Method and apparatus for memory usage of auxiliary user equipment during sidelink retransmission

Abstract

Disclosed herein are apparatus, methods, and computer-readable media for facilitating use of a memory of an assistive UE during a sidelink retransmission. An example method for wireless communication at a first user equipment (UE) includes receiving a first packet and a second packet from a wireless device for sidelink retransmission to at least one second UE, the second packet being received after the first packet. The example method also includes discarding the first packet or the second packet before retransmission based on at least one of a packet priority or an indication from the wireless device.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Patent Application No. 16 / 844,823, filed on April 9, 2020, entitled “METHODS AND APPARATUS FOR MEMORYUSAGE OF HELPING USER EQUIPMENT DURING SIDELINK RETRANSMISSION,” which is expressly incorporated herein by reference in its entirety.

[0003] background Technical Field

[0005] The present disclosure relates generally to communication systems and, more particularly, to wireless communications including sidelink retransmissions.

[0006] introduction

[0007] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0008] These multiple access technologies have been adopted in various telecommunication standards to provide common protocols that enable different wireless devices to communicate at city, country, region, and even global levels. An example telecommunication standard is 5G New Radio (NR). 5G NR is a part of the continuous mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)) and other requirements. 5GNR includes services associated with enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low latency communication (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. Various aspects of wireless communication may include direct communication between devices, such as in V2X, V2V, and / or D2D communications. There is a need for further improvements in 5G NR technology (including V2X, V2V, and / or D2D technology). These improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies.

[0009] Overview

[0010] A brief summary of one or more aspects is given below to provide a basic understanding of such aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be presented later.

[0011] In one aspect of the present disclosure, a method, computer-readable medium, and apparatus for wireless communication at a first user equipment (UE) are provided. An example apparatus receives a first packet and a second packet from a wireless device for sidelink retransmission to at least one second UE, the second packet being received after the first packet. The apparatus then discards the first packet or the second packet before retransmission based on at least one of a packet priority or an indication from the wireless device.

[0012] In another aspect of the present disclosure, a method, computer-readable medium, and apparatus for wireless communication at a wireless device are provided, the wireless device including a base station or a programmable logic controller (PLC). An example apparatus transmits a first packet and a second packet to a first UE for sidelink retransmission to at least one additional UE, the second packet being transmitted after the first packet. Then, the apparatus transmits an indication to the first UE to discard the first packet or the second packet.

[0013] To achieve the foregoing and related ends, the one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and drawings set forth in detail certain illustrative features of the one or more aspects. However, these features are merely indicative of several of the various ways in which the principles of the various aspects may be employed, and this description is intended to cover all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0016] Figure 2 Various example aspects of a sidelink slot structure are illustrated.

[0017] Figure 3 is a diagram illustrating an example of a base station and a UE in an access network.

[0018] Figure 4 An example of sidelink transmission is illustrated.

[0019] Figure 5 An example wireless communication system including a base station, a PLC, and sensor / actuator(s) is illustrated.

[0020] Fig. 6A and Figure 6B Example aspects of a wireless communication system including a base station, PLC(s), and sensors / actuators are illustrated.

[0021] Fig. 7A and Figure 7B Example aspects of a wireless communication system including a base station, PLC(s), and sensors / actuators are illustrated.

[0022] Figure 8 Example aspects of a wireless communication system including a wireless device and a UE are illustrated.

[0023] Fig. 9 An example communication flow between devices communicating based on sidelink communications is illustrated.

[0024] Fig.10 is a flow chart of a wireless communication method.

[0025] Fig.11 is a conceptual data flow diagram illustrating the flow of data between different devices / components in an example apparatus.

[0026] Fig.12 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

[0027] Fig.13 is a flow chart of a wireless communication method.

[0028] Fig.14 is a conceptual data flow diagram illustrating the flow of data between different devices / components in an example apparatus.

[0029] Fig.15 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

[0030] Detailed Description

[0031] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. This detailed description includes specific details to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid diluting such concepts.

[0032] Some wireless communications may be performed in conjunction with, for example, factory automation, and may include communications based on the Industrial IoT (IIoT). Certain equipment may include a sensor, an actuator, a piece of industrial equipment, and the like. A programmable logic controller (PLC) may receive information from such sensor / actuator(s), and may provide commands to the sensor / actuator(s) or to factory equipment associated with the sensor / actuator(s). For example, a PLC may automatically control machines and control systems in industrial electromechanical processes, such as controlling machines on a factory assembly line, rides, lamps, and the like. Communications between wireless devices (such as base stations and / or PLCs) and sensors / actuators may have low latency requirements and high reliability requirements. For example, there may be a latency requirement of less than 2 ms or less than 1 ms for the communication. Additionally or alternatively, there may be a latency requirement of 10 ms for the communication. -5 or 10 -6 Reliability requirements of the order of 99.9999% reliability. Latency and reliability may apply to data channels and / or control channels.

[0033] Various aspects of the present disclosure help improve reliability by utilizing a side link to retransmit an obstructed transmission between a wireless device (such as a base station and / or PLC) and a target IIOT device (such as a sensor, an actuator, a piece of industrial equipment, etc.). For example, a wireless device may transmit a first data transmission to a target IIOT device, and may receive feedback indicating data to be retransmitted to the target IIOT device. The wireless device may transmit the data to a helper IIOT device, and the helper IIOT device may retransmit the data to the target IIOT device.

[0034] However, the helper IIOT device may have limited memory storage capacity and may not be able to store all the data received for retransmission. Various aspects of the present disclosure help improve reliability by adopting a technique that utilizes the memory storage capacity of the helper IIOT device when retransmitting using a side link. For example, when the helper IIOT device receives a new packet for retransmission, the helper IIOT device may determine whether to discard the stored packet or the new packet based on the priority of the stored packet and the new packet. In some examples, the helper IIOT device may receive an indication of which packet to discard from the wireless device. In some examples, the helper IIOT device may provide memory storage capacity information to the wireless device. The wireless device may then determine whether to transmit the new packet to the helper IIOT device based on the memory storage capacity information. Additionally or alternatively, the wireless device may use the memory storage capacity information to determine whether to include the helper IIOT device as a helper IIOT device for side link retransmission to the target IIOT device. The reliability of communication between the wireless device and the target IIOT device can be improved by utilizing the memory storage capacity of the helper IIOT device retransmission.

[0035] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0036] As an example, an element, or any part of an element, or any combination of elements may be implemented as a "processing system" including one or more processors. Examples of processors include: microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuits, and other suitable hardware configured to perform various functionalities described throughout this disclosure. One or more processors in a processing system may execute software. Software should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether it is described in software, firmware, middleware, microcode, hardware description languages, or other terms.

[0037] Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, each function may be stored or encoded as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media. Storage media may be any available medium that can be accessed by a computer. As an example and not limitation, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, a combination of the aforementioned types of computer-readable media, or any other medium that can be used to store instructions or data structures in the form of computer executable code that can be accessed by a computer.

[0038] As used herein, the term "computer-readable medium" is expressly defined to include any type of computer-readable storage device and / or storage disk, and to exclude propagating signals and transmission media. As used herein, "computer-readable medium," "machine-readable medium," "computer-readable memory," and "machine-readable memory" are used interchangeably.

[0039] Figure 1 1 is a diagram illustrating an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). A macro cell includes a base station. A small cell includes a femto cell, a pico cell, and a micro cell.

[0040] The base station 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). The base station 102 configured for 5G NR (collectively referred to as the Next Generation RAN (NG-RAN)) can interface with the core network 190 via a second backhaul link 184. Among other functions, the base station 102 can also perform one or more of the following functions: delivery of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracking, RAN information management (RIM), paging, positioning, and delivery of alert messages. The base stations 102 may communicate with each other directly or indirectly (eg, through the EPC 160 or the core network 190) over a third backhaul link 134 (eg, an X2 interface). The third backhaul link 134 may be wired or wireless.

[0041] Base stations 102 may communicate wirelessly with UEs 104. Each base station 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102' may have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network that includes both small cells and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include a home evolved Node B (eNB) (HeNB), which may provide services to a restricted group referred to as a closed subscriber group (CSG). A communication link 120 between a base station 102 and a UE 104 may include an uplink (UL) (also referred to as a reverse link) transmission from the UE 104 to the base station 102 and / or a downlink (DL) (also referred to as a forward link) transmission from the base station 102 to the UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. These communication links may be over one or more carriers. For each carrier allocated in a carrier aggregation of up to Yx MHz (x component carriers) for transmission in each direction, the base station 102 / UE 104 may use a spectrum of up to Y MHz (e.g., 5, 10, 15, 20, 100, 400 MHz, etc.) bandwidth. These carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL compared to UL). The component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

[0042] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through a variety of wireless D2D communication systems, such as, for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0043] The wireless communication system may further include a Wi-Fi access point (AP) 150 in communication with a Wi-Fi station (STA) 152 via a communication link 154 in the 5 GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) to determine whether the channel is available prior to communication.

[0044] The small cell 102' may operate in a licensed and / or unlicensed spectrum. When operating in an unlicensed spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed spectrum as used by the Wi-Fi AP 150. The small cell 102' employing NR in the unlicensed spectrum may boost the coverage of the access network and / or increase the capacity of the access network.

[0045] Whether it is a small cell 102' or a large cell (e.g., a macro base station), the base station 102 may include and / or be referred to as an eNB, a gB node (gNB), or another type of base station. Some base stations 180 (such as gNBs) may operate in traditional sub-6 GHz spectrum, millimeter wave (mmW) frequencies, and / or near mmW frequencies to communicate with UE 104. When the base station 180 operates at mmW or near mmW frequencies, the base station 180 may be referred to as a mmW base station. Extremely high frequency (EHF) is part of the radio frequency (RF) in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 mm and 10 mm. The radio waves in this band may be referred to as millimeter waves. Near mmW can be extended down to 3 GHz frequencies with a wavelength of 100 mm. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, which is also referred to as centimeter waves. Communications using mmW / near mmW radio frequency bands (e.g., 3 GHz–300 GHz) have extremely high path loss and short range. A mmW base station (eg, base station 180) may utilize beamforming 182 with UE 104 to compensate for extremely high path loss and short range. Base station 180 and UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays to facilitate beamforming.

[0046] The electromagnetic spectrum is often subdivided into different categories, bands, channels, etc. based on frequency / wavelength by different authors or entities. For example, in 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410MHz-7125 MHz) and FR2 (24250MHz–52600MHz). Although a portion of FR1 is greater than 6GHz (>6000MHz), FR1 is often (interchangeably) referred to as the sub-6GHz band in various documents and articles on the subject of 5G NR. Similar naming issues sometimes arise in various documents and articles on the subject of 5G NR regarding FR2. Although a portion of FR2 is less than 30GHz (<30000MHz), FR2 is often (interchangeably) referred to as the millimeter wave band. However, some authors / entities prefer to define wireless signals with wavelengths between 1-10 mm as falling within the millimeter wave band (30GHz–300GHz).

[0047] With the above examples in mind, unless specifically stated otherwise, it should be understood that the term "sub-6 GHz," if used as an example herein, may refer to all or a portion of FR1 for 5G NR. Additionally, unless specifically stated otherwise, it should be understood that the term "millimeter wave," as used as an example herein, may refer to all or a portion of FR2 for 5G NR and / or all or a portion of the 30 GHz-300 GHz band. It should also be understood that the terms "sub-6 GHz" and "millimeter wave" are intended to represent modifications to such example frequency bands that may occur (which may affect an author / entity's decision regarding wireless communications), for example, as given by example herein.

[0048] It should be understood that the above examples are not necessarily intended to limit the claimed subject matter. For example, unless specifically stated, the claimed subject matter related to wireless communications is not necessarily intended to be limited to frequency bands defined by any particular author / entity, etc.

[0049] Base station 180 may transmit beamformed signals to UE 104 in one or more transmit directions 182'. UE 104 may receive beamformed signals from base station 180 in one or more receive directions 182". UE 104 may also transmit beamformed signals to base station 180 in one or more transmit directions. Base station 180 may receive beamformed signals from UE 104 in one or more receive directions. Base station 180 / UE 104 may perform beam training to measure and select a receive direction and a transmit direction for each of base station 180 / UE 104. The transmit direction and the receive direction of base station 180 may be the same or may be different. The transmit direction and the receive direction of UE 104 may be the same or may be different.

[0050] The EPC 160 may include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 may be in communication with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. In general, the MME 162 provides bearer and connection management. User Internet Protocol (IP) packets are delivered through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The PDN gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area broadcasting a specific service, and may be responsible for session management (start / stop) and for collecting eMBMS related charging information.

[0051] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may be in communication with a unified data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. In general, the AMF 192 provides QoS flow and session management. User Internet Protocol (IP) packets are delivered through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, and / or other IP services.

[0052] A base station may include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmission reception point (TRP), or some other suitable term. Base station 102 provides an access point to EPC 160 or core network 190 for UE 104. Examples of UE 104 include a cellular phone, a smart phone, a Session Initiation Protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet device, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a health care device, an implant, a sensor / actuator, a display, or any other similar functional device. Some UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, ovens, vehicles, heart monitors, etc.). UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0053] Some wireless communications may be performed in conjunction with, for example, factory automation, and may include IIoT-based communications. Certain equipment may include a sensor, an actuator, a piece of industrial equipment, and the like. The PLC 145 may receive information from such sensor / actuator(s) 143, and may provide commands to the sensor / actuator(s) 143 or to factory equipment associated with the sensor / actuator(s) 143. For example, a PLC may automatically control machines and control systems in an industrial electromechanical process, such as controlling machines on a factory assembly line, amusement rides, lamps, and the like. In some aspects, the PLC 145 may transmit data (uplink data or sidelink data) to the sensor / actuator(s) 143.

[0054] Refer again Figure 1 In certain aspects, an IIOT device (such as sensor / actuator(s) 143) (and generally referred to herein as UE 104) may be configured to manage one or more aspects of wireless communication via a packet discard policy when one or more packets for sidelink retransmissions may be discarded due to memory storage capacity of the IIOT device. As an example, in Figure 1, UE 104 / (s) sensor / actuator 143 may include a packet discarding component 198 configured to receive a first packet and a second packet from a wireless device for sidelink retransmission to at least one second UE (e.g., sensor / actuator 144), the second packet being received after the first packet. The packet discarding component 198 may also be configured to discard the first packet or the second packet before retransmission based on at least one of a packet priority or an indication from the wireless device.

[0055] Another reference Figure 1 In certain aspects, the base station 180 / PLC 145 (generally referred to herein as a wireless device) may be configured to manage one or more aspects of wireless communication via a packet discard policy when one or more packets for sidelink retransmission may be discarded by a helper UE (e.g., sensor / actuator 143) due to the memory storage capacity of the helper UE. As an example, in Figure 1 , the base station 180 / PLC 145 may include an indication component 199 configured to transmit a first packet and a second packet to a first UE (e.g., sensor / actuator 143) for sidelink retransmission to at least one additional UE (e.g., sensor / actuator 144), the second packet being transmitted after the first packet. The indication component 199 may also be configured to transmit an indication to the first UE (e.g., sensor / actuator 143) to discard the first packet or the second packet.

[0056] Although the following description provides examples involving sidelink communications in an IIOT environment, the concepts described herein may be applicable to uplink communications and / or downlink communications and / or environments where sidelink communications may be beneficial. Aspects of the communications may be based on PC5 or sidelink communications, for example, as combined with Figure 2 Furthermore, while the following description provides examples involving 5G NR, the concepts described herein may be applicable to other similar areas such as LTE, LTE-A, CDMA, GSM, and / or other wireless technologies where the memory storage capacity of the helper UE may limit the number of packets that can be stored at the helper UE for retransmission.

[0057] Figure 2 An example diagram 200 illustrating a sidelink subframe within a frame structure that may be used for sidelink communications (eg, between UEs 104, between a UE and infrastructure, between a UE and an RSU, etc.) is illustrated. Figure 1This is only one example of a potential frame structure, and the various aspects presented herein may also be applied to other frame structures. In some examples, the frame structure may be based on an LTE frame structure. In some examples, the time slot structure may be based on a 5G NR frame structure. For example, the concepts described herein may be applicable to other similar fields, such as 5G NR, LTE, LTE-A, CDMA, GSM, and other wireless technologies. Figure 2 The example in is only an example, and other wireless communication technologies may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 equally sized subframes (1ms). Each subframe may include two time slots. Each time slot may include 7 SC-FDMA symbols. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. Although diagram 200 illustrates a single RB subframe, sidelink communications may include multiple RBs.

[0058] A resource grid may be used to represent the frame structure. Each time slot may include a resource block (RB) (also called a physical RB (PRB)) extending over 12 consecutive subcarriers. The resource grid is divided into a number of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme. Figure 2 As explained in , some REs may include reference signals, such as demodulation RS (DMRS). At least one codeword may be used for feedback, as described herein. Codewords before and / or after the feedback may be used to switch between data reception and feedback transmission. Another codeword (for example, at the end of a subframe) may be used as a protection codeword that does not need to be transmitted / received. This protection enables the device to switch from operating as a transmitting device to preparing to operate as a receiving device (for example, in a subsequent subframe). As explained, data or control may be transmitted in the remaining REs. For example, data may be carried in the PSSCH, and control information may be carried in the PSCCH. The control information may include SCI. The location of any of the reference signals, control, and data may be related to Figure 2 The examples explained in are different.

[0059] Figure 3300 is a block diagram of a first device 310 configured for wireless communication with a second device 350. Devices 310 and 350 may be configured to transmit and / or receive V2X or other D2D communications. The communication may be based on, for example, a side link and may be exchanged using a PC5 interface. Device 310 may include a UE, an RSU, or another wireless device that communicates using V2X or D2D. The receiving device may include a UE, an RSU, or another wireless device that communicates using V2X or D2D. Packets may be provided to a controller / processor 375 that implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a media access control (MAC) layer.

[0060] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) coding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 handles the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The decoded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. Channel estimates from channel estimator 374 can be used to determine coding and modulation schemes and for spatial processing. The channel estimates can be derived from reference signals and / or channel condition feedback transmitted by device 350. Each spatial stream can then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX can modulate an RF carrier with a corresponding spatial stream for transmission.

[0061] At the device 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for the device 350. If there are multiple spatial streams destined for the device 350, they can be combined into a single OFDM symbol stream by the RX processor 356. The RX processor 356 then transforms the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signal, are recovered and demodulated by determining the signal constellation point most likely transmitted by the device 310. These soft decisions can be based on the channel estimates calculated by the channel estimator 358. These soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted on the physical channel by device 310. These data and control signals are then provided to controller / processor 359 which implements layer 3 and layer 2 functionality.

[0062] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. The controller / processor 359 may provide demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport and logical channels. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0063] Similar to the functionality described in conjunction with transmissions performed by device 310, the controller / processor 359 may provide RRC layer functionality associated with system information (e.g., MIB, SIB) capture, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression, and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with delivery of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0064] Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the device 310 may be used by a TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0065] The transmission is processed at device 310 in a manner similar to that described in conjunction with the receiver functionality at device 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers the information modulated onto the RF carrier and provides the information to a RX processor 370.

[0066] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. The controller / processor 375 provides demultiplexing, packet reassembly, decryption, header decompression, control signal processing between transport and logical channels. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0067] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform operations related to Figure 1 The packet discard component 198 combines various aspects.

[0068] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform operations related to Figure 1 The indicative component 199 combines various aspects.

[0069] Figure 4 An example diagram 400 illustrates sidelink communications. Figure 4 The concept of using subframes is illustrated, but these aspects can be similarly applied to communications based on slots or other timing information.The transmission includes sidelink control information (SCI) 402 and data 404. Figure 4The example in illustrates SCI 402 and data 404 in adjacent frequency resources. This is merely an example of the concept of illustrating a transmission including data and SCI. In other examples, SCI 402 and data 404 may be transmitted alternatively in non-adjacent frequency resources. SCI 402 may be transmitted in PSCCH, and data 404 may be transmitted in PSSCH. As illustrated by arrow 403, SCI 402 includes information about data transmission 404 that enables a receiving device to receive data 404, such as MCS information, frequency resources and / or time resources for transmitting the data, whether the data is in an initial transmission or a retransmission, and the like. In some examples, a transmission (e.g., data 404) may be an initial transmission. In some examples, a transmission (e.g., data 404) may be a retransmission of a previous initial transmission. In an example in which a transmission is a retransmission, SCI 402 may indicate resources for the retransmission.

[0070] In some examples, the transmission may be based on the SPS, and the transmission may indicate a subsequent transmission period (e.g., 20 subframes, 50 subframes, 100 subframes, 200 subframes, 1000 subframes, etc.) before the next transmission.

[0071] SCI 402 may carry information about the time and / or frequency of resources used for subsequent transmissions. As illustrated, SCI 402 may carry information about the time gap (e.g., subframe gap) between the two transmissions, information about the frequency resources (e.g., starting subchannel) used for the second transmission.

[0072] Wireless communication can be based on IIoT. Such communication can include communication between a base station and one or more UEs and / or between a PLC and one or more UEs. In some examples, communications can be exchanged between a PLC and sensors, actuators, etc. The PLC can provide commands to factory equipment in wireless signals. (All) sensors / actuators can be separated from factory equipment and / or can be included in or located at a piece of factory equipment. (All) PLCs can automate the control of machines and control systems for, for example, industrial electromechanical processes, such as control of machinery, amusement facilities, lighting devices, etc. on a factory assembly line. Figure 5 An example communication system 500 is illustrated that includes a PLC 502 exchanging wireless communications 520 with sensors / actuators 506 that may be associated with equipment. Communications may also include a base station 503 exchanging communications 522 with the PLC 502 and / or exchanging communications 522 with the sensors / actuators 506.

[0073] A wirelessly connected PLC can be positioned closer to factory equipment. For example, the PLC can be positioned close to a machine, while the base station can be mounted on the ceiling or at a greater distance from the equipment. Fig. 6A and 6B Communication systems 600 and 650 are illustrated that include one or more PLCs, multiple sensors / actuators, and a base station.

[0074] exist Fig. 6A In the embodiment, the communication system 600 includes a PLC 602, a plurality of sensors / actuators 606a, 606b, and a base station 603. As illustrated, the link between the base station 603 and the PLC can be based on a Uu interface. The link between the base station 603 and the sensors / actuators 606a, 606b can also be based on a Uu interface. The link between the PLC 602 and the sensors / actuators 606a, 606b can be based on a PC5 interface. Fig. 6A The PLC 602 in the UE may operate similarly to a UE or as a sidelink device. Fig. 6A The PLC 602 in may use the base station 603 for inter-PLC coordination with other PLCs. Fig. 6A The PLC 602 in may use the base station 603 for backhaul to a human machine interface (HMI). Fig. 6A The PLC 602 in the UE may use the base station 603 as a system controller. The base station 603 may perform interference management (IM) across multiple PLCs 602. The base station 603 may handle other network functions for the sensors / actuators 606a and 606b, such as initial access to the network, mobility, etc. Fig. 6A The sensors / actuators 606a and 606b of the PLC 602 communicate with the PLC 602 based on the side link and communicate with the base station 603 based on the uplink / downlink, so the sensors / actuators 606a and 606b support both the Uu-based communication and the PC5-based communication. Since the PLC 602 communicates with the sensors / actuators 606a and 606b based on the side link and communicates with the base station 603 based on the uplink / downlink, the PLC 602 supports both the Uu-based communication and the PC5-based communication.

[0075] In some examples, PLC 602 can operate similarly to a small cell or relay node with a wireless backhaul to base station 603. Figure 6BIn the embodiment, the communication system 650 includes a first PLC 602a and a second PLC 602b, a plurality of sensors / actuators 606a, 606b, 606c, 606d and a base station 603. As illustrated, the link between the base station 603 and the PLC 602 can be based on a Uu interface. The link between the base station 603 and the sensors / actuators 606a, 606b, 606c, 606d can be based on a Uu interface. The sensors / actuators 606a, 606b, 606c, 606d can interact with their respective PLCs 602a, 602b based on the Uu interface. The PLCs 602a, 602b can use the base station 603 for inter-PLC coordination between the PLCs 602a, 602b, for backhaul to the HMI, for system controllers, etc. The PLCs 602a, 602b can include aspects of an integrated access and backhaul (IAB) framework. Each of the PLCs 602 may operate based on a dual role. Each of the PLCs 602 may include a mobile terminal (MT) component 605, for example, which operates similarly to a UE when receiving control / data from a base station 603. Each of the PLCs 602 may include a distributed unit (DU) component 607, which schedules resources to communicate with their respective sensors / actuators 606a, 606b, 606c, 606d and provides downlink communications to their respective sensors / actuators 606a, 606b, 606c, 606d.

[0076] Control of transmission by base station 603 can help improve reliability. Such control of base station 603 can involve two hops to provide control to the sensor / actuator (e.g., a first hop from the PLC to the base station and a second hop from the base station to the sensor / actuator). In some examples, a portion of the scheduling for sensors / actuators 606a, 606b may be provided by base station 603, while another portion of the scheduling for sensors / actuators 606a, 606b may be provided by PLC 602. Providing some control directly from PLC can help reduce air signaling and can improve latency. However, for a particular sensor / actuator, transmission from PLC 602 may be blocked (e.g., due to the presence of physical objects in the environment of PLC 602, base station 602 and / or sensor / actuator 606). Link blocking between a wireless device (such as PLC 602 and / or base station 603) and each sensor / actuator 606 can last for different amounts of time.

[0077] Fig. 7A and 7B 1 and 2 illustrate examples of wireless communication systems 700 and 750, respectively, according to aspects of the present disclosure. The wireless communication system 700 includes a base station 702 and a UE 704. Aspects of the UE 704 may be implemented by Figure 5The sensor / actuator(s) 504, 506 and / or Fig. 6A and 6B The communication link 706 of the base station 702 and the UE 704 can be realized by the sensor / actuator 606. In the illustrated example, the base station 702 can establish a corresponding communication link 706 with the UE 704.

[0078] Due to problems such as blocking or fading, the communication link 706a between the base station 702 and the first (or target) UE 704a may be degraded, failed, or dropped. Accordingly, the base station 702 may utilize a sidelink channel (e.g., sidelink channel 708) to communicate with the target UE 704a. Fig. 7A In the illustrated example of , the base station 702 may determine that the second UE 704b is in the assistor UE group to facilitate communication between the base station 702 and the target UE 704a. Fig. 7A In the example, the second UE 704b helps or assists the target UE 704a by forwarding or retransmitting data received from the base station 702 to the target UE 704a via the side link 708.

[0079] In some examples, in order to facilitate communication between the base station 702 and the target UE 704a, the base station 702 may transmit a control message to one or more UEs near the target UE 704a to request one or more reports. For example, the base station 702 may transmit a control message to the second UE 704b and the third UE 706b to request the corresponding UE 704b, 704c to report various information to the base station 702, such as side link measurements, UE capability information, etc. In some examples, the UE capability information may include the storage capacity of the corresponding UE 704. For example, the storage capacity may include the memory size of the corresponding UE 704 for retransmission storage. In some such examples, the base station 702 may use the storage capacity of the UE 704 to determine whether to include the corresponding UE 704 in the helper UE group to facilitate communication between the base station 702 and the target UE 704a. For example, the base station 702 may compare the storage capacity of each of the UEs 704b, 704c with the sidelink retransmission storage capacity threshold to determine whether to use the corresponding UE as a helper UE and transmit packets to the corresponding UE for sidelink retransmission. In the illustrated example, the base station 702 may determine to include the second (or helper) UE 704b in the helper UE group associated with the target UE 704a, and may determine to exclude the third UE 704c in the helper UE group.

[0080] Figure 7B A wireless communication system 750 including a base station 702a, a PLC 702b, and a UE 704 is illustrated. Aspects of the UE 704 may be implemented by Figure 5 The sensor / actuator(s) 504, 506 and / or Fig. 6A and 6B The PLC 702b is implemented by the sensor / actuator(s) 606. In the illustrated example, the PLC 702b communicates with the base station 702a over the communication link 710. In addition, the PLC 702b communicates with the UE 704 over the corresponding communication link 706.

[0081] However, due to problems such as blocking or fading, the communication link 706a between the PLC 702b and the target UE 704a may be degraded, failed, or dropped. Accordingly, the PLC 702b may utilize a sidelink channel (e.g., sidelink channel 708) to communicate with the target UE 704a. Figure 7B In the illustrated example of , PLC 702b may determine that second UE 704b is in the helper UE group to facilitate communication between PLC 702b and target UE 704a. Figure 7B In the example embodiment, the second UE 704b helps or assists the target UE 704a by forwarding or retransmitting data received from the PLC 702b to the target UE 704a via the side link 708.

[0082] In some examples, to facilitate communication between the PLC 702b and the target UE 704a, the PLC 702b may use various reports received from one or more UEs near the target UE 704a. Since the base station 702a or the PLC 702b can configure the reporting of the UE 704, the PLC 702b may utilize various reports received from nearby UEs (e.g., the second UE 704b and the third UE 704c) to select a side link channel 708 between the target UE 704a and possible helper UEs (e.g., the second UE 704b and / or the third UE 704c). For example, the PLC 702b may transmit a control message to the second UE 704b and the third UE 706b to request the respective UEs 704b, 704c to report various information to the PLC 702b, such as side link measurements, UE capability information, etc. In some examples, the UE capability information may include the storage capacity of the respective UE 704. For example, the storage capacity may include the memory size of the corresponding UE 704 for retransmission storage. In some such examples, the PLC 702b may use the storage capacity of the UE 704 to determine whether to include the corresponding UE 704 in the helper UE group to facilitate communication between the PLC 702b and the target UE 704a. For example, the PLC 702b may compare the storage capacity of each of the UEs 704b, 704c with the sidelink retransmission storage capacity threshold to determine whether to use the corresponding UE as a helper UE, and transmit packets to the corresponding UE for sidelink retransmission. In the illustrated example, the PLC 702b may determine to include the second UE 704b in the helper UE group associated with the target UE 704a, and may determine to exclude the third UE 704c in the helper UE group.

[0083] However, in some examples, after a UE is selected as a helper UE (e.g., second UE 704b), the helper UE may cause an instance in which it may not have sufficient storage capacity to store one or more packets received for retransmission. Figure 8 An example wireless communication system 800 is illustrated that includes a wireless device 802 in communication with a plurality of UEs 804. Aspects of the wireless device 802 may be implemented by a base station such as Figure 5 Base station 503, Fig. 6A and 6B Base station 603, Fig. 7A Base station 702, and / or Figure 7B 702a) and / or may be implemented by a PLC (such as Figure 5 PLC 502, Figure 6B PLC602, and / or Figure 7BVarious aspects of UE 804 may be implemented by Figure 5 The sensor / actuator(s) 504, 506, Fig. 6A and 6B sensor / actuator 606, and / or Fig. 7A and 7B The wireless device 802 may establish a corresponding communication link 806 to communicate with the UE 804.

[0084] However, due to problems such as blocking or fading, the communication links between the wireless device 802 and the three UEs 804b, 804c, 804d may be degraded, failed, or dropped. Accordingly, the wireless device 802 may utilize a side link channel (e.g., side link channel 808) to communicate with the target UEs 804b, 804c, 804d. Figure 8 In the illustrated example of , the wireless device 802 may determine to use the UE 804a as a helper UE to facilitate communication between the wireless device 802 and respective target UEs 804, 804c, 804d.

[0085] exist Figure 8 In the illustrated example of , the wireless device 802 determines a first assistor UE group including assistor UE 804a to facilitate communication between the wireless device 802 and a first target UE 804b. The wireless device 802 may also determine a second UE group including assistor UE 804a to facilitate communication between the wireless device 802 and a second target UE 804c, and determine a third UE group including assistor UE 804a to facilitate communication between the wireless device 802 and a third target 804d.

[0086] In the illustrated example, since the helper UE 804a can serve multiple target UEs 804b, 804c, 804d, the helper UE 804a can store packets for those respective target UEs 804b, 804c, 804d for sidelink retransmission (e.g., via respective sidelink channels 808). If the helper UE 804a does not have memory resources capable of storing every packet, the helper UE 804 may discard one or more packets.

[0087] The examples disclosed herein provide techniques for determining which packet(s), if any, a helper UE may discard when, for example, the helper UE is unable to store all packets received for sidelink retransmission. As disclosed herein, in some examples, the helper UE may determine which packet(s) to discard based on priority. For example, the helper UE may store one or more packets for sidelink retransmission, each associated with a respective priority. The helper UE may then receive a new packet and discard at least one packet (e.g., one of the stored packets or the new packet) due to the limited storage capacity of the helper UE. In some such examples, the helper UE may determine to discard one of the stored packets or the new packet based on the respective priority.

[0088] In some examples, the helper UE may determine which packet(s) to discard based on the packet identification information. For example, the helper UE may store one or more packets for sidelink retransmission, each associated with a corresponding helper UE group and / or target UE. The helper UE may then receive a new packet and discard at least one packet (e.g., one of the stored packets or the new packet) due to the limited storage capacity of the helper UE. In some such examples, the helper UE may determine to discard one of the stored packets or the new packet based on the helper UE group and / or target UE associated with the packet. For example, the helper UE may receive (e.g., from a wireless device) an indication of the helper UE group and / or target UE for which the helper UE is to discard packet(s) when the helper UE is unable to store a new packet.

[0089] Fig. 9 An example communication flow 900 between a wireless device 902, a first UE 904, and a second UE 906 involving sidelink retransmission using a memory of an assisting UE is illustrated. Aspects of the wireless device 902 may be implemented by Figure 1 Base station 120 / 180, Figure 5 Base station 503, Fig. 6A and 6B Base station 603, Fig. 7A Base station 702 and / or Fig. 7A Base station 702a, and / or Figure 1 PLC 145, Figure 5 PLC 502, Fig. 6A and 6B PLC 602, Figure 7B PLC 702b, and / or (more generally) Figure 8 Aspects of the first UE 802 and the second UE 804 may be implemented by Figure 1 UE 104, Figure 1 Sensor / actuator 143, Figure 5 Sensor / actuator 506, Fig. 6A and 6B Sensor / actuator 606, Fig. 7A and 7B UE 704, and / or Figure 8 The UE 804 is implemented.

[0090] exist Fig. 9 In the illustrated example of FIG. 1 , the communication link between the wireless device 902 and the second UE 906 may be degraded, failed, or dropped due to problems such as blocking or fading. The wireless device 902 may then attempt to use the first UE 904 as an assistor UE (sometimes referred to as an “assistant UE”) to help or assist the target UE 906 by forwarding or retransmitting data received from the wireless device 902 to the target UE 906 via a sidelink channel between the first UE 904 and the target UE 906.

[0091] In some examples, the first UE 904 may transmit a storage capacity information message 910, which is received by the wireless device 902. The storage capacity information message 910 may include a memory size for retransmission storage of the first UE 904. In some examples, the storage capacity information message 910 may be included in a UE capability report provided by the first UE 904. For example, the first UE 904 may transmit the storage capacity information message 910 after receiving a control message from the wireless device 902 requesting the first UE 904 to provide various reports (including UE capability information) to the wireless device 902.

[0092] At 920, the wireless device 902 may determine at 920 whether to use the first UE 904 as a helper UE. For example, the wireless device 902 may compare the memory size of the first UE 904 for retransmission storage with the sidelink retransmission storage capacity threshold to determine whether to use the first UE 904 as a helper UE for facilitating communication between the wireless device 902 and the target UE 906. In some such examples, the wireless device 902 may determine that the first UE 904 is to be used as a helper UE when the memory size of the first UE 904 for retransmission storage is greater than or equal to the sidelink retransmission storage capacity threshold, or may determine not to use the first UE 904 as a helper UE when the memory size is less than the sidelink retransmission storage capacity threshold. However, other examples may employ additional or alternative techniques for determining whether to use the first UE 904 as a helper UE based on the storage capacity information message 910.

[0093] Assuming that the wireless device 902 determines that the first UE 904 is to be used as a helper UE, the wireless device 902 may then transmit packets (sometimes referred to as "transmission blocks") (including at least a first packet 930a and a second packet 930b), which are received by the helper UE 904. In the illustrated example, the helper UE 904 may receive the first packet 930a before the second packet 930b. In some examples, the packet 930 may be a downlink packet received from a base station. In some examples, the packet 930 may be a downlink packet or a sidelink packet received from a PLC. In some examples, the helper UE 904 may receive the packet 930 for sidelink retransmission to one or more different UEs (such as the target UE 906).

[0094] In some examples, the wireless device 902 may transmit a packet discard indication 940, which may be received by the helper UE 904. In some examples, the packet discard indication 940 may signal the helper UE 904 to discard packets based on the storage capacity of the helper UE 904. For example, the helper UE 904 may receive and store the first packet 930a. The helper UE 904 may then receive the second packet 930b and determine that the helper UE 904 cannot store the second packet 930b due to the memory size used for the retransmission storage of the helper UE 904. In some examples, the packet discard indication 940 may include a priority-based indication that indicates to the helper UE 904 that a priority-based technique is to be employed for determining which packet(s) to discard, if any. In some examples, the packet discard indication 940 may include an identifier of a packet or group of packets to be discarded.

[0095] At 950, the helper UE 904 may determine which packet(s) to discard. In some examples, the helper UE 904 may determine to discard the packet based on the priority of the packet. For example, the helper UE 904 may compare the priority of the first packet 930a with the priority of the second packet 930b and determine to discard the packet with a relatively lower priority.

[0096] In some examples, the helper UE 904 may receive the priority of the first packet 930a and the priority of the second packet 930b from the wireless device 902. For example, the wireless device 902 may transmit the priorities of the packets 930a, 930b in the group information. In some such examples, the group information may include an SPS configuration. For example, the wireless device 902 may transmit the SPS configuration via RRC signaling. Based on the received priorities, the helper UE 904 may determine to discard the stored packets when the priority of the stored packets (e.g., the first packet 930a) is less than the priority of the new packet (e.g., the second packet 930b), and may determine to discard the new packets when the priority of the new packets is less than the priorities of the stored packets. In some examples, if the helper UE 904 determines that the corresponding priorities of the stored packets are higher than the priority of the new packet, the helper UE 904 may determine to discard the new packet.

[0097] In some examples, the priorities of the packets may be included in the corresponding payloads of the packets. For example, the first packet 930a may include an SCI (such as Figure 4 SCI 402) and data (such as Figure 4 Example data 404 of ). Similarly, the second packet 930b may include SCI and data. In some such examples, the priority of each of the packets 930a, 930b may be included in the data portion of the corresponding packets 930a, 930b. In some such examples, the packets 930a, 930b may be received in an SPS transmission. Although the helper UE 904 may be able to determine the priority of the stored packets (e.g., via the decoding or processing technology of the corresponding payload when received), the helper UE 904 may not be able to determine the priority of the new packet (e.g., the second packet 930b). In some such examples, the helper UE 904 may determine to discard the stored packets associated with the lowest priority. For example, the helper UE 904 may store multiple packets including the first packet 930a, and based on the corresponding priorities, determine to discard the packet with the lowest priority. In some examples, the helper UE 904 may determine to discard the new packet (e.g., the second packet 930b).

[0098] In some examples, the assistor UE 904 may determine the priority of the packet 930 based on the time at which the corresponding packet was received. Fig. 9 In the illustrated example of , the helper UE 904 receives the first packet 930a before receiving the second packet 930b. In some examples, the helper UE 904 may determine to discard the most recently received packet (e.g., the second packet 930b). In some examples, the helper UE 904 may determine to discard the oldest received packet (e.g., the first packet 930a).

[0099] In some examples, the helper UE 904 may determine the priority of the packets 930 based on the delivery deadline associated with each packet. For example, the SCI of each of the packets 930a, 930b may indicate the delivery deadline for delivering each respective packet. In some examples, the helper UE 904 may determine to discard the first expired packet based on the respective delivery deadlines. In some examples, the helper UE 904 may determine to discard the last expired packet based on the respective delivery deadlines.

[0100] In some examples, the helper UE 904 may determine to discard packets based on the packet identification information provided by the wireless device 902. For example, the helper UE 904 may explicitly signal to the helper UE 904 (e.g., via a packet discard indication 940) that certain received packets are to be discarded. As described above, when the wireless device 902 determines the one or more helper UE groups for facilitating communication between the wireless device 902 and the target UE(s), the wireless device 902 may transmit a control message (e.g., via a DCI) to indicate to the helper UE that the helper UE is part of the helper UE group. In some such examples, each helper UE group may be associated with a corresponding group identifier. In some examples, the wireless device 902 may indicate to the helper UE 904 that packets associated with the helper UE group are to be discarded. For example, the wireless device 902 may include the group identifier in the packet discard indication 940 to indicate to the helper UE 904 that the received packets associated with the helper UE group corresponding to the group identifier are to be discarded for sidelink retransmission.

[0101] At 960, the assistor UE 904 may drop the determined packet. For example, the assistor UE 904 may drop the packet based on priority and / or based on packet identification information.

[0102] The helper UE 904 may then use a sidelink channel such as Figure 8 The helper UE 904 may retransmit the non-discarded packet(s) 970 to the target UE 906 using an example sidelink channel 808 of the wireless device 902. In some examples, the helper UE 904 may relay the non-discarded packet(s) 970 to the target UE 906 without any processing or decoding. In some examples, the helper UE 904 may at least partially decode the data received from the wireless device 902 before retransmitting the non-discarded packet(s) 970 to the target UE 906. In some examples, the helper UE 904 may retransmit the non-discarded packet(s) 970 according to a grant received from the wireless device 902, and the grant may schedule the transmission of the non-discarded packet(s) 970 via the sidelink channel.

[0103] Fig.10 1000 is a flow chart of a wireless communication method. The method may be performed by a first UE (eg, Figure 1 UE 104, Figure 3 Equipment 350, Figure 1 Sensor / actuator 143, Figure 5 Sensor / actuator 506, Fig. 6A and 6B Sensor / actuator 606, Fig. 7A and 7B UE 704, Figure 8 UE 804, and / or Fig. 9 Auxiliary UE 904; Fig.11 The apparatus 1102 / 1102' of / 12 may include a memory 360 and may be executed by the entire UE (e.g., device 350) or a component of the device 350, such as a TX processor 368, an RX processor 356 and / or a controller / processor 359). Optional aspects are illustrated with dashed lines. The method may help improve the reliability of sidelink retransmissions by adopting a packet discard strategy for the first UE based on memory storage capacity information associated with the first UE (e.g., a helper UE).

[0104] At 1010, the first UE may report the memory size of the first UE for retransmission storage, as described above in conjunction with, for example, Fig. 9 The storage capacity information message 910 is described. For example, Fig.11 The reporting component 1108 of the apparatus 1102 can be configured to report the memory size of the first UE for retransmission storage to the wireless device. In some examples, the first UE can report the memory size to the wireless device (e.g., a base station or PLC) in a UE capability information message.

[0105] At 1020, the first UE receives the first packet and the second packet for sidelink retransmission to at least one second UE, as described above in conjunction with, for example Fig. 9 As described by the first group 930a and the second group 930b. For example, Fig.11 The receiving component 1104 of the equipment 1102 may be configured to receive a first packet and a second packet from a wireless device. In some examples, the first packet and the second packet include a downlink packet received from a base station. In some examples, the first packet and the second packet include a downlink packet or a side link packet received from a PLC. In some examples, the first packet and the second packet may be used for side link retransmission to different UEs.

[0106] At 1030, the first UE may determine whether to discard the first packet or the second packet based on at least one of the packet priority or the indication from the wireless device, as described above in conjunction with, for example, Fig. 9 950 as described. For example, Fig.11 The packet discarding component 1114 of the apparatus 1102 in the embodiment may be configured to determine whether to discard the first packet or the second packet based on at least one of a packet priority or an indication from the wireless device.

[0107] At 1040, the first UE may discard the first packet or the second packet before retransmission based on at least one of the packet priority or an indication from the wireless device, as described above in conjunction with, for example, Fig. 9 960 as described. For example, Fig.11 The packet discarding component 1114 of the equipment 1102 in the embodiment may be configured to discard the first packet or the second packet before retransmission. In some examples, the first UE may discard the first packet or the second packet based on the memory storage capacity of the first UE (e.g., the memory size of the first UE for retransmission storage).

[0108] Referring again to 1030, in some examples, the first UE may determine whether to discard the first packet or the second packet based on at least the packet priority. For example, at 1032, the first UE may receive a first priority for the first packet and a second priority for the second packet, as described above in conjunction with, for example Fig. 9 As described by the group 930. For example, Fig.11 The priority handling component 1110 of the equipment 1102 in may be configured to receive a first priority for a first packet and a second priority for a second packet. In some examples, the first UE may receive the first priority and the second priority in group information from a base station. In some such examples, the group information may include an SPS configuration. In some examples, the first priority may be included in a first payload of the first packet, and the second priority may be included in a second payload of the second packet. In some such examples, the first packet and the second packet may be received in an SPS transmission. In some examples, the first UE may determine the first priority based on a first reception time of the first packet, and may determine the second priority based on a second reception time of the second packet. In some examples, the first UE may determine the first priority based on a first delivery deadline of the first packet, and may determine the second priority based on a second delivery deadline of the second packet.

[0109] At 1034, the first UE may determine to discard the first packet when the first priority is less than the second priority, or determine to discard the second packet when the second priority is less than the first priority, as described above in conjunction with, for example Fig. 9 950 as described. For example, Fig.11The priority handling component 1110 of the equipment 1102 in may be configured to determine to discard the first packet when the first priority is less than the second priority, or to determine to discard the second packet when the second priority is less than the first priority. In some examples, when the first UE determines the priority of the first packet and the second packet based on the reception time of the corresponding packets, the first UE may determine whether to discard the most recently received packet (e.g., the second packet) or the oldest received packet (e.g., the first packet). In some examples, when the first UE determines the priority of the first packet and the second packet based on the delivery deadline of the corresponding packets, the first UE may determine whether to discard the first expired packet or the last expired packet.

[0110] In some examples, the first UE may determine whether to discard the first packet or the second packet based on at least the indication. For example, at 1036, the first UE may receive an indication to discard the first packet or the second packet, as described above in conjunction with, for example Fig. 9 The packet discard indication 940 is described. For example, Fig.11 The indication handling component 1112 of the device 1102 in the embodiment can be configured to receive an indication of discarding the first packet or the second packet. In some examples, the first UE can receive the indication in a DCI from the base station. In some such examples, the DCI can include a group identifier.

[0111] At 1038, the first UE may determine whether to discard the first packet or the second packet based on the indication, as described above in conjunction with, for example Fig. 9 950 as described. For example, Fig.11 The indication handling component 1112 of the equipment 1102 in the device 1102 can be configured to determine whether to discard the first packet or the second packet based on the indication. In some examples, the first UE can determine whether to discard the first packet or the second packet based on the first packet or the second packet being associated with the group identifier (received at 1036).

[0112] Fig.11 1100 is a conceptual data flow diagram illustrating data flow between different devices / components in an example equipment 1102 in communication with a wireless device 1150. The equipment may be a UE or a component of a UE. The equipment includes a receiving component 1104, a transmitting component 1106, a reporting component 1108, a priority handling component 1110, an indication handling component 1112, and a packet discarding component 1114. The wireless device 1150 may include information related to Fig. 9 The wireless device 902 may be the same or similar components as shown.

[0113] The receiving component 1104 can be configured to receive various types of signals / messages and / or other information from other devices, including, for example, the wireless device 1150. The messages / information can be received via the receiving component 1104 and provided to one or more components of the equipment 1102 for further processing and / or for use in performing various operations. For example, the receiving component 1104 can be configured to receive a first packet and a second packet from the wireless device, such as in conjunction with, for example, Fig.10 1020 as described.

[0114] Transmitting component 1106 may be configured to communicate various types of signals / messages and / or other information to other devices (including, for example, wireless device 1150).

[0115] The reporting component 1108 can be configured to report the memory size of the first UE for retransmission storage to a wireless device (e.g., wireless device 1150), such as in conjunction with, for example Fig.10 1010 as described.

[0116] The priority handling component 1110 can be configured to receive a first priority of a first packet and a second priority of a second packet, and / or determine to discard the first packet when the first priority is less than the second priority or determine to discard the second packet when the second priority is less than the first priority, such as in combination with Fig.10 As described in 1032 and 1034.

[0117] The indication handling component 1112 can be configured to receive an indication to drop the first packet or the second packet, and / or determine whether to drop the first packet or the second packet based on the indication, such as in conjunction with, for example Fig.10 As described in 1036 and 1038.

[0118] The packet discarding component 1114 can be configured to determine whether to discard the first packet or the second packet based on at least one of a packet priority or an indication from a wireless device, and / or to discard the first packet or the second packet before retransmission, such as in conjunction with, for example Fig.10 As described in 1030 and 1040.

[0119] The equipment may include performing Fig.10 The additional components of each box of the algorithm in the preceding flowchart. Thus, Fig.10 Each block in the aforementioned flow chart of can be performed by a component and the equipment may include one or more of these components. These components can be one or more hardware components specially configured to execute the process / algorithm, implemented by a processor configured to execute the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0120] Fig.121200 is a diagram illustrating an example of a hardware implementation of an apparatus 1102' employing a processing system 1214. The processing system 1214 may be implemented with a bus architecture generally represented by a bus 1224. Depending on the specific application of the processing system 1214 and the overall design constraints, the bus 1224 may include any number of interconnecting buses and bridges. The bus 1224 links various circuits together, including one or more processors and / or hardware components (represented by the processor 1204, components 1104, 1106, 1108, 1110, 1112, 1114, and computer readable medium / memory 1206). The bus 1224 may also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further.

[0121] The processing system 1214 may be coupled to the transceiver 1210. The transceiver 1210 is coupled to one or more antennas 1220. The transceiver 1210 provides a means for communicating with various other devices over a transmission medium. The transceiver 1210 receives signals from the one or more antennas 1220, extracts information from the received signals, and provides the extracted information to the processing system 1214 (specifically, the receiving component 1104). In addition, the transceiver 1210 receives information from the processing system 1214 (specifically, the transmitting component 1106) and generates signals to be applied to the one or more antennas 1220 based on the received information. The processing system 1214 includes a processor 1204 coupled to a computer-readable medium / memory 1206. The processor 1204 is responsible for general processing, including the execution of software stored on the computer-readable medium / memory 1206. The software, when executed by the processor 1204, causes the processing system 1214 to perform the various functions described above for any particular device. The computer-readable medium / memory 1206 may also be used to store data manipulated by the processor 1204 when executing software. The processing system 1214 further includes at least one of the components 1104, 1106, 1108, 1110, 1112, 1114. These components may be software components running in the processor 1204, software components resident / stored in the computer-readable medium / memory 1206, one or more hardware components coupled to the processor 1204, or some combination thereof. The processing system 1214 may be a component of a UE (e.g., device 350) and may include the memory 360 and / or at least one of the following: the TX processor 368, the RX processor 356, and the controller / processor 359. Alternatively, the processing system 1214 may be the entire UE (e.g., see Figure 3 device 350).

[0122] In one configuration, an apparatus 1102 / 1102' for wireless communication includes a device for receiving a first packet and a second packet from a wireless device for sidelink retransmission to at least one second UE, the second packet being received after the first packet. The apparatus 1102 / 1102' may also include a device for discarding the first packet or the second packet before retransmission based on at least one of a packet priority or an indication from the wireless device. The apparatus 1102 / 1102' may also include a device for discarding the first packet or the second packet based on a storage capacity of the first UE. The apparatus 1102 / 1102' may also include a device for receiving a first priority and a second priority in group information from a base station. The apparatus 1102 / 1102' may also include a device for receiving an indication of discarding the first packet or the second packet from the base station, and wherein the first UE discards the first packet or the second packet based on the indication. The apparatus 1102 / 1102' may also include a device for reporting to the base station a memory size of the first UE for retransmission storage, and wherein the second packet is received based on the memory size.

[0123] The aforementioned means may be one or more of the aforementioned components of the equipment 1102 and / or the processing system 1214 in the equipment 1102' configured to perform the functions recited by the aforementioned means. As previously described, the processing system 1214 may include the TX processor 368, the RX processor 356, and the controller / processor 359. Thus, in one configuration, the aforementioned means may be the TX processor 368, the RX processor 356, and the controller / processor 359 configured to perform the functions recited by the aforementioned means.

[0124] Fig.13 1300 is a flow chart of a wireless communication method. The method may be performed by a wireless device (e.g., Fig. 9 A wireless device 902 (such as a base station (e.g., Figure 1 Base station 102 / 108, Figure 5 Base station 503, Fig. 6A and 6B Base station 603, Fig. 7A Base station 702, Fig. 7A Base station 702, and / or Fig. 7A Base station 702a; Fig.14 / 15 equipment 1402 / 1402'; processing system 1514, which may include memory 376 and which may be the entire base station (e.g., device 310) or a component of device 310, such as TX processor 316, RX processor 370 and / or controller / processor 375) and / or PLC (e.g., Figure 1 PLC 145, Figure 5 PLC502, Fig. 6A and6B PLC 602, Figure 7B 702b)) of the PLC. Optional aspects are illustrated with dashed lines. The method may help improve the reliability of sidelink retransmissions by adopting a packet discard strategy for the first UE based on memory storage capacity information associated with the first UE (e.g., the helper UE).

[0125] At 1320, the wireless device transmits the first packet and the second packet to the first UE for sidelink retransmission to at least one additional UE, as described above in conjunction with, for example Fig. 9 As described by the first group 930a and the second group 930b. For example, Fig.14 The transmission component 1406 of the device 1402 in the embodiment may be configured to transmit the first packet and the second packet for retransmission to at least one additional UE. In some examples, the wireless device may transmit the second packet after the first packet. In some examples, the first packet and the second packet are used for sidelink retransmission to different UEs. In some examples, the first packet and the second packet include downlink packets and / or sidelink packets.

[0126] At 1330, the wireless device transmits an indication to the first UE to discard the first packet or the second packet, as described above in conjunction with, for example, Fig. 9 The packet discard indication 940 is described. For example, Fig.14 The transmission component 1406 of the device 1402 in the embodiment can be configured to transmit an indication to discard the first packet or the second packet to the first UE. In some examples, the indication to discard the second packet or the second packet can be based on the memory storage capacity of the first UE.

[0127] In some examples, the indication to the first UE may be a priority-based indication. For example, at 1332, the wireless device may transmit a priority-based indication to discard the first packet when the first priority of the first packet is less than the second priority of the second packet or to discard the second packet when the second priority is less than the first priority, as described above in conjunction with, for example Fig. 9 The packet discard indication 940 is described. For example, Fig.14 The priority handling component 1408 of the apparatus 1402 in may be configured to transmit a priority-based indication to the first UE.

[0128] In some examples, the wireless device may transmit the corresponding priority to the first UE. For example, the wireless device may transmit the first priority and the second priority to the first UE in the group information. In some such examples, the group information may include an SPS configuration. In some examples, the wireless device may transmit the first priority in the first payload of the first packet and the second priority in the second payload of the second packet. In some such examples, the first packet and the second packet may be transmitted in an SPS transmission.

[0129] In some examples, the priority-based indication may cause the first UE to determine the respective priorities of the first packet and the second packet based on the reception time of the respective priorities. For example, the priority-based indication may cause the first UE to determine the first priority based on the first reception time of the first packet and determine the second priority based on the second reception time of the second packet. In some such examples, the first UE may determine whether to discard the most recently received packet (e.g., the second packet) or to discard the oldest received packet (e.g., the first packet).

[0130] In some examples, the priority-based indication may cause the first UE to determine a first priority based on a first delivery deadline for the first packet and a second priority based on a second delivery deadline for the second packet. In some such examples, the first UE may determine whether to discard the first expired packet or the last expired packet.

[0131] In some examples, the indication to the first UE may be a packet identification indication. For example, at 1334, the wireless device may transmit a packet identification indication to discard the first packet or the second packet based on the identified packet, as described above in conjunction with, for example Fig. 9 The packet discard indication 940 is described. For example, Fig.14 The group identification component 1410 of the apparatus 1402 in the embodiment can be configured to transmit a group identification indication to the first UE. In some examples, the group identification indication can be transmitted to the first UE in a DCI. In some such examples, the DCI can include a group identifier that identifies the group to be discarded.

[0132] In some examples, the wireless device may determine whether to use the first UE as a helper UE for sidelink retransmission based on the memory size information provided by the first UE. For example, at 1310, the wireless device may receive a memory size for retransmission storage from the first UE, as described above in conjunction with, for example Fig. 9 The storage capacity information message 910 is described. For example, Fig.14 The memory size handling component 1412 of the apparatus 1402 in the wireless device can be configured to receive a memory size for retransmission storage from the first UE. In some examples, the wireless device can receive the memory size in a UE capability information message from the first UE.

[0133] At 1312, the wireless device may determine whether to transmit a packet to the first UE for sidelink retransmission based on the memory size, as described above in conjunction with, for example Fig. 9 920 as described. For example, Fig.14The memory size handling component 1412 of the apparatus 1402 in the wireless device may be configured to determine whether to transmit packets to the first UE for sidelink transmission based on the memory size. In some examples, the wireless device may compare the received memory size with a sidelink retransmission storage capacity threshold to determine whether to use the first UE as a helper UE and transmit packets to the first UE for sidelink retransmission.

[0134] If at 1312, the wireless device determines not to transmit the packet to the first UE for sidelink retransmission (e.g., the received memory size is less than the sidelink retransmission storage capacity threshold), then at 1340, the wireless device may determine not to use the first UE as a helper UE for sidelink retransmission, as described above in conjunction with, for example Fig. 9 920 as described. For example, Fig.14 The memory size handling component 1412 of the apparatus 1402 in may be configured to determine not to use the first UE as a helper UE for sidelink retransmission when the received memory size is less than a sidelink retransmission storage capacity threshold.

[0135] If at 1312, the wireless device determines to transmit a packet to the first UE for sidelink retransmission (e.g., the received memory size is greater than or equal to a sidelink retransmission storage capacity threshold), the UE may proceed to 1320 to transmit the first packet and the second packet for sidelink retransmission to at least one additional UE, as described above.

[0136] Fig.14 1400 is a conceptual data flow diagram illustrating data flow between different devices / components in an example equipment 1402 in communication with a UE 1450. The equipment may be a wireless device, such as a base station or a PLC, or a component of a wireless device. The equipment includes a receiving component 1404, a transmitting component 1406, a priority handling component 1408, a group identification component 1410, and a memory size handling component 1412. The UE 1450 may include information related to Fig. 9 The components shown in UE 904 are the same or similar.

[0137] The receiving component 1404 can be configured to receive various types of signals / messages and / or other information from other devices (including, for example, receiving uplink transmissions from the UE 1450). The messages / information can be received via the receiving component 1404 and provided to one or more components of the equipment 1402 for further processing and / or for performing various operations. Transmissions from the UE 1450 can originate from another UE 1415, which are provided to the UE 1450 via a sidelink.

[0138] Transmitting component 1406 can be configured to transmit various types of signals / messages and / or other information to other devices (including, for example, transmitting a downlink transmission to UE 1450). For example, transmitting component 1406 can be configured to transmit the first packet and the second packet to at least one additional UE for retransmission, and / or transmit an indication to discard the first packet or the second packet to the first UE, as described above in conjunction with, for example Fig.13 1320 and 1330. The downlink transmissions may be intended to be received by another UE 1451, and UE 1450 may receive these downlink transmissions and provide them to UE 1451 via a side link.

[0139] Priority handling component 1408 may be configured to transmit a priority-based indication to the first UE, such as in conjunction with, for example Fig.13 of 1332 described.

[0140] The group identification component 1410 may be configured to transmit a group identification indication to the first UE, such as in conjunction with, for example Fig.13 of 1334 described.

[0141] The memory size handling component 1412 may be configured to receive a memory size for retransmission storage from the first UE, determine whether to transmit a packet to the first UE for sidelink transmission based on the memory size, and / or determine not to use the first UE as a helper UE for sidelink retransmission when the received memory size is less than a sidelink retransmission storage capacity threshold, such as in conjunction with e.g. Fig.13 As described in 1310, 1312 and / or 1340.

[0142] The equipment may include performing Fig.13 The additional components of each box of the algorithm in the preceding flowchart. Thus, Fig.13 Each block in the aforementioned flow chart of can be performed by a component and the equipment may include one or more of these components. These components can be one or more hardware components specially configured to execute the process / algorithm, implemented by a processor configured to execute the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0143] Fig.1515 is a diagram 1500 illustrating an example of a hardware implementation of an apparatus 1402' employing a processing system 1514. The processing system 1514 may be implemented with a bus architecture generally represented by a bus 1524. Depending on the specific application of the processing system 1514 and the overall design constraints, the bus 1524 may include any number of interconnecting buses and bridges. The bus 1524 links together various circuits, including one or more processors and / or hardware components (represented by the processor 1504, components 1404, 1406, 1408, 1410, 1412, and computer readable medium / memory 1506). The bus 1524 may also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further.

[0144] The processing system 1514 may be coupled to the transceiver 1510. The transceiver 1510 is coupled to one or more antennas 1520. The transceiver 1510 provides a means for communicating with various other devices over a transmission medium. The transceiver 1510 receives signals from the one or more antennas 1520, extracts information from the received signals, and provides the extracted information to the processing system 1514 (specifically, the receiving component 1404). In addition, the transceiver 1510 receives information from the processing system 1514 (specifically, the transmission component 1406) and generates signals to be applied to the one or more antennas 1520 based on the received information. The processing system 1514 includes a processor 1504 coupled to a computer-readable medium / memory 1506. The processor 1504 is responsible for general processing, including the execution of software stored on the computer-readable medium / memory 1506. The software, when executed by the processor 1504, causes the processing system 1514 to perform the various functions described above for any particular device. The computer-readable medium / memory 1506 may also be used to store data manipulated by the processor 1504 when executing software. The processing system 1514 further includes at least one of the components 1404, 1406, 1408, 1410, 1412. These components may be software components running in the processor 1504, software components residing / stored in the computer-readable medium / memory 1506, one or more hardware components coupled to the processor 1504, or some combination thereof. The processing system 1514 may be a component of a base station (e.g., device 310) and may include the memory 376 and / or at least one of the following: the TX processor 316, the RX processor 370, and the controller / processor 375. Alternatively, the processing system 1514 may be the entire base station (e.g., see Figure 3 device 310).

[0145] In one configuration, an apparatus 1402 / 1402' for wireless communication includes means for transmitting a first packet and a second packet to a first user equipment (UE) for sidelink retransmission to at least one additional UE, the second packet being transmitted after the first packet. The apparatus 1402 / 1402' may also include means for transmitting an indication of discarding the first packet or the second packet to the first UE. The apparatus 1402 / 1402' may also include means for transmitting the first priority and the second priority to the first UE in group information. The apparatus 1402 / 1402' may also include means for receiving from the first UE a memory size for retransmission storage of the first UE. The apparatus 1402 / 1402' may also include means for determining whether to transmit a packet to the first UE for sidelink retransmission based on the memory size.

[0146] The aforementioned means may be one or more of the aforementioned components of the equipment 1402 and / or the processing system 1514 in the equipment 1402' configured to perform the functions recited by the aforementioned means. As previously described, the processing system 1514 may include the TX processor 316, the RX processor 370, and the controller / processor 375. Thus, in one configuration, the aforementioned means may be the TX processor 316, the RX processor 370, and the controller / processor 375 configured to perform the functions recited by the aforementioned means.

[0147] It should be understood that the specific order or hierarchy of each box in the disclosed process / flowchart is an illustration of an example approach. It should be understood that the specific order or hierarchy of each box in these process / flowcharts can be rearranged based on design preferences. In addition, some boxes can be combined or omitted. The attached method claims present the elements of various boxes in an exemplary order and are not meant to be limited to the specific order or hierarchy presented.

[0148] The following examples are merely illustrative and may be combined with other embodiments or aspects of the teachings described herein without limitation.

[0149] Example 1 is a method for performing wireless communication at a first UE, the method comprising: receiving a first packet and a second packet from a wireless device for sidelink retransmission to at least one second UE, the second packet being received after the first packet; and discarding the first packet or the second packet before retransmission based on at least one of a packet priority or an indication from the wireless device.

[0150] In Example 2, the method of Example 1 further includes: the first packet and the second packet include downlink packets received from a base station.

[0151] In Example 3, the method of Example 1 or Example 2 further includes: the first packet and the second packet include downlink packets or sidelink packets received from the PLC.

[0152] In Example 4, the method of any one of Examples 1 to 3 further includes discarding the first packet or the second packet based on a storage capacity of the first UE.

[0153] In Example 5, the method of any one of Examples 1 to 4 further includes: the first packet and the second packet are used for sidelink retransmission to different UEs.

[0154] In Example 6, the method of any one of Examples 1 to 5 further includes discarding the first packet when the first priority of the first packet is less than the second priority of the second packet, or discarding the second packet when the second priority is less than the first priority.

[0155] In Example 7, the method of any one of Examples 1 to 6 further comprises: receiving the first priority and the second priority in group information from the base station.

[0156] In Example 8, the method of any one of Examples 1 to 7 further includes: the group information includes an SPS configuration.

[0157] In Example 9, the method of any one of Examples 1 to 8 further includes: the first priority is included in a first payload of the first packet, and the second priority is included in a second payload of the second packet.

[0158] In Example 10, the method of any one of Examples 1 to 9 further includes: the first packet and the second packet are received in an SPS transmission.

[0159] In Example 11, the method of any one of Examples 1 to 10 further includes: the first priority includes a first reception time of the first packet, and the second priority includes a second reception time of the second packet.

[0160] In Example 12, the method of any one of Examples 1 to 11 further comprises: the first priority comprises a first delivery deadline of the first packet, and the second priority comprises a second delivery deadline of the second packet.

[0161] In Example 13, the method of any one of Examples 1 to 12 further includes: receiving an indication to discard the first packet or the second packet from the base station, wherein the first UE discards the first packet or the second packet based on the indication.

[0162] In Example 14, the method of any one of Examples 1 to 13 further includes: the indication is received in a DCI including a group identifier, and wherein the first UE discards the first packet or the second packet based on the first packet or the second packet being associated with the group identifier.

[0163] In Example 15, the method of any one of Examples 1 to 14 further comprises: reporting a memory size of the first UE for retransmission storage to the base station, wherein the second packet is received based on the memory size.

[0164] In Example 16, the method of any one of Examples 1 to 15 further comprises: the memory size is reported to the base station in a UE capability information message.

[0165] Example 17 is a device comprising one or more processors and one or more memories in electronic communication with the one or more processors, the one or more memories storing instructions executable by the one or more processors to cause the system or device to implement a method as any of Examples 1 to 16.

[0166] Example 18 is a system or apparatus comprising means for implementing the method of any one of Examples 1 to 16 or implementing the apparatus of any one of Examples 1 to 16.

[0167] Example 19 is a non-transitory computer-readable medium storing instructions executable by one or more processors to cause the one or more processors to implement the method of any one of Examples 1 to 16.

[0168] Example 20 is a method for performing wireless communications at a wireless device, the wireless device comprising a base station or a PLC, the method comprising: transmitting a first packet and a second packet to a first UE for sidelink retransmission to at least one additional UE, the second packet being transmitted after the first packet; and transmitting an indication to the first UE to discard the first packet or the second packet.

[0169] In Example 21, the method of Example 20 further includes: the indication to discard the first packet or the second packet is based on a storage capacity of the first UE.

[0170] In Example 22, the method as in either Example 20 or Example 21 further includes: the first packet and the second packet are used for sidelink retransmission to different UEs.

[0171] In Example 23, the method as in any one of Examples 20 to 22 further includes: the indication includes a priority-based indication, and wherein the first packet is indicated to be discarded when the first priority of the first packet is less than the second priority of the second packet, or the second packet is indicated to be discarded when the second priority is less than the first priority.

[0172] In Example 24, the method of any one of Examples 20 to 23 further includes: transmitting the first priority and the second priority to the first UE in the group information.

[0173] In Example 25, the method of any one of Examples 20 to 24 further includes: the group information includes an SPS configuration.

[0174] In Example 26, the method of any one of Examples 20 to 25 further comprises: the first priority is included in a first payload of the first packet, and the second priority is included in a second payload of the second packet.

[0175] In Example 27, the method of any one of Examples 20 to 26 further includes: the first packet and the second packet are transmitted in an SPS transmission.

[0176] In Example 28, the method of any one of Examples 20 to 27 further includes: the first priority includes a first reception time of the first packet and the second priority includes a second reception time of the second packet, wherein the first packet is indicated to be discarded when the first reception time is less than the second reception time.

[0177] In Example 29, the method of any one of Examples 20 to 28 further comprises: the first priority is based on a first delivery deadline of the first packet, and the second priority comprises a second delivery deadline of the second packet.

[0178] In Example 30, the method of any one of Examples 20 to 29 further comprises: the indication identifies a packet to be discarded.

[0179] In Example 31, the method of any one of Examples 20 to 30 further comprises: the indication comprises a group identifier transmitted in the DCI, the group identifier identifying the packet to be discarded.

[0180] In Example 32, the method of any one of Examples 20 to 31 further includes: receiving a memory size for retransmission storage of the first UE from the first UE; and determining whether to transmit a packet to the first UE for sidelink transmission based on the memory size.

[0181] In Example 33, the method of any one of Examples 20 to 32 further includes: the memory size is received in a UE capability information message from the first UE.

[0182] Example 34 is a device comprising one or more processors and one or more memories in electronic communication with the one or more processors, the one or more memories storing instructions executable by the one or more processors to cause the system or equipment to implement a method as in any of Examples 20 to 33.

[0183] Example 35 is a system or apparatus comprising means for implementing a method as in any one of Examples 20 to 33 or implementing an apparatus as in any one of Examples 20 to 33.

[0184] Example 36 is a non-transitory computer-readable medium storing instructions executable by one or more processors to cause the one or more processors to implement the method of any one of Examples 20 to 33.

[0185] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be easily understood by those skilled in the art, and the universal principles defined herein can be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but should be granted the full scope consistent with the claims in language, wherein the singular reference to the elements is not intended to mean "there is and only one", but "one or more", unless otherwise stated. The wording "exemplary" is used herein to mean "used as an example, instance, or explanation". Any aspect described as "exemplary" herein is not necessarily interpreted as being superior to or superior to other aspects. Unless otherwise stated, the term "some / some" refers to one or more. Unless otherwise stated, the term "some / some" refers to one or more. In addition, nothing disclosed herein is intended to be donated to the public, regardless of whether such disclosure is explicitly recorded in the claims. The wording "module", "mechanism", "element", "equipment", etc. may not be a replacement for the wording "device". In this way, no claim element should be interpreted as a device plus function unless the element is explicitly stated using the phrase "device for..."

Claims

1. A method for wireless communication at a first user equipment (UE), comprising: receiving, from a wireless device, a first packet and a second packet for sidelink retransmission to at least one second UE, the second packet being received after the first packet; discarding the first packet or the second packet prior to retransmission based on at least one of a packet priority or an indication from the wireless device; as well as Remaining packets that are not discarded among the first packets and the second packets received from the wireless device are retransmitted from the first UE to the at least one second UE.

2. The method of claim 1, wherein: The first packet and the second packet comprise downlink packets received from a network node.

3. The method of claim 1, wherein: The first packet and the second packet include downlink packets or sidelink packets from a programmable logic controller (PLC).

4. The method of claim 1, wherein: Discarding the first packet or the second packet is performed based on a memory storage capacity of the first UE.

5. The method of claim 1, wherein: The first packet and the second packet are used for sidelink retransmission to different UEs.

6. The method of claim 1, wherein: The first packet is discarded when a first priority of the first packet is smaller than a second priority of the second packet, or the second packet is discarded when the second priority is smaller than the first priority.

7. The method of claim 6, further comprising: The first priority and the second priority are received in group information from a network node.

8. The method of claim 7, wherein: The group information includes a semi-persistent scheduling (SPS) configuration.

9. The method of claim 6, wherein: The first priority is included in a first payload of the first packet, and the second priority is included in a second payload of the second packet.

10. The method of claim 9, wherein: The first packet and the second packet are received in a semi-persistently scheduled (SPS) transmission.

11. The method of claim 6, wherein: The first priority includes a first reception time of the first packet and the second priority includes a second reception time of the second packet, or the first priority includes a first delivery deadline of the first packet and the second priority includes a second delivery deadline of the second packet.

12. The method of claim 1, further comprising: An indication is received from a network node to discard the first packet or the second packet, wherein the first UE discards the first packet or the second packet based on the indication.

13. The method of claim 12, wherein: The indication is received in downlink control information (DCI) including a group identifier, and wherein the first UE discards the first packet or the second packet based on the first packet or the second packet being associated with the group identifier.

14. The method of claim 1, further comprising: Reporting a memory size of the first UE for retransmission storage to a network node, wherein the second packet is received based on the memory size, wherein the memory size is reported to the network node in a UE capability information message.

15. An apparatus for wireless communication at a first user equipment (UE), comprising: Memory; as well as at least one processor coupled to the memory and configured to: receiving, from a wireless device, a first packet and a second packet for sidelink retransmission to at least one second UE, the second packet being received after the first packet; discarding the first packet or the second packet prior to retransmission based on at least one of a packet priority or an indication from the wireless device; as well as Remaining packets that are not discarded among the first packets and the second packets received from the wireless device are retransmitted from the first UE to the at least one second UE.

16. The device of claim 15, wherein: The first packet and the second packet comprise downlink packets received from a network node.

17. The device of claim 15, wherein: The first packet and the second packet include downlink packets or sidelink packets from a programmable logic controller (PLC).

18. The device of claim 15, wherein: Discarding the first packet or the second packet is performed based on a memory storage capacity of the first UE.

19. The device of claim 15, wherein: The first packet and the second packet are used for sidelink retransmission to different UEs.

20. The device of claim 15, wherein: The first packet is discarded when a first priority of the first packet is smaller than a second priority of the second packet, or the second packet is discarded when the second priority is smaller than the first priority.

21. The device of claim 20, wherein: The at least one processor is further configured to: The first priority and the second priority are received in group information from a network node.

22. The device of claim 21, wherein: The group information includes a semi-persistent scheduling (SPS) configuration.

23. The device of claim 20, wherein: The first priority is included in a first payload of the first packet, and the second priority is included in a second payload of the second packet.

24. The device of claim 23, wherein: The first packet and the second packet are received in a semi-persistently scheduled (SPS) transmission.

25. The apparatus of claim 20, wherein: The first priority includes a first reception time of the first packet and the second priority includes a second reception time of the second packet, or the first priority includes a first delivery deadline of the first packet and the second priority includes a second delivery deadline of the second packet.

26. The apparatus of claim 15, wherein: The at least one processor is further configured to: An indication is received from a network node to discard the first packet or the second packet, wherein the first UE discards the first packet or the second packet based on the indication.

27. The device of claim 26, wherein: The indication is received in downlink control information (DCI) including a group identifier, and wherein the first UE discards the first packet or the second packet based on the first packet or the second packet being associated with the group identifier.

28. The apparatus of claim 15, wherein: The at least one processor is further configured to: Reporting a memory size of the first UE for retransmission storage to a network node, wherein the second packet is received based on the memory size, wherein the memory size is reported to the network node in a UE capability information message.

29. A method of wireless communication at a wireless device, the wireless device comprising a network node or a programmable logic controller (PLC), the method comprising: transmitting a first packet and a second packet to a first user equipment (UE) for sidelink retransmission to at least one additional UE, the second packet being transmitted after the first packet; as well as An indication is transmitted to the first UE to discard the first packet or the second packet from the sidelink retransmission to the at least one additional UE.

30. The method of claim 29, wherein: The indication to discard the first packet or the second packet is based on a memory storage capacity of the first UE.

31. The method of claim 29, wherein: The first packet and the second packet are used for sidelink retransmission to different UEs.

32. The method of claim 29, wherein: The indication comprises an indication based on priority, and wherein a first packet is indicated to be dropped when a first priority of the first packet is less than a second priority of the second packet, or the second packet is indicated to be dropped when the second priority is less than the first priority.

33. The method of claim 32, further comprising: The first priority and the second priority are transmitted to the first UE in group information.

34. The method of claim 33, wherein: The group information includes a semi-persistent scheduling (SPS) configuration.

35. The method of claim 32, wherein: The first priority is included in a first payload of the first packet, and the second priority is included in a second payload of the second packet.

36. The method of claim 35, wherein: The first packet and the second packet are transmitted in a semi-persistently scheduled (SPS) transmission.

37. The method of claim 32, wherein: The first priority includes a first reception time of the first packet and the second priority includes a second reception time of the second packet, and wherein the first packet is indicated to be discarded when the first reception time is less than the second reception time.

38. The method of claim 32, wherein: The first priority is based on a first delivery deadline of the first packet, and the second priority includes a second delivery deadline of the second packet.

39. The method of claim 29, wherein: The indication identifies packets to be discarded.

40. The method of claim 39, wherein: The indication comprises a group identifier transmitted in downlink control information (DCI), the group identifier identifying the packets to be discarded.

41. The method of claim 29, further comprising: receiving a memory size for retransmission storage from the first UE; as well as A determination is made based on the memory size whether to transmit a packet to the first UE for sidelink retransmission.

42. The method of claim 41, wherein: The memory size is received in a UE capability information message from the first UE.

43. An apparatus for wireless communication at a wireless device, the wireless device comprising a network node or a programmable logic controller (PLC), the apparatus comprising: Memory; as well as at least one processor coupled to the memory and configured to: transmitting a first packet and a second packet to a first user equipment (UE) for sidelink retransmission to at least one additional UE, the second packet being transmitted after the first packet; as well as An indication is transmitted to the first UE to discard the first packet or the second packet from the sidelink retransmission to the at least one additional UE.

44. The apparatus of claim 43, wherein: The indication to discard the first packet or the second packet is based on a memory storage capacity of the first UE.

45. The apparatus of claim 43, wherein: The first packet and the second packet are used for sidelink retransmission to different UEs.

46. ​​The apparatus of claim 43, wherein: The indication comprises an indication based on priority, and wherein a first packet is indicated to be dropped when a first priority of the first packet is less than a second priority of the second packet, or the second packet is indicated to be dropped when the second priority is less than the first priority.

47. The apparatus of claim 46, wherein: The at least one processor is further configured to: The first priority and the second priority are transmitted to the first UE in group information.

48. The apparatus of claim 47, wherein: The group information includes a semi-persistent scheduling (SPS) configuration.

49. The apparatus of claim 46, wherein: The first priority is included in a first payload of the first packet, and the second priority is included in a second payload of the second packet.

50. The apparatus of claim 49, wherein: The first packet and the second packet are transmitted in a semi-persistently scheduled (SPS) transmission.

51. The apparatus of claim 46, wherein: The first priority includes a first reception time of the first packet and the second priority includes a second reception time of the second packet, and wherein the first packet is indicated to be discarded when the first reception time is less than the second reception time.

52. The apparatus of claim 46, wherein: The first priority is based on a first delivery deadline of the first packet, and the second priority includes a second delivery deadline of the second packet.

53. The apparatus of claim 43, wherein: The indication identifies packets to be discarded.

54. The apparatus of claim 53, wherein: The indication comprises a group identifier transmitted in downlink control information (DCI), the group identifier identifying the packets to be discarded.

55. The apparatus of claim 43, wherein: The at least one processor is further configured to: receiving a memory size for retransmission storage from the first UE; and A determination is made based on the memory size whether to transmit a packet to the first UE for sidelink retransmission.

56. The apparatus of claim 55, wherein: The memory size is received in a UE capability information message from the first UE.

Images