases when unicast transmissions and group cast transmissions are encoded by the same field. In general case, codepoints of the link direction bit-field are summarized in a table, which is defined in specification or can be configured by RRC. Table 2 is an example of such a table. It may be noted that the connectivity provided by the table may not be full because, from network point of view, some links may not be necessary.

Table 2

It can be observed from the example above, that the length of the link direction bit-field increases exponentially as the number of UEs in a group increases. Thus, it may be beneficial to maintain unicast transmissions in pairs by multiple Radio Network Temporary Identifiers (RNTIs) associating with the pairs. For example, in a case of 3 UEs, there are three possible unicast pairs: UE1 and UE2, UE2 and UE3, and UE1 and UE3. Therefore, 3 different RNTIs can be required to differentiate the pairs, and a one-bit link direction field is used to indicate a link direction in each pair.

In case of groupcast/broadcast SL transmission, when there is a plurality of Rx UEs 104, 204, 304, but only one transmission UE, a group common DCI can be used to transmit SA to all Rx UEs 104, 204, 304. New group-common DCI format (e.g., DCI format 2_7) can be introduced for this purpose. A new RNTI, e.g., Group-SL-RNTI (G-SL-RNTI), can be used by group of UEs receiving the group-common DCI. Content of this new group common DCI can be the same or similar to SA and partial SA, as described above. Since Tx UE 108, 208, 308 is not supposed to receive its own transmission, the Tx UE 108, 208, 308 receiving regular DCI for SL transmission may either skip reception of group common DCI or ignore it.

Enhanced DCI transmission for SL-CG activation

As discussed above, NR SL supports both DGs and CGs for SL Mode 1. According to certain embodiments, a framework of SL-CG activation is provided where gNB 110, 210, 310 can activate SL-CG transmission by transmitting the activation DCIs to both Tx UE 108, 208, 308 and Rx UE 104, 204, 304.

The activation DCIs transmitted to Tx UE and Rx UE 104, 204, 304 at least contain some common information which enable SL-CG transmission without the need for any additional SCI transmission from the Tx UE 108, 208, 308 to the Rx UE 104, 204, 304. This common information can include, for example, SL-CG periodicity, SL-CG offset, time and frequency domain resource allocation for each SL-CG transmission occasion, MCS, power control parameters, and the number of repetitions, in various particular embodiments.

The activation DCIs transmitted to Tx UE 108, 208, 308 and Rx UE 104, 204, 304 also contain some fields which can be used to validate the activation command. The fields used for activation validation at the Tx UE 108, 208, 308 and Rx UE 104, 204, 304 can be the same or different, in particular embodiments. Some examples of the fields include HARQ process number and redundancy version fields.

It may be noted that, in general, the activation DCIs transmitted from gNB 110, 210, 310 to Tx UE 108, 208, 308 and Rx UE 104, 204, 304 may consist of the same or different set of information similar to various options/variants described above.

A similar framework to that described above can also be considered for SL-CG release DCI. That is, SL-CG release command is sent from gNB 110, 210, 310 to both Tx UE 108, 208, 308 and Rx UE 104, 204, 304 to release the activated SL-CG transmission.

Other Signaling Aspects

Other signaling aspects relate to the information that the UE may provide to the gNB 110, 210, 310 and how such information is provided. According to certain embodiments, methods are provided for the Tx UE 108, 208, 308 to inform the gNB 110, 210, 310 of the necessary information for controlling the Rx UE 104, 204, 304.

In an example particular embodiment, the SR or a BSR sent from the Tx UE 108, 208, 308 to the gNB 110, 210, 310 (to request resources for SL communication to the Rx UE 104, 204, 304) carries at least one of the following information: a Tx UE identity, a Rx UE identity, and a link ID for the Tx UE - Rx UE link.

In another example embodiment, a message carrying assistance information from the Tx UE 108, 208, 308 to the network carries at least one of the following information: a Tx UE identity, a Rx UE identity, and a link ID for the Tx UE - Rx UE link.

In a particular embodiment, the above-described assistance information is exchanged during the connection establishment procedure. For example, when TX-UE 108, 208, 308 establishes a connection with RX-UE 104, 204, 304, the TX-UE 108, 208, 308 sends the RX UE 104, 204, 304 identity to the network. In another example, the network allocates the link ID for the TX UE - RX UE link.

HARQ Feedback

In current NR SL design, HARQ feedback in response to the PSSCH reception, if enabled, is only transmitted from Rx UE 104, 204, 304 to Tx UE 108, 208, 308 through PSFCH. This approach is reasonable in the current NR SL design since only the Tx UE 108, 208, 308 is responsible for SL scheduling and possible SL retransmission. As an alternative approach, a gNB 110, 210, 310 may be allowed to schedule both the Tx UE 108, 208, 308 and the Rx UE 104, 204, 304 for a SL communication when both UEs are under network coverage. With this approach, the Rx UE 104, 204, 304 may receive both SCI from the Tx UE 108, 208, 308 and DCI from the gNB 110, 210, 310 or a combination of the two in various forms. Several possible solutions for HARQ- ACK feedback transmission and SL CSI reporting to the gNB 110, 210, 310 are described herein.

It is noted that the core methods, solutions, concepts, and embodiments described herein may also apply to the case where multiple gNB 110, 210, 310 are involved (e.g., gNBl controls Tx UE 108, 208, 308 and gNB2 controls Rx UE 104, 204, 304) and to the case where multiple Rx UEs 104, 204, 304 are involved (e.g., SL groupcast or broadcast.)

According to certain embodiments, methods, systems and solutions provide new HARQ- ACK feedback and CSI reporting mechanisms for network-controlled SL communications where the HARQ-ACK feedback and/or CSI report can be transmitted from the Rx UE 104, 204, 304 directly to gNB 110, 210, 310. These methods, systems, and solutions can work in combination with or replace the existing mechanisms (i.e., feedback and report only to Tx UE 108, 208, 308) based on some conditions, rules, semi-static configurations, or dynamic indication.

For example, according to certain embodiments, the new SL HARQ-ACK feedback mechanism can make use of both HARQ-ACK feedback transmissions to Tx UE 108, 208, 308 and gNB 110, 210, 310 depending on the conditions. For CSI reporting mechanism, the CSI report can still be computed based on the CSI-RS configured and transmitted on SL, but the report is instead transmitted to gNB 110, 210, 310.

HARQ-ACK feedback in response to PSSCH reception

According to certain embodiments, solutions are disclosed for how HARQ-ACK feedback in response to the PSSCH reception can be transmitted from Rx UE when the gNB schedules both Tx UE and Rx UE.

FIGURE 6 illustrates an example 400 where the gNB 410 controls both the Tx UE 408 and the Rx UE 404 for SL communication and receives feedback 414 from the Rx UE 404, according to certain embodiments.

According to a particular embodiment, for example, the HARQ-ACK feedback 414a is transmitted to gNB 410 from Rx UE 404 in response to the PSSCH reception instead of or in addition to transmitting it to Tx UE 408 . The main benefit of this is that it can increase reliability and/or reduce latency. Moreover, it is better suited for cases where both UEs are under network coverage and the scheduling information available at the Rx UE 404 can comprise information received from both DCI and SCI, as shown in FIGURE 6.

In a first particular embodiment, the Rx UE 404 sends HARQ-ACK feedback 414a in response to the PSSCH reception separately to both the Tx UE 408 and the gNB 410. The transmissions of HARQ-ACK feedback 414a to gNB 410 can be done through PUCCH. The transmission of HARQ-ACK feedback from Rx UE 404 to Tx UE 408 is not explicitly shown in FIGURE 6; however, such transmission may be via PSFCH, in a particular embodiment.

In a particular embodiment, the transmission of HARQ-ACK feedback 414a to the gNB 410 can be triggered and indicated by some request field in any of the DCI (i.e. DCI 412 to Tx UE 408 or DCI 402 to Rx UE 404) received from the gNB 410 and/or the SCI 406 received from the Tx UE 408.

In a second particular embodiment, the Rx UE 404 sends HARQ-ACK feedback to one of the Tx UE 408 or the gNB 410 in response to the PSSCH reception of the same HARQ process ID for a maximum number of N consecutive times. After that, if the HARQ-ACK feedback in response to the PSSCH reception of the same HARQ process ID is still a negative acknowledgment (NACK), the Rx UE 404 sends the feedback to the other node. The value N can be configured to the Rx UE 404 by the gNB 410, as indicated in the SCI 406 and/or DCI 402 available at the Rx UE 404, or it can be defined in the specification.

In a particular embodiment, for example, the Rx UE 404 may be configured, by default, to send HARQ-ACK feedback to the Tx UE 408 in response to the PSSCH reception of the same HARQ process ID for a maximum of number of N1 consecutive times. After the N1 consecutive transmissions, if the HARQ-ACK feedback is still NACK, the RxUE 404 sends the feedback to gNB 410.

In another particular embodiment, for example, the Rx UE 404 is configured to, by default, send the HARQ-ACK feedback to gNB 410 in response to the PSSCH reception of the same HARQ process ID for a maximum of number of N2 consecutive times. After the maximum number of N2 consecutive transmissions, the Rx UE 404 sends the feedback to the Tx UE 408.

In a third particular embodiment, the Rx UE 404 sends HARQ-ACK feedback to either the Tx UE 408 or the gNB 410 in response to the PSSCH reception of the same HARQ process ID for a maximum of number of N consecutive times. After the maximum number of N consecutive times, the Rx UE 404 sends the feedback to both the Tx UE 408 and the gNB 410. The feedback to the Tx UE 408 and the gNB 410 can be transmitted separately through PSFCH and PUCCH, respectively.

In the current NR SL Mode 1 design, in each DG or in each period of a CG, the Tx UE 408 is assigned several resources (up to 3 resources, for example) for transmission and retransmissions of a TB. The gNB 410 needs to wait until after the PSFCH occasion associated with the last resources among the assigned resources to receive an aggregated HARQ-ACK report from the Tx UE 408. That means there is no way the gNB 410 can know that the first transmission among the (re)transmissions was already successful. However, when the Rx UE 404 sends HARQ-ACK feedback to gNB 410, the gNB 410 can take advantage of that and somehow use the 2^nd, 3^rd resources for other transmissions, either from the same or different Tx UE 408, leading to better resource utilization and/or lower latency. As such, according to a fourth particular embodiment, when both ACK and NACK feedback are enabled in the SL, the Rx UE 404 prioritizes sending NACK feedback to the Tx UE 408 over the SL and sending ACK feedback directly to the gNB 410 over the UL.

Typically, a UE cannot perform two simultaneous or overlapping transmissions. However, where HARQ-ACK feedback transmissions to Tx UE 408 and gNB 410, using the respective PSFCH and PUCCH resources respectively, overlap in time domain, the Rx UE 404 is able to transmit only one HARQ-ACK feedback.

In a fifth particular embodiment, when the Rx UE 404 transmits HARQ-ACK feedback in response to PSSCH reception separately to both the Tx UE 408 and the gNB 410, and where the corresponding PSFCH and PUCCH resources overlap in time-domain, the Rx UE 404 only transmits one feedback to either the Tx UE 408 or the gNB 410 using the respective PSFCH or PUCCH resources, respectively. Whether the RX UE 404 transmits the feedback to the Tx UE 408 or gNB 410 can be either defined based on a fixed priority rule in the specification or a configured priority or indicated in the SCI 406 and/or DCI 402 available at the Rx UE 404. Alternatively, whether the Rx UE 404 transmits the feedback to the Tx UE 408 or gNB 410 can be determined based on the PSFCH/PUCCH resources, in another particular embodiment.

In another particular embodiment, for example, when the resources to use for transmitting feedback to the Tx UE 408 and the gNB 410 overlap in time domain, the Rx UE 404 only transmits the feedback to the gNB 410 if the configured priority of transmitting feedback to the gNB 410 is higher than that of transmitting feedback to the Tx UE 408. Alternatively, the Rx UE 404 only transmits the feedback to the Tx UE 408 if the configured priority of transmitting feedback to the Tx UE 408 is higher than that of transmitting feedback to the gNB 410.

In further particular embodiment, for example, feedback to the gNB 410 is prioritized if the priority of the corresponding packet transmitted on SL is higher than the corresponding threshold.

In still another particular embodiment, feedback to the gNB 410 is prioritized if the corresponding packet transmitted on the SL is indicated as URLLC/high priority in either SCI 406 or DCI 402.

In still another particular embodiment, the Rx UE 404 transmits the feedback to either the Tx UE 408 or the gNB 410 using the respective PSFCH or PUCCH resource that starts earlier. In still another particular embodiment, the PSFCH and PUCCH which overlap can be one or more PSFCH/PUCCH of the PSFCH repetition and/or PUCCH repetition.

In a sixth particular embodiment, the Rx UE 404 transmits HARQ-ACK feedback 414a in response to PSSCH reception to both the Tx UE 408 and the gNB 410 in a single feedback transmission using one single resource such as, for example where the HARQ-ACK feedback 414a is to the Tx UE 408 and the gNB 410 are multiplexed in the same transmission. In a particular embodiment, for example, the resource to use for transmitting a single HARQ-ACK feedback 414a to both the Tx UE 408 and the gNB 410 is determined based on configured parameters such as, for example, control channel format and cyclic shift for SL HARQ-ACK feedback.

In another particular embodiment, the resource to use for transmitting a single HARQ- ACK feedback 414a to both the Tx UE 408 and the gNB 410 is determined based on SL resources configured for SL feedback transmission.

In still another particular embodiment, the resource to use for transmitting a single HARQ- ACK feedback 414a to both the Tx UE 408 and the gNB 410 is determined based on resources configured specifically for feedback transmission to both the Tx UE 408 and gNB 410.

In any of above described embodiments, the Rx UE 404 determines the resource to use for transmitting a single HARQ-ACK feedback 414a to both the Tx UE 408 and gNB 410 from a feedback resource indication in a DCI 402 sent from the gNB 410 and/or a feedback resource indication in SCI 406 sent from the Tx UE 408.

When the Rx UE 404 transmits HARQ-ACK feedback 414a in response to PSSCH reception to both the Tx UE 406 and gNB 410 in a single feedback transmission, the feedback transmission follows some power control parameter configured and indicated to the Rx UE 404. The Rx UE 404 can be configured with both open-loop power control (OLPC) parameters for UL and SL, e.g., OLPC for PUCCH and OLPC for PSFCH.

In a particular embodiment, for example, when the Rx UE 404 is configured with both OLPC parameters for both the UL and SL, the single HARQ-ACK feedback transmission to both the Tx UE 408 and gNB 410 follows the UL OLPC parameters.

In another particular embodiment, when the Rx UE 404 is configured with both OLPC parameters for both UL and SL, the single HARQ-ACK feedback transmission to both the Tx UE 408 and gNB 410 follows the SL OLPC parameters.

In another particular embodiment, when the Rx UE 404 is configured with both OLPC parameters for both UL and SL, the single HARQ-ACK feedback transmission to both the Tx UE 408 and gNB 410 follows the minimum or maximum value between the SL OLPC and UL OLPC parameters. In another particular embodiment, when the Rx UE 404 is configured with both OLPC parameters for both UL and SL, the Rx UE 404 can be indicated in DCI 402 or SCI 406 which OLPC parameter to use for the single HARQ-ACK feedback transmission to both the Tx UE 408 and gNB 410.

It may be noted that any of the embodiments described above can be applied in cases where the gNB 410 schedules both the Tx UE 408 and Rx UE 404 for a PSSCH transmission on the SL.

Scheduling of a Retransmission of SL Transmission

As discussed in the previous section, when the gNB 410 is allowed to schedule both the Tx UE 408 and the Rx UE 404 for a SL communication and when both UEs are under network coverage, there can be several possible solutions for the transmission of HARQ-ACK feedback 414a in response to PSSCH reception. In a similar fashion, several SL retransmission solutions can also be considered. Accordingly, solutions are provided for SL retransmission when the gNB 410 schedules both the Tx UE 408 and Rx UE 404 where the retransmission is performed based on the HARQ-ACK feedback 414a described above.

According to certain embodiments, when the HARQ-ACK feedback 414a in response to PSSCH reception is a NACK, depending on how the feedback is transmitted (to Tx UE 408, gNB 410, or both), the SL retransmission is performed differently. In a particular embodiment, for example, when the NACK feedback is transmitted only to the gNB 410, the gNB 410 transmits a new DCI 412 to the Tx UE 408 to schedule for a SL retransmission with possible new scheduling parameters.

In another particular embodiment, when the NACK feedback is transmitted to both the Tx UE 408 and gNB 410, the Tx UE 408 can schedule for the SL retransmission using SCI 406 for a maximum number of N3 times. After the maximum number of N3 times, if the feedback is still NACK, the gNB 410 transmits a new DCI 412 to the Tx UE 408 (and the Rx UE 404) to schedule for a subsequent SL retransmission. In a particular embodiment, the value N3 can be configured by the gNB 410 or defined in the specification.

It is noted that this is different from the current NR SL design because there is no need for the gNB 410 to wait for a HARQ-ACK feedback from the Tx UE 408 before the gNB 410 transmits a new DCI to the Tx UE 408 to schedule further SL retransmission.

According to certain other embodiments, the gNB 410 waits for HARQ-ACK feedback 414a from both the Tx UE 408 and Rx UE 404 before scheduling a SL retransmission. In a particular embodiment, for example, the HARQ-ACK feedback transmission from the Tx UE 408 and Rx UE 404 to the gNB 410 are scheduled or configured to be transmitted at different time instances.

In a particular embodiment, if NACK (or no feedback) is first received from one of the Tx UE 408 or Rx UE 404, the gNB 410 also waits for HARQ-ACK feedback from the other node before scheduling a SL retransmission.

In a particular embodiment, if positive ACKnowledgement (ACK) is received first, the gNB 410 can preempt the later HARQ-ACK feedback resource and use it for other purposes. This preemption can involve the gNB 410 transmitting a preemption indication to the UE scheduled or configured to transmit the later HARQ-ACK feedback.

Channel Measurement and CSI Report

In current NR SL design, the CSI report (CQI and RI) by the Rx UE is computed based on some measurement on the configured SL CSLRS and is sent only to the Tx UE. When the gNB is allowed to schedule both the Tx UE and the Rx UE for a SL communication and when both UEs are under network coverage, it is beneficial that the SL CSI report is available at the gNB (e.g., for the purpose of link adaptation). Accordingly, solutions are provided for SL CSI reporting when the gNB 410 schedules both the Tx UE 408 and Rx UE 404, as depicted in FIGURE 6. It is assumed that the Tx UE 408 and Rx UE 404 can be configured with SL CSI-RS configurations containing SL CSI- RS resources for SL channel and interference measurements.

According to certain embodiments, after performing SL channel and/or interference measurement based on the SL CSLRS transmitted from the Tx UE 408, the Rx UE 404 transmits a corresponding SL CSI report. Though FIGURE 6 depicts the RX UE 404 transmitting the CSI report 414b to only the gNB 410, various embodiments disclosed herein include the Rx UE 404 transmitting the CSI report 414b to either the Tx UE 408 over SL or to the gNB 410 through PUCCH or PUSCH, or to both the Tx UE 408 and gNB 410.

In a particular embodiment, for example, the Rx UE 404 determines the intended recipient(s) of the SL CSI report 414b. That is, the Rx UE 404 determines whether to transmit SL CSI report 414b to gNB 410, to Tx UE 408, or to both. In a particular embodiment, this determination may be based on some specific indication in the SL CSLRS configuration. Some examples of such indication include a new parameter in the SL CSLRS configuration indicating the recipient of the SL CSI report 414b. In another particular embodiment, the SL CSI-RS configuration may be configured separately for each intended recipient of SL CSI reporting. This CSI reporting mode can be applicable, for example, to periodic CSI reporting. In another particular embodiment, the Rx UE 404 determines intended recipient(s) of the SL CSI report 414b based on an indication in the triggering SCI 406 and/or DCI 402 received from the Tx UE 408 and/or gNB 410, respectively. This CSI reporting mode can be applicable, for example, to semi-persistent and aperiodic CSI reporting.

In a particular embodiment, the Rx UE 404 decides to send the SL CSI report 414b for a SL connection based on the contents of the DCI 402 it received from the gNB 410 for that connection. For example, if the DCI 402 contains information about the MCS, the Rx UE 404 sends the SL CSI report 414b to the gNB 410 (though it may send the SL CSI report 414b to the Tx UE 408 as well) because the Rx UE 404 can deduce that the gNB 410 is in control of the MCS via link adaptation.

In a particular embodiment, the Rx UE 404 has a default path for reporting the SL CSI measurements and the Rx UE 404 switches to (or adds) an alternative path under certain conditions. For example, in a particular embodiment, the default path may be to the Tx UE 408, but the Rx UE is configured to switch to the direct path to the gNB 410 (or sending on both paths) when the SL quality (e.g., a SL RSRP measurement) drops below a threshold. Alternatively, the default path could be the direct path to the gNB 410, but the Rx UE 404 is configured to switch to the path to the Tx UE 408 (i.e., SL) when an UL connection quality indicator (e.g., a DL RSRP measurement) drops below a threshold.

Currently, the SL CSI report 414b includes only RI and CQI. However, according to particular embodiments disclosed herein, PMI can also be included in the SL CSI report 414b. Different ways of reporting RI/CQI/PMI are provided herein where, when all of RI, CQI,, and PMI are included the SL CSI report 414b, the report is considered to be a full content SL CSI report and the Rx UE 404 is considered to be performing full content SL CSI reporting. However, where the SL CSI report 414b includes less than all of RI, CQI, and PMI, the report is considered to be a partial SL CSI report and the Rx UE 404 is considered to be performing partial SL CSI reporting.

According to certain other embodiments, the Rx UE 404 transmits a partial SL CSI reports to Tx UE 408 and gNB 410 and the contents of the multiple partial CSI reports may or may not overlap. In a particular embodiment, for example, RI can be reported to gNB 410, while PMI and CQI are reported to Tx UE 408. In that way, the gNB 410 only decides the rank of the transmission, while the Tx UE 408 has the freedom to choose the precoding matrix (within those of the same rank) and MCS based on the Tx UE’s antenna configurations and other sensing results. In another particular embodiment, for example, a full SL CSI report is transmitted to the gNB 410, while only a partial SL CSI report containing PMI and CQI are reported to the Tx UE 408.

FIGURE 7 illustrates an example of a communication system 500 in accordance with some embodiments. In the example, the communication system 500 includes a telecommunication network 502 that includes an access network 504, such as a radio access network (RAN), and a core network 506, which includes one or more core network nodes 508. The access network 504 includes one or more access network nodes, such as network nodes 510a and 510b (one or more of which may be generally referred to as network nodes 510), or any other similar 3^rd Generation Partnership Project (3GPP) access node or non-3GPP access point. The network nodes 510 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 512a, 512b, 512c, and 512d (one or more of which may be generally referred to as UEs 512) to the core network 506 over one or more wireless connections.

Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 500 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. The communication system 500 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system.

The UEs 512 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with the network nodes 510 and other communication devices. Similarly, the network nodes 510 are arranged, capable, configured, and/or operable to communicate directly or indirectly with the UEs 512 and/or with other network nodes or equipment in the telecommunication network 502 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in the telecommunication network 502.

In the depicted example, the core network 506 connects the network nodes 510 to one or more hosts, such as host 516. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 506 includes one more core network nodes (e.g., core network node 508) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 508. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDE), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

The host 516 may be under the ownership or control of a service provider other than an operator or provider of the access network 504 and/or the telecommunication network 502, and may be operated by the service provider or on behalf of the service provider. The host 516 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio/video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

As a whole, the communication system 500 of FIGURE 7 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and/or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

In some examples, the telecommunication network 502 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 502 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 502. For example, the telecommunications network 502 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and/or Massive Machine Type Communication (mMTC)/Massive loT services to yet further UEs. In some examples, the UEs 512 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 504 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 504. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi -radio dual connectivity (MR-DC), such as E-UTRAN (Evolved- UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

In the example, the hub 514 communicates with the access network 504 to facilitate indirect communication between one or more UEs (e.g., UE 512c and/or 512d) and network nodes (e.g., network node 510b). In some examples, the hub 514 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 514 may be a broadband router enabling access to the core network 506 for the UEs. As another example, the hub 514 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 510, or by executable code, script, process, or other instructions in the hub 514. As another example, the hub 514 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 514 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 514 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 514 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub 514 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

The hub 514 may have a constant/persistent or intermittent connection to the network node 510b. The hub 514 may also allow for a different communication scheme and/or schedule between the hub 514 and UEs (e.g., UE 512c and/or 512d), and between the hub 514 and the core network 506. In other examples, the hub 514 is connected to the core network 506 and/or one or more UEs via a wired connection. Moreover, the hub 514 may be configured to connect to an M2M service provider over the access network 504 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 510 while still connected via the hub 514 via a wired or wireless connection. In some embodiments, the hub 514 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to the network node 510b. In other embodiments, the hub 514 may be a non- dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 510b, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

FIGURE 8 shows a UE 600 in accordance with some embodiments. As used herein, a UE 600 refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle-mounted or vehicle embedded/integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.

A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to- vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

The UE 600 includes processing circuitry 602 that is operatively coupled via a bus 604 to an input/output interface 606, a power source 608, a memory 610, a communication interface 612, and/or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in FIGURE 8. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

The processing circuitry 602 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 610. The processing circuitry 602 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 602 may include multiple central processing units (CPUs).

In the example, the input/output interface 606 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and/or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 600. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence- sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

In some embodiments, the power source 608 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 608 may further include power circuitry for delivering power from the power source 608 itself, and/or an external power source, to the various parts of the UE 600 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 608. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 608 to make the power suitable for the respective components of the UE 600 to which power is supplied.

The memory 610 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 610 includes one or more application programs 614, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 616. The memory 610 may store, for use by the UE 600, any of a variety of various operating systems or combinations of operating systems. The memory 610 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and/or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 610 may allow the UE 600 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 610, which may be or comprise a device-readable storage medium.

The processing circuitry 602 may be configured to communicate with an access network or other network using the communication interface 612. The communication interface 612 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 622. The communication interface 612 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 618 and/or a receiver 620 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 618 and receiver 620 may be coupled to one or more antennas (e.g., antenna 622) and may share circuit components, software or firmware, or alternatively be implemented separately.

In the illustrated embodiment, communication functions of the communication interface 612 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and/or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol/intemet protocol (TCP/IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 612, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door/window sensor, a flood/moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or itemtracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and/or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 600 shown in FIGURE 8.

As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another UE and/or a network node. The UE may in this case be an M2M device, which may in a 3 GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and/or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

FIGURE 9 shows a network node 700 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a UE and/or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)).

Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and/or Minimization of Drive Tests (MDTs).

The network node 700 includes a processing circuitry 702, a memory 704, a communication interface 706, and a power source 708. The network node 700 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 700 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 700 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 704 for different RATs) and some components may be reused (e.g., a same antenna 710 may be shared by different RATs). The network node 700 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 700, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 700.

The processing circuitry 702 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application- specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 700 components, such as the memory 704, to provide network node 700 functionality.

In some embodiments, the processing circuitry 702 includes a system on a chip (SOC). In some embodiments, the processing circuitry 702 includes one or more of radio frequency (RF) transceiver circuitry 712 and baseband processing circuitry 714. In some embodiments, the radio frequency (RF) transceiver circuitry 712 and the baseband processing circuitry 714 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 712 and baseband processing circuitry 714 may be on the same chip or set of chips, boards, or units.

The memory 704 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device-readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by the processing circuitry 702. The memory 704 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and/or other instructions capable of being executed by the processing circuitry 702 and utilized by the network node 700. The memory 704 may be used to store any calculations made by the processing circuitry 702 and/or any data received via the communication interface 706. In some embodiments, the processing circuitry 702 and memory 704 is integrated.

The communication interface 706 is used in wired or wireless communication of signaling and/or data between a network node, access network, and/or UE. As illustrated, the communication interface 706 comprises port(s)/terminal(s) 716 to send and receive data, for example to and from a network over a wired connection. The communication interface 706 also includes radio frontend circuitry 718 that may be coupled to, or in certain embodiments a part of, the antenna 710. Radio front-end circuitry 718 comprises filters 720 and amplifiers 722. The radio front-end circuitry 718 may be connected to an antenna 710 and processing circuitry 702. The radio frontend circuitry may be configured to condition signals communicated between antenna 710 and processing circuitry 702. The radio front-end circuitry 718 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 718 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 720 and/or amplifiers 722. The radio signal may then be transmitted via the antenna 710. Similarly, when receiving data, the antenna 710 may collect radio signals which are then converted into digital data by the radio front-end circuitry 718. The digital data may be passed to the processing circuitry 702. In other embodiments, the communication interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, the network node 700 does not include separate radio front-end circuitry 718, instead, the processing circuitry 702 includes radio front-end circuitry and is connected to the antenna 710. Similarly, in some embodiments, all or some of the RF transceiver circuitry 712 is part of the communication interface 706. In still other embodiments, the communication interface 706 includes one or more ports or terminals 716, the radio front-end circuitry 718, and the RF transceiver circuitry 712, as part of a radio unit (not shown), and the communication interface 706 communicates with the baseband processing circuitry 714, which is part of a digital unit (not shown).

The antenna 710 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. The antenna 710 may be coupled to the radio front-end circuitry 718 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, the antenna 710 is separate from the network node 700 and connectable to the network node 700 through an interface or port.

The antenna 710, communication interface 706, and/or the processing circuitry 702 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node. Any information, data and/or signals may be received from a UE, another network node and/or any other network equipment. Similarly, the antenna 710, the communication interface 706, and/or the processing circuitry 702 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and/or signals may be transmitted to a UE, another network node and/or any other network equipment.

The power source 708 provides power to the various components of network node 700 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 708 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 700 with power for performing the functionality described herein. For example, the network node 700 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 708. As a further example, the power source 708 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

Embodiments of the network node 700 may include additional components beyond those shown in FIGURE 9 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, the network node 700 may include user interface equipment to allow input of information into the network node 700 and to allow output of information from the network node 700. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 700. FIGURE 10 is a block diagram of a host 800, which may be an embodiment of the host 516 of FIGURE 7, in accordance with various aspects described herein. As used herein, the host 800 may be or comprise various combinations hardware and/or software, including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, container, or processing resources in a server farm. The host 800 may provide one or more services to one or more UEs.

The host 800 includes processing circuitry 802 that is operatively coupled via a bus 804 to an input/output interface 806, a network interface 808, a power source 810, and a memory 812. Other components may be included in other embodiments. Features of these components may be substantially similar to those described with respect to the devices of previous figures, such as Figures 6 and 7, such that the descriptions thereof are generally applicable to the corresponding components of host 800.

The memory 812 may include one or more computer programs including one or more host application programs 814 and data 816, which may include user data, e.g., data generated by a UE for the host 800 or data generated by the host 800 for a UE. Embodiments of the host 800 may utilize only a subset or all of the components shown. The host application programs 814 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., FLAC, Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., handsets, desktop computers, wearable display systems, heads-up display systems). The host application programs 814 may also provide for user authentication and licensing checks and may periodically report health, routes, and content availability to a central node, such as a device in or on the edge of a core network. Accordingly, the host 800 may select and/or indicate a different host for over-the-top services for a UE. The host application programs 814 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (MPEG-DASH), etc.

FIGURE 11 is a block diagram illustrating a virtualization environment 900 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 900 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized.

Applications 902 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.

Hardware 904 includes processing circuitry, memory that stores software and/or instructions executable by hardware processing circuitry, and/or other hardware devices as described herein, such as a network interface, input/output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 906 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 908a and 908b (one or more of which may be generally referred to as VMs 908), and/or perform any of the functions, features and/or benefits described in relation with some embodiments described herein. The virtualization layer 906 may present a virtual operating platform that appears like networking hardware to the VMs 908.

The VMs 908 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 906. Different embodiments of the instance of a virtual appliance 902 may be implemented on one or more of VMs 908, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

In the context of NFV, a VM 908 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non- virtualized machine. Each of the VMs 908, and that part of hardware 904 that executes that VM, be it hardware dedicated to that VM and/or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 908 on top of the hardware 904 and corresponds to the application 902. Hardware 904 may be implemented in a standalone network node with generic or specific components. Hardware 904 may implement some functions via virtualization. Alternatively, hardware 904 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 910, which, among others, oversees lifecycle management of applications 902. In some embodiments, hardware 904 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 912 which may alternatively be used for communication between hardware nodes and radio units.

FIGURE 12 shows a communication diagram of a host 1002 communicating via a network node 1004 with a UE 1006 over a partially wireless connection in accordance with some embodiments.

Example implementations, in accordance with various embodiments, of the UE (such as a UE 512a of FIGURE 11 and/or UE 600 of FIGURE 12), network node (such as network node 510a of FIGURE 11 and/or network node 700 of FIGURE 9), and host (such as host 516 of FIGURE 11 and/or host 800 of FIGURE 10) discussed in the preceding paragraphs will now be described with reference to FIGURE 12.

Like host 800, embodiments of host 1002 include hardware, such as a communication interface, processing circuitry, and memory. The host 1002 also includes software, which is stored in or accessible by the host 1002 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as the UE 1006 connecting via an over-the-top (OTT) connection 1050 extending between the UE 1006 and host 1002. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection 1050.

The network node 1004 includes hardware enabling it to communicate with the host 1002 and UE 1006. The connection 1060 may be direct or pass through a core network (like core network 506 of FIGURE 11) and/or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

The UE 1006 includes hardware and software, which is stored in or accessible by UE 1006 and executable by the UE’s processing circuitry. The software includes a client application, such as a web browser or operator-specific “app” that may be operable to provide a service to a human or non-human user via UE 1006 with the support of the host 1002. In the host 1002, an executing host application may communicate with the executing client application via the OTT connection 1050 terminating at the UE 1006 and host 1002. In providing the service to the user, the UE's client application may receive request data from the host's host application and provide user data in response to the request data. The OTT connection 1050 may transfer both the request data and the user data. The UE's client application may interact with the user to generate the user data that it provides to the host application through the OTT connection 1050.

The OTT connection 1050 may extend via a connection 1060 between the host 1002 and the network node 1004 and via a wireless connection 1070 between the network node 1004 and the UE 1006 to provide the connection between the host 1002 and the UE 1006. The connection 1060 and wireless connection 1070, over which the OTT connection 1050 may be provided, have been drawn abstractly to illustrate the communication between the host 1002 and the UE 1006 via the network node 1004, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

As an example of transmitting data via the OTT connection 1050, in step 1008, the host 1002 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE 1006. In other embodiments, the user data is associated with a UE 1006 that shares data with the host 1002 without explicit human interaction. In step 1010, the host 1002 initiates a transmission carrying the user data towards the UE 1006. The host 1002 may initiate the transmission responsive to a request transmitted by the UE 1006. The request may be caused by human interaction with the UE 1006 or by operation of the client application executing on the UE 1006. The transmission may pass via the network node 1004, in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1012, the network node 1004 transmits to the UE 1006 the user data that was carried in the transmission that the host 1002 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1014, the UE 1006 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 1006 associated with the host application executed by the host 1002.

In some examples, the UE 1006 executes a client application which provides user data to the host 1002. The user data may be provided in reaction or response to the data received from the host 1002. Accordingly, in step 1016, the UE 1006 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input/output interface of the UE 1006. Regardless of the specific manner in which the user data was provided, the UE 1006 initiates, in step 1018, transmission of the user data towards the host 1002 via the network node 1004. In step 1020, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 1004 receives user data from the UE 1006 and initiates transmission of the received user data towards the host 1002. In step 1022, the host 1002 receives the user data carried in the transmission initiated by the UE 1006.

One or more of the various embodiments improve the performance of OTT services provided to the UE 1006 using the OTT connection 1050, in which the wireless connection 1070 forms the last segment. More precisely, the teachings of these embodiments may improve one or more of, for example, data rate, latency, and/or power consumption and, thereby, provide benefits such as, for example, reduced user waiting time, relaxed restriction on file size, improved content resolution, better responsiveness, and/or extended battery lifetime.

In an example scenario, factory status information may be collected and analyzed by the host 1002. As another example, the host 1002 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 1002 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1002 may store surveillance video uploaded by a UE. As another example, the host 1002 may store or control access to media content such as video, audio, VR or AR which it can broadcast, multicast or unicast to UEs. As other examples, the host 1002 may be used for energy pricing, remote control of non-time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc. from data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing and/or transmitting data.

In some examples, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1050 between the host 1002 and UE 1006, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of the host 1002 and/or UE 1006. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 1050 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1050 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of the network node 1004. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency and the like, by the host 1002. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1050 while monitoring propagation times, errors, etc.

FIGURE 13 illustrates a method 1100 by a UE 512 for network controlled sidelink communications, according to certain embodiments. The method begins at step 1102 when the UE 512 receives control information for establishing a sidelink communication session with at least one other UE 512. At step 1104, the UE 512 transmits, to a network node 510, first feedback in response to a reception of a transmission associated with the sidelink communication session.

In a particular embodiment, the control information comprises scheduling information for transmitting and/or receiving communications by the UE and/or the at least one other UE on a PSSCH.

In a particular embodiment, the UE 512 transmits sidelink data to the at least one other UE 512 during the sidelink communication session.

In a particular embodiment, the UE 512 receives sidelink data from the at least one other UE 512 during the sidelink communication session, and the at least one other UE transmits sidelink data to the UE during the sidelink communication session.

In a particular embodiment, at least a first portion of the control information 106, 206, 306, 406 is received from the at least one other UE on at least one of a PSCCH and a PSSCH.

In a particular embodiment, at least a second portion of the control information(102, 202, 302, 402 is received from the network node via at least one of: downlink control information, radio resource control, RRC, signaling, and a unicast transmission transmitted to the UE and the at least one other UE.

In a particular embodiment, at least one of the second portion of the control information received from the network node and the first portion of the control information received from the at least one other UE indicates that the UE is to send the first feedback to the network node.

In a particular embodiment, at least one of the second portion of the control information from the network node and the first portion of the control information from the at least one other UE comprises a partial scheduling assignment. In a particular embodiment, at least one of the second portion of the control information from the network node and the first portion of the control information from the at least one other UE comprises a full scheduling assignment.

In a particular embodiment, the first portion of the control information from the at least one other UE is SCI2 and the second portion of the control information from the network node is SCI1. In an alternative embodiment, the first portion of the control information from the at least one other UE is SCI1 and the second portion of the control information from the network node is SCI2. In still another alternative embodiment, the first portion of the control information from the at least one other UE is SCI1 and the second portion of the control information from the network node is SCI1 and additional information associated with SCI2. In yet another alternative embodiment, the first portion of the control information from the at least one other UE is SCI1 and SCI2 and the second portion of the control information from the network node is at least one of: SCI, SCI2, and other control information.

In a particular embodiment, the UE 512 transmits the second portion of the control information received from the network node 510 to the at least one other UE 512.

In a particular embodiment, the UE 512 transmits second feedback to the at least one other UE.

In a particular embodiment, at least one of the first feedback and the second feedback comprises at least one of: CSI 414b, positive acknowledgement feedback 414a (HARQ-ACK), and negative acknowledgement feedback 414a (HARQ-NACK).

In a particular embodiment, a content of the first feedback does not overlap with a content of the second feedback.

In a particular embodiment, the first feedback transmitted to the network node and the second feedback transmitted to the at least one other UE is transmitted in single feedback transmission using a same transmission resource.

In a particular embodiment, the UE 512 determines that the first feedback has been unsuccessfully transmitted to the network node 510 a number of times that is equal to or greater than a threshold and transmits the second feedback to the at least one other UE based on the first feedback having been transmitted to the network node 510 the number of times that is equal to or greater than the threshold.

In a particular embodiment, the UE 512 determines that the transmission associated with the sidelink communication session has been unsuccessfully received and that the first feedback has been transmitted to the network node 510 a number of times that is equal to or greater than a threshold. The second feedback is transmitted to the at least one other UE based on the transmission being unsuccessfully received and the first feedback having been transmitted to the network node the number of times that is equal to or greater than the threshold.

In a particular embodiment, prior to transmitting the first feedback to the network node, the UE 512 attempts a number of times to transmit the second feedback to the at least one other UE and determines that the transmission associated with the sidelink communication session has been unsuccessfully received based on the number of times that the transmission of the second feedback to the at least one other UE has been attempted is equal to or has exceeded a threshold. The first feedback is transmitted to the network node based on the transmission associated with the sidelink communication session being unsuccessfully received.

In a particular embodiment, the UE 512 transmits the second feedback to the network node 510 and/or the first feedback to the at least one other UE 512.

In a particular embodiment, the first feedback indicates whether the control information was successfully received by the UE 512 or not.

In a particular embodiment, the UE 512 transmits, to the at least one other UE 512, second feedback indicating whether the control information was successfully received or not.

In a particular embodiment, prior to receiving the control information, the UE 512 transmits assistance information to the network node 510.

In a particular embodiment, the assistance information comprises an identifier associated with the UE and/or an identifier associated with the at least one other UE.

In a particular embodiment, the assistance information comprises an identifier associated with the sidelink communication session and/or a sidelink between the UE and the at least one other UE.

In a particular embodiment, the assistance information is transmitted with or as part of a scheduling request and/or a buffer status report.

FIGURE 14 illustrates a method 1200 by a network node 510 for network controlled sidelink communications, according to certain embodiments. The method includes receiving, from a UE 512 a first feedback associated with a reception of a transmission associated with a sidelink communication session between the UE and at least one other UE 512.

In a particular embodiment, the network node 510 receives, from the at least one other UE 512, second feedback associated with the reception, by the UE 512, of the transmission associated with a sidelink communication session between the UE 512 and at least one other UE.

In a particular embodiment, the network node 510 configures the UE 512 to transmit, to the at least one other UE, third feedback associated with the reception of the transmission by the UE. In a particular embodiment, at least one of the first feedback, the second feedback, and the third feedback comprises at least one of: CSI 414b, positive acknowledgement feedback (HARQ- ACK) 415a, and negative acknowledgement feedback (HARQ-NACK) 414a.

In a particular embodiment, a content of the first feedback does not overlap with a content of the third feedback.

In a particular embodiment, the network node 510 configures the UE 512 to transmit the first feedback to the network node 510 and the third feedback to the at least one other UE in a single feedback transmission using a same transmission resource.

In a particular embodiment, the network node 510 configures the UE 512 to determine that the first feedback has been unsuccessfully transmitted to the network node 510 a number of times that is equal to or greater than a threshold and transmit the second feedback to the at least one other UE based on the first feedback having been transmitted to the network node 510 the number of times that is equal to or greater than the threshold.

In a particular embodiment, the network node 510 configures the UE 512 to determine that the transmission associated with the sidelink communication session has been unsuccessfully received and that the first feedback has been transmitted to the network node a number of times that is equal to or greater than a threshold and transmit the second feedback to the at least one other UE based on the transmission being unsuccessfully received and the first feedback having been transmitted to the network node 510 the number of times that is equal to or greater than the threshold.

In a particular embodiment, the network node 510 configures the UE 512 to attempt a number of times to transmit the second feedback to the at least one other UE. The network node 510 configures the UE 512 to determine that the transmission associated with the sidelink communication session has been unsuccessfully received based on the number of times that the transmission of the second feedback to the at least one other UE has been attempted is equal to or has exceeded a threshold and transmit the first feedback to the network node 510 based on the transmission associated with the sidelink communication session being unsuccessfully received.

In a particular embodiment, the network node 510 transmits, to the UE 512, information indicating the threshold.

In a particular embodiment, the network node 510 configures the UE 512 to determine that at least one resource for transmitting the first feedback to the network node 510 overlaps in a time and/or frequency domain with at least one resource for transmitting a second feedback to the at least one other UE. Based on at least one priority rule, the UE prioritizes sending the first feedback to the network node or prioritize sending the third feedback to the at least one other UE. In a particular embodiment, the first feedback comprises positive acknowledgement feedback (HARQ-ACK) indicating that the transmission to the at least one other UE was successfully received. The network node 510 transmits, to the UE 512 and/or the at least one other UE, an indication that at least one resource reserved for use for a retransmission of the transmission is to be used for a different purpose.

In a particular embodiment, first feedback comprises negative acknowledgement feedback (HARQ-NACK), and the network node 510 transmits DCI to the at least one other UE. The DCI includes scheduling information for a retransmission of the transmission by the at least one other UE.

In a particular embodiment, prior to receiving the first feedback, the network node 510 transmits, to the UE 512, a first portion of control information for establishing the sidelink communication session between the UE 512 and the at least one other UE.

In a particular embodiment, the network node 510 transmits, to the at least one other UE, a second portion of control information for establishing the sidelink communication session between the UE 512 and the at least one other UE.

In a particular embodiment, at least one of the first portion of the control information and the second portion of the control information comprises scheduling information for transmitting and/or receiving communications by the UE and/or the at least one other UE on a PSSCH.

In a particular embodiment, at least one of the first portion of the control information and the second portion of the control information indicates that feedback is to be sent to the network node.

In a particular embodiment, at least one of the first portion of the control information and the second portion of the control information is transmitted via at least one of: DCI, RRC signaling, and a unicast transmission transmitted to the UE and the at least one other UE.

In a particular embodiment, at least one of the first portion of the control information and the second portion of the control information comprises a partial scheduling assignment.

In a particular embodiment, at least one of the first portion of the control information and the second portion of the control information comprises a full scheduling assignment.

In a particular embodiment, the first portion of the control information transmitted to the UE is at least one of SCI1, SCI2, and control information other than SCI1 and SCI2 control information.

In a particular embodiment, the second portion of the control information transmitted to the at least one other UE is at least one of SCI1, SCI2, and control information other than SCI1 and SCI2 control information. In a particular embodiment, prior to transmitting the first portion of the control information and/or the second portion of the control information, the network node 510 receives assistance information from the UE 512 and/or the at least one other UE.

In a particular embodiment, the assistance information comprises an identifier associated with the UE and/or an identifier associated with the at least one other UE.

In a particular embodiment, the assistance information comprises an identifier associated with the sidelink communication session and/or a sidelink between the receiving UE and the transmitting UE.

In a particular embodiment, the assistance information is received with or as part of a scheduling request and/or a buffer status report.

Although the computing devices described herein (e.g., UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and/or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and/or by end users and a wireless network generally.

EXAMPLE EMBODIMENTS

Group A Example Embodiments

Example Embodiment Al. A method by a user equipment for enhanced feedback transmission for network controlled sidelink communications, the method comprising: any of the user equipment steps, features, or functions described above, either alone or in combination with other steps, features, or functions described above.

Example Embodiment A2. The method of the previous embodiment, further comprising one or more additional user equipment steps, features or functions described above.

Example Embodiment A3. The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host computer via the transmission to the network node.

Group B Example Embodiments

Example Embodiment Bl. A method performed by a network node for enhanced feedback transmission for network controlled sidelink communications, the method comprising: any of the network node steps, features, or functions described above, either alone or in combination with other steps, features, or functions described above.

Example Embodiment B2. The method of the previous embodiment, further comprising one or more additional network node steps, features or functions described above.

Example Embodiment B3. The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host or a user equipment.

Group C Example Embodiments

Example Embodiment Cl. A method by a user equipment (UE) for enhanced feedback transmission for network controlled sidelink communications, the method comprising: receiving control information for establishing a sidelink communication session with at least one other UE; and transmitting, to a network node, feedback indicating whether the control information was successfully received.

Example Embodiment C2. The method of Example Embodiment Cl, wherein the control information comprises scheduling information for transmitting and/or receiving communications by the UE and/or the at least one other UE on a physical sidelink shared channel.

Example Embodiment C3. The method of any one of Example Embodiments Cl to C2, wherein: the UE comprises a receiving UE associated with the sidelink communication session, and the at least one other UE comprises a transmitting UE associated with the sidelink communication session.

Example Embodiment C4. The method of any one of Example Embodiments Cl to C3, wherein at least a portion of the control information is received from the at least one other UE on a physical sidelink shared channel.

Example Embodiment C5. The method of Example Embodiment C4, wherein the portion of the control information received from the at least one other UE indicates tha the UE is to send the feedback to the network node.

Example Embodiment C6. The method of any one of Example Embodiments Cl to C5, wherein at least a portion of the control information is received from the network node as downlink control information.

Example Embodiment C7. The method of Example Embodiment C6, wherein the portion of the control information received from the network node indicates tha the UE is to send the feedback to the network node.

Example Embodiment C8. The method of any one of Example Embodiments Cl to C7, wherein the feedback comprises HARQ-ACK feedback or HARQ-NACK feedback.

Example Embodiment C9. The method of any one of Example Embodiments, Cl to C8, wherein the feedback comprises channel state information.

Example Embodiment ClO.The method of Example Emboidment C9, further comprising transmitting feedback comprising additional channel state information to the at least one other UE.

Example Embodiment Cl 1. The method of Example Embodiment CIO, wherein the channel state information transmitted to the network node does not overlap with the additional channel state information transmitted to the at least one other UE.

Example Embodiment Cl 2. The method of any one of Example Embodiments Cl to Cll, further comprising transmitting, to the at least one other UE, feedback indicating whether the control information was successfully received. Example Embodiment Cl 3. The method of Example Emboidment C12, wherein the feedback transmitted to the network node and the feedback transmitted to the at least one other UE is transmitted in single feedback transmission using a same transmission resource.

Example Embodiment Cl 4. The method of any one of Example Embodiments Cl to C13, wherein prior to transmitting the feedback to the network node, the method comprises: attempting a number of times to transmit the feedback to the at least one other UE; and determining that the number of times that the transmission of the feedback to the at least one other UE has been attempted is equal to or has exceeded a threshold, and wherein the feedback is transmitted to the network node based on determining that the number of times is equal to or has exceeded the threshold.

Example Embodiment C15.The method of any one of Example Embodiments Cl to C14, further comprising determining that the control information has been successfully received from the at least one other UE a number of times that is equal to or greater than a threshold, and wherein the feedback is transmitted to the network node based on the control information having been successfully received from the at least one other UE the number of times that is equal to or greater than the threshold.

Example Embodiment Cl 6. The method of any one of Example Embodiments Cl to C15, further comprising: determining that the feedback has been transmitted to the network node a number of times that is equal to or greater than a threshold; and transmitting the feedback to the at least one other UE based on the feedback having been transmitted to the network node the number of times that is equal to or greater than the threshold.

Example Embodiment C17.The method of any one of Example Embodiments C14 to C16, further comprising receiving information indicating the threshold from the network node and/or the at least one other UE.

Example Emboidment Cl 8. The method of any one of Example Embodiments Cl to C17, wherein the feedback comprises positive acknowledgement feedback indicating that the control information was successfully received.

Example Embodiment C19.The method of any one of Example Embodiments Cl to C18, wherein the UE is configured to transmit positive acknowledgement feedback indicating that the control information was successfully received to the network node, and wherein the UE is configured to transmit negative acknowledgement feedback indicating that the control information was not successfully received to the at least one other UE.

Example Embodiment C20.The method of any one of Example Embodiments Cl to C19, further comprising: determining that at least one resource for transmitting the feedback to the network node overlaps in a time and/or frequency domain with at least one resource for transmitting the feedback to the at least one other UE, and prioritizing sending the feedback to the network node rather than the at least one other UE when the at least one resources overlap based on at least one priority rule.

Example Emboidment C21.The method of Example Embodiment C20, wherein the at least one priority rule is configured in the UE.

Example Emboidment C22.The method of Example Embodiment C20, wherein the at least one priority rule is received from the at least one other UE or the network node.

Example Emboidment C23.The method of Example Embodiment C20, wherein the at least one priority rule is determined based on the at least one overlapping resources.

Example Embodiment C24. The method of Example Embodiments Cl to C23, further comprising: providing user data; and forwarding the user data to a host via the transmission to the network node.

Example Embodiment C25.A user equipment comprising processing circuitry configured to perform any of the methods of Example Embodiments Cl to C24.

Example Embodiment C26.A wireless device comprising processing circuitry configured to perform any of the methods of Example Embodiments Cl to C24.

Example Emboidment C27.A user equipment adapted to perform any of the methods of Example Embodiments Cl to C24.

Example Embodiment C28. A computer program comprising instructions which when executed on a computer perform any of the methods of Example Embodiments Cl to C24.

Example Embodiment C29. A computer program product comprising computer program, the computer program comprising instructions which when executed on a computer perform any of the methods of Example Embodiments Cl to C24.

Example Embodiment C30.A non-transitory computer readable medium storing instructions which when executed by a computer perform any of the methods of Example Embodiments Cl to C24.

Group D Example Embodiments

Example Embodiment DI. A method by a network node for enhanced feedback transmission for network controlled sidelink communications, the method comprising: receiving, from a user equipment (UE), feedback indicating whether control information for establishing a sidelink communication session between the UE and at least one other UE was successfully received. Example Embodiment D2. The method of Example Emboidment DI, wherein prior to receiving the feedback, the method further comprises transmitting, to the UE, at least a portion of the control information for establishing the sidelink communication session with the at least one other UE.

Example Embodiment D3. The method of Example Embodiment D2, wherein the portion of the control information transmitted to the UE indicates that the UE is to send the feedback to the network node.

Example Embodiment D4. The method of any one of Example Embodiments D2 to D3, wherein the portion of the control information is transmitted from the network node as downlink control information.

Example Embodiment D5. The method of any one of Example Embodiments D2 to D4, wherein portion of the control information comprises scheduling information for transmitting and/or receiving communications by the UE and/or the at least one other UE on a physical sidelink shared channel.

Example Embodiment D6. The method of any one of Example Embodiments DI to D5, wherein: the UE from which the feedback is received comprises a receiving UE associated with the sidelink communication session, and the at least one other U E comprises a transmitting UE associated with the sidelink communication session.

Example Embodiment D7. The method of any one of Example Embodiments DI to D6, wherein the feedback indicates whether control information from the at least one other UE was successfully received by the UE on a physical sidelink shared channel.

Example Embodiment D8. The method of any one of Example Embodiments DI to D7, wherein the feedback indicates whether control information from the network node was successfully received by the UE as downlink control information.

Example Embodiment D9. The method of any one of Example Embodiments DI to D8, wherein the feedback comprises HARQ-ACK feedback or HARQ-NACK feedback.

Example Embodiment D10. The method of any one of Example Embodiments, DI to D9, wherein the feedback comprises channel state information.

Example Embodiment Dll. The method of Example Emboidment D10, wherein the channel state information received by the network node does not overlap with additional channel state information transmitted to the at least one other UE.

Example Embodiment D12. The method of any one of Example Embodiments DI to Dll, further comprising configuring the UE to transmit, to the at least one other UE, feedback indicating whether the control information was successfully received. Example Embodiment D 13. The method of Example Emboidment D12, further comprising configuring the UE to transmit the feedback to the network node and the at least one other UE in single feedback transmission using a same transmission resource.

Example Embodiment D14. The method of any one of Example Embodiments DI to DI 3, further comprising configuring the UE to: prior to transmitting the feedback to the network node, attempt to transmit the feedback to the at least one other UE a number of times; and transmit the feedback to the network node when the number of times is equal to or has exceeded the threshold.

Example Embodiment D15. The method of any one of Example Embodiments DI to D14, wherein the feedback indicates that the control information has been successfully received by the UE from the at least one other UE a number of times that is equal to or greater than a threshold.

Example Embodiment DI 6. The method of any one of Example Embodiments D14 to D15, further comprising transmitting, to the UE, information indicating the threshold.

Example Emboidment D17. The method of any one of Example Embodiments DI to C16, wherein the feedback comprises positive acknowledgement feedback indicating that the control information was successfully received.

Example Embodiment DI 8. The method of Example Embodiment D17, further comprising transmitting, to the UE and/or the at least one other UE, an indication that at least one resource reserved for use for retransmission of the feedback is to be used for a different purpose.

Example Embodiment D19. The method of any one of Example Embodiments DI to D16, wherein the feedback comprises negative acknowledgement feedback indicating that the control information was not successfully received.

Example Emboidment D20. The method of Example Embodiment D19, further comprising transmitting downlink control information (DCI) to the at least one other UE, the DCI comprising scheduling information for a retransmission of the control information by the at least one other UE.

Example Embodiment D21. The method of Example Embodiment D20, further comprising receiving additional feedback from the at least one other UE, and wherein the DCI is transmitted to the at least one other UE based on receiving the feedback from the UE and the additional feedback from the at least one other UE.

Example Embodiment D22. The method of any one of Example Embodiments DI to D21 , further comprising configuring the UE to : determine that at least one resource for transmitting the feedback to the network node overlaps in a time and/or frequency domain with at least one resource for transmitting the feedback to the at least one other UE, and prioritize sending the feedback to the network node rather than the at least one other UE when the at least one resources overlap based on at least one priority rule.

Example Emboidment D23. The method of Example Embodiment 22, further comprising transmitting the at least one priority rule to the UE.

Example Embodiment D24. The method of any one of Example Embodiments DI to D23, wherein the network node comprises a gNodeB (gNB).

Example Embodiment D25. The method of any of the previous Example Embodiments, further comprising: obtaining user data; and forwarding the user data to a host or a user equipment.

Example Embodiment D26. A network node comprising processing circuitry configured to perform any of the methods of Example Embodiments DI to D25.

Example Embodiment D27. A network node adapted to perform any of the methods of Example Embodiments DI to D25.

Example Embodiment D28. A computer program comprising instructions which when executed on a computer perform any of the methods of Example Embodiments DI to D25.

Example Embodiment D29. A computer program product comprising computer program, the computer program comprising instructions which when executed on a computer perform any of the methods of Example Embodiments DI to D25.

Example Embodiment D30. A non-transitory computer readable medium storing instructions which when executed by a computer perform any of the methods of Example Embodiments DI to D25.

Group E Example Embodiments

Example Embodiment El. A user equipment for enhanced feedback transmission for network controlled sidelink communications, comprising: processing circuitry configured to perform any of the steps of any of the Group A and C Example Embodiments; and power supply circuitry configured to supply power to the processing circuitry.

Example Embodiment E2. A network node for enhanced feedback transmission for network controlled sidelink communications, the network node comprising: processing circuitry configured to perform any of the steps of any of the Group B and D Example Embodiments; power supply circuitry configured to supply power to the processing circuitry.

Example Embodiment E3. A user equipment (UE) for enhanced feedback transmission for network controlled sidelink communications, the UE comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform any of the steps of any of the Group A and C Example Embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE.

Example Embodiment E4. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the steps of any of the Group A and C Example Embodiments to receive the user data from the host.

Example Embodiment E5. The host of the previous Example Embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data to the UE from the host.

Example Embodiment E6. The host of the previous 2 Example Embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

Example Embodiment E7. A method implemented by a host operating in a communication system that further includes a network node and a user equipment (UE), the method comprising: providing user data for the UE; and initiating a transmission carrying the user data to the UE via a cellular network comprising the network node, wherein the UE performs any of the operations of any of the Group A embodiments to receive the user data from the host.

Example Emboidment E8. The method of the previous Example Embodiment, further comprising: at the host, executing a host application associated with a client application executing on the UE to receive the user data from the UE.

Example Embodiment E9. The method of the previous Example Embodiment, further comprising: at the host, transmitting input data to the client application executing on the UE, the input data being provided by executing the host application, wherein the user data is provided by the client application in response to the input data from the host application. Example Emboidment El 0. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the steps of any of the Group A and C Example Embodiments to transmit the user data to the host.

Example Emboidment Ell. The host of the previous Example Embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data from the UE to the host.

Example Embodiment E12.The host of the previous 2 Example Embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

Example Embodiment El 3. A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: at the host, receiving user data transmitted to the host via the network node by the UE, wherein the UE performs any of the steps of any of the Group A and C Example Embodiments to transmit the user data to the host.

Example Embodiment El 4. The method of the previous Example Embodiment, further comprising: at the host, executing a host application associated with a client application executing on the UE to receive the user data from the UE.

Example Embodiment El 5. The method of the previous Example Embodiment, further comprising: at the host, transmitting input data to the client application executing on the UE, the input data being provided by executing the host application, wherein the user data is provided by the client application in response to the input data from the host application.

Example Embodiment El 6. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a network node in a cellular network for transmission to a user equipment (UE), the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B and D Example Embodiments to transmit the user data from the host to the UE.

Example Embodiment E17.The host of the previous Example Embodiment, wherein: the processing circuitry of the host is configured to execute a host application that provides the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application to receive the transmission of user data from the host.

Example Embodiment El 8. A method implemented in a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: providing user data for the UE; and initiating a transmission carrying the user data to the UE via a cellular network comprising the network node, wherein the network node performs any of the operations of any of the Group B and D Example Embodiments to transmit the user data from the host to the UE.

Example Embodiment El 9. The method of the previous Example Embodiment, further comprising, at the network node, transmitting the user data provided by the host for the UE.

Example Emboidment E20.The method of any of the previous 2 Example Embodiments, wherein the user data is provided at the host by executing a host application that interacts with a client application executing on the UE, the client application being associated with the host application.

Example Embodiment E21. A communication system configured to provide an over-the- top service, the communication system comprising: a host comprising: processing circuitry configured to provide user data for a user equipment (UE), the user data being associated with the over-the-top service; and a network interface configured to initiate transmission of the user data toward a cellular network node for transmission to the UE, the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B and D Example Embodiments to transmit the user data from the host to the UE.

Example Embodiment E22. The communication system of the previous Example Embodiment, further comprising: the network node; and/or the user equipment.

Example Embodiment E23. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to initiate receipt of user data; and a network interface configured to receive the user data from a network node in a cellular network, the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B and D Example Embodiments to receive the user data from a user equipment (UE) for the host.

Example Embodiment E24.The host of the previous 2 Example Embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

Example Embodiment E25.The host of the any of the previous 2 Example Embodiments, wherein the initiating receipt of the user data comprises requesting the user data. Example Embodiment E26. A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: at the host, initiating receipt of user data from the UE, the user data originating from a transmission which the network node has received from the UE, wherein the network node performs any of the steps of any of the Group B and D Example Embodiments to receive the user data from the UE for the host.

Example Embodiment E27. The method of the previous Example Embodiment, further comprising at the network node, transmitting the received user data to the host.

Claims

1. A method (1100) by a user equipment, UE (512, 600), for network controlled sidelink communications, the method comprising: receiving (1102) control information (102, 202, 302, 402) for establishing a sidelink communication session with at least one other UE (512, 600); and transmitting (1104), to a network node (510, 700), first feedback (414a, 414b) in response to a reception of a transmission associated with the sidelink communication session.

2. The method of Claim 1, wherein the control information comprises scheduling information for transmitting and/or receiving communications by the UE and/or the at least one other UE on a physical sidelink shared channel, PSSCH.

3. The method of any one of Claims 1 to 2, wherein the UE (512, 108, 208, 308, 408) transmits sidelink data to the at least one other UE (512, 104, 204, 304, 404) during the sidelink communication session.

4. The method of any one of Claims 1 to 2, wherein: the UE (512, 104, 204, 304, 404) receives sidelink data from the at least one other UE (512, 108, 208, 308, 408) during the sidelink communication session, and the at least one other UE transmits sidelink data to the UE during the sidelink communication session.

5. The method of any one of Claims 1 to 4, wherein at least a first portion of the control information (106, 206, 306, 406) is received from the at least one other UE on at least one of a physical sidelink control channel (PSCCH) and a physical sidelink shared channel, PSSCH .

6. The method of any one of Claims 1 to 5, wherein at least a second portion of the control information (102, 202, 302, 402) is received from the network node via at least one of: downlink control information, radio resource control, RRC, signaling, and a unicast transmission transmitted to the UE and the at least one other UE.

7. The method of any one of Claims 5 to 6, wherein at least one of the second portion of the control information received from the network node and the first portion of the control information received from the at least one other UE indicates that the UE is to send the first feedback to the network node.

8. The method of any one of Claims 5 to 7, wherein at least one of the second portion of the control information from the network node and the first portion of the control information from the at least one other UE comprises a partial scheduling assignment.

9. The method of any one of Claims 5 to 8, wherein at least one of the second portion of the control information from the network node and the first portion of the control information from the at least one other UE comprises a full scheduling assignment.

10. The method of any one of Claims 5 to 9, wherein: the first portion of the control information from the at least one other UE is 2^nd Stage Sidelink Control Information, SCI2, and the second portion of the control information from the network node is 1st Stage Sidelink Control Information, SCI1, or the first portion of the control information from the at least one other UE is SCI1 and the second portion of the control information from the network node is SCI2, or the first portion of the control information from the at least one other UE is SCI1 and the second portion of the control information from the network node is SCI1 and additional information associated with SCI2, or the first portion of the control information from the at least one other UE is SCI1 and SCI2 and the second portion of the control information from the network node is at least one of: SCI, SCI2, and other control information.

11. The method of any one of Claims 5 to 10, comprising transmitting the second portion of the control information received from the network node to the at least one other UE.

12. The method of any one of Claims 1 to 11, comprising transmitting second feedback to the at least one other UE.

13. The method of Claim 12, wherein at least one of the first feedback and the second feedback comprises at least one of:

Channel State Information, CSI, (414b), positive acknowledgement feedback (414a), and negative acknowledgement feedback (414a).

14. The method of any one of Claims 12 to 13, wherein a content of the first feedback does not overlap with a content of the second feedback.

15. The method of any one of Claims 12 to 14, wherein the first feedback transmitted to the network node and the second feedback transmitted to the at least one other UE is transmitted in single feedback transmission using a same transmission resource.

16. The method of any one of Claims 12 to 15, comprising: determining that the first feedback has been unsuccessfully transmitted to the network node a number of times that is equal to or greater than a threshold; and wherein the second feedback is transmitted to the at least one other UE based on the first feedback having been transmitted to the network node the number of times that is equal to or greater than the threshold.

17. The method of any one of Claims 12 to 15, comprising: determining that the transmission associated with the sidelink communication session has been unsuccessfully received and that the first feedback has been transmitted to the network node a number of times that is equal to or greater than a threshold; and wherein the second feedback is transmitted to the at least one other UE based on the transmission being unsuccessfully received and the first feedback having been transmitted to the network node the number of times that is equal to or greater than the threshold.

18. The method of any one of Claims 12 to 17, wherein prior to transmitting the first feedback to the network node, the method comprises: attempting a number of times to transmit the second feedback to the at least one other UE; and determining that the transmission associated with the sidelink communication session has been unsuccessfully received based on the number of times that the transmission of the second feedback to the at least one other UE has been attempted is equal to or has exceeded a threshold, and wherein the first feedback is transmitted to the network node based on the transmission associated with the sidelink communication session being unsuccessfully received.

19. The method of any one of Claims 12 to 18, comprising transmitting the second feedback to the network node and/or the first feedback to the at least one other UE.

20. The method of any one of Claims 1 to 19, wherein the first feedback indicates whether the control information was successfully received by the UE or not.

21. The method of any one of Claims 1 to 20, further comprising transmitting, to the at least one other UE, second feedback indicating whether the control information was successfully received or not.

22. The method of any one of Claims 1 to 21 , wherein prior to receiving the control information the method comprises transmitting assistance information to the network node.

23. The method of Claim 22, wherein the assistance information comprises an identifier associated with the UE and/or an identifier associated with the at least one other UE.

24. The method of any one of Claims 22 to 23, wherein the assistance information comprises an identifier associated with the sidelink communication session and/or a sidelink between the UE and the at least one other UE.

25. The method of any one of Claims 22 to 24, wherein the assistance information is transmitted with or as part of a scheduling request and/or a buffer status report.

26. A method (1200) by a network node (510, 700) for network controlled sidelink communications, the method comprising: receiving (1202), from a user equipment (UE) (512, 600), a first feedback (514a, 514b) associated with a reception of a transmission associated with a sidelink communication session between the UE and at least one other UE (512, 600).

27. The method of Claim 26, comprising receiving, from the at least one other UE, second feedback associated with the reception, by the UE, of the transmission associated with a sidelink communication session between the UE and at least one other UE.

28. The method of any one of Claims 26 to 27, comprising configuring the UE to transmit, to the at least one other UE, third feedback associated with the reception of the transmission by the UE.

29. The method of any one of Claims 26 to 28, wherein at least one of the first feedback, the second feedback, and the third feedback comprises at least one of:

Channel State Information, CSI, (414b), positive acknowledgement feedback (415a), and negative acknowledgement feedback (414a).

30. The method of any one of Claims 28 to 29, wherein a content of the first feedback does not overlap with a content of the third feedback.

31. The method any one of Claims 28 to 30, comprising configuring the UE to transmit the first feedback to the network node and the third feedback to the at least one other UE in a single feedback transmission using a same transmission resource.

32. The method of any one of Claims 28 to 31, comprising configuring the UE to: determine that the first feedback has been unsuccessfully transmitted to the network node a number of times that is equal to or greater than a threshold; and transmit the second feedback to the at least one other UE based on the first feedback having been transmitted to the network node the number of times that is equal to or greater than the threshold.

33. The method of any one of Claims 28 to 31, comprising configuring the UE to: determine that the transmission associated with the sidelink communication session has been unsuccessfully received and that the first feedback has been transmitted to the network node a number of times that is equal to or greater than a threshold; and transit the second feedback to the at least one other UE based on the transmission being unsuccessfully received and the first feedback having been transmitted to the network node the number of times that is equal to or greater than the threshold.

34. The method of any one of Claims 28 to 31, comprising configuring the UE to: attempt a number of times to transmit the second feedback to the at least one other UE; and determine that the transmission associated with the sidelink communication session has been unsuccessfully received based on the number of times that the transmission of the second feedback to the at least one other UE has been attempted is equal to or has exceeded a threshold, and transmit the first feedback to the network node based on the transmission associated with the sidelink communication session being unsuccessfully received.

35. The method of any one of Claims 32 to 34, comprising transmitting, to the UE, information indicating the threshold.

36. The method of any one of Claims 26 to 35, comprising configuring the UE to: determine that at least one resource for transmitting the first feedback to the network node overlaps in a time and/or frequency domain with at least one resource for transmitting a second feedback to the at least one other UE, and based on at least one priority rule, prioritize sending the first feedback to the network node or prioritize sending the third feedback to the at least one other UE.

37. The method of any one of Claims 26 to 36, wherein the first feedback comprises positive acknowledgement feedback indicating that the transmission to the at least one other UE was successfully received, and wherein the method comprises transmitting, to the UE and/or the at least one other UE, an indication that at least one resource reserved for use for a retransmission of the transmission is to be used for a different purpose.

38. The method of any one of Claims 26 to 36, wherein the first feedback comprises negative acknowledgement feedback, and wherein the method comprises transmitting downlink control information, DCI, to the at least one other UE, the DCI comprising scheduling information for a retransmission of the transmission by the at least one other UE.

39. The method of any one of Claims 26 to 38, wherein prior to receiving the first feedback, the method comprises transmitting, to the UE, a first portion of control information for establishing the sidelink communication session between the UE and the at least one other UE.

40. The method of any one of Claims 26 to 39, comprising transmitting, to the at least one other UE, a second portion of control information for establishing the sidelink communication session between the UE and the at least one other UE.

41. The method of any one of Claims 39 to 40, wherein at least one of the first portion of the control information and the second portion of the control information comprises scheduling information for transmitting and/or receiving communications by the UE and/or the at least one other UE on a physical sidelink shared channel, PSSCH.

42. The method of any one of Claims 39 to 41, wherein at least one of the first portion of the control information and the second portion of the control information indicates that feedback is to be sent to the network node.

43. The method of any one of Claims 39 to 42, wherein at least one of the first portion of the control information and the second portion of the control information is transmitted via at least one of: downlink control information, radio resource control, RRC, signaling, and a unicast transmission transmitted to the UE and the at least one other UE.

44. The method of any one of Claims 39 to 43, wherein at least one of the first portion of the control information and the second portion of the control information comprises a partial scheduling assignment.

45. The method of any one of Claims 39 to 43, wherein at least one of the first portion of the control information and the second portion of the control information comprises a full scheduling assignment.

46. The method of any one of Claims 39 to 43, wherein the first portion of the control information transmitted to the UE is at least one of:

1^st Stage Sidelink Control Information, SCI1, 2^nd Stage Sidelink Control Information, SCI2, and control information other than SCI1 and SCI2 control information.

47. The method of any one of Claims 39 to 43, wherein the second portion of the control information transmitted to the at least one other UE is at least one of:

1^st Stage Sidelink Control Information, SCI1,

2^nd Stage Sidelink Control Information, SCI2, and control information other than SCI1 and SCI2 control information.

48. The method of any one of Claims 39 to 47, wherein prior to transmitting the first portion of the control information and/or the second portion of the control information, the method comprises receiving assistance information from the UE and/or the at least one other UE.

49. The method of Claim 48, wherein the assistance information comprises an identifier associated with the UE and/or an identifier associated with the at least one other UE.

50. The method of any one of Claims 48 to 49, wherein the assistance information comprises an identifier associated with the sidelink communication session and/or a sidelink between the receiving UE and the transmitting UE.

51. The method of any one of Claims 48 to 50, wherein the assistance information is received with or as part of a scheduling request and/or a buffer status report.

52. A user equipment, UE, (512, 600) for network controlled sidelink communications, the UE comprising processing circuitry (602) adapted to: receive (1102) control information (102, 202, 302, 402) for establishing a sidelink communication session with at least one other UE (512, 600); and transmit (1104), to a network node (510, 700), first feedback (414a, 414b) in response to a reception of a transmission associated with the sidelink communication session.

53. The UE of Claim 52, wherein the processing circuitry is adapted to perform any of the methods of Claims 2 to 25.

54. A network node (510, 700) for network controlled sidelink communications, the network node comprising processing circuitry (702) adapted to: receive (1202), from a user equipment (UE) (512, 600), a first feedback (514a, 514b) associated with a reception of a transmission associated with a sidelink communication session between the UE and at least one other UE (512, 600).

55. The network node of Claim 54, wherein the processing circuitry is adapted to perform any of the methods of Claims 27 to 51.