Patent Description:
Sidelink communication capabilities have been developed, for example, to facilitate direct communication between UEs. Sidelink communications allow for communication between two or more nearby UEs, such as using evolved Universal Terrestrial Radio Access Network (E-UTRAN) technology, without the sidelink transmissions passing through a base station. Such sidelink communications can be used for out-of-network coverage scenarios. For example, sidelink communications can be used to enable communications to UEs otherwise outside of a network coverage area. Additionally or alternatively, sidelink communications can be used for public safety communications, such as to provide public safety communications using different standards in different geographical regions (e.g., different countries) to UEs roaming within an area of a network, etc. Sidelink communication functionality can likewise be used in conjunction with conventional wireless communication network connections to mobile networks to enable a wide variety of innovative connected device (e.g., connected car) services. <INSERT New Page 2a>.

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

This disclosure relates generally to providing or participating in communication as between two or more wireless devices in one or more wireless communications systems, also referred to as wireless communications networks. In various embodiments, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, <NUM>th Generation (<NUM>) or new radio (NR) networks (sometimes referred to as "<NUM> NR" networks/systems/devices), as well as other communications networks. As described herein, the terms "networks" and "systems" may be used interchangeably.

A TDMA network may, for example implement a radio technology such as GSM. 3GPP defines standards for the GSM EDGE (enhanced data rates for GSM evolution) radio access network (RAN), also denoted as GERAN. GERAN is the radio component of GSM/EDGE, together with the network that joins the base stations (for example, the Ater and Abis interfaces) and the base station controllers (A interfaces, etc.). The radio access network represents a component of a GSM network, through which phone calls and packet data are routed from and to the public switched telephone network (PSTN) and Internet to and from subscriber handsets, also known as user terminals or user equipments (UEs). A mobile phone operator's network may comprise one or more GERANs, which may be coupled with Universal Terrestrial Radio Access Networks (UTRANs) in the case of a UMTS/GSM network. An operator network may also include one or more LTE networks, and/or one or more other networks. The various different network types may use different radio access technologies (RATs) and radio access networks (RANs).

UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named "<NUM>rd Generation Partnership Project" (3GPP), and cdma2000 is described in documents from an organization named "<NUM>rd Generation Partnership Project <NUM>" (3GPP2). For example, the <NUM>rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (<NUM>) mobile phone specification.

<NUM> networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. To achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for <NUM> NR networks. The <NUM> NR will be capable of scaling to provide coverage (<NUM>) to a massive Internet of things (IoTs) with an ultra-high density (e.g., ~<NUM> nodes/km<NUM>), ultra-low complexity (e.g., ~<NUM> of bits/sec. ), ultra-low energy (e.g., ~<NUM>+ years of battery life), and deep coverage with the capability to reach challenging locations; (<NUM>) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ~<NUM>% reliability), ultra-low latency (e.g., ~ <NUM>), and users with wide ranges of mobility or lack thereof; and (<NUM>) with enhanced mobile broadband including extreme high capacity (e.g., ~ <NUM> Tbps/km<NUM>), extreme data rates (e.g., multi-Gbps rate, <NUM>+ Mbps user experienced rates), and deep awareness with advanced discovery and optimizations.

<NUM> NR devices, networks, and systems may be implemented to use optimized OFDM-based waveform features. These features may include scalable numerology and transmission time intervals (TTIs); a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD)/frequency division duplex (FDD) design; and advanced wireless technologies, such as massive multiple input, multiple output (MIMO), robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in <NUM> NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than <NUM> FDD/TDD implementations, subcarrier spacing may occur with <NUM>, for example over <NUM>, <NUM>, <NUM>, <NUM>, and the like bandwidth. For other various outdoor and small cell coverage deployments of TDD greater than <NUM>, subcarrier spacing may occur with <NUM> over <NUM>/<NUM> bandwidth. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the <NUM> band, the subcarrier spacing may occur with <NUM> over a <NUM> bandwidth. Finally, for various deployments transmitting with mmWave components at a TDD of <NUM>, subcarrier spacing may occur with <NUM> over a <NUM> bandwidth.

The scalable numerology of <NUM> NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements.

For clarity, certain aspects of the apparatus and techniques may be described below with reference to exemplary LTE implementations or in an LTE-centric way, and LTE terminology may be used as illustrative examples in portions of the description below; however, the description is not intended to be limited to LTE applications. Indeed, the present disclosure is concerned with shared access to wireless spectrum between networks using different radio access technologies or radio air interfaces, such as those of <NUM> NR.

Moreover, it should be understood that, in operation, wireless communication networks adapted according to the concepts herein may operate with any combination of licensed or unlicensed spectrum depending on loading and availability. Accordingly, it will be apparent to one of skill in the art that the systems, apparatus and methods described herein may be applied to other communications systems and applications than the particular examples provided.

While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses may come about via integrated chip embodiments and/or other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregated, distributed, or OEM devices or systems incorporating one or more described aspects. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments. It is intended that innovations described herein may be practiced in a wide variety of implementations, including both large/small devices, chip-level components, multicomponent systems (e.g. RF-chain, communication interface, processor), distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.

<FIG> shows wireless network <NUM> for communication according to some embodiments. Wireless network <NUM> may, for example, comprise a <NUM> wireless network. As appreciated by those skilled in the art, components appearing in <FIG> are likely to have related counterparts in other network arrangements including, for example, cellular-style network arrangements and non-cellular-style-network arrangements (e.g., device to device or peer to peer or ad hoc network arrangements, etc.).

Wireless network <NUM> illustrated in <FIG> includes a number of base stations <NUM> and other network entities. A base station may be a station that communicates with the UEs and may also be referred to as an evolved node B (eNB), a next generation eNB (gNB), an access point, and the like. Each base station <NUM> may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" can refer to this particular geographic coverage area of a base station and/or a base station subsystem serving the coverage area, depending on the context in which the term is used. In implementations of wireless network <NUM> herein, base stations <NUM> may be associated with a same operator or different operators (e.g., wireless network <NUM> may comprise a plurality of operator wireless networks), and may provide wireless communications using one or more of the same frequencies (e.g., one or more frequency bands in licensed spectrum, unlicensed spectrum, or a combination thereof) as a neighboring cell. In some examples, an individual base station <NUM> or UE <NUM> may be operated by more than one network operating entity. In other examples, each base station <NUM> and UE <NUM> may be operated by a single network operating entity.

A base station may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A base station for a macro cell may be referred to as a macro base station. A base station for a small cell may be referred to as a small cell base station, a pico base station, a femto base station or a home base station. In the example shown in <FIG>, base stations 105d and 105e are regular macro base stations, while base stations 105a-105c are macro base stations enabled with one of <NUM> dimension (3D), full dimension (FD), or massive MIMO. Base stations 105a-105c take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. Base station 105f is a small cell base station which may be a home node or portable access point. A base station may support one or multiple (e.g., two, three, four, and the like) cells.

Wireless network <NUM> may support synchronous or asynchronous operation. In some scenarios, networks may be enabled or configured to handle dynamic switching between synchronous or asynchronous operations.

UEs <NUM> are dispersed throughout wireless network <NUM>, and each UE may be stationary or mobile. It should be appreciated that, although a mobile apparatus is commonly referred to as user equipment (UE) in standards and specifications promulgated by the <NUM>rd Generation Partnership Project (3GPP), such apparatus may also be referred to by those skilled in the art as a mobile station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. Within the present document, a "mobile" apparatus or UE need not necessarily have a capability to move, and may be stationary. Some non-limiting examples of a mobile apparatus, such as may comprise embodiments of one or more of UEs <NUM>, include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a laptop, a personal computer (PC), a notebook, a netbook, a smart book, a tablet, and a personal digital assistant (PDA). A mobile apparatus may additionally be an "Internet of Things" (IoT) or "Internet of Everything" (IoE) device such as an automotive or other transportation vehicle, a satellite radio, a global positioning system (GPS) device, a logistics controller, a drone, a multi-copter, a quad-copter, a smart energy or security device, a solar panel or solar array, municipal lighting, water, or other infrastructure; industrial automation and enterprise devices; consumer and wearable devices, such as eyewear, a wearable camera, a smart watch, a health or fitness tracker, a mammal implantable device, gesture tracking device, medical device, a digital audio player (e.g., MP3 player), a camera, a game console, etc.; and digital home or smart home devices such as a home audio, video, and multimedia device, an appliance, a sensor, a vending machine, intelligent lighting, a home security system, a smart meter, etc. In one aspect, a UE may be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE may be a device that does not include a UICC. In some aspects, UEs that do not include UICCs may also be referred to as IoE devices. UEs 115a-115d of the embodiment illustrated in <FIG> are examples of mobile smart phone-type devices accessing wireless network <NUM> A UE may also be a machine specifically configured for connected communication, including machine type communication (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT) and the like. UEs 115e-<NUM> illustrated in <FIG> are examples of various machines configured for communication that access wireless network <NUM>.

A mobile apparatus, such as UEs <NUM>, may be able to communicate with any type of the base stations, whether macro base stations, pico base stations, femto base stations, relays, and the like. In <FIG>, a lightning bolt (e.g., communication link) indicates wireless transmissions between a UE and a serving base station, which is a base station designated to serve the UE on the downlink and/or uplink, or desired transmission between base stations, and backhaul transmissions between base stations. Backhaul communication between base stations of wireless network <NUM> may occur using wired and/or wireless communication links.

In operation at wireless network <NUM>, base stations 105a-105c serve UEs 115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. Macro base station 105d performs backhaul communications with base stations 105a-105c, as well as small cell, base station 105f. Macro base station 105d also transmits multicast services which are subscribed to and received by UEs 115c and 115d.

Wireless network <NUM> of embodiments supports mission critical communications with ultra-reliable and redundant links for mission critical devices, such as UE 115e, which is a drone. Redundant communication links with UE 115e include links from macro base stations 105d and 105e, as well as small cell base station 105f. Other machine type devices, such as UE 115f (thermometer), UE <NUM> (smart meter), and UE <NUM> (wearable device) may communicate through wireless network <NUM> either directly with base stations, such as small cell base station 105f, and macro base station 105e, or in multi-hop configurations by communicating (e.g., using sidelink communications) with another user device which relays its information to/from the network, such as UE 115f communicating temperature measurement information to the smart meter, UE <NUM>, which is then reported to the network through small cell base station 105f. Wireless network <NUM> may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as in a vehicle-to-vehicle (V2V) mesh network between UEs 115i-<NUM> communicating with macro base station 105e.

<FIG> shows a block diagram of a design of an example of base station <NUM> and an example of UE <NUM>, which may be any of the base stations and one of the UEs in <FIG>. For a restricted association scenario (as mentioned above), base station <NUM> may be small cell base station 105f in <FIG>, and UE <NUM> may be UE 115c or 115D operating in a service area of base station 105f, which in order to access small cell base station 105f, would be included in a list of accessible UEs for small cell base station 105f. Base station <NUM> may also be a base station of some other type. As shown in <FIG>, base station <NUM> may be equipped with antennas 234a through 234t, and UE <NUM> may be equipped with antennas 252a through 252r for facilitating wireless communications.

At base station <NUM>, transmit processor <NUM> may receive data from data source <NUM> and control information from controller/processor <NUM>. The control information may be for the physical broadcast channel (PBCH), physical control format indicator channel (PCFICH), physical hybrid-ARQ (automatic repeat request) indicator channel (PHICH), physical downlink control channel (PDCCH), enhanced physical downlink control channel (EPDCCH), MTC physical downlink control channel (MPDCCH), etc. The data may be for the PDSCH, etc. Transmit processor <NUM> may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Transmit processor <NUM> may also generate reference symbols, e.g., for the primary synchronization signal (PSS) and secondary synchronization signal (SSS), and cell-specific reference signal. Transmit (TX) multiple-input multiple-output (MIMO) processor <NUM> may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to modulators (MODs) 232a through 232t. Each modulator <NUM> may additionally or alternatively process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 232a through 232t may be transmitted via antennas 234a through 234t, respectively.

At UE <NUM>, antennas 252a through 252r may receive the downlink signals from base station <NUM> and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. MIMO detector <NUM> may obtain received symbols from demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor <NUM> may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE <NUM> to data sink <NUM>, and provide decoded control information to controller/processor <NUM>.

On the uplink, at UE <NUM>, transmit processor <NUM> may receive and process data (e.g., for the physical uplink shared channel (PUSCH)) from data source <NUM> and control information (e.g., for the physical uplink control channel (PUCCH)) from controller/processor <NUM>. Transmit processor <NUM> may also generate reference symbols for a reference signal. The symbols from transmit processor <NUM> may be precoded by TX MIMO processor <NUM> if applicable, further processed by modulators 254a through 254r (e.g., for SC-FDM, etc.), and transmitted to base station <NUM>. At base station <NUM>, the uplink signals from UE <NUM> may be received by antennas <NUM>, processed by demodulators <NUM>, detected by MIMO detector <NUM> if applicable, and further processed by receive processor <NUM> to obtain decoded data and control information sent by UE <NUM>. Processor <NUM> may provide the decoded data to data sink <NUM> and the decoded control information to controller/processor <NUM>.

Controllers/processors <NUM> and <NUM> may direct the operation at base station <NUM> and UE <NUM>, respectively. Controller/processor <NUM> and/or other processors and modules at base station <NUM> and/or controller/processor <NUM> and/or other processors and modules at UE <NUM> may perform or direct the execution of various processes for the techniques described herein, such as to perform or direct the execution illustrated in <FIG>, <FIG>, <FIG>, and <FIG>, and/or other processes for the techniques described herein. Memories <NUM> and <NUM> may store data and program codes for base station <NUM> and UE <NUM>, respectively. Scheduler <NUM> may schedule UEs for data transmission on the downlink and/or uplink.

One or more UEs operating in wireless network <NUM> may be configured with sidelink communication capabilities facilitating direct communication between two or more nearby UEs, such as using E-UTRAN technology, without the sidelink transmissions passing through a base station. UEs 115c, 115d, <NUM>, and 115i-115j are shown in <FIG> as implementing sidelink communication links. Sidelink communication link 126c-d between UEs 115c and 115d may, for example, be implemented with respect to an out-of-network coverage scenario in which UE 115c is disposed in an area at which direct communication with base stations <NUM> is not available or otherwise inadequate. As another example, sidelink communication links 126i-j, 126j-k, and 126i-k between UEs 115i-<NUM> may be implemented to enable various connected car services. In providing the foregoing sidelink communications between UEs, one of the UEs may implement a communication link with the wireless network (e.g., network communication link 125d-d), such as may comprise a conventional wireless communication link with one or more base stations <NUM>, to operate as an intermediary communication device with respect to a sidelinked UE. An intermediary communication device may, for example, comprise a communication device providing a node in a sidelink communication link with a sidelinked UE, such as a node providing a link between the sidelinked UE and a base station or other network node.

Various feedback signaling may be utilized between the UEs and/or the intermediary UE and a corresponding base station. For example, hybrid automatic repeat request (HARQ) feedback may be utilized in association with sidelink communications. As an example of HARQ feedback, data receipt acknowledgement/negative acknowledgement (e.g. HARQ-ACK and/or HARQ-NACK) may be transmitted by physical sidelink feedback channel (PSFCH) from a receiver UE to a transmitter UE of a sidelink communication pair. In some cases, the transmitter UE (e.g., an intermediary UE) may forward the data receipt acknowledgement/negative acknowledgement from the transmitter UE to a base station, such as via PUCCH/PUSCH, to obtain retransmission resources from the network. This forwarding operation is illustrated in the communication flow diagram of <FIG>.

In the data receipt acknowledgement/negative acknowledgement forwarding example of flow <NUM> shown in <FIG>, a sidelink grant may be made by base station <NUM> (e.g., any of base stations <NUM> shown in <FIG>, such as base stations 105d, 105e, or 105f). The sidelink grant may be communicated by base station <NUM> to UE 315a (e.g., any of UEs <NUM> shown in <FIG> served by base station <NUM> and configured operate as an intermediary UE in sidelink communications, such as UEs 115d, <NUM>, 115i, or <NUM>) via a PDCCH of network communication link <NUM> (e.g., any of the network communication links of <FIG>, such as network communication link 125d-d). UE 315a, operating as a transmitter intermediary UE in this example may correspondingly communicate the sidelink grant via a physical sidelink control channel (PSCCH) of sidelink communication link <NUM> (e.g., any of the sidelink communication links of <FIG>, such as sidelink communication links 126c-d, 126i-j, 126j-k, or 126i-k) to UE 315b (e.g., any of UEs <NUM> within communication range of an intermediary UE and configured to operate as a sidelinked UE, such as UE 115c, 115f, 115i, 115j, or <NUM>). UE 315a may, in accordance with the sidelink grant, communicate sidelink data to UE 315b, such as via a physical sidelink shared channel (PSSCH) of sidelink communication link <NUM>. Thereafter, sidelink HARQ feedback may be transmitted from the receiver UE to transmitter UE. For example, UE 315b may provide sidelink HARQ feedback to UE 315a, such as via a physical sidelink feedback channel (PSFCH) of sidelink communication link <NUM>. The sidelink HARQ may be forwarded from the transmitter UE to the base station, such as to request one or more retransmission resources. For example, as shown in <FIG>, UE 315a may forward the sidelink HARQ to base station <NUM> via a PUCCH/PUSCH of network communication link <NUM>.

Sidelink HARQ feedback forwarding, such as provided in flow <NUM> of <FIG>, may have an impact on the existing radio interface (e.g., radio interface between a mobile and the radio access network, referred to as the Uu interface or Uu) network communication link PUCCH/PUSCH transmissions, such as with respect to collision handling and criterion determination. For example, as illustrated in <FIG>, sidelink HARQ may be collided with other uplink signals in the Uu interface (e.g., Uu HARQ and/or other uplink channel information (UCI), such as scheduling requests (SR), channel state information (CSI), etc., in the PUCCH and/or with Uu HARQ and/or other UCI, such as SR, CSI, etc., in the PUSCH). As an example of sidelink HARQ colliding with other uplink signals in the Uu interface, the same time and/or frequency resource (e.g., time slot, channel, resource block, etc.) may be scheduled for UE 315a, operating as the intermediary UE in the sidelink communication link, to both forward sidelink HARQ to base station <NUM> and communicate one or more other uplink signals (e.g., Uu HARQ, SR, CSI, etc.) to base station <NUM>.

Techniques for handling sidelink feedback signaling in situations where collisions would otherwise be experienced in a network communication link are provided according to aspects of the present disclosure. For example, sidelink feedback signaling handling techniques of some implementations provide for collision handling when sidelink HARQ is to be simultaneously transmitted with Uu UCI (e.g., Uu HARQ, SR, CSI, etc.) on one or more Uu channel (e.g., PUCCH, PUSCH, etc.). In operation of sidelink feedback signaling handling according to aspects of the present disclosure, a transmitter or intermediary UE of a sidelink communication link decides whether and how to forward the sidelink HARQ to a corresponding base station.

<FIG> shows a flow diagram implementing techniques for handling sidelink feedback signaling in situations where collisions would otherwise be experienced in a network communication link according to aspects of the present disclosure. The functions of flow <NUM> may, for example, be performed by sidelink feedback signaling logic of a UE (e.g., any of UEs <NUM> of <FIG>) configured for handling sidelink feedback signaling according to aspects of the present disclosure. The sidelink feedback signaling logic may, for example, comprise program code stored in memory accessible to the UE (e.g., memory <NUM> of <FIG>) which when executed by one or more processors of the UE (e.g., a processor of controller/processor <NUM>) operates to provide functions as described herein (e.g., controlling transmit processor with respect to transmission of sidelink feedback signaling).

In the exemplary sidelink feedback signaling handling operation of flow <NUM> in <FIG>, a sidelink feedback signal is received at block <NUM>. For example, a UE operating as an intermediary UE with respect to a sidelink communication link may receive sidelink feedback signaling (e.g., sidelink HARQ) from a corresponding sidelinked UE, such as for forwarding the sidelink feedback signaling to a base station or other network entity.

At block <NUM> of the illustrated example of flow <NUM>, sidelink feedback signaling processing avoiding an impending collision with respect to forwarding the sidelink feedback signaling to a base station over a network communication link and other uplink signaling to the base station over the network communication link is implemented. For example, the intermediary UE may identify an impending collision with respect to forwarding the sidelink feedback signaling and the other uplink signaling communication of the sidelink feedback signaling and other uplink signaling from the intermediary UE, such as due to an overlap in an allocation of at least a time or frequency resource for use by the sidelink feedback signaling and other uplink signaling. Accordingly, the intermediary UE may determine whether and/or how to forward the sidelink feedback signaling to the base station. For example, the intermediary UE may determine to drop the sidelink feedback signaling and to communicate the other uplink signaling to the base station. Similarly, the intermediary UE may determine to drop the other uplink signaling and to communicate the sidelink feedback signaling to the base station. Further detail with respect to operation implementing sidelink feedback signaling handling according to aspects of the present disclosure is provided below with reference to <FIG> and <FIG>. Although specific examples are given in the sidelink feedback signaling handling operation described below in order to aid in understanding the concepts of the present disclosure, it should be appreciated that the examples are non-limiting with respect to the applicability of the concepts here.

<FIG> show operation implementing sidelink feedback signaling handling according to aspects of the present disclosure. In the example of flow <NUM> shown in <FIG>, sidelink feedback signaling comprises sidelink HARQ provided by a sidelinked UE (UE 615b) to a UE (UE 615a) operating as an intermediary in a sidelink communication link with the sidelinked UE, such as for forwarding to a corresponding base station (base station <NUM>). In this exemplary implementation, base station <NUM> may correspond to any of base stations <NUM> shown in <FIG>, such as base stations 105d, 105e, or 105f, UE 615A may correspond to any of UEs <NUM> shown in <FIG> served by base station <NUM> and configured operate as an intermediary UE in sidelink communications, such as UEs 115d, <NUM>, 115i, or <NUM>, and UE 615b may correspond to any of UEs <NUM> shown in <FIG> within communication range of an intermediary UE and configured to operate as a sidelinked UE, such as UE 115c, 115f, 115i, 115j, or <NUM>.

In the exemplary operation of flow <NUM> shown in <FIG>, a sidelink grant may be made by base station <NUM>. With resource allocation mode <NUM>, for example, a dynamic or configured sidelink grant may provide resources for one or multiple sidelink transmissions. The sidelink grant may be communicated by base station <NUM> to UE 615a, which is served by base station <NUM> and configured operate as an intermediary UE in sidelink communications, via a PDCCH of network communication link <NUM>. Network communication link <NUM> may, for example, comprise a Uu network communication link such as network communication link 125d-d of <FIG>. UE 615a, operating as a transmitter intermediary UE in this example, may correspondingly communicate the sidelink grant via a physical sidelink control channel (PSCCH) of sidelink communication link <NUM> to UE 615b, which is within communication range of UE 615a and configured to operate as a sidelinked UE. Sidelink communication link <NUM> may, for example, comprise any of the sidelink communication links of <FIG>, such as sidelink communication links 126c-d, 126i-j, 126j-k, or 126i-k. UE 615a may, in accordance with the sidelink grant, communicate sidelink data (e.g., data sourced by UE 615a and/or data relayed from base station <NUM> by UE 615a) to UE 615b, such as via a physical sidelink shared channel (PSSCH) of sidelink communication link <NUM>. Thereafter, sidelink HARQ feedback (e.g., SL HARQ <NUM>) may be transmitted from UE 615b to UE 615a, such as via a physical sidelink feedback channel (PSFCH) of sidelink communication link <NUM>.

The sidelink HARQ may be intended for forwarding from UE 615a via network communication link <NUM> to base station <NUM>, such as to request one or more retransmission resources. However, UE 615a may itself have one or more other uplink UCI (e.g., Uu HARQ, SR, CSI, etc.) to communicate to base station <NUM> via network communication link <NUM>. For example, as shown in exemplary flow <NUM>, UE 615a may have received a downlink grant from base station <NUM> (e.g., via a PDCCH of network communication link <NUM>) and corresponding downlink data (e.g., via a PDSCH of network communication link <NUM>). Accordingly, UE 615a may have Uu HARQ feedback (e.g., Uu HARQ <NUM>) and/or other uplink signals to be transmitted from UE 615a to base station <NUM>. Where the same time and/or frequency resource (e.g., time slot, channel, resource block, etc.) is scheduled for UE 615a to both forward the sidelink HARQ to base station <NUM> and to communicate the Uu HARQ and/or one or more other uplink signals to base station <NUM>, the sidelink HARQ may be collided with the other uplink signals in the Uu interface.

UE 615a shown in the example of <FIG> is configured to implement a sidelink feedback signaling technique according to aspects of the present disclosure. In particular, UE 615a comprises sidelink feedback signaling logic configured to decide whether and how to forward the sidelink feedback signaling (e.g., SL HARQ <NUM>) to corresponding base station <NUM>. The sidelink feedback signaling logic may, for example, comprise program code stored in memory accessible to the UE (e.g., memory <NUM> of <FIG>) which when executed by one or more processors of the UE (e.g., a processor of controller/processor <NUM>) operates to provide functions as described herein (e.g., controlling transmit processor with respect to transmission of sidelink feedback signaling).

In accordance with example flow <NUM> of <FIG>, sidelink feedback signaling logic of UE 615a implements sidelink feedback signaling processing <NUM> to handle sidelink feedback signaling in situations where collisions would otherwise be experienced in network communication link <NUM>. For example, the sidelink feedback signaling logic may analyze the sidelink feedback signaling, Uu uplink signaling, aspects of network communication resources (e.g., uplink grants, resource block allocations, transmission block utilization, etc.) to identify an impending collision with respect to communication of the sidelink feedback signaling and other uplink signaling. Impending collisions may, for example, comprise identification of an overlap in the allocation of one or more time and/or frequency resources for use by the sidelink feedback signaling and other uplink signaling.

In accordance with some aspects of the present disclosure, when an impending collision with respect to communication of the sidelink feedback signaling and other uplink signaling is identified, sidelink feedback signaling processing <NUM> of the sidelink feedback signaling logic makes a determination regarding handling of the sidelink feedback signaling. For example, when an impending collision with respect to communication of the sidelink feedback signaling and other uplink signaling is identified, sidelink feedback signaling processing <NUM> may determine to drop the sidelink feedback signaling and communicate the other uplink signaling in order to avoid the collision. This operation is illustrated in the example of flow 600b of <FIG> (e.g., Uu HARQ <NUM> is communicated by UE 615a to base station <NUM> via a PUCCH or PUSCH of network communication link <NUM>), as may be invoked by the sidelink feedback signaling logic to follow flow <NUM>. Alternatively, when an impending collision with respect to communication of the sidelink feedback signaling and other uplink signaling is identified, sidelink feedback signaling processing <NUM> may determine to drop the some or all of the other uplink signaling (e.g., that portion of the other uplink signaling that would overlap the sidelink feedback signaling) and communicate the sidelink feedback signaling in order to avoid the collision. This operation is illustrated in the example of flow 600c of <FIG> (e.g., SL HARQ <NUM> is communicated by UE 615a to base station <NUM> via a PUCCH or PUSCH of network communication link <NUM>), as may be invoked by the sidelink feedback signaling logic to follow flow <NUM>.

Determinations with respect to whether to communicate or drop sidelink feedback signaling and/or to communicate or drop other uplink signaling may be variously based according to aspects of the present disclosure. Some implementations may, for example, be configured (e.g., at a time of deployment, when joining a particular network, when establishing a communication link with a particular base station, etc.) to drop sidelink feedback signaling when an impending collision is identified, wherein the determination to communicate or drop signaling is based upon this configuration attribute. Alternatively, some implementations may be configured (e.g., at a time of deployment, when joining a particular network, when establishing a communication link with a particular base station, etc.) to drop other uplink signaling (e.g., Uu HARQ, SR, CSI, etc.) when an impending collision is identified, wherein the determination to communicate or drop signaling is based upon this configuration attribute. Additionally or alternatively, some implementations may base determinations to communicate or drop signaling upon higher layer signaling, such as signaling regarding sidelink feedback signaling handling provided to the UE from the network (e.g., a base station, an access and mobility management function (AMF), etc.). Such higher layer signaling may, for example, provide signaling to configure the UE to drop sidelink feedback signaling when an impending collision is identified, to drop other uplink signaling when an impending collision is identified, to dynamically determine to drop sidelink feedback signaling or other uplink signaling when an impending collision is identified, etc. Some implementations of sidelink feedback signaling handling according to aspects of the present disclosure may, for example, determine to communicate or drop signaling based upon one or more predefined rules (e.g., sidelink feedback signaling rules).

Determinations to communicate or drop signaling based upon one or more predefined rules may utilize various attributes regarding a sidelink communication link, a network communication link, data being communicated, devices transmitting and/or receiving data communication, etc. Examples of the various attributes utilized according to some aspects of the present disclosure include HARQ mode, data priority level, data size, data retransmission attempt, etc., as well as combinations thereof.

As an example of a determination to communicate or drop signaling based upon predefined rules, a sidelink feedback signaling rule may provide for dropping or communicating sidelink feedback signaling when an impending collision is identified based upon a HARQ mode implemented by the sidelinked UE (e.g., UE 615b). For example, sidelink feedback signaling processing <NUM> of the sidelink feedback signaling logic of UE 615a may determine to drop Uu HARQ <NUM> and communicate sidelink HARQ <NUM> (e.g., invoke flow 600c of <FIG>) when an impending collision is identified and UE 615b is operating according to a "NACK-only" HARQ mode. Such a rule facilitates obtaining a retransmission resource from the network for the sidelink data when the sidelinked UE has been unable to recover the data. Sidelink feedback signaling processing <NUM> of the sidelink feedback signaling logic of UE 615a may implement one or more other sidelink feedback signaling rules (e.g., based upon a sidelink communication link, a network communication link, data being communicated, devices transmitting and/or receiving data communication, etc.) when an impending collision is identified and UE 615b is operating according to a "ACK/NACK" HARQ mode. Such rules may, for example, facilitate fairness in obtaining retransmission resources from the network for the sidelink data and Uu data when the intermediary UE and sidelinked UE have been unable to recover data.

In another example of a determination to communicate or drop signaling based upon predefined rules, a sidelink feedback signaling rule may provide for dropping or communicating sidelink feedback signaling when an impending collision is identified based upon a priority determination. For example, data priority, size priority, retransmission priority, etc. may be utilized in determining to communicate or drop signaling according to aspects of the present disclosure.

<FIG> show operation implementing sidelink feedback signaling handling wherein a determination to communicate or drop signaling is based upon a predefined rule utilizing priority information according to aspects of the present disclosure. Similar to the example of <FIG>, in the example of flow <NUM> shown in <FIG> the sidelink feedback signaling comprises sidelink HARQ provided by a sidelinked UE (UE 715b) to a UE (UE 715a) operating as an intermediary in a sidelink communication link with the sidelinked UE, such as for forwarding to a corresponding base station (base station <NUM>). As in the above example, base station <NUM> may correspond to any of base stations <NUM> shown in <FIG>, such as base stations 105d, 105e, or 105f, UE 715A may correspond to any of UEs <NUM> shown in <FIG> served by base station <NUM> and configured operate as an intermediary UE in sidelink communications, such as UEs 115d, <NUM>, 115i, or <NUM>, and UE 715b may correspond to any of UEs <NUM> shown in <FIG> within communication range of an intermediary UE and configured to operate as a sidelinked UE, such as UE 115c, 115f, 115i, 115j, or <NUM>.

UE 715a comprises sidelink feedback signaling logic configured to decide whether and how to forward the sidelink feedback signaling (e.g., SL HARQ <NUM>) to corresponding base station <NUM>. The sidelink feedback signaling logic may, for example, comprise program code stored in memory accessible to the UE (e.g., memory <NUM> of <FIG>) which when executed by one or more processors of the UE (e.g., a processor of controller/processor <NUM>) operates to provide functions as described herein (e.g., controlling transmit processor with respect to transmission of sidelink feedback signaling). The sidelink feedback signaling logic of UE 715a implements sidelink feedback signaling processing <NUM> to handle sidelink feedback signaling in situations where collisions would otherwise be experienced in network communication link <NUM> (e.g., SL HARQ <NUM> may have been transmitted from UE 715b to UE 715a via sidelink communication link <NUM> for forwarding to base station <NUM> via network communication link <NUM> and UE 715a may have Uu HARQ <NUM> and/or other uplink signals to be transmitted from UE 715a to base station <NUM> via network communication link <NUM>).

In accordance with some aspects of the present disclosure, sidelink feedback signaling handling operation according to flow <NUM> may base a determination to communicate or drop signaling upon a predefined rule utilizing data priority. For example, data priority information may be provided with respect to the sidelink data of UE 715b and/or the downlink data of UE 715a. In the illustrated example of flow <NUM>, a transmission block priority level (e.g., TB priority = Xp) may be provided (e.g., from a high layer of the network communication link, such as in indicated by sidelink control information) with respect to the sidelink data corresponding to sidelink HARQ <NUM> and/or a transmission block priority level (e.g., TB priority = Yp) may be provided (e.g., from a high layer of the network communication link, such as in network link configuration information) with respect to downlink data corresponding to Uu HARQ <NUM>. Sidelink feedback signaling processing <NUM> of the sidelink feedback signaling logic of UE 715a may analyze such transmission block priority level information to determine whether to drop Uu HARQ <NUM> and communicate sidelink HARQ <NUM> or to drop sidelink HARQ <NUM> and communicate Uu HARQ <NUM>. For example, if it is determined that the transmission block priority level (Yp) of the downlink data corresponding to Uu HARQ <NUM> is greater than the transmission block priority level (Xp) of the sidelink data corresponding to sidelink HARQ <NUM> (Yp > Xp), sidelink feedback signaling processing <NUM> may determine that sidelink HARQ <NUM> is to be dropped and Uu HARQ <NUM> is to be communicated (e.g., invoke flow 700b of <FIG>). However, if it is determined that the transmission block priority level (Xp) of the sidelink data corresponding to sidelink HARQ <NUM> is greater than or equal to the transmission block priority level (Yp) of the downlink data corresponding to Uu HARQ <NUM> (Xp ≥ Yp), sidelink feedback signaling processing <NUM> may determine that Uu HARQ <NUM> is to be dropped and sidelink HARQ <NUM> is to be communicated (e.g., invoke flow 700c of <FIG>). If the reported HARQ is for multiple transmission blocks, the priority may be defined based on the minimal or maximum or average priority for the transmission blocks. Data priority based rules may, for example, facilitate obtaining retransmission resources from the network for data having a higher priority when the intermediary UE and sidelinked UE have been unable to recover data.

Additionally or alternatively, sidelink feedback signaling handling operation according to flow <NUM> may base a determination to communicate or drop signaling upon a predefined rule utilizing size priority. For example, transmission block size information may be obtained for the sidelink data of UE 715b and/or the downlink data of UE 715a. In the illustrated example of flow <NUM>, a transmission block size (e.g., TB size = Xs) may be determined (e.g., from analyzing the sidelink data block size, from a transmission block size configured with respect to the sidelink, etc.) with respect to the sidelink data corresponding to sidelink HARQ <NUM> and/or a transmission block size (e.g., TB size = Ys) may be determined (e.g., from analyzing the downlink data block size, from a transmission block size configured with respect to the downlink, etc.) with respect to downlink data corresponding to Uu HARQ <NUM>. Sidelink feedback signaling processing <NUM> of the sidelink feedback signaling logic of UE 715a may analyze such transmission block size information in combination with a transmission block size rule establishing sized-based priority to determine whether to drop Uu HARQ <NUM> and communicate sidelink HARQ <NUM> or to drop sidelink HARQ <NUM> and communicate Uu HARQ <NUM>. For example, if it is determined that the transmission block size (Ys) of the downlink data corresponding to Uu HARQ <NUM> is greater than the transmission block size (Xs) of the sidelink data corresponding to sidelink HARQ <NUM> (Ys > Xs), sidelink feedback signaling processing <NUM> may determine that sidelink HARQ <NUM> is to be dropped and Uu HARQ <NUM> is to be communicated (e.g., invoke flow 700B of <FIG>). However, if it is determined that the transmission block size (Xs) of the sidelink data corresponding to sidelink HARQ <NUM> is greater than or equal to the transmission block size (Ys) of the downlink data corresponding to Uu HARQ <NUM> (Xs ≥ Ys), sidelink feedback signaling processing <NUM> may determine that Uu HARQ <NUM> is to be dropped and sidelink HARQ <NUM> is to be communicated (e.g., invoke flow 700c of <FIG>). If the feedback signaling corresponds to multiple transmission blocks, the transmission block size may be the maximum transmission block or sum of all transmission blocks indicated by this feedback signaling. Size priority based rules may, for example, facilitate obtaining retransmission resources from the network for the larger portions of unrecovered data when the intermediary UE and sidelinked UE have been unable to recover data.

Further, sidelink feedback signaling handling operation according to flow <NUM> may additionally or alternatively base a determination to communicate or drop signaling upon a predefined rule utilizing retransmission priority. For example, retransmission data information (e.g., a number of times data retransmission has been requested or attempted) may be obtained for the sidelink data of UE 715b and/or the downlink data of UE 715a. In the illustrated example of flow <NUM>, a retransmission index value (e.g., retransmission index = Xr) may be determined (e.g., from analyzing the number of retransmission attempts made with respect to the sidelink data, from a retransmission index of a previous transmission block of the sidelink, etc.) with respect to the sidelink data corresponding to sidelink HARQ <NUM> and/or a retransmission index value (e.g., retransmission index = Yr) may be determined (e.g., from analyzing the number of retransmission attempts made with respect to the downlink data, from a retransmission index of a previous transmission block of the downlink, etc.) with respect to downlink data corresponding to Uu HARQ <NUM>. Sidelink feedback signaling processing <NUM> of the sidelink feedback signaling logic of UE 715a may analyze such retransmission information in combination with a rule establishing retransmission priority to determine whether to drop Uu HARQ <NUM> and communicate sidelink HARQ <NUM> or to drop sidelink HARQ <NUM> and communicate Uu HARQ <NUM>. For example, if it is determined that the retransmission index value (Yr) of the downlink data corresponding to Uu HARQ <NUM> is greater than the retransmission index value (Xr) of the sidelink data corresponding to sidelink HARQ <NUM> (Yr > Xr), sidelink feedback signaling processing <NUM> may determine that sidelink HARQ <NUM> is to be dropped and Uu HARQ <NUM> is to be communicated (e.g., invoke flow 700B of <FIG>). However, if it is determined that the retransmission index value (Xr) of the sidelink data corresponding to sidelink HARQ <NUM> is greater than or equal to the retransmission index value (Yr) of the downlink data corresponding to Uu HARQ <NUM> (Xr ≥ Yr), sidelink feedback signaling processing <NUM> may determine that Uu HARQ <NUM> is to be dropped and sidelink HARQ <NUM> is to be communicated (e.g., invoke flow 700c of <FIG>). If the feedback signaling corresponds to multiple transmission blocks, the retransmission information of all transmission blocks indicated by this feedback signaling may be averaged. Retransmission priority based rules may, for example, facilitate obtaining retransmission resources from the network for unrecovered data which has experienced the greatest difficulty in reaching the intended UE when the intermediary UE and sidelinked UE have been unable to recover data (e.g., transmission blocks with more retransmission times may be given higher priority to request retransmission resource).

Various of the determinations regarding communicating or dropping signaling in sidelink feedback signaling handling operation may be used in combination according to aspects of the present disclosure. For example, combinations of data priority, size priority, and/or retransmission priority rules may be implemented by sidelink feedback signaling logic. As a specific example, where data priority information provides a same priority level (or is not provided) with respect to the sidelink data and the downlink data, one or more size priority information and/or retransmission priority information may be analyzed in determining to communicate or drop signaling feedback.

Although examples have been discussed with respect to impending collisions between sidelink HARQ and Uu HARQ, sidelink feedback signaling handling operation according to aspects of the present disclosure is applicable with respect to Uu signaling in addition to Uu HARQ. For example, sidelink feedback signaling processing <NUM> of the sidelink feedback signaling logic of UE 715a may provide for dropping or communicating sidelink feedback signaling when an impending collision is identified based upon a priority determination using UCI content information. In operation according to some aspects of the present disclosure, a predefined rule utilizing priority information may establish signaling feedback priority such that SR is communicated and sidelink HARQ dropped, whereas sidelink HARQ is communicated and UCI other than SR is dropped, perhaps combined with one or more of the above rules regarding determinations as between sidelink HARQ and Uu HARQ for use when UCI includes Uu HARQ (e.g., SR > SL HARQ > UCI other than SR/HARQ). As another example, in operation according to some aspects of the present disclosure, a predefined rule utilizing priority information may establish signaling feedback priority such that sidelink HARQ is communicated and SR is dropped, whereas SR is communicated SR is communicated and UCI other than sidelink HARQ is dropped, perhaps combined with one or more of the above rules regarding determinations as between sidelink HARQ and Uu HARQ for use when UCI includes Uu HARQ (e.g., SL HARQ > SR > UCI other than SR/HARQ). As yet another example, in operation according to some aspects of the present disclosure, a predefined rule utilizing priority information may establish signaling feedback priority such that Uu UCI is communicated and sidelink HARQ is dropped (e.g., Uu UCI > SL HARQ).

<FIG> is a block diagram illustrating example blocks executed to implement aspects of the present disclosure. UE <NUM> of <FIG> includes the structure, hardware, and components as illustrated for UE <NUM> of <FIG>, and thus is described with respect to UE <NUM> as illustrated in <FIG>. For example, UE <NUM> includes controller/processor <NUM>, which operates to execute logic or computer instructions stored in memory <NUM>, as well as controlling the components of UE <NUM> that provide the features and functionality of UE <NUM>. In accordance with aspects of the present disclosure, controller/processor <NUM> executes logic of sidelink feedback signaling logic <NUM>, possibly using one or more predefined rules of sidelink feedback signaling rules <NUM>, to provide sidelink feedback signaling handling operation as described above. UE <NUM>, under control of controller/processor <NUM>, transmits and receives signals (e.g., the above mentioned sidelink feedback signaling and/or other uplink signaling) via wireless radios 800a-r and antennas 252a-r. Wireless radios 800a-r include various components and hardware, as illustrated in <FIG> for UE <NUM>, including modulator/demodulators 254a-r, MIMO detector <NUM>, receive processor <NUM>, transmit processor <NUM>, and TX MIMO processor <NUM>.

The functional blocks and modules described herein (e.g., the functional blocks and modules in <FIG> and <FIG>) may comprise processors, electronics devices, hardware devices, electronics components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof. In addition, features discussed herein relating to handling sidelink feedback signaling may be implemented via specialized processor circuitry, via executable instructions, and/or combinations thereof.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps (e.g., the logical blocks in <FIG>, <FIG>, and <FIG>) described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both.

Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), hard disk, solid state disk, and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

Claim 1:
A method (<NUM>) of wireless communication, comprising:
receiving (<NUM>), by a user equipment, UE, operating as a transmitter UE of a sidelink communication link, a sidelink feedback signal from a UE operating as a receiver UE of the sidelink communication link; and
implementing (<NUM>), by the transmitter UE, sidelink feedback signaling processing for avoiding an impending collision with respect to forwarding the sidelink feedback signaling to a base station over a network communication link and other uplink signaling to the base station over the network communication link, wherein the implementing sidelink feedback signaling processing comprises:
determining to drop or communicate the sidelink feedback signaling based at least in part on a sidelink data retransmission priority of the sidelink transmission.