Retransmitting a transport block without enabling sidelink feedback

Abstract

Apparatuses, methods, and systems are disclosed for retransmitting a transport block without sidelink feedback enabled. One method includes determining whether sidelink feedback is enabled for a transport block. The method includes retransmitting the transport block a predetermined number of times in response to sidelink feedback being disabled for the transport block.

Description

[0001] This application claims priority to U.S. Patent Application Serial No. 62 / 961,821, filed January 16, 2020, entitled “Apparatus, Methods, and Systems for Blind Retransmission in NR V2X,” which is incorporated herein by reference in its entirety. Technical Field

[0002] The topics disclosed in this article generally relate to wireless communication, and more specifically to retransmitting transport blocks without enabling side link feedback. Background Technology

[0003] As defined herein, at least some of these abbreviations are referenced in the following descriptions: Third Generation Partnership Project (“3GPP”), Fifth Generation (“5G”), QoS for NR V2X Communication (“5QI / PQI”), Authentication, Authorization and Accounting (“AAA”), Positive Acknowledgment (“ACK”), Application Function (“AF”), Authentication and Key Protocol (“AKA”), Aggregation Level (“AL”), Access and Mobility Management Function (“AMF”), Angle of Arrival (“AoA”), Angle of Departure (“AoD”), Access Point (“AP”), Application Server (“AS”), Application Service Provider (“ASP”), Autonomous Uplink (“AUL”), Authentication Server Function (“AUSF”), Authentication Token (“AUTN”), Background Data (“BD”), Background Data Delivery (“BDT”) Beam Fault Detection (“BFD”), Beam Fault Recovery (“BFR”), Binary Phase Shift Keying (“BPSK”), Blind Repeat (“BR”), Base Station (“BS”), Buffer State Report (“BSR”), Bandwidth (“BW”), Bandwidth Portion (“BWP”), Cell RNTI (“C-RNTI”), Carrier Aggregation (“CA”), Channel Access Priority Class (“CAPC”), Contention-Based Random Access (“CBRA”), Idle Channel Assessment (“CCA”), Common Control Channel (“CCCH”), Control Channel Elements (“CCE”), Cyclic Delay Diversity (“CDD”), Code Division Multiple Access (“CDMA”) Control Elements (“CE”), Contention-Free Random Access (“CFRA”), Configuration Grant (“CG”), Closed Loop (“CL”), Cooperative Multipoint (“CoMP”), Channel Occupancy Time (“COT”), Cyclic Prefix (“CP”), Cyclic Redundancy Check (“CRC”), Channel State Information (“CSI”), Channel State Information-Reference Signal (“CSI-RS”), Common Search Space (“CSS”), Control Resource Set (“CORESET”), Discrete Fourier Transform Extended (“DFTS”), Downlink Control Information (“DCI”), Downlink Feedback Information (“DFI”), Downlink (“DL”), Demodulation Reference Signal (“DMRS”), Data Network Name (“DNN”), Data Radio Bearer (“DRB”), Discontinuous Receive (“DRX”), Dedicated Short Range Communications (“DSRC”), Downlink Pilot Slots (“DwPTS”), Enhanced Free Channel Assessment (“eCCA”), Enhanced Mobile Broadband (“eMBB”), Evolved Node B (“eNB”), Extensible Authentication Protocol (“EAP”), Effective Isotropic Radiated Power (“EIRP”), European Telecommunications Standards Institute (“ETSI”), Frame-Based Equipment (“FBE”), Frequency Division Duplex (“FDD”), Frequency Division Multiplexing (“FDM”), Frequency Division Multiple Access (“FDMA”).Frequency Division Orthogonal Coverage Code (“FD-OCC”), frequency range from 1 to below 6 GHz and / or 410 MHz to 7125 MHz (“FR1”), frequency range from 2 to 24.25 GHz to 52.6 GHz (“FR2”), Common Geographic Area Description (“GAD”), Guaranteed Bit Rate (“GBR”), Group Leader (“GL”), 5G Node B or Next Generation Node B (“gNB”), Global Navigation Satellite System (“GNSS”), General Packet Radio Service (“GPRS”), Guard Period (“GP”), Global Positioning System (“GPS”), Common Public Subscription Identifier (“GPSI”), Global System for Mobile Communications (“GSM”), Globally Unique Temporary UE Identifier (“GUTI”), Home AMF (“hAMF”), Hybrid Automatic Repeat Request (“HARQ”), HARQ Feedback (“HF”), Home Location Register (“HLR”), Handover (“HO”), Home PLMN (“HPLMN”), Home Subscriber Server (“HSS”), Hash Expected Response (“HXRES”), Identifier or Identifier (“ID”), Information Element (“IE”), International Mobile Equipment Identity (“IMEI”), International Mobile Subscriber Identity (“IMSI”), International Mobile Telecommunications Equipment (“IMT”), Internet of Things (“IoT”), Key Management Function (“KMF”), Layer 1 (“L1”), Layer 2 (“L2”) Layer 3 (“L3”), Licensed Auxiliary Access (“LAA”), Local Area Data Network (“LADN”), Local Area Network (“LAN”), Load-Based Equipment (“LBE”), Listen-After-Speak (“LBT”), Logical Channel (“LCH”), Logical Channel Group (“LCG”), Logical Channel Priority (“LCP”), Log-Likelihood Ratio (“LLR”), Long Term Evolution (“LTE”), Multiple Access (“MA”), Media Access Control (“MAC”), Multimedia Broadcast Multicast Service (“MBMS”), Maximum Bit Rate (“MBR”), Minimum Communication Range (“MCR”), Modulation and Coding Scheme (“MCS”), Master Information Block (“MIB”), Multimedia Interconnect Network Keying (“MIKEY”), Multiple-Input Multiple-Output (“MIMO”), Mobility Management (“MM”), Mobility Management Entity (“MME”), Mobile Network Operator (“MNO”), Mobile Initiation (“MO”), Massive MTC (“mMTC”), Maximum Power Reduction (“MPR”), Machine Type Communication (“MTC”), Multi-User Shared Access (“MUSA”), Non-Access Stratum (“NAS”), Narrowband (“NB”), Negative Acknowledgment (“NACK”) or (“NAK”), New Data Indicator (“NDI”), Network Entity (“NE”), Network Exposure Function (“NEF”), Network Function (“NF”), Next Generation (“NG”), NG 5G S-TMSI (“NG-5G-S-TMSI”)Non-Orthogonal Multiple Access (“NOMA”), New Radio (“NR”), Unlicensed NR (“NR-U”), Network Repository Function (“NRF”), Network Scheduling Mode (“NS Mode”) (e.g., Network Scheduling Mode for V2X Communication Resource Allocation - Mode 1 in NR V2X and Mode 3 in LTE V2X), Network Slice Instance (“NSI”), Network Slice Selection Assist Information (“NSSAI”), Network Slice Selection Function (“NSSF”), Network Slice Selection Policy (“NSSP”), Operation, Management and Maintenance System or Operation and Maintenance Center (“OAM”), Orthogonal Frequency Division Multiplexing (“OFDM”), Out-of-Order (“OOO”), Open Loop (“OL”), Other System Information (“OSI”), Power Angle Spectrum (“PAS”), Physical Broadcast Channel (“PBCH”), Power Control (“PC”), UE-to-UE Interface (“PC5”), Policy and Charging Control (“PCC”), Primary Cell (“PC”) Physical Cell Identifier (“PCell”), Policy Control Function (“PCF”), Physical Cell Identifier (“PCI”), Packet Delay Budget (“PDB”), Physical Downlink Control Channel (“PDCCH”), Packet Data Aggregation Protocol (“PDCP”), Packet Data Network Gateway (“PGW”), Physical Downlink Shared Channel (“PDSCH”), Pattern Division Multiple Access (“PDMA”), Packet Data Unit (“PDU”), Physical Hybrid ARQ Indicator Channel (“PHICH”), Power Headroom (“PH”), Power Headroom Report (“PHR”), Physical Layer (“PHY”), Public Land Mobile Network (“PLMN”), PC5 QoS Category Identifier (“PQI”), Physical Random Access Channel (“PRACH”), Physical Resource Block (“PRB”), Proximity Service (“ProSe”), Location Reference Signal (“PRS”), Physical Side Link Control Channel (“PSCCH”), Primary and Secondary Cell (“PSCell”), Physical Side Link Feedback Control Channel (“PSFCH”), Physical Side Link Control Channel (“PSSCH”), Physical Uplink Control Channel (“PUCCH”), Physical Uplink Shared Channel (“PUSCH”), QoS Category Identifier (“QCI”), Quasi-Co-location (“QCL”), Quality of Service (“QoS”), Quadrature Phase Shift Keying (“QPSK”), Registration Area (“RA”), RA RNTI (“RA-RNTI”), Radio Access Network (“RAN”), Random (“RAND”), Radio Access Technology (“RAT”), Serving RAT (“RAT-1”) (serving Uu), Other RAT (“RAT-2”) (no service Uu), Random Access Procedure (“RACH”), Random Access Preamble Identifier (“RAPID”), Random Access Response (“RAR”), Resource Block Allocation (“RBA”)Resource Element Group (“REG”), Radio Link Control (“RLC”), RLC Acknowledgment Mode (“RLC-AM”), RLC Unacknowledgment Mode / Transparent Mode (“RLC-UM / TM”), Radio Link Failure (“RLF”), Radio Link Monitoring (“RLM”), Radio Network Temporary Identifier (“RNTI”), Reference Signal (“RS”), Remaining Minimum System Information (“RMSI”), Radio Resource Control (“RRC”), Radio Resource Management (“RRM”), Resource Extended Multiple Access (“RSMA”), Reference Signal Received Power (“RSRP”), Received Signal Strength Indicator (“RSSI”), Round Trip Time (“RTT”), Receive (“RX”), Sparse Code Multiple Access (“SCMA”), Scheduling Request (“SR”), Sounding Reference Signal (“SRS”), Single Carrier Frequency Division Multiple Access (“SC-FDMA”), Secondary Cell (“SCell”), Secondary Cell Group (“SCG”), Shared Channel (“SCH”), Side Link Control Information ( “SCI”, Subcarrier Spacing (“SCS”), Serving Data Unit (“SDU”), Security Anchor Function (“SEAF”), Sidelink Feedback Content Information (“SFCI”), Serving Gateway (“SGW”), System Information Block (“SIB”), System Information Block Type 1 (“SIB1”), System Information Block Type 2 (“SIB2”), Subscriber Identifier / Identifier Module (“SIM”), Signal-to-Interference-plus-Noise Ratio (“SINR”), Sidelink (“SL”), Service Level Agreement (“SLA”), Sidelink Radio Bearer (“SLRB”), Sidelink Synchronization Signal (“SLSS”), Session Management (“SM”), Session Management Function (“SMF”), Special Cell (“SpCell”), Single Network Slice Selection Auxiliary Information (“S-NSSAI”), Scheduling Request (“SR”), Signaling Radio Bearer (“SRB”), Shortened TMSI (“S-TMSI”), Shortened TTI (“sTTI”), Synchronization Signal (“SS”), Sidelink CSI RS (“S-CSI RS”), Side Link PRS (“S-PRS”), Side Link SSB (“S-SSB”), Synchronization Signal Block (“SSB”), Subscription Hidden Identifier (“SUCI”), Scheduled User Equipment (“SUE”), Supplemental Uplink (“SUL”), Subscriber Permanent Identifier (“SUPI”), Tracking Area (“TA”), TA Identifier (“TAI”), TA Update (“TAU”), Timing Calibration Timer (“TAT”), Transport Block (“TB”), Transport Block Size (“TBS”), Time Division Duplex (“TDD”), Time Division Multiplexing (“TDM”), Time Division Orthogonal Cover Code (“TD-OCC”), Temporary Mobile Subscriber Identifier (“TMSI”), Time of Flight (“ToF”), Transmit Power Control (“TPC”).Transmitter Receiver Point (“TRP”), Transmission Time Interval (“TTI”), Transmit (“TX”), Transmitter User Equipment (“TX UE”), Uplink Control Information (“UCI”), Unified Data Management Function (“UDM”), Unified Data Repository (“UDR”), User Entity / Equipment (Mobile Terminal) (“UE”) (e.g., V2X UE), UE Autonomy Mode (UE autonomously selects V2X communication resources - e.g., Mode 2 in NR V2X and Mode 4 in LTE V2X. UE autonomy may be based on or not based on resource sensing operations), Uplink (“UL”), UL SCH (“UL-SCH”), Universal Mobile Telecommunications System (“UMTS”), User Plane (“UP”), UP Function (“UPF”), Uplink Pilot Slot (“UpPTS”), Ultra-Reliable Low-Latency Communication (“URLLC”), UE Routing Policy (“URSP”), Vehicle-to-Vehicle (“V2V”), Vehicle-to-Everything (“V2X”), V2X The UE (e.g., a UE capable of vehicular communication using 3GPP protocols), the visited AMF (“vAMF”), V2X encryption key (“VEK”), V2X group key (“VGK”), V2X MIKEY key (“VMK”), the visited NSSF (“vNSSF”), the visited PLMN (“VPLMN”), the V2X service key (“VTK”), the wide area network (“WAN”), and global microwave access interoperability (“WiMAX”).

[0004] In some wireless communication networks, side link feedback can be disabled. Summary of the Invention

[0005] Methods for retransmitting transport blocks without enabling lateral crosslink feedback are disclosed. Apparatus and systems also perform the functions of these methods. One embodiment of a method includes determining whether lateral crosslink feedback is enabled for a transport block. In some embodiments, the method includes retransmitting the transport block a predetermined number of times in response to disabling lateral crosslink feedback for the transport block.

[0006] An apparatus for retransmitting a transport block without enabling lateral crosslink feedback includes a processor that determines whether lateral crosslink feedback is enabled for the transport block. In various embodiments, the apparatus includes a transmitter that retransmits the transport block a predetermined number of times in response to disabling lateral crosslink feedback for the transport block. Attached Figure Description

[0007] A more detailed description of the embodiments briefly described above will be presented with reference to specific embodiments illustrated in the accompanying drawings. It should be understood that these drawings depict only some embodiments and are therefore not intended to limit the scope. The embodiments will be described and explained with additional specificity and detail using the drawings, in which:

[0008] Figure 1 This is a schematic block diagram illustrating one embodiment of a wireless communication system for retransmitting transport blocks without enabling side link feedback;

[0009] Figure 2 This is a schematic block diagram illustrating one embodiment of an apparatus that can be used to retransmit transport blocks without enabling side link feedback;

[0010] Figure 3 This is a schematic block diagram illustrating one embodiment of an apparatus that can be used to retransmit transport blocks without enabling side link feedback;

[0011] Figure 4 This is a timing diagram illustrating an embodiment of responding to feedback received from an SL authorization;

[0012] Figure 5 This is a flowchart illustrating one embodiment of the UE's behavior after receiving SL authorization;

[0013] Figure 6 This is a table illustrating one embodiment of different UE behaviors based on whether sidelink feedback is enabled; and

[0014] Figure 7 This is a flowchart illustrating an embodiment of a method for retransmitting transport blocks without enabling side link feedback. Detailed Implementation

[0015] As those skilled in the art will understand, aspects of the embodiments can be embodied as a system, apparatus, method, or program product. Therefore, embodiments can take the form of a completely hardware embodiment, a completely software embodiment (including firmware, resident software, microcode, etc.), or an embodiment combining software and hardware aspects, which may generally be referred to herein as "circuit," "module," or "system." Furthermore, embodiments can take the form of a program product embodied in one or more computer-readable storage devices stored in machine-readable code, computer-readable code, and / or program code, hereinafter referred to as code. The storage device can be tangible, non-transitory, and / or non-transferable. The storage device may not embody signals. In one embodiment, the storage device uses only signals for accessing the code.

[0016] Certain functional units described in this specification may be designated as modules to more specifically emphasize their implementation independence. For example, modules may be implemented as hardware circuits comprising custom-designed very large-scale integration (“VLSI”) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. Modules may also be implemented in programmable hardware devices such as field-programmable gate arrays, programmable array logic, programmable logic devices, etc.

[0017] Modules can also be implemented in code and / or software for execution by various types of processors. The identified code modules can, for example, comprise one or more physical or logical blocks of executable code, which can be organized, for example, as objects, procedures, or functions. However, the executable files of the identified modules do not need to be physically located together, but can include entirely different instructions stored in different locations that, when logically combined, encompass the module and implement its stated purpose.

[0018] In practice, a code module can be a single instruction or many instructions, and can even be distributed across several different code segments, different programs, and across several memory devices. Similarly, in this document, operational data can be identified and illustrated within a module, and can be represented in any suitable form and organized within any suitable type of data structure. Operational data can be collected as a single dataset or can be distributed across different locations, including across different computer-readable storage devices. Where a module or part of a module is implemented in software, the software portion is stored on one or more computer-readable storage devices.

[0019] Any combination of one or more computer-readable media can be used. A computer-readable medium can be a computer-readable storage medium. A computer-readable storage medium can be a storage device for storing code. A storage device can be, for example, but not limited to, electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof.

[0020] More specific examples of storage devices (a non-exhaustive list) will include the following: electrical connections having one or more cables, portable computer disks, hard disks, random access memory (“RAM”), read-only memory (“ROM”), erasable programmable read-only memory (“EPROM” or flash memory), portable optical disc read-only memory (“CD-ROM”), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium can be any tangible medium capable of containing or storing programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0021] The code used to perform the operations of the embodiments can be any number of lines and can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Python, Ruby, Java, Smalltalk, C++, and conventional procedural programming languages ​​such as the "C" programming language, and / or machine languages ​​such as assembly language. The code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer via any type of network, including a local area network ("LAN") or a wide area network ("WAN"), or can connect to an external computer (e.g., via the Internet provided by an Internet service provider).

[0022] Throughout this specification, references to "an embodiment," "embodiment," or similar language mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Therefore, unless explicitly stated otherwise, the phrases "in an embodiment," "in an embodiment," and similar language throughout this specification may, but do not necessarily all refer to the same embodiment, but rather mean "one or more, but not all, embodiments." Unless explicitly stated otherwise, the terms "comprising," "including," "having," and variations thereof mean "including, but not limited to,". Unless explicitly stated otherwise, the list of enumerated items does not imply that any or all of the items are mutually exclusive. Unless explicitly stated otherwise, the terms "a," "an," and "the" also mean "one or more".

[0023] Furthermore, the features, structures, or characteristics of the described embodiments can be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selection, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of the embodiments. However, those skilled in the art will recognize that the embodiments can be practiced without one or more specific details or using other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the embodiments.

[0024] The following description of aspects of embodiments is based on schematic flowcharts and / or schematic block diagrams of methods, apparatus, systems, and program products according to embodiments. It will be understood that each block of the schematic flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. The code can be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to generate machinery, such that instructions executable via the processor of the computer or other programmable data processing apparatus create means for implementing the functions / actions specified in the blocks or blocks of the schematic flowcharts and / or schematic block diagrams.

[0025] The code can also be stored in a storage device that can instruct a computer, other programmable data processing device or other device to operate in a particular manner, such that the instructions stored in the storage device produce an article of art including instructions that implement the functions / actions specified in the schematic flowchart and / or schematic block diagram boxes or blocks.

[0026] The code may also be loaded onto a computer, other programmable data processing apparatus or other device to cause a series of operational steps to be executed on the computer, other programmable apparatus or other device to produce a computer-implemented process, such that the code executing on the computer or other programmable apparatus provides a process for implementing the function / action specified in the flowchart and / or block diagram boxes or boxes.

[0027] The schematic flowcharts and / or schematic block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, systems, methods, and program products according to various embodiments. In this regard, each block in the schematic flowcharts and / or schematic block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions for implementing a specified logical function.

[0028] It should also be noted that in some alternative implementations, the functions indicated in the boxes may not occur in the order shown in the figures. For example, depending on the functions involved, two consecutively shown boxes may actually be executed substantially simultaneously, or these boxes may sometimes be executed in reverse order. Other steps and methods that are functionally, logically, or effectively equivalent to one or more boxes or portions thereof in the illustrated figures are conceivable.

[0029] While various arrow and line types may be employed in flowcharts and / or block diagrams, understanding them does not limit the scope of the corresponding embodiments. In fact, some arrows or other connectors may be used solely to indicate the logical flow of the depicted embodiments. For example, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of a depicted embodiment. It will also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system or by a combination of dedicated hardware and code that performs a specific function or action.

[0030] The description of elements in each figure may refer to elements in the figure in progress. In all figures, the same reference numerals refer to the same elements, including alternative embodiments of the same elements.

[0031] Figure 1 An embodiment of a wireless communication system 100 for retransmitting transport blocks without enabling lateral crosslink feedback is described. In one embodiment, the wireless communication system 100 includes a remote unit 102 and a network unit 104. Although Figure 1 A specific number of remote units 102 and network units 104 are depicted, but those skilled in the art will recognize that any number of remote units 102 and network units 104 can be included in the wireless communication system 100.

[0032] In one embodiment, remote unit 102 may include computing devices such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smartphones, smart TVs (e.g., internet-connected televisions), set-top boxes, game consoles, security systems (including security cameras), in-vehicle computers, network devices (e.g., routers, switches, modems), aircraft, drones, etc. In some embodiments, remote unit 102 includes wearable devices such as smartwatches, fitness bands, optical head-mounted displays, etc. Furthermore, remote unit 102 may be referred to as a subscriber unit, mobile device, mobile station, user, terminal, mobile terminal, fixed terminal, subscriber station, UE, user terminal, device, or other terms used in the art. Remote unit 102 may communicate directly with one or more network units 104 via UL communication signals. In some embodiments, remote unit 102 may communicate directly with other remote units 102 via sidelink communication.

[0033] Network unit 104 may be distributed across a geographical area. In some embodiments, network unit 104 may also be referred to as an access point, access terminal, base station, base station, node B, eNB, gNB, home node B, relay node, device, core network, air server, wireless access node, AP, NR, network entity, AMF, UDM, UDR, UDM / UDR, PCF, RAN, NSSF, AS, NEF, key management server, KMF, or any other term used in the art. Network unit 104 is typically part of a radio access network that includes one or more controllers communicatively coupled to one or more corresponding network units 104. The radio access network is typically communicatively coupled to one or more core networks, which may be coupled to other networks such as the Internet and the public switched telephone network, etc. These and other elements of the radio access and core networks are not illustrated but are generally well known to those skilled in the art.

[0034] In one implementation, the wireless communication system 100 conforms to the standardized NR protocol in 3GPP, wherein network unit 104 transmits over DL using an OFDM modulation scheme, and remote unit 102 transmits over UL using an SC-FDMA scheme or an OFDM scheme. However, more generally, the wireless communication system 100 can implement other open or proprietary communication protocols, such as WiMAX, IEEE 802.11 variants, GSM, GPRS, UMTS, LTE variants, CDMA2000, etc. ZigBee, Sigfoxx, and other protocols. This disclosure is not intended to limit implementation to any particular wireless communication system architecture or protocol.

[0035] Network unit 104 can serve multiple remote units 102 within a service area, such as a cell or cell sector, via a wireless communication link. Network unit 104 transmits DL communication signals to serve remote units 102 in the time, frequency, and / or spatial domains.

[0036] In various embodiments, remote unit 102 and / or network unit 104 can determine whether lateral crosslink feedback is enabled for a transport block. In some embodiments, remote unit 102 and / or network unit 104 can retransmit the transport block a predetermined number of times in response to lateral crosslink feedback being disabled for the transport block. Therefore, remote unit 102 and / or network unit 104 can be used to retransmit the transport block without lateral crosslink feedback being enabled.

[0037] Figure 2An embodiment of an apparatus 200 is depicted that can be used to retransmit transport blocks without enabling lateral crosslink feedback. The apparatus 200 includes one embodiment of a remote unit 102. Furthermore, the remote unit 102 may include a processor 202, a memory 204, an input device 206, a display 208, a transmitter 210, and a receiver 212. In some embodiments, the input device 206 and the display 208 are combined into a single device, such as a touchscreen. In some embodiments, the remote unit 102 may not include any input device 206 and / or the display 208. In various embodiments, the remote unit 102 may include one or more of the processor 202, memory 204, transmitter 210, and receiver 212, and may not include the input device 206 and / or the display 208.

[0038] In one embodiment, processor 202 may include any known controller capable of executing computer-readable instructions and / or performing logical operations. For example, processor 202 may be a microcontroller, microprocessor, central processing unit (“CPU”), graphics processing unit (“GPU”), auxiliary processing unit, field-programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, processor 202 executes instructions stored in memory 204 to perform the methods and routines described herein. Processor 202 is communicatively coupled to memory 204, input device 206, display 208, transmitter 210, and receiver 212.

[0039] In one embodiment, memory 204 is a computer-readable storage medium. In some embodiments, memory 204 includes volatile computer storage media. For example, memory 204 may include RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and / or static RAM (“SRAM”). In some embodiments, memory 204 includes non-volatile computer storage media. For example, memory 204 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 204 includes both volatile and non-volatile computer storage media. In some embodiments, memory 204 also stores program code and associated data, such as an operating system or other controller algorithms operating on remote unit 102.

[0040] In one embodiment, input device 206 may include any known computer input device, including a touchpad, button, keyboard, stylus, microphone, etc. In some embodiments, input device 206 may be integrated with display 208, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, input device 206 includes a touchscreen, allowing text to be entered using a virtual keyboard displayed on the touchscreen and / or by handwriting on the touchscreen. In some embodiments, input device 206 includes two or more different devices such as a keyboard and a touchpad.

[0041] In one embodiment, display 208 may include any known electronically controllable display or display device. Display 208 may be designed to output visual, auditory, and / or tactile signals. In some embodiments, display 208 includes an electronic display capable of outputting visual data to a user. For example, display 208 may include, but is not limited to, LCD displays, LED displays, OLED displays, projectors, or similar display devices capable of outputting images, text, etc., to a user. As another non-limiting example, display 208 may include wearable displays such as smartwatches, smart glasses, head-up displays, etc. Furthermore, display 208 may be a component of a smartphone, personal digital assistant, television, desktop computer, laptop computer, personal computer, vehicle dashboard, etc.

[0042] In some embodiments, display 208 includes one or more speakers for generating sound. For example, display 208 may generate an audible alarm or notification (e.g., a beep or ringtone). In some embodiments, display 208 includes one or more haptic devices for generating vibration, motion, or other haptic feedback. In some embodiments, all or part of display 208 may be integrated with input device 206. For example, input device 206 and display 208 may form a touchscreen or similar touch-sensitive display. In other embodiments, display 208 may be positioned near input device 206.

[0043] In some embodiments, processor 202 may determine whether sidelink feedback is enabled for a transport block. In various embodiments, transmitter 210 may retransmit the transport block a predetermined number of times in response to sidelink feedback being disabled for a transport block.

[0044] Although only one transmitter 210 and one receiver 212 are illustrated, the remote unit 102 can have any suitable number of transmitters 210 and receivers 212. The transmitters 210 and receivers 212 can be of any suitable type. In one embodiment, the transmitters 210 and receivers 212 can be part of a transceiver.

[0045] Figure 3 An embodiment of an apparatus 300 is depicted that can be used to retransmit transport blocks without enabling side link feedback. Apparatus 300 includes one embodiment of a network unit 104. Furthermore, network unit 104 may include a processor 302, a memory 304, an input device 306, a display 308, a transmitter 310, and a receiver 312. As will be understood, processor 302, memory 304, input device 306, display 308, transmitter 310, and receiver 312 may be substantially similar to processor 202, memory 204, input device 206, display 208, transmitter 210, and receiver 212 of remote unit 102, respectively.

[0046] In some embodiments, processor 302 may determine whether sidelink feedback is enabled for a transport block. In various embodiments, transmitter 310 may retransmit the transport block a predetermined number of times in response to sidelink feedback being disabled for a transport block.

[0047] In some embodiments, if the gNB provides a Mode 1-based SL grant to a transmitter (TX) UE, and the TX UE uses the Mode 1-based SL grant to transmit data to one or more receiver UEs, the gNB may additionally provide PUCCH resources. These PUCCH resources can be used to send aggregated and / or combined feedback to the gNB. Based on the feedback received from the TX UE, the gNB can provide resources for new transmissions or for retransmitting the current TB in a transmission from the transmitter.

[0048] Figure 4This is a timing diagram 400 illustrating an embodiment of a response to receiving feedback on an SL grant. Timing diagram 400 illustrates signals that appear as time 402 elapses. At a first time 404, a DCI is transmitted from the gNB to the TX UE. The DCI may include a PSCCH grant, an SL feedback grant on the Uu, etc. A first time period 406Kb may occur from the first time 404 to a second time 410. At the second time 410, an SCI (e.g., a PSCCH) may be transmitted from the TX UE to the RX UE. A second time period 412Kb may occur from the second time 410 to a third time 414. At the third time 414, the TX UE may transmit a PSSCH to the RX UE. At a fourth time 416, a fifth time 418, and / or a sixth time 420, respectively, a first RX UE may transmit feedback to the TX UE, a second RX UE may transmit feedback to the TX UE, and a third RX UE may transmit feedback to the TX UE. At a seventh time 422, the TX UE may transmit an SL feedback to the gNB. The third time period, 424Kc, can occur from the first time period, 404, to the seventh time period, 422. At the eighth time period, 426, the gNB can transmit DCI to the TX UE. DCI can include retransmission PSCCH authorization, SL feedback authorization on the Uu, etc.

[0049] In various embodiments, if the TX UE receives an SL authorization from the gNB, the TX UE can use the received SL authorization to prepare a TB to be transmitted. In some embodiments, various UE behaviors exist if the TX UE makes multiple determinations, such as whether the UE needs to perform a blind retransmission instead of seeking feedback from the receiver UE on the PC5.

[0050] In some embodiments, blind retransmission may be available in NR V2X communication. In various embodiments, a deterministic mechanism may be used to determine whether a transmitter UE needs to perform a blind retransmission. In some embodiments, a transmitter UE operating in NR V2X mode 1 may obtain authorization for retransmission without first seeking feedback from a receiver UE.

[0051] In some embodiments, enabling and / or disabling SL HARQ feedback can be supported (e.g., configured at the SLRB level). This can be configured via RRC messages for both Mode 1 and Mode 2 UEs. In various embodiments, such as for idle, inactive, and / or OOC UEs, this can be configured in SIB and / or pre-configured messages.

[0052] In some embodiments, the meaning of "enabled" and "disabled" regarding HARQ feedback ("HF") may be unknown. In one embodiment, "enabled" may mean that for a given LCH, the TX UE is "allowed" to seek HARQ feedback from the receiver, but it may decide not to seek feedback. In another embodiment, "enabled" may mean that once the LCH restriction for HF is set to "enabled," the TX UE must seek feedback from the receiver. In some embodiments, "disabled" may mean that the TX UE can only perform one (e.g., a single) transmission of the corresponding data, or, in other embodiments, "disabled" may mean that the TX UE performs a fixed number of transmissions and / or retransmissions of the corresponding data without seeking feedback from the receiver (e.g., blind transmissions and / or blind retransmissions). Because different combinations of TX UE behavior are possible, the behavior of the UE may differ if there is no uniform definition for "enabled" and "disabled." This may lead to system inefficiency or malfunction.

[0053] In various embodiments, after receiving an SL grant from the gNB, the TX UE can use the received SL grant in various ways. In one example, the TX UE decides for itself whether it needs to seek feedback for the TB prepared for the received SL grant. In another example, the gNB indicates to the TX UE whether to seek feedback for the TB (e.g., in a DCI containing the SL grant). In one embodiment, the gNB makes all determinations (e.g., feedback, blind retransmission, etc.) and the TX UE complies with the instructions from the gNB.

[0054] In some embodiments, the gNB can decide everything, including whether the UE should perform a blind retransmission. These decisions in the gNB may be based on the UE's buffer state report (“BSR”). In such embodiments, the gNB may not know how long the packet base has been waiting for transmission in the UE buffer, and the gNB may have difficulty determining whether a feedback-based retransmission should be performed or whether the remaining time is short (e.g., the remaining packet delay budget “PDB”). Furthermore, in such embodiments, if sidelink communication is widely deployed and / or used, the capacity availability of network nodes may be limited in their ability to control every aspect of sidelink communication. As can be understood, network node control may be difficult to perform if a short latency (e.g., 3ms) is required.

[0055] In the first embodiment, there may be a new sequence of TX UE behaviors that are executed once SL authorization (e.g., mode 1 or mode 2) becomes available.

[0056] Figure 5This is a flowchart 500 illustrating one embodiment of UE behavior after receiving SL authorization. The described steps can be performed by the TX UE after it receives SL authorization.

[0057] In the first step 502, the TX UE may perform the first round of LCH restrictions (e.g., based on restrictions such as cell restrictions, parameter sets, etc.).

[0058] In the second step 504, the TX UE can perform destination selection based on the highest priority logical channel across all destinations.

[0059] In the third step 506, the TX UE can use the HF enable and / or disable status of the highest priority LCH used in the second step 504 to determine the HF enable and / or disable status of the entire TB.

[0060] In step 508, the TX UE can perform a second round of LCH constraints, where the TX UE selects only those LCHs that conform to steps 502, 504, and 506 and have the same feedback pattern determined for the entire TB. The LCP process can then be run on the resulting LCHs.

[0061] In step 510, the TX UE may determine whether BR is required for TB as follows: 1) BR is performed whenever HARQ feedback is determined to be disabled for TB; and / or 2) even when HARQ feedback is determined to be enabled for TB, the UE may still decide to perform blind retransmission (e.g., based on the remaining PDB and / or the required reliability, i.e., the highest reliability required by any LCH data that is part of TB).

[0062] In step 6, 514, if BR is to be performed, the TX UE can submit the number of TBs and blind retransmissions (e.g., configured values) to the lower layer and / or the physical layer.

[0063] In step 7, 518, if BR is not performed, the TX UE can determine whether the HF option should be used.

[0064] In step 8, 520, TX UE can determine the MCR.

[0065] In step 9, 522, the TX UE may submit TB, HF options, and / or MCR to the lower layer and / or physical layer.

[0066] In various embodiments, PUCCH resources are signaled to the TX UE, the TX UE can combine feedback from the receiver UE, and / or the TX UE can signal the combined feedback to the gNB.

[0067] In some embodiments, if, for Mode 1 authorization, the TX UE has received PUCCH resources from the gNB for signaling combined PC5 HARQ feedback, and the TX UE has determined that a blind retransmission will be performed on the corresponding transmission, the TX UE may transmit the combined PC5 HARQ feedback as "NACK" without seeking and / or receiving HARQ feedback from its receiver. This may trigger the gNB to provide resources for PC5 retransmission. In such embodiments, the transmitter may provide the combined PC5 HARQ feedback as "NACK" for further retransmissions, provided that the packet delay budget (e.g., delay) from any or all data from any included logical channel does not exceed or is not greater than the maximum number of blind retransmissions. As used herein, the "maximum number of blind retransmissions" may be configured, pre-configured, specified, or determined by the UE implementation. In various embodiments, the last PC5 HARQ feedback sent to the gNB is always set to "ACK," causing the gNB to stop providing resources for retransmission. In such an embodiment, the TXUE determines the final combined PC5 HARQ feedback as feedback corresponding to the last retransmission or the maximum number of blind retransmissions within the packet delay budget (e.g., the last transmission is the transmission whose next potential retransmission will exceed at least one of these thresholds).

[0068] In some embodiments, if PUCCH resources are unavailable (e.g., for mode 1 authorization, the TX UE has not yet received PUCCH resources from the gNB for signaling combined PC5 HARQ feedback), the TX UE may autonomously switch to mode 2 resource acquisition for blind retransmission if it determines that blind retransmission is required for the corresponding TB, or for retransmission based on sidelink PC5 feedback.

[0069] Figure 6 Table 600 illustrates one embodiment of different UE behaviors based on whether sidelink feedback is enabled.

[0070] Specifically, Figure 6Four different options for UE behavior are illustrated depending on how the LCH (e.g., SLRB) configuration for HARQ feedback enabled and / or disabled is interpreted. In some embodiments, such as for each new transmission, the TX UE selects the destination of the logical channel with the highest priority (e.g., among logical channels with data available for transmission and no mapping restrictions on sidelink grants). In such embodiments, the logical channel responsible for destination selection can determine whether HARQ feedback for TB is enabled or disabled. Therefore, in such embodiments, if the selected highest priority LCH already has HARQ feedback enabled, the LCP can only consider the LCHs with HARQ feedback enabled for the selected destination. On the other hand, if the selected highest priority LCH has HARQ feedback disabled, the LCP can only consider the LCHs with HARQ feedback disabled for the selected destination. Thus, HARQ feedback for TB is determined to be HF enabled or disabled based on the LCH (e.g., SLRB) configuration for HARQ feedback of the selected highest priority LCH.

[0071] exist Figure 6 In the first option illustrated in the diagram (e.g., option 1), if HARQ feedback for the TB is disabled, the TXUE can perform multiple blind retransmissions. The number of retransmissions can be configured, pre-configured, specified, and / or based on the UE implementation. Figure 6 In the first option shown in the diagram, if HARQ feedback for the TB is enabled, the TX UE can assess whether to perform blind transmission or feedback-based retransmission based on the reliability of the selected logical channel in the remaining PDB and TB.

[0072] exist Figure 6 In the second option illustrated in the diagram (e.g., option 2), if HARQ feedback for TB is disabled, the TXUE can perform multiple blind retransmissions. The number of retransmissions can be configured, pre-configured, specified, and / or based on the UE implementation. Figure 6 In the second option illustrated in the diagram, if HARQ feedback for TB is enabled, the TX UE can decide to perform feedback-based HARQ retransmission, seek HARQ feedback from the receiver UE, and / or provide the necessary information (e.g., PSCCH) in the SCI.

[0073] exist Figure 6 In the third option shown in the diagram (e.g., option 3), regardless of whether HARQ feedback for the TB is enabled or disabled, the TX UE can assess whether to perform blind transmission or feedback-based retransmission based on the reliability of the selected logical channel in the remaining PDB and TB.

[0074] exist Figure 6In the fourth option illustrated in the diagram (e.g., option 4), if the number of blind retransmissions is fixed at 0, the TX UE performs one TB transmission (e.g., no retransmission), does not seek any HARQ feedback from the receiver, and then moves on to the next TB. Figure 6 In the fourth option shown in the diagram, if HARQ feedback for TB is enabled, the TX UE can assess whether to perform blind retransmission or feedback-based retransmission based on the reliability of the selected logical channel in the remaining PDB and TB.

[0075] In various embodiments, if the TX UE or receiver UE does not have GPS capability during transmission and / or reception, it can be assumed that the distance between the transmitter and receiver is less than or equal to the MCR. In some embodiments, the feedback mechanism can operate regardless of the MCR value (e.g., whether it is signaled in the SCI). In such embodiments, if the receiver can successfully decode both the PSCCH and PSSCH, the receiver can send an "ACK" feedback to the transmitter; otherwise, the receiver can send a "NACK". In some embodiments, the feedback signaling can be a DTX transmission (e.g., a DTX transmission can be used to signal an "ACK").

[0076] Figure 7 This is a flowchart illustrating one embodiment of a method 700 for retransmitting transport blocks without enabling side-link feedback. In some embodiments, method 700 is performed by means such as remote unit 102 and / or network unit 104. In some embodiments, method 700 may be performed by a processor executing program code, such as a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0077] In various embodiments, method 700 includes determining 702 whether lateral crosslink feedback is enabled for a transport block. In some embodiments, method 700 includes retransmitting 704 a predetermined number of transport blocks in response to disabling lateral crosslink feedback for a transport block.

[0078] In some embodiments, method 700 further includes transmitting unacknowledged feedback to the network device on the physical uplink control channel in response to disabling sidelink feedback for the transport block. In some embodiments, transmitting unacknowledged feedback to the network device includes transmitting unacknowledged feedback to the network device after each transmission of the transport block except for the last transmission of the transport block. In various embodiments, method 700 further includes transmitting acknowledgment feedback to the network device on the physical uplink control channel after the last transmission of the transport block.

[0079] In one embodiment, method 700 further includes receiving resources for retransmitting the transport block in response to transmitting unacknowledged feedback to the network device. In some embodiments, method 700 further includes determining whether to retransmit the transport block. In some embodiments, determining whether to retransmit the transport block includes determining whether to retransmit the transport block based on the remaining packet delay budget, a reliability factor, or a combination thereof.

[0080] In various embodiments, method 700 further includes determining what feedback to transmit to the network device in response to enabling sidelink feedback for a transport block. In one embodiment, determining what feedback to transmit to the network device includes determining what feedback to transmit based on remaining packet delay budget, reliability factor, remaining retransmission count, availability of physical sidelink feedback channel resources, availability of physical uplink control channel resources, or a combination thereof. In some embodiments, the predetermined number of retransmissions is the maximum number of retransmissions after the first transmission has been performed.

[0081] In one embodiment, a method includes: determining whether sidelink feedback is enabled for a transport block; and retransmitting the transport block a predetermined number of times in response to disabling sidelink feedback for the transport block.

[0082] In some embodiments, the method further includes transmitting unacknowledged feedback to the network device on the physical uplink control channel in response to the disabling of sidelink feedback for the transport block.

[0083] In some embodiments, sending an unacknowledged feedback to a network device includes sending an unacknowledged feedback to the network device after each transmission of a transport block, except for the last transmission of the transport block.

[0084] In various embodiments, the method further includes transmitting an acknowledgment feedback to the network device on the physical uplink control channel after the final transmission of the transport block.

[0085] In one embodiment, the method further includes receiving resources for retransmitting transport blocks in response to transmitting unacknowledged feedback to the network device.

[0086] In some embodiments, the method further includes determining whether to retransmit the transport block.

[0087] In some embodiments, determining whether to retransmit a transport block includes determining whether to retransmit the transport block based on the remaining packet delay budget, the reliability factor, or a combination thereof.

[0088] In various embodiments, the method further includes determining what feedback to transmit to the network device in response to enabling side link feedback for a transport block.

[0089] In one embodiment, determining what feedback to send to the network device includes determining what feedback to send to the network device based on the remaining packet delay budget, reliability factor, remaining retransmission count, availability of physical side downlink feedback channel resources, availability of physical uplink control channel resources, or a combination thereof.

[0090] In some embodiments, the predetermined number of times is the maximum number of retransmissions after the first transmission has been performed.

[0091] In one embodiment, an apparatus includes: a processor that determines whether sidelink feedback is enabled for a transport block; and a transmitter that retransmits the transport block a predetermined number of times in response to sidelink feedback being disabled for the transport block.

[0092] In some embodiments, the transmitter transmits unacknowledged feedback to the network device on the physical uplink control channel in response to the disabling of sidelink feedback for the transport block.

[0093] In some embodiments, transmitting unacknowledged feedback to a network device includes transmitting unacknowledged feedback to the network device after each transmission of a transport block, except for the last transmission of the transport block.

[0094] In various embodiments, after the final transmission of the transport block, the transmitter sends an acknowledgment feedback to the network device on the physical uplink control channel.

[0095] In one embodiment, the apparatus further includes a receiver that receives resources for retransmitting transport blocks in response to transmitting unacknowledged feedback to the network device.

[0096] In some embodiments, the processor determines whether to retransmit the transport block.

[0097] In some embodiments, the processor determines whether to retransmit the transport block based on the remaining packet delay budget, the reliability factor, or a combination thereof.

[0098] In various embodiments, the processor determines what feedback to send to the network device in response to enabling side link feedback for the transport block.

[0099] In one embodiment, the processor determines what feedback to send to the network device by basing the processor's decision on remaining packet delay budget, reliability factor, remaining retransmission count, availability of physical-side downlink feedback channel resources, availability of physical uplink control channel resources, or a combination thereof.

[0100] In some embodiments, the predetermined number of times is the maximum number of retransmissions after the first transmission has been performed.

[0101] The embodiments may be practiced in other specific forms. The described embodiments are to be regarded in all respects as illustrative rather than restrictive. Therefore, the scope of the invention is indicated by the appended claims rather than by the foregoing description. All variations within the meaning and equivalents of the claims are included within their scope.

Claims

1. A method performed by a user equipment (UE), the method comprising: Receive logical channel (LCH) configuration, which indicates whether side-link feedback is enabled or disabled for LCH; Based on the received LCH configuration, it was determined that side-link feedback was disabled; In response to the disabling of the side link feedback, the transport block is retransmitted in response to the availability of retransmission authorization; In response to the disabling of the side-link feedback for the transport block, an unacknowledged NACK feedback is transmitted to the network device on the Physical Uplink Control Channel (PUCCH); and In response to the NACK feedback, an authorization for retransmission is received, wherein the transport block is retransmitted a maximum number of times after the first transmission has been performed.

2. The method according to claim 1, wherein, Sending the NACK feedback to the network device includes sending the NACK feedback to the network device after each transmission of the transport block, except for the last transmission of the transport block.

3. The method according to claim 2, further comprising: After the final transmission of the transport block, an ACK feedback is sent to the network device on the PUCCH.

4. The method according to claim 1, further comprising: Whether to retransmit the transport block is determined based on the remaining packet delay budget, the reliability factor, or a combination thereof.

5. A user equipment (UE), comprising: At least one memory; as well as At least one processor, coupled to the at least one memory and configured such that the UE: Receive logical channel (LCH) configuration, which indicates whether side-link feedback is enabled or disabled for LCH; Based on the received LCH configuration, it was determined that side-link feedback was disabled; In response to the disabling of the side link feedback, the transport block is retransmitted in response to the availability of retransmission authorization; In response to the disabling of the side-link feedback for the transport block, an unacknowledged NACK feedback is transmitted to the network device on the Physical Uplink Control Channel (PUCCH); and In response to the NACK feedback, an authorization for retransmission is received, wherein the transport block is retransmitted a maximum number of times after the first transmission has been performed.

6. The UE according to claim 5, wherein, The at least one processor is configured such that the UE sends the NACK feedback to the network device after each transmission of the transport block, except for the last transmission of the transport block.

7. The UE according to claim 6, wherein, The at least one processor is further configured such that the UE: After the final transmission of the transport block, an ACK feedback is sent to the network device on the PUCCH.

8. The UE according to claim 5, wherein, The at least one processor is configured such that the UE: Determine whether to retransmit the transport block.

9. A method performed by a base station, the method comprising: Send logical channel (LCH) configuration, which indicates whether the LCH for the user equipment (UE) is enabled or disabled for side-link feedback; In response to the sidelink feedback being disabled for the UE, a non-acknowledgmented NACK feedback is received from the UE, wherein the NACK feedback is received after each transmission of the UE except for the last transmission of the UE, wherein at least one transmission includes a retransmission in response to a retransmission authorization. An ACK (acknowledgment) is received after the final transmission of the transmission block. as well as In response to the NACK feedback, an authorization for retransmission is sent, wherein the transport block is retransmitted a maximum number of times after the first transmission has been performed.

10. A base station, comprising: At least one memory; as well as At least one processor, coupled to the at least one memory and configured such that the base station: Send logical channel (LCH) configuration, which indicates whether the LCH for the user equipment (UE) is enabled or disabled for side-link feedback; In response to the sidelink feedback being disabled for the UE, a non-acknowledgmented NACK feedback is received from the UE, wherein the NACK feedback is received after each transmission of the UE except for the last transmission of the UE, wherein at least one transmission includes a retransmission in response to a retransmission authorization. An ACK (acknowledgment) is received after the final transmission of the transmission block. as well as In response to the NACK feedback, an authorization for retransmission is sent, wherein the transport block is retransmitted a maximum number of times after the first transmission has been performed.

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