Method and apparatus for hybrid automatic repeat request buffer management

Abstract

Certain aspects of the present disclosure provide techniques for managing a hybrid automatic repeat request (HARQ) buffer. An example method that may be performed by a first user equipment (UE) includes: in response to a HARQ budget being exceeded relative to the number of active HARQ processes, discarding at least one transmission or one or more transport blocks (TBs) associated with the at least one transmission so that they are not processed according to one or more rules. The method further includes processing remaining transmissions and taking one or more actions based on the processed remaining transmissions.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 16 / 993,068, filed on August 13, 2020, which claims priority to U.S. Provisional Application No. 62 / 891,884, filed on August 26, 2019, both of which are assigned to the assignee of this application and are hereby expressly incorporated herein by reference in their entirety.

[0003] introduction

[0004] Aspects of the present disclosure relate to wireless communications, and more particularly to techniques for managing a hybrid automatic repeat request (HARQ) buffer.

[0005] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcast, etc. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems include 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, 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, to name just a few.

[0006] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. New radio (e.g., 5G NR) is an example of an emerging telecommunication standard. NR is an enhancement set of the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and better integrating with other open standards using OFDMA with cyclic prefix (CP) on downlink (DL) and uplink (UL). To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0007] However, as the demand for mobile broadband access continues to grow, there is a need for further improvements to NR and LTE technologies. Preferably, these improvements should be applicable to other multiple access technologies and the telecommunication standards that employ these technologies.

[0008] Overview

[0009] The systems, methods, and apparatus of the present disclosure each have several aspects, no single aspect of which is solely responsible for its desired attributes. Without limiting the scope of the present disclosure as expressed in the appended claims, some features will now be briefly discussed. After considering this discussion and specifically after reading the section entitled "Detailed Description," it will be understood how the various features of the present disclosure provide various advantages including management of hybrid automatic repeat request (HARQ) buffers, which can provide desirable HARQ operations and / or desirable sidelink communications.

[0010] Certain aspects provide a method for wireless communication by a first user equipment (UE). The method generally includes: in response to a HARQ budget being exceeded relative to the number of active HARQ processes, discarding at least one transmission or one or more transport blocks (TBs) associated with the at least one transmission from being processed according to one or more rules. The method further includes processing remaining transmissions and taking one or more actions based on the processed remaining transmissions.

[0011] Certain aspects provide a method for wireless communication by a first user equipment (UE). The method generally includes: in response to a HARQ budget being exceeded relative to the number of active HARQ processes, discarding at least one transmission or one or more TBs associated with the at least one transmission so that they are not transmitted according to one or more rules. The method also includes transmitting the remaining transmission to one or more second UEs.

[0012] Certain aspects provide an apparatus for wireless communication. The apparatus generally includes a memory and a processor coupled to the memory. The processor and the memory are configured to: in response to a HARQ budget being exceeded relative to the number of active HARQ processes, discard at least one transmission or one or more TBs associated with the at least one transmission from being processed according to one or more rules; process the remaining transmissions; and take one or more actions based on the processed remaining transmissions.

[0013] Certain aspects provide an apparatus for wireless communication. The apparatus generally includes a memory and a processor coupled to the memory. The processor and the memory are configured to: in response to a HARQ budget being exceeded relative to the number of active HARQ processes, discard at least one transmission or one or more TBs associated with the at least one transmission so that they are not processed according to one or more rules. The apparatus further includes a transmitter configured to transmit the remaining transmission to one or more UEs.

[0014] Certain aspects provide an apparatus for wireless communication. The apparatus generally includes: means for discarding at least one transmission or one or more TBs associated with the at least one transmission from being processed according to one or more rules in response to a HARQ budget being exceeded relative to the number of active HARQ processes; means for processing remaining transmissions; and means for taking one or more actions based on the processed remaining transmissions.

[0015] Certain aspects provide an apparatus for wireless communication. The apparatus generally includes: in response to a HARQ budget being exceeded relative to the number of active HARQ processes, discarding at least one transmission or one or more TBs associated with the at least one transmission from being transmitted according to one or more rules; and transmitting the remaining transmission to one or more second UEs.

[0016] Certain aspects provide a computer-readable medium having instructions stored thereon for: in response to a HARQ budget being exceeded relative to the number of active HARQ processes, discarding at least one transmission or one or more TBs associated with the at least one transmission so that they are not processed according to one or more rules; processing the remaining transmissions; and taking one or more actions based on the processed remaining transmissions.

[0017] Certain aspects provide a computer-readable medium having instructions stored thereon for: in response to a HARQ budget being exceeded relative to the number of active hybrid automatic repeat request (HARQ) processes, discarding at least one transmission or one or more transport blocks (TBs) associated with the at least one transmission so that they are not transmitted according to one or more rules; and transmitting the remaining transmissions to one or more second UEs.

[0018] Certain aspects provide a method for wireless communication by a first user equipment (UE). The method generally includes: determining that a hybrid automatic repeat request (HARQ) budget is exceeded based on transmissions received from one or more second UEs; and discarding at least one transmission or one or more transport blocks (TBs) associated with the at least one transmission from being processed according to one or more rules based on the determination. The method further includes processing remaining transmissions and taking one or more actions based on the processed remaining transmissions.

[0019] 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 the accompanying drawings set forth in detail certain illustrative features of the one or more aspects. However, these features are only indicative of several of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to understand in detail the manner in which the above-stated features of the present disclosure are used, a more particular description of the content briefly summarized above may be made with reference to various aspects, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only certain typical aspects of the present disclosure and are not to be considered limiting of its scope, as the description may admit to other equally effective aspects.

[0022] Figure 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

[0023] Figure 2 is a block diagram conceptually illustrating designs of example base stations (BSs) and user equipment (UEs) in accordance with certain aspects of the present disclosure.

[0024] Figure 3A , 3B and 4 illustrate a vehicle-to-everything (V2X) system according to certain aspects of the present disclosure.

[0025] Figure 5A is a call flow diagram illustrating example operations for managing a HARQ budget at a receiver in accordance with certain aspects of the present disclosure.

[0026] Figure 5B is a call flow diagram illustrating example operations for managing a HARQ budget at a transmitter in accordance with certain aspects of the present disclosure.

[0027] Figure 6 is a flow diagram illustrating example operations for wireless communications in which a UE manages a hybrid automatic repeat request (HARQ) budget at a receiver in accordance with certain aspects of the present disclosure.

[0028] Figure 7 is a flow diagram illustrating example operations for wireless communications in which a UE manages a HARQ budget at a transmitter in accordance with certain aspects of the present disclosure.

[0029] Figure 8 A communication device according to aspects of the present disclosure is illustrated that may include various components configured to perform operations for the techniques disclosed herein.

[0030] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized in other aspects without specific recitation.

[0031] Detailed Description

[0032] Various aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for managing HARQ budgets. In certain wireless communications, HARQ retransmissions may be supported in sidelink communications. In the absence of a centralized scheduler, sidelink transmissions may easily overload the processing capacity of a UE to perform HARQ operations on all received transmissions. Various aspects of the present disclosure provide mechanisms for selecting which transmissions to discard when a HARQ budget (e.g., a soft buffer limit or processing capacity) is exceeded. The HARQ buffer management described herein can provide desirable HARQ operations and / or desirable sidelink communications.

[0033] The following description provides an example of HARQ budget management in a communication system, without limiting the scope, applicability or examples set forth in the claims. Changes may be made to the functions and arrangements of the elements discussed without departing from the scope of the present disclosure. Various examples may appropriately omit, replace, or add various procedures or components. For example, the described method may be performed in an order different from the order described, and various steps may be added, omitted, or combined. Moreover, the features described with reference to some examples may be combined in some other examples. For example, any number of aspects set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such devices or methods practiced using other structures, functionalities, or structures and functionalities as supplements to the various aspects of the present disclosure set forth herein or in addition. It should be understood that any aspect of the present disclosure disclosed herein may be implemented by one or more elements of the claims. The wording "exemplary" is used herein to mean "used as an example, instance, or explanation". Any aspect described as "exemplary" herein is not necessarily to be interpreted as being superior to or superior to other aspects.

[0034] In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. RAT may also be referred to as radio technology, air interface, etc. Frequency may also be referred to as carrier, subcarrier, frequency channel, frequency modulation, subband, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, a 5G NR RAT network may be deployed.

[0035] Figure 1 An example wireless communication network 100 is illustrated in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be a NR system (e.g., a 5G NR network). Figure 1As shown, UEs 120a, 120b include HARQ managers 122a, 122b, respectively, that determine which transmissions or transport blocks to drop from HARQ operations to avoid exceeding the HARQ budget based on various rules, as further described herein.

[0036] NR access (e.g., 5G NR) can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or higher), millimeter wave (mmWave) targeting high carrier frequency (e.g., 25 GHz or higher), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC technology, and / or mission-critical services targeting ultra-reliable low latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet corresponding quality of service (QoS) requirements. In addition, these services may coexist in the same time domain resources (e.g., time slots or subframes) and / or frequency domain resources (e.g., component carriers).

[0037] like Figure 1 As illustrated in , the wireless communication network 100 may include several base stations (BSs) 110a-z (each also individually referred to herein as BS 110 or collectively referred to as BS 110) and other network entities. BS 110 may provide communication coverage for a specific geographic area (sometimes referred to as a "cell"), which may be stationary or mobile depending on the location of the mobile BS 110. In some examples, BS 110 may be interconnected to each other and / or to one or more other BSs or network nodes (not shown) in the wireless communication network 100 using any suitable transport network via various types of backhaul interfaces (e.g., direct physical connections, wireless connections, virtual networks, etc.). Figure 1 In the example shown in , BS110a, 110b, and 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS110x may be a pico BS for a pico cell 102x. BS110y and 110z may be femto BSs for femto cells 102y and 102z, respectively. The BS may support one or more cells. BS110 communicates with user equipment (UE) 120a-y (each also individually referred to herein as UE 120 or collectively referred to as UE 120) in the wireless communication network 100. UE 120 (e.g., 120x, 120y, etc.) may be dispersed throughout the wireless communication network 100, and each UE 120 may be stationary or mobile.

[0038] The wireless communication network 100 may also include a relay station (e.g., relay station 110r) (also referred to as a relay, etc.), which receives transmissions of data and / or other information from an upstream station (e.g., BS110a or UE 120r) and sends transmissions of data and / or other information to a downstream station (e.g., UE 120 or BS110), or which relays transmissions between UEs 120 to facilitate communication between the devices.

[0039] A network controller 130 may couple to a set of BSs 110 and provide coordination and control for the BSs 110. The network controller 130 may communicate with the BSs 110 via a backhaul. The BSs 110 may also communicate with each other (eg, directly or indirectly) via a wireless or wired backhaul.

[0040] Figure 2 BS 110 and UE 120 (eg, in Figure 1 Example components of the wireless communication network 100).

[0041] At BS 110, a transmit processor 220 may receive data from a data source 212 and control information from a controller / processor 240. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), etc. The data may be for a physical downlink shared channel (PDSCH), etc. The processor 220 may process (e.g., encode and symbol map) the data and the control information to obtain data symbols and control symbols, respectively. The transmit processor 220 may also generate reference symbols (such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell-specific reference signal (CRS)). A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, and / or reference symbols, where applicable, and may provide output symbol streams to modulators (MODs) 232a-232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 232a-232t may be transmitted via antennas 234a-234t, respectively.

[0042] At UE 120, antennas 252a-252r may receive downlink signals from BS 110 and may provide received signals to demodulators (DEMODs) 254a-254r in the transceiver, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all demodulators in transceivers 254a-254r, perform MIMO detection on the received symbols where applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information to a controller / processor 280.

[0043] On the uplink, at the UE 120, the transmit processor 264 may receive and process data from the data source 262 (e.g., data for a physical uplink shared channel (PUSCH)) and control information from the controller / processor 280 (e.g., control information for a physical uplink control channel (PUCCH)). The transmit processor 264 may also generate reference symbols for a reference signal (e.g., a sounding reference signal (SRS)). The symbols from the transmit processor 264 may be precoded by the TX MIMO processor 266, if applicable, further processed by a demodulator in the transceiver 254a-254r (e.g., for SC-FDM, etc.), and transmitted to the BS 110. At the BS 110, the uplink signal from the UE 120 may be received by the antenna 234, processed by the modulator 232, detected by the MIMO detector 236, if applicable, and further processed by the receive processor 238 to obtain decoded data and control information sent by the UE 120. Receive processor 238 may provide decoded data to data sink 239 and decoded control information to controller / processor 240 .

[0044] Memories 242 and 282 may store data and program codes, respectively, for BS 110 and UE 120. Scheduler 244 may schedule UEs for data transmission on the downlink and / or uplink.

[0045] The controller / processor 280 and / or other processors and modules at the UE 120 may perform or direct the execution of processes for the techniques described herein. Figure 2As shown, the controller / processor 280 of the UE 120 has a HARQ manager 281, which determines which transmissions or transmission blocks to discard from the HARQ operation based on various rules, as further described herein. Although shown at the controller / processor, other components of the UE 120 may also be used to perform the operations described herein.

[0046] Figure 3A and 3B A vehicle-to-everything (V2X) system in accordance with certain aspects of the present disclosure is illustrated. Figure 3A and 3B The V2X system provided in the present invention provides two complementary transmission modes. The first transmission mode involves direct communication between participants in a local area (e.g., also known as sidelink communication). Figure 3A The second transmission mode involves Figure 3B The network communication through the network explained in , the network communication may be implemented through a Uu interface (eg, a wireless communication interface between a radio access network (RAN) and a UE).

[0047] Reference Figure 3A , a V2X system 300A is illustrated as having two vehicles 302, 304. A first transmission mode allows direct communication between different participants in a given geographic location. As illustrated, the vehicle 302 may have a wireless communication link with an individual (V2P) (e.g., via a UE) through a PC5 interface 306. Communication (V2V) between the vehicles 302, 304 may also occur through a PC5 interface 308. Communication from the vehicle 302 to other highway components 310 (such as traffic signals or signs) (V2I) may occur in a similar manner through a PC5 interface 312. For Figure 3A For each communication explained in the above, bidirectional communication can be performed between elements, so each element can be a transmitter and receiver of information. In some aspects, the V2X system 300A can be a self-managed system and does not provide network assistance. The self-managed system can achieve improved spectrum efficiency, reduced costs, and increased reliability because no network service interruption occurs during the switching operation of the vehicle used for movement. Resource assignment does not require coordination between operators, and subscription to the network is also unnecessary, thereby reducing the complexity of such self-managed systems. The V2X system 300A can be configured to operate in a licensed or unlicensed spectrum, whereby any vehicle with an equipped system can access the common frequency and share information. Such coordinated / shared spectrum operations allow safe operation.

[0048] Reference Figure 3B, the V2X system 300B is illustrated as having vehicles 352, 354 and a network entity 356. The second transmission mode of the two complementary transmission modes is illustrated. In this example, the vehicle 352 can communicate with another vehicle 354 through network communications via, for example, the network entity 356. These network communications can occur through discrete nodes (such as base stations (e.g., BS110a)) that send and receive information between vehicles. Network communications through vehicle-to-network (V2N) links 358, 360 can be used for long-range communications between vehicles, such as noticing that there is a traffic accident at a certain distance (e.g., 1 mile) ahead on a road or highway. Other types of communications, such as traffic flow conditions, road hazard warnings, environmental / weather reports, service station availability, and other similar data, can be sent by the node to the vehicle. Such data can be obtained from a cloud-based sharing service.

[0049] Figure 4 Shows the implementation Figure 3A and 3B 4. Example V2X system 400 of various aspects of the present invention. Communication between vehicles 302 and 304a may occur through PC5 interface 308a, while communication between vehicles 302 and 304b may occur through PC5 interface 308b. V2I communication may occur through PC5 interface 312. V2N communication may occur through wireless links 358, 360.

[0050] Example Hybrid Automatic Repeat Request Buffer Management

[0051] In some wireless communication systems (e.g., 5G NR systems), HARQ is used to improve the reliability of data transmission. For example, HARQ may provide a mechanism for detecting errors in transmission (such as cyclic redundancy check) and introducing forward error correction coding of redundancy (e.g., parity bits) in transmission so that the receiver can correct the detected errors. HARQ may also provide a feedback mechanism that enables the receiver to trigger a retransmission from the transmitter when an error is detected in a received transmission. In some cases, the UE may combine retransmissions of the same transport block (TB) to improve decoding performance. For example, the UE may store a received TB with errors in a soft buffer (e.g., a HARQ buffer), and upon receiving a retransmission of the TB, the UE may combine the received data with the data currently in the HARQ buffer and attempt to decode the combined data.

[0052] In some cases, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Real-world applications of such sidelink communications may include public safety, proximity services, UE-to-network relay, vehicle-to-vehicle (V2V) communication, vehicle-to-everything (V2X) communication, device-to-device (D2D) communication, Internet of Everything (IoE) communication, IoT communication, mission-critical mesh networks, and / or various other suitable applications. Generally, a sidelink signal may refer to a signal that is communicated from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying the communication through a scheduling entity (e.g., BS), even if the scheduling entity may be used for scheduling and / or control purposes. In some examples, the sidelink signal may be communicated using a licensed spectrum (unlike wireless local area networks, which typically use unlicensed spectrum).

[0053] Various sidelink channels may be used for sidelink communications, including a physical sidelink discovery channel (PSDCH), a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), and a physical sidelink feedback channel (PSFCH). The PSDCH may carry discovery expressions that enable neighboring devices to discover each other. The PSCCH may carry control signaling for data transmission, such as sidelink resource configuration or other parameters. The PSSCH may carry data transmission, and the PSFCH may carry feedback related to the sidelink channel quality, such as channel state information.

[0054] In certain aspects, HARQ retransmissions may be supported in sidelink communications. In sidelink communications, a UE may receive transmissions from multiple UEs simultaneously. In the absence of a centralized scheduler (e.g., a BS), there may be no guarantee that the HARQ budget will be met. That is, there may be processing limitations (e.g., HARQ budget) on how many different TBs a UE can buffer simultaneously and still perform HARQ combining. For example, due to soft buffer capacity and / or limited processing resources, a UE may be limited by the number of parallel HARQ processes. The HARQ budget may also be limited by how far apart temporal retransmissions of the same TB can be. If the HARQ budget limit is exceeded or fully loaded, the UE may need to discard some TBs or transmissions.

[0055] Various aspects of the present disclosure provide mechanisms for selecting which TBs or transmissions to discard when a HARQ budget (e.g., soft buffer limit or processing capacity) is exceeded. For example, after determining that the HARQ budget is exceeded, the UE may discard transmissions so that they are not processed based on time (e.g., discard the earliest received), priority (e.g., discard the lowest priority), delay budget (e.g., discard the least delay budget), number of stored retransmissions, distance between the receiver and the transmitter (e.g., discard the farthest), signal strength / quality (e.g., discard the weakest signal), or feedback type (e.g., discard ACK feedback-based), as further described herein. Discarding transmissions and / or TBs may enable the UE to avoid overloading the HARQ operation and / or provide reliable sidelink communications.

[0056] Figure 5A 5 is a call flow diagram illustrating example operations 500A for managing a HARQ budget at a receiver (e.g., UE 120a) while communicating via a sidelink air interface in accordance with certain aspects of the present disclosure. At 502, UE 120a may receive one or more transmissions from one or more UEs 120b via a sidelink air interface (e.g., PSDCH, PSSCH, or PSFCH). At 504, UE 120a may determine that the HARQ budget is exceeded based on the received transmissions. At 506, UE 120a may discard a group of received transmissions or TBs associated with the group of received transmissions from being processed based on various rules, such as rules based on time, priority, packet delay budget, distance, signal strength / quality, or feedback type, as further described herein.

[0057] At 508, UE 120a may process the remaining received transmissions according to the HARQ operation, such as attempting to decode the received transmissions. For example, if one of the received transmissions is a retransmission, UE 120a may combine the received data with data currently in the soft buffer for a TB associated with the retransmission and attempt to decode the combined data. As another example, if data was not successfully decoded for the TB, UE 120a may replace the data in the soft buffer for the TB with the data that UE 120a has attempted to decode.

[0058] At 510, UE 120a may send an acknowledgement (ACK) message and / or a negative acknowledgement (NACK) message to UE 120b or a base station (not shown). For example, if UE 120a successfully decodes one of the transmissions, UE 120a may send an ACK message to UE 120b. In other cases, if UE 120a does not successfully decode one of the transmissions, UE 120a may send a NACK message to UE 120b, or UE 120a may not send a NACK message, and the absence of an ACK message may indicate to UE 120b that the transmission was not successfully decoded.

[0059] Although to promote understanding Figure 5A The example depicted in FIG. 1 is about a receiver (e.g., Figure 5A 120a) discards the transmission or TB, but aspects of the present disclosure may also be applied to a transmitter (e.g., Figure 5A UE 120b) discards transmission or TB to manage HARQ budget, as described herein Figure 5B and 7 Further described.

[0060] Figure 5B 5 is a call flow diagram illustrating example operations 500B for managing a HARQ budget at a transmitter (e.g., UE 120b) while communicating via a sidelink air interface in accordance with certain aspects of the present disclosure. At 512, UE 120b may determine that a HARQ budget is exceeded based on individual transmissions scheduled to be transmitted to one or more UEs 120a. For example, UE 120b may generate or obtain individual payloads for transmission to UE 120a, and UE 120b may determine that a HARQ budget is exceeded based on the number of active HARQ processes associated with the scheduled transmissions for the individual payloads. At 514, UE 120b may discard a group of transmissions or TBs associated with the group of transmissions so that they are not transmitted according to various rules, such as rules based on time, priority, packet delay budget, distance, or feedback type, as further described herein. At 516, UE 120b may transmit the remaining transmissions (e.g., transmissions that are not discarded) to UE 120a via a sidelink channel. UE 120b may receive an ACK message and / or a NACK message from UE 120a at 518. In some cases, UE 120b may transmit an ACK message and / or a NACK message to a base station (not shown) based on the discarded transmission.

[0061] Figure 66 is a flow diagram illustrating example operations 600 for wireless communication in accordance with certain aspects of the present disclosure. Operations 600 may be performed, for example, by a UE (e.g., UE 120a or UE 120b in wireless communication network 100). Operations 600 may be implemented as a processor on one or more processors (e.g., Figure 2 In addition, signal transmission and reception by the UE in operation 600 may be performed by one or more antennas (e.g., Figure 2 In some aspects, the transmission and / or reception of signals by the UE may be implemented via a bus interface of one or more processors (eg, controller / processor 280) or a circuit system that obtains and / or outputs signals.

[0062] Operations 600 may begin at 602, where the first UE may, in response to a HARQ budget being exceeded relative to the number of active HARQ processes, discard at least one transmission or one or more TBs associated with the at least one transmission from being processed according to one or more rules. At 604, the first UE may process the remaining transmissions (e.g., transmissions that were not discarded). At 606, the first UE may take one or more actions based on the processed remaining transmissions.

[0063] Since the first UE may have a limited HARQ budget, the first UE may determine that the HARQ budget is exceeded based on various thresholds. As used herein, an exceeded HARQ budget may refer to a HARQ budget at a certain capacity or state in which certain transmissions cannot be processed or transmitted. For example, the HARQ budget relative to the number of active HARQ processes is exceeded when a specific number of active HARQ processes is reached. That is, when there is a specific number of active HARQ processes, the HARQ budget may be exceeded or at full capacity, and the first UE may discard transmissions and / or TBs. In various aspects, the HARQ budget monitored by the first UE may be a HARQ budget allocated to sidelink communications. That is, the first UE may have a HARQ budget allocated to sidelink communications with the same base station (e.g., Figure 1110a) and associated with sidelink communications with other UEs. In some aspects, the UE may determine that at least one of the number of received transmissions, the number of time domain resources associated with the received transmissions (e.g., packet delay budget or reception time), the number of active HARQ processes, and the soft buffer capacity, or a combination thereof, is equal to or greater than one or more thresholds. As an example, the UE may determine that the number of received transmissions is at or above (greater than or equal to) a threshold. In other aspects, the UE may determine that the reception time of the received transmission (in terms of time domain resources (e.g., time slots)) is greater than or equal to a threshold (e.g., the maximum number of time slots from the current time slot or the latest time slot of the received transmission). In some cases, the UE may determine that the number of active HARQ processes associated with the received transmission may be equal to or greater than a threshold (e.g., a maximum of 16 HARQ processes). In other cases, the UE may determine that the soft buffer capacity is equal to or greater than a threshold (e.g., the number of bits or transport blocks). That is, because the UE has previously stored transmissions in the soft buffer, the UE may not have sufficient storage capacity to perform HARQ operations on new transmissions and / or retransmissions.

[0064] After determining that the HARQ budget is exceeded, the first UE may discard the received transmission by identifying the transmission that satisfies one or more rules and discarding the transmission or the TB associated with the transmission based on the identification so that it is not processed. In other words, the first UE may select some transmissions based on the transmissions that satisfy one or more rules and discard the selected transmissions so that they are not processed. For example, the first UE may choose to discard the transmission with the lowest priority so that it is not processed. In other words, the first UE may select other transmissions to be processed based on the fact that these other transmissions do not satisfy one or more rules. For example, the first UE may choose to process other transmissions with a priority higher than the lowest priority.

[0065] The first UE may determine to discard a transmission and / or a TB associated with one of the transmissions based on various rules. In various aspects, the various rules may be based on at least one of a time domain threshold (e.g., number of time slots) associated with the received transmission, a priority level associated with the received transmission, a number of remaining retransmissions, a distance between the first UE and the second UEs, a signal quality of the received transmission, a feedback type associated with the received transmission, or a combination thereof. The first UE may select a transmission to discard based on a combination of one or more rules.

[0066] The first UE may determine to discard transmissions and / or TBs based on the reception time associated with each received transmission. As an example, the UE may discard the earliest (oldest) received transmission so that it is not processed. In various aspects, the UE may identify the transmissions that are received in the time domain resources (e.g., the time interval between the current time slot and the received time slot).N Time slot N-i , where i is the time slot N The UE may discard transmissions received before a certain window (e.g., a window of 4 time slots or a window of 20 ms) relative to the current time domain resource or another suitable reference time domain resource, such as the latest (or most recent) received transmission. In other words, if the HARQ budget is defined in time slots, then the HARQ budget is defined in time slots. N-i The previous transmission may be discarded. In other aspects, the first UE may discard the transmission with the latest reception time.

[0067] In certain aspects, the first UE may determine to discard a transmission and / or TB based on a priority associated with a received transmission. The priority level may indicate a priority for scheduling resources between quality of service (QoS) flows. The lowest priority level value may correspond to the highest priority. In various aspects, the first UE may identify a transmission with a lowest priority level compared to the priorities (e.g., priority level values) of other received transmissions, and discard the lowest priority transmission so that it is not processed. In other words, the transmission with the lowest priority may be discarded. In other aspects, the transmission with the highest priority may be discarded. In still other aspects, the first UE may discard a transmission based on a priority associated with the transmission relative to a threshold (e.g., discarding a transmission with a priority of ≥ priority level value 20).

[0068] The priority of a transmission may be determined based on a priority level encoded in a file or packet of the transmission. For example, a QoS indicator (e.g., 5QI) encoded in a packet may correspond to various QoS characteristics, including resource type, priority level, packet delay budget, packet error rate, average window, or maximum data burst. That is, the QoS indicator may indicate various QoS characteristics including priority level.

[0069] In various aspects, the first UE may determine to discard a transmission and / or TB based on the number of remaining retransmissions associated with the transmission. For example, the first UE may discard the transmission with the largest number of remaining retransmissions or the smallest number of remaining retransmissions. In other aspects, the first UE may discard a transmission based on the number of remaining retransmissions associated with the transmission relative to a threshold (e.g., discarding a transmission with a number of retransmissions ≥ 4 remaining retransmissions).

[0070] In certain aspects, the first UE may determine to discard transmissions and / or TBs based on the distance associated with each of the second UEs relative to the first UE. For example, the first UE may discard transmissions from the second UEs that are farthest from the first UE. That is, the first UE may identify the second UEs that are farthest from the first UE compared to the other second UEs, and the first UE may discard transmissions from the second UEs farthest from the first UE. In other aspects, the first UE may discard transmissions from the second UEs that are closest to the first UE. In other aspects, the first UE may discard transmissions based on the distance associated with the transmission relative to a threshold (e.g., discarding transmissions with a distance of ≥500 meters).

[0071] In various aspects, the first UE may determine to discard a transmission and / or TB based on a signal quality associated with a received transmission. The signal quality may include at least one of the following: signal and noise plus interference ratio (SINR), signal to noise ratio (SNR), reference signal received power (RSRP), reference signal received quality (RSRQ), received signal strength indicator (RSSI), or a combination thereof. The first UE may discard the transmission with the weakest signal quality. That is, the first UE may identify the transmission with the weakest signal quality compared to the signal quality of other received transmissions, and the first UE may discard the identified transmission. In other aspects, the first UE may discard the transmission with the strongest signal quality. In other aspects, the first UE may discard the transmission based on the signal quality associated with the transmission relative to a threshold (e.g., discarding a transmission with a signal quality of ≤-100dBm (RSRP) or 7dB (SINR)).

[0072] Additionally or alternatively, the first UE may determine to discard a transmission and / or TB based on a feedback type associated with the received transmission. For example, the first UE may discard a transmission with ACK-based feedback. ACK-based feedback may refer to a HARQ feedback configuration in which the receiver sends an ACK message to the transmitter when the receiver successfully decodes the transmission, but the receiver may not send a NACK message to the transmitter when the receiver detects an error in the received transmission. The first UE may identify that the transmission has an acknowledgment-based feedback type and discard the transmission so that it is not processed.

[0073] Although some examples provided herein to facilitate understanding are described with respect to discarding transmissions so that they are not processed, aspects of the present disclosure may also be applicable to discarding a transport block or code block group (e.g., a code block group that constitutes part of a transport block) associated with a transmission identified as satisfying one or more rules for managing a HARQ budget. For example, a first UE may discard one or more TBs associated with a transmission that satisfies one or more rules, as described herein. In such a case, the first UE may discard any remaining or subsequent retransmissions of the TB so that they are not processed. For example, a first UE may receive a retransmission associated with a discarded TB, determine that the retransmission is associated with the discarded TB, and discard the retransmission based on the determination so that it is not processed.

[0074] If a first UE discards a transmission and subsequently receives a retransmission of the discarded transmission, the first UE may attempt to decode the TB associated with the retransmission assuming that the HARQ budget has not been exceeded. That is, discarding the transmission may not affect the HARQ operations associated with subsequent retransmissions, while discarding a TB will prevent the processing of any subsequent retransmissions associated with the TB.

[0075] In certain aspects, the first UE may identify multiple received transmissions to be discarded based on rules and resolve the ties according to various tie-breaker systems. For example, the first UE may resolve the tie by discarding all transmissions that satisfy one of the rules. In other words, the first UE may identify all transmissions that satisfy one of the rules and discard all of the identified transmissions. For example, the first UE may discard all earliest received transmissions.

[0076] In other aspects, the first UE may apply another rule to resolve ties or reduce the number of discarded transmissions. That is, the first UE may use another rule to decide the winner or reduce the number of discarded transmissions. For example, the first UE may identify the transmission with the lowest priority, and then identify the transmission with the earliest reception time among the transmissions with the lowest priority. The first UE may then discard the identified transmission with the earliest reception time among the transmissions with the lowest priority. In other words, the first UE may identify a first group of transmissions that satisfy a first rule among one or more rules; after identifying the first group of transmissions, identify a second group of transmissions in the first group of transmissions that satisfy a second rule among the one or more rules; and discard the second group of transmissions in the first group of transmissions or one or more TBs associated with the second group of transmissions in the first group of transmissions so that they are not processed.

[0077] In still other aspects, the first UE may determine the winner according to a rule by randomly selecting one or more transmissions identified as satisfying one of the rules. For example, the first UE may identify a transmission that satisfies one of the rules; randomly select at least one of the identified transmissions; and discard the selected transmission or one or more TBs associated with the selected transmission so that it is not processed.

[0078] The first UE may communicate with the second UE via various side link communication channels or air interfaces. Before discarding at 602, the first UE may, for example, receive a transmission from one or more second UEs via a side link channel. In various aspects, the first UE may communicate with the second UE on PSCCH, PSSCH and / or PSFCH. Any of the side link channels may support the HARQ buffer management operations described herein. In certain aspects, the transmission selected and discarded so that it is not processed may be a side link transmission received via a side link communication channel (such as PSCCH, PSSCH and / or PSFCH). That is, the first UE may have a separate HARQ budget and corresponding HARQ operation for managing downlink and / or uplink transmissions.

[0079] The first UE may process the remaining transmissions by attempting to decode the remaining transmissions data according to HARQ operations, such as combining data stored in a HARQ buffer with received retransmissions. The remaining transmissions may include received transmissions that were not discarded at 602 so that they are not processed.

[0080] The first UE may take various actions based on the processed remaining transmission. In certain aspects, the first UE may forward the decoded transmission to at least one of a base station (e.g., BS110a) or a third UE. In various aspects, taking one or more actions based on the processed remaining transmission may include the first UE sending at least one of an ACK message or a NACK message to a second UE or a base station (e.g., BS110a). For example, if the first UE successfully decodes one of the transmissions, the first UE may send an ACK message to the second UE that transmitted the decoded transmission. If the first UE does not successfully decode one of the transmissions, the first UE may send a NACK message to the second UE that transmitted the decoded transmission, or the first UE may send a resource grant to indicate to the second UE that the transmission is to be retransmitted, or the first UE may not send any message to the second UE.

[0081] In certain aspects, the first UE may receive a configuration from the BS indicating one or more rules for discarding transmissions to exempt them from HARQ processing, as described herein. For example, the first UE may receive downlink control signaling (such as a radio resource control (RRC) message), downlink control information (DCI), or a media access control (MAC) control element (MAC-CE) indicating one or more rules for discarding transmissions.

[0082] Figure 7 700 for wireless communications in accordance with certain aspects of the present disclosure. Operations 700 may be performed, for example, by a UE (e.g., UE 120a or UE 120b in wireless communication network 100). Operations 700 may be implemented as a processor (e.g., Figure 2 In addition, signal transmission and reception by the UE in operation 700 may be performed by one or more antennas (e.g., Figure 2 In some aspects, the transmission and / or reception of signals by the UE may be implemented via a bus interface of one or more processors (eg, controller / processor 280) or a circuit system that obtains and / or outputs signals.

[0083] Operations 700 may begin at 702, where a first UE may, in response to a HARQ budget being exceeded relative to the number of active HARQ processes, discard at least one transmission or one or more TBs associated with the at least one transmission so that they are not transmitted according to one or more rules. At 704, the first UE may transmit the remaining transmissions (e.g., transmissions that are not discarded) to one or more second UEs.

[0084] Since the first UE may have a limited HARQ budget, the first UE may determine that the HARQ budget is exceeded based on various thresholds, such as described herein with reference to operation 600. In certain aspects, the UE may determine that at least one of the number of transmissions, the number of time domain resources associated with the transmission (e.g., packet delay budget or reception time), the number of active HARQ processes, the soft buffer capacity, or a combination thereof is equal to or greater than one or more thresholds. As an example, the UE may determine that the number of transmissions is at or above (greater than or equal to) a threshold. In other aspects, the UE may determine that the scheduled transmission time of the transmission (in terms of time domain resources (e.g., time slots)) is greater than or equal to a threshold (e.g., the maximum number of time slots from the current time slot). In some cases, the UE may determine that the number of active HARQ processes associated with the transmission may be equal to or greater than a threshold (e.g., a maximum of 16 HARQ processes). In other cases, the UE may determine that the soft buffer capacity is equal to or greater than a threshold (e.g., the number of bits or transport blocks). That is, because the UE has previously stored transmissions in the soft buffer, the UE may not have sufficient storage capacity to perform HARQ operations on new transmissions and / or retransmissions.

[0085] After determining that the HARQ budget is exceeded, the first UE may discard the transmission by identifying that the transmission satisfies one or more rules and discarding the transmission or a TB associated with the transmission based on the identification so that it is not processed. In other words, the first UE may select some transmissions based on the transmissions that meet the one or more rules and discard the selected transmissions so that they are not processed. For example, the first UE may select the transmission with the lowest priority to be discarded so that it is not processed. In other words, the first UE may select other transmissions to be transmitted based on other transmissions that do not meet the one or more rules. For example, the first UE may select other transmissions with a priority higher than the lowest priority to be transmitted.

[0086] The first UE may determine to discard a transmission and / or a TB associated with one of the transmissions based on various rules. In various aspects, the various rules may be based on at least one of a time domain threshold associated with the transmission (e.g., number of time slots), a priority level associated with the transmission, a delay budget associated with the transmission, a number of remaining retransmissions, a distance between the first UE and the second UEs, a feedback type associated with the transmission, or a combination thereof. The first UE may select the transmission to be discarded based on a combination of one or more rules.

[0087] The first UE may determine to discard transmissions and / or TBs based on the transmission time associated with each transmission. As an example, the UE may discard the earliest (oldest) transmission so that it is not transmitted. In various aspects, the UE may identify the transmissions in the time domain resources (e.g., the time interval between the current time slot and the transmission time). N Time slot N-i , where i is the time slot NThe UE may identify transmissions that were scheduled before a certain window (e.g., a window of 4 time slots or a window of 20 ms) of the time domain resources relative to the current time domain resources or another suitable reference, such as the latest (or most recent) scheduled transmission. In other words, if the HARQ budget is defined in time slots, then the HARQ budget is defined in time slots. N -i before may be discarded. In other aspects, the first UE may discard the transmission with the latest transmission time.

[0088] In certain aspects, the first UE may determine to discard a transmission and / or TB based on a priority associated with a scheduled transmission. The priority level may indicate a priority for scheduling resources between quality of service (QoS) flows. The lowest priority level value may correspond to the highest priority. In various aspects, the first UE may identify a transmission with a lowest priority level compared to the priorities (e.g., priority level values) of other transmissions, and discard the lowest priority transmission so that it is not processed. In other words, the transmission with the lowest priority may be discarded. In other aspects, the transmission with the highest priority may be discarded. In still other aspects, the first UE may discard a transmission based on a priority associated with the transmission relative to a threshold (e.g., discarding a transmission with a priority of ≥ priority level value 20). The priority of a transmission may be determined based on a priority level encoded in a file or packet of the transmission, as described herein with reference to operation 600.

[0089] In various aspects, the first UE may determine to discard a transmission and / or TB based on a packet delay budget associated with the transmission. In general, a packet delay budget may refer to an upper limit on the time a packet is delayed between a UE and a packet destination / originating point in a wireless communication system, such as another UE in a sidelink transmission or a user plane function (UPF) of a 5G core network (5GC) terminating in a data network (DN). The packet delay budget may be derived from QoS indicators associated with various services, such as V2X messages, augmented reality, conversational voice, etc. For example, a transmission with a minimal packet delay budget amount (e.g., 10ms) may include low latency transmissions, such as URLLC (including discrete automation or augmented / virtual reality services), and a transmission with an available larger packet delay budget (e.g., 100ms) may include eMBB transmissions (including conversational voice or video services).

[0090] In certain aspects, the first UE may identify transmissions that have the least amount of remaining time in terms of a packet delay budget compared to the delay budgets of other scheduled transmissions, and the first UE may discard these transmissions so that they are not processed. That is, the transmissions that have the least amount of remaining time in terms of the packet delay budget may be discarded. In other aspects, the first UE may identify transmissions that have the largest amount of remaining time in terms of a packet delay budget compared to the delay budgets of other transmissions, and the first UE may discard these transmissions so that they are not processed. In other words, the transmissions that have the largest amount of remaining time in terms of the packet delay budget may be discarded. In still other aspects, the first UE may discard transmissions based on the packet delay budget associated with the transmission relative to a threshold (e.g., discarding transmissions with a packet delay budget of ≤10ms).

[0091] In various aspects, the first UE may determine to discard a transmission and / or TB based on the number of remaining retransmissions associated with the transmission. For example, the first UE may discard the transmission with the largest number of remaining retransmissions or the smallest number of remaining retransmissions. In other aspects, the first UE may discard a transmission based on the number of remaining retransmissions associated with the transmission relative to a threshold (e.g., discarding a transmission with a number of retransmissions ≥ 4 remaining retransmissions).

[0092] In certain aspects, the first UE may determine to discard transmissions and / or TBs based on a distance associated with each of the second UEs relative to the first UE. For example, the first UE may discard transmissions from the second UE farthest from the first UE. That is, the first UE may identify the second UE farthest from the first UE compared to other second UEs, and the first UE may discard transmissions from the second UE farthest from the first UE. In other aspects, the first UE may discard transmissions from the second UE closest to the first UE. In other aspects, the first UE may discard transmissions based on a distance associated with the transmission relative to a threshold (e.g., discarding transmissions with a distance of ≥500 meters).

[0093] Additionally or alternatively, the first UE may determine to discard the transmission and / or TB based on a feedback type associated with the transmission. For example, the first UE may discard a transmission with ACK-based feedback. ACK-based feedback may refer to a HARQ feedback configuration in which the receiver sends an ACK message to the transmitter when the receiver successfully decodes the transmission, but the receiver may not send a NACK message to the transmitter when the receiver detects an error in the received transmission. The first UE may identify that the transmission has an acknowledgment-based feedback type and discard the transmission so that it is not processed.

[0094] Although some examples provided herein to facilitate understanding are described with respect to discarding transmissions so that they are not processed, aspects of the present disclosure may also be applicable to discarding transmission blocks associated with transmissions identified as satisfying one or more rules for managing HARQ budgets. For example, a first UE may discard one or more TBs associated with transmissions that satisfy one or more rules, as described herein. In such a case, the first UE may discard any remaining or subsequent retransmissions of the TB so that they are not transmitted. For example, the first UE may obtain an indication that a retransmission associated with a discarded TB is to be sent, determine that the retransmission is associated with the discarded TB, and discard the retransmission based on the determination so that it is not transmitted.

[0095] If the first UE discards a transmission and subsequently obtains an indication to retransmit the discarded transmission, the first UE may transmit a retransmission of the discarded transmission assuming that the HARQ budget has not been exceeded. That is, discarding the transmission may not affect the HARQ operations associated with subsequent retransmissions, whereas discarding a TB will prevent processing of any subsequent retransmissions associated with the TB.

[0096] In certain aspects, the first UE may identify multiple transmissions to discard based on rules and resolve the ties according to various tie-breaking schemes, as described herein with reference to operation 600 .

[0097] The first UE may communicate with the second UEs via various side link communication channels or air interfaces. In various aspects, the first UE may communicate with the second UEs on PSCCH, PSSCH and / or PSFCH. For example, the remaining transmission at 704 may be transmitted to one or more second UEs via a side link channel. Any of the side link channels may support the HARQ buffer management operations described herein. In some cases, the first UE may have a separate HARQ budget and corresponding HARQ operations for managing downlink and / or uplink transmissions.

[0098] In certain aspects, the first UE may receive a configuration from the BS indicating one or more rules for discarding transmissions to exempt them from HARQ processing, as described herein. For example, the first UE may receive downlink control signaling, such as an RRC message, DIC, or MAC-CE, indicating one or more rules for discarding transmissions.

[0099] In some cases, the first UE may transmit an ACK message or a NACK message to the base station based on the discarded transmission or the remaining transmission sent to the second UE. The ACK / NACK message may indicate to the base station whether the first UE successfully transmitted the remaining transmission or whether the first UE discarded the transmission.

[0100] Figure 8 The description may include operations configured to perform the techniques disclosed herein (such as, Figure 6 and / or Figure 7 800 (eg, corresponding to the operations illustrated in FIG. 8 ) and various components (eg, corresponding to means-plus-function components) of the communication device 800 (eg, Figure 1 120a or UE 120b shown in FIG. 120b). The communication device 800 includes a processing system 802 coupled to a transceiver 808 (e.g., a transmitter and / or a receiver). The transceiver 808 is configured to transmit and receive signals for the communication device 800 (such as various signals as described herein) via an antenna 810. The processing system 802 may be configured to perform processing functions for the communication device 800, including processing signals received and / or to be transmitted by the communication device 800.

[0101] The processing system 802 includes a processor 804 coupled to a computer readable medium / memory 812 via a bus 806. In some aspects, the computer readable medium / memory 812 is configured to store instructions (e.g., computer executable code) that, when executed by the processor 804, cause the processor 804 to perform Figure 6 and / or Figure 7 812 or other operations for performing the various techniques for managing HARQ budgets discussed herein. In some aspects, the computer-readable medium / memory 812 stores code 814 for transmitting, code 816 for receiving, code 818 for discarding, code 820 for processing, code 822 for taking action, and / or code 824 for identifying. In some aspects, the processing system 802 has a circuit system 826 configured to implement the code stored in the computer-readable medium / memory 812. In some aspects, the circuit system 826 is coupled to the processor 804 and / or the computer-readable medium / memory 812 via the bus 806. Circuit system 826 includes circuit system 828 for transmitting (an example of an apparatus for transmitting), circuit system 830 for receiving (an example of an apparatus for receiving), circuit system 832 for discarding (an example of an apparatus for discarding), circuit system 834 for processing (an example of an apparatus for processing), circuit system 836 for taking action (an example of an apparatus for taking action), and / or circuit system 838 for identification (an example of an apparatus for identification).

[0102] Means for transmitting may include an antenna (e.g., antennas 252a-252r), a transceiver (e.g., transceivers 254a-254r), a processor (e.g., controller / processor 280), and / or circuitry for receiving (e.g., circuitry for receiving 830). Means for receiving may include an antenna (e.g., antennas 252a-252r), a transceiver (e.g., transceivers 254a-254r), a processor (e.g., controller / processor 280), and / or circuitry for transmitting (e.g., circuitry for transmitting 828). Means for discarding may include a processor (e.g., controller / processor 280) and / or circuitry for discarding (e.g., circuitry for discarding 832). Means for processing may include a processor (e.g., controller / processor 280) and / or circuitry for processing (e.g., circuitry for processing 834). The means for taking an action may include a processor (e.g., controller / processor 280) and / or circuitry for taking an action (e.g., circuitry for taking an action 836). The means for identifying may include a processor (e.g., controller / processor 280) and / or circuitry for identifying (e.g., circuitry for identifying 838). In various aspects, each processor and / or each circuitry may include circuits designed to perform the functions described herein, a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or a combination thereof.

[0103] In addition to the above examples, many examples of specific combinations are also within the scope of the present disclosure, some of which are described in detail below:

[0104] Example 1: A method for wireless communication by a first user equipment (UE), comprising: in response to an exceeded HARQ budget relative to the number of active hybrid automatic repeat request (HARQ) processes, discarding at least one transmission or one or more transmission blocks (TBs) associated with the at least one transmission so that they are not processed according to one or more rules; processing the remaining transmissions; and taking one or more actions based on the processed remaining transmissions.

[0105] Example 2: A method as in Example 1, wherein discarding at least one transmission or one or more TBs so that they are not processed includes determining that at least one of the number of received transmissions, the number of time domain resources associated with the received transmissions, or the soft buffer capacity is equal to or greater than one or more thresholds, or a combination of the above.

[0106] Example 3: A method according to any of the preceding examples, wherein discarding at least one transmission or one or more TBs so that they are not processed comprises: identifying at least one transmission that satisfies the one or more rules; and discarding at least one transmission or one or more TBs so that they are not processed based on the identification.

[0107] Example 4: A method according to any of the preceding examples, wherein the one or more rules are based on at least one of a time domain threshold associated with the received transmission, a priority level associated with the received transmission, the number of remaining retransmissions, the distance between the first UE and the second UEs, the signal quality of the received transmission, a feedback type associated with the received transmission, or a combination thereof.

[0108] Example 5: The method of Examples 3-4, wherein identifying at least one transmission comprises identifying that the at least one transmission is received before the time domain resource.

[0109] Example 6: The method of Examples 3-5, wherein identifying at least one transmission comprises identifying the at least one transmission as having a lowest priority compared to priorities of other received transmissions.

[0110] Example 7: The method of Examples 3-6, wherein identifying at least one transmission comprises identifying at least one of the second UEs that has transmitted the at least one transmission is farthest from the first UE compared to other of the second UEs.

[0111] Example 8: The method of Examples 3-7, wherein identifying at least one transmission comprises identifying the at least one transmission as having a weakest signal quality compared to signal qualities of other received transmissions.

[0112] Example 9: The method of Examples 3-8, wherein identifying at least one transmission comprises identifying that the at least one transmission has an acknowledgement-based feedback type.

[0113] Example 10: A method as in Example 1, wherein discarding at least one transmission or one or more TBs so that they are not processed includes: identifying all transmissions in at least one transmission that satisfy one of the one or more rules; and discarding all of these transmissions in the at least one transmission or one or more TBs associated with all of these transmissions in the at least one transmission so that they are not processed based on the identification.

[0114] Example 11: A method as in Example 1, wherein discarding at least one transmission or one or more TBs so that they are not processed includes: identifying a first group of transmissions that satisfy a first rule among the one or more rules; after identifying the first group of transmissions, identifying a second group of transmissions in the first group of transmissions that satisfy a second rule among the one or more rules; and discarding the second group of transmissions in the first group of transmissions or one or more TBs associated with the second group of transmissions in the first group of transmissions so that they are not processed.

[0115] Example 12: The method of any of the preceding examples, further comprising receiving a transmission from one or more second UEs via a sidelink channel.

[0116] Example 13: The method of any of the preceding examples, wherein processing the remaining transmission comprises decoding the remaining transmission.

[0117] Example 14: The method of any of the preceding examples, wherein taking one or more actions based on the processed remaining transmission comprises forwarding the decoded transmission to at least one of the base station or a third UE.

[0118] Example 15: A method according to any of the preceding examples, wherein taking one or more actions based on the processed remaining transmission includes sending at least one of an acknowledgement (ACK) message or a negative acknowledgement (NACK) message to one or more second UEs or base stations.

[0119] Example 16: A method for wireless communication by a first user equipment (UE), comprising: in response to a HARQ budget being exceeded relative to the number of active hybrid automatic repeat request (HARQ) processes, discarding at least one transmission or one or more transmission blocks (TBs) associated with the at least one transmission according to one or more rules so that they are not transmitted; and transmitting the remaining transmissions to one or more second UEs.

[0120] Example 17: A method as in Example 16, wherein discarding at least one transmission or one or more TBs so that they are not transmitted includes determining that at least one of the number of transmissions, the number of time domain resources associated with the transmissions, or the soft buffer capacity is equal to or greater than one or more thresholds, or a combination of the above.

[0121] Example 18: A method according to Example 16 or 17, wherein discarding at least one transmission or one or more TBs so that they are not transmitted includes: identifying at least one transmission that satisfies the one or more rules; and discarding at least one transmission or one or more TBs so that they are not transmitted based on the identification.

[0122] Example 19: A method according to Examples 16-18, wherein the one or more rules are based on at least one of a time domain threshold associated with the transmission, a priority level associated with the transmission, a delay budget associated with the transmission, the number of remaining retransmissions, a distance between the first UE and the second UEs, a feedback type associated with the transmission, or a combination thereof.

[0123] Example 20: The method of Examples 18-19, wherein identifying at least one transmission comprises identifying that the at least one transmission is to be transmitted before the time domain resource.

[0124] Example 21: The method of Examples 18-20, wherein identifying at least one transmission comprises identifying the at least one transmission as having a lowest priority compared to priorities of other transmissions.

[0125] Example 22: The method of Examples 18-21, wherein identifying at least one transmission comprises identifying the at least one transmission as having a packet delay budget with a minimum amount of remaining time compared to delay budgets of other transmissions.

[0126] Example 23: The method of Examples 18-22, wherein identifying at least one transmission comprises identifying the at least one transmission having a greatest amount of remaining time in a packet delay budget compared to delay budgets of other transmissions.

[0127] Example 24: The method of Examples 18-23, wherein identifying at least one transmission comprises identifying at least one of the second UEs as being farthest from the first UE compared to other of the second UEs.

[0128] Example 25: The method of Examples 18-24, wherein identifying at least one transmission comprises identifying that the at least one transmission has an acknowledgement-based feedback type.

[0129] Example 26: A method as in Example 16, wherein discarding at least one transmission or one or more TBs so that they are not transmitted includes: identifying all transmissions in at least one transmission that satisfy one of the one or more rules; and discarding all of these transmissions in the at least one transmission or one or more TBs associated with all of these transmissions in the at least one transmission so that they are not transmitted based on the identification.

[0130] Example 27: A method as in Example 16, wherein discarding at least one transmission or one or more TBs so that they are not transmitted includes: identifying a first group of transmissions that satisfy a first rule among the one or more rules; after identifying the first group of transmissions, identifying a second group of transmissions in the first group of transmissions that satisfy a second rule among the one or more rules; and discarding the second group of transmissions in the first group of transmissions or one or more TBs associated with the second group of transmissions in the first group of transmissions so that they are not transmitted.

[0131] Example 28: The method according to Examples 16-27 further includes: transmitting at least one of an acknowledgement (ACK) message or a negative acknowledgement (NACK) message to a base station based on the at least one transmission or the remaining transmission; and wherein the remaining transmission is transmitted to one or more second UEs via a side link channel.

[0132] Example 29: An apparatus for wireless communication, comprising: a memory and a processor coupled to the memory, the processor and the memory being configured to: in response to a HARQ budget being exceeded relative to the number of active hybrid automatic repeat request (HARQ) processes, discard at least one transmission or one or more transmission blocks (TBs) associated with the at least one transmission according to one or more rules so that they are not processed, process remaining transmissions, and take one or more actions based on the processed remaining transmissions.

[0133] Example 30: The apparatus of Example 29, further comprising a communication interface, wherein the communication interface, the processor, and / or the memory are configured to perform any one or more of the aspects or methods included in Examples 1-15.

[0134] Example 31: An apparatus for wireless communication, comprising: a memory and a processor coupled to the memory, the processor and the memory being configured to: in response to a HARQ budget being exceeded relative to the number of active hybrid automatic repeat request (HARQ) processes, discard at least one transmission or one or more transport blocks (TBs) associated with the at least one transmission so that they are not processed according to one or more rules. The apparatus also includes a transmitter configured to transmit the remaining transmissions to one or more UEs.

[0135] Example 32: The apparatus of Example 31, wherein the transmitter, the processor, and / or the memory are configured to perform any one or more of the aspects or methods included in Examples 16-28.

[0136] The techniques described herein may be used for various wireless communication technologies, such as NR (e.g., 5G NR), 3GPP Long Term Evolution (LTE), Advanced LTE (LTE-A), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network may implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, and the like. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95, and IS-856 standards. A TDMA network may implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks can implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are parts of Universal Mobile Telecommunications System (UMTS). LTE and LTE-A are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). cdma2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). NR is an emerging wireless communication technology under development.

[0137] The techniques described herein can be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, although various aspects may be described herein using terms commonly associated with 3G, 4G and / or 5G wireless technologies, various aspects of the present disclosure may be applied in communication systems based on other generations.

[0138] In 3GPP, the term "cell" may refer to the coverage area of ​​a B node (NB) and / or a NB subsystem serving the coverage area, depending on the context in which the term is used. In NR systems, the terms "cell" and BS, next-generation B node (gNB or g B node), access point (AP), distributed unit (DU), carrier, or transmission reception point (TRP) may be used interchangeably. The BS may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell may cover a relatively large geographic area (e.g., a radius of several thousand meters) and may allow unrestricted access by UEs with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in a residence, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS.

[0139] UE may also be referred to as a mobile station, terminal, access terminal, subscriber unit, station, customer premises equipment (CPE), cellular phone, smart phone, personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet computer, camera, gaming device, netbook, smartbook, ultrabook, appliance, medical device or medical equipment, biometric sensor / device, wearable device (such as smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet, etc.)), entertainment device (e.g., music device, video device, satellite radio, etc.), transportation component or sensor, smart meter / sensor, industrial manufacturing equipment, global positioning system device, or any other suitable device configured to communicate via wireless or wired medium. Some UEs may be considered machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which can communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node can provide connectivity for or to a network (e.g., a wide area network (such as the Internet) or a cellular network), for example, via a wired or wireless communication link. Some UEs may be considered Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0140] Some wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are also often referred to as frequency modulation, frequency bins, etc. Each subcarrier can be modulated with data. In general, modulation symbols are sent in the frequency domain for OFDM and in the time domain for SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the spacing of subcarriers can be 15kHz, and the minimum resource allocation (called a "resource block" (RB)) can be 12 subcarriers (or 180kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal fast Fourier transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may also be divided into subbands. For example, a subband may cover 1.08 MHz (e.g., 6 RBs), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively. In LTE, the basic transmission time interval (TTI) or packet duration is a 1 ms subframe.

[0141] NR can utilize OFDM with CP on the uplink and downlink and includes support for half-duplex operation using TDD. In NR, a subframe is still 1ms, but the basic TTI is called a time slot. A subframe contains a variable number of time slots (e.g., 1, 2, 4, 8, 16...time slots), depending on the subcarrier spacing. NR RB is 12 consecutive frequency subcarriers. NR can support a base subcarrier spacing of 15KHz, and other subcarrier spacings can be defined relative to the base subcarrier spacing, such as 30kHz, 60kHz, 120kHz, 240kHz, etc. The CP length also depends on the subcarrier spacing. Beamforming can be supported and the beam direction can be dynamically configured. MIMO transmission with precoding can also be supported. In some examples, the MIMO configuration in DL can support up to 8 transmit antennas (multi-layer DL transmission with up to 8 streams) and up to 2 streams per UE. In some examples, multi-layer transmission of up to 2 streams per UE can be supported. Up to 8 serving cells may be used to support aggregation of multiple cells.

[0142] In some examples, access to the air interface may be scheduled. A scheduling entity (e.g., BS) allocates resources for communication between some or all devices and equipment within its service area or cell. A scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, subordinate entities utilize resources allocated by the scheduling entity. A base station is not the only entity that can be used as a scheduling entity. In some examples, a UE may act as a scheduling entity, and may schedule resources for one or more subordinate entities (e.g., one or more other UEs), and other UEs may utilize resources scheduled by the UE for wireless communication. In some examples, a UE may act as a scheduling entity in a peer-to-peer (P2P) network and / or in a mesh network. In a mesh network example, UEs may communicate directly with each other in addition to communicating with a scheduling entity.

[0143] Each method disclosed herein includes one or more steps or actions for implementing the method. These method steps and / or actions can be interchangeable with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions can be changed without departing from the scope of the claims.

[0144] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0145] As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, a database, or another data structure), ascertaining, and the like. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Also, "determining" may include resolving, selecting, choosing, establishing, and the like.

[0146] 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 various aspects shown herein, but should be granted the full scope consistent with the language of the claims, wherein the singular reference to the element is not intended to mean "there is and only one" (unless specifically stated) but "one or more". Unless otherwise specifically stated, the term "some / some" refers to one or more. The elements of the various aspects described throughout this disclosure are all structural and functional equivalents currently or hereafter known to those of ordinary skill in the art and are expressly incorporated herein by reference, and are intended to be covered by the claims. In addition, nothing disclosed herein is intended to be donated to the public, regardless of whether such disclosure is explicitly recorded in the claims. Any element of the claim should not be interpreted under the provisions of 35 U.S.C. § 112 (f), unless the element is explicitly stated using the phrase "device for..." or in the case of a method claim, the element is stated using the phrase "step for...".

[0147] The various operations of the methods described above may be performed by any suitable device capable of performing the corresponding functions. These devices may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs), or processors. Generally, where there are operations illustrated in the accompanying drawings, these operations may have corresponding paired device-plus-function components with similar numbers.

[0148] The various illustrative logical blocks, modules, and circuits described in conjunction with the present disclosure may be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0149] If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented using a bus architecture. Depending on the specific application of the processing system and the overall design constraints, the bus may include any number of interconnecting buses and bridges. The bus may link together various circuits including a processor, a machine-readable medium, and a bus interface. The bus interface may be used to connect a network adapter, etc., to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In user equipment 120 (see Figure 1 ), a user interface (e.g., a keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits, such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art and will not be described further. The processor may be implemented with one or more general and / or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuit systems capable of executing software. Those skilled in the art will recognize how to best implement the functionality described with respect to the processing system, depending on the specific application and the overall design constraints imposed on the overall system.

[0150] If implemented in software, each function may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Software should be broadly interpreted to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or other. Computer-readable media include both computer storage media and communication media, which include any media that facilitate the transfer of computer programs from one place to another. The processor may be responsible for managing the bus and general processing, including executing software modules stored on a machine-readable storage medium. A computer-readable storage medium may be coupled to a processor so that the processor can read and write information from / to the storage medium. In an alternative, a storage medium may be integrated into a processor. As an example, a machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium having instructions stored thereon that is separated from a wireless node, all of which may be accessed by a processor through a bus interface. Alternatively or additionally, a machine-readable medium or any part thereof may be integrated into a processor, such as a cache and / or a general register file, which may be the case. As an example, examples of machine-readable storage media may include RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage media, or any combination thereof. Machine-readable media may be implemented in a computer program product.

[0151] A software module may include a single instruction, or many instructions, and may be distributed over several different code segments, distributed between different programs, and distributed across multiple storage media. A computer-readable medium may include several software modules. These software modules include instructions that cause a processing system to perform various functions when executed by an apparatus such as a processor. These software modules may include a transmission module and a receiving module. Each software module may reside in a single storage device or may be distributed across multiple storage devices. As an example, when a triggering event occurs, a software module may be loaded into a RAM from a hard drive. During the execution of a software module, a processor may load some instructions into a cache to increase access speed. One or more cache lines may then be loaded into a general register file for execution by the processor. When describing the functionality of a software module as described below, it will be understood that such functionality is implemented by the processor when the processor executes instructions from the software module.

[0152] Likewise, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technology (such as infrared (IR), radio, and microwave), then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technology (such as infrared, radio, and microwave) is included in the definition of medium. Disk and disc, as used herein, include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Disks, where disks often reproduce data magnetically, and discs reproduce data optically with lasers. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Additionally, for other aspects, computer-readable media may include transient computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0153] Thus, certain aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having stored (and / or encoded) thereon instructions that can be executed by one or more processors to perform the operations described herein, such as for performing the operations described herein and in Figure 6 and / or Figure 7 Instructions for the operations explained in .

[0154] In addition, it should be appreciated that modules and / or other appropriate means for performing the methods and techniques described herein may be downloaded and / or otherwise obtained by a user terminal and / or base station where applicable. For example, such a device can be coupled to a server to facilitate the transfer of means for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage device (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or a floppy disk, etc.) so that once the storage device is coupled to or provided to a user terminal and / or base station, the device can obtain the various methods. In addition, any other suitable technology suitable for providing the methods and techniques described herein to a device may be utilized.

[0155] It will be understood that the claims are not limited to the precise configuration and components illustrated above. Various changes, substitutions and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A method for wireless communication by a first user equipment (UE), comprising: In response to a Hybrid Automatic Repeat Request (HARQ) budget being exceeded relative to a number of active HARQ processes, discarding at least one of a plurality of transmissions received from one or more second UEs or one or more transport blocks (TBs) associated with the at least one of the plurality of transmissions from being processed according to one or more rules, wherein the one or more rules are based at least in part on whether the at least one of the plurality of transmissions is received outside of a window of one or more time domain resources associated with the received plurality of transmissions; processing one or more remaining transmissions of the plurality of transmissions; as well as One or more actions are taken based on the processed one or more remaining transmissions.

2. The method of claim 1, wherein discarding at least one of the plurality of transmissions or one or more TBs from being processed comprises determining that at least one of the number of the plurality of transmissions received, the number of time domain resources associated with the plurality of transmissions received, or the soft buffer capacity is equal to or greater than one or more thresholds, or a combination of the foregoing.

3. The method of claim 1 , wherein discarding at least one transmission or one or more TBs of the plurality of transmissions to not be processed comprises: identifying at least one transmission from among a plurality of transmissions that satisfies the one or more rules; as well as The at least one transmission of the plurality of transmissions or the one or more TBs are discarded based on the identification so as not to be processed.

4. The method of claim 3, wherein the one or more rules are further based on at least one of: the priority levels associated with the received multiple transmissions, The number of remaining retransmissions, The distance between the first UE and the one or more second UEs, The signal quality of the received transmission, the feedback type associated with the multiple transmissions received, or Its combination.

5. The method of claim 3, wherein identifying at least one of a plurality of transmissions comprises identifying that the at least one of the plurality of transmissions was received before a time domain resource.

6. The method of claim 3, wherein identifying at least one transmission of a plurality of transmissions comprises identifying that the at least one transmission of the plurality of transmissions has a lowest priority compared to priorities of other received transmissions of the plurality of transmissions.

7. The method of claim 3, wherein identifying at least one of the multiple transmissions comprises identifying at least one of the one or more second UEs that has transmitted the at least one of the multiple transmissions as being farthest from the first UE compared to other second UEs of the one or more second UEs.

8. The method of claim 3, wherein identifying at least one of a plurality of transmissions comprises identifying that the at least one of the plurality of transmissions has a weakest signal quality compared to signal qualities of other received transmissions of the plurality of transmissions.

9. The method of claim 3, wherein identifying at least one transmission of a plurality of transmissions comprises identifying that the at least one transmission of the plurality of transmissions has an acknowledgment-based feedback type.

10. The method of claim 1, wherein discarding at least one transmission or one or more TBs of the plurality of transmissions to not be processed comprises: identifying all transmissions of the at least one transmission of the plurality of transmissions that satisfy one of the one or more rules; as well as All of the at least one of the plurality of transmissions or one or more TBs associated with all of the at least one of the plurality of transmissions are discarded from being processed based on the identification.

11. The method of claim 1 , wherein discarding at least one transmission or one or more TBs of the plurality of transmissions to not be processed comprises: identifying a first plurality of transmissions that satisfy a first rule of the one or more rules; After identifying the first plurality of transmissions, identifying a second group of transmissions in the first plurality of transmissions that satisfies a second rule of the one or more rules; as well as A second set of transmissions in the first plurality of transmissions or one or more TBs associated with the second set of transmissions in the first plurality of transmissions are discarded from being processed.

12. The method of claim 1, further comprising receiving a plurality of transmissions from the one or more second UEs via a sidelink channel.

13. The method of claim 1, wherein processing one or more remaining transmissions comprises decoding the one or more remaining transmissions.

14. The method of claim 1, wherein taking one or more actions based on the processed one or more remaining transmissions comprises forwarding the one or more remaining transmissions to at least one of a base station or a third UE.

15. The method of claim 1, wherein taking one or more actions based on the processed one or more remaining transmissions comprises sending at least one of an acknowledgement (ACK) message or a negative acknowledgement (NACK) message to the one or more second UEs or base stations.

16. A method for wireless communication by a first user equipment (UE), comprising: In response to a Hybrid Automatic Repeat Request (HARQ) budget being exceeded relative to a number of active HARQ processes, discarding at least one of a plurality of transmissions to one or more second UEs or one or more transport blocks (TBs) associated with the at least one of the plurality of transmissions from being transmitted according to one or more rules, wherein the one or more rules are based at least in part on whether the at least one of the plurality of transmissions is transmitted outside of a window of one or more time domain resources associated with the plurality of transmissions; as well as One or more remaining transmissions of the plurality of transmissions are transmitted to the one or more second UEs.

17. The method of claim 16, wherein discarding at least one transmission or one or more TBs from a plurality of transmissions so that they are not transmitted comprises determining that at least one of the number of the plurality of transmissions, the number of time domain resources associated with the plurality of transmissions, or a soft buffer capacity is equal to or greater than one or more thresholds, or a combination of the above.

18. The method of claim 16, wherein discarding at least one transmission or one or more TBs of the plurality of transmissions so that they are not transmitted comprises: identifying at least one transmission from among a plurality of transmissions that satisfies the one or more rules; as well as The at least one transmission of the plurality of transmissions or the one or more TBs are discarded from being transmitted based on the identification.

19. The method of claim 18, wherein the one or more rules are further based on at least one of: the priority levels associated with multiple transfers, The delay budget associated with multiple transfers, The number of remaining retransmissions, The distance between the first UE and the one or more second UEs, The type of feedback associated with multiple transmissions, or Its combination.

20. The method of claim 18, wherein identifying at least one of a plurality of transmissions comprises identifying that the at least one of the plurality of transmissions is to be transmitted prior to a time domain resource.

21. The method of claim 18, wherein identifying at least one transmission of a plurality of transmissions comprises identifying the at least one transmission of the plurality of transmissions as having a lowest priority compared to priorities of other transmissions.

22. The method of claim 18, wherein identifying at least one transmission of a plurality of transmissions comprises identifying the at least one transmission of the plurality of transmissions as having a packet delay budget that has a smallest amount of remaining time compared to delay budgets of other transmissions.

23. The method of claim 18, wherein identifying at least one transmission of a plurality of transmissions comprises identifying the at least one transmission of the plurality of transmissions as having a largest amount of remaining time in a packet delay budget compared to delay budgets of other transmissions.

24. The method of claim 18, wherein identifying at least one of the plurality of transmissions comprises identifying at least one of the one or more second UEs as being farthest from the first UE compared to other second UEs of the one or more second UEs.

25. The method of claim 18, wherein identifying at least one transmission of a plurality of transmissions comprises identifying that the at least one transmission of the plurality of transmissions has an acknowledgment-based feedback type.

26. The method of claim 16, wherein discarding at least one transmission or one or more TBs from being transmitted comprises: identifying all transmissions of at least one transmission of the plurality of transmissions that satisfy one of the one or more rules; as well as All of the at least one of the plurality of transmissions or one or more TBs associated with all of the at least one of the plurality of transmissions are discarded from being transmitted based on the identification.

27. The method of claim 16, wherein discarding at least one transmission or one or more TBs from the plurality of transmissions to not be transmitted comprises: identifying a first plurality of transmissions that satisfy a first rule of the one or more rules; After identifying the first plurality of transmissions, identifying a second group of transmissions in the first plurality of transmissions that satisfies a second rule of the one or more rules; as well as A second set of transmissions in the first plurality of transmissions or one or more TBs associated with the second set of transmissions in the first plurality of transmissions are discarded from being transmitted.

28. The method of claim 16, further comprising: transmitting at least one of an acknowledgement (ACK) message or a negative acknowledgement (NACK) message to a base station based on at least one of the plurality of transmissions or the remaining transmissions; and The one or more remaining transmissions are transmitted to the one or more second UEs via a sidelink channel.

29. An apparatus for wireless communication, comprising: Memory; as well as a processor coupled to the memory, the processor and the memory being configured to: In response to a hybrid automatic repeat request (HARQ) budget being exceeded relative to a number of active HARQ processes, discarding at least one of a plurality of transmissions received from one or more user equipments (UEs) or one or more transport blocks (TBs) associated with the at least one of the plurality of transmissions from being processed according to one or more rules, wherein the one or more rules are based at least in part on whether the at least one of the plurality of transmissions is received outside of a window of one or more time domain resources associated with the received plurality of transmissions, processing one or more remaining transmissions of the plurality of transmissions, and One or more actions are taken based on the processed one or more remaining transmissions.

30. The apparatus of claim 29, wherein the processor and the memory configured to discard at least one transmission of a plurality of transmissions or one or more TBs so that they are not processed are further configured to determine that at least one of the number of received plurality of transmissions, the number of time domain resources associated with the received plurality of transmissions, or the soft buffer capacity is equal to or greater than one or more thresholds, or a combination of the above.

31. The apparatus of claim 29, wherein the processor and the memory configured to discard at least one of a plurality of transmissions or one or more TBs from being processed are further configured to: identifying at least one transmission from among the plurality of transmissions that satisfies the one or more rules; and The at least one transmission of the plurality of transmissions or the one or more TBs are discarded based on the identification so as not to be processed.

32. The apparatus of claim 31 , wherein the one or more rules are based on at least one of: the priority levels associated with the received multiple transmissions, The number of remaining retransmissions, a distance between the apparatus and the one or more UEs, The signal quality of the received transmission, the feedback type associated with the multiple transmissions received, or Its combination.

33. The apparatus of claim 31 , wherein the processor and the memory configured to identify at least one of a plurality of transmissions are further configured to identify that the at least one of the plurality of transmissions was received prior to a time domain resource.

34. The apparatus of claim 31 , wherein the processor and the memory configured to identify at least one of a plurality of transmissions are further configured to identify the at least one of the plurality of transmissions as having a lowest priority compared to priorities of other received transmissions of the plurality of transmissions.

35. The apparatus of claim 31, wherein the processor and the memory configured to identify at least one of a plurality of transmissions are further configured to identify at least one of the one or more UEs that has transmitted the at least one of the plurality of transmissions as being farthest from the apparatus compared to other UEs of the one or more UEs.

36. The apparatus of claim 31 , wherein the processor and the memory configured to identify at least one of a plurality of transmissions are further configured to identify that the at least one of the plurality of transmissions has a weakest signal quality compared to signal qualities of other received transmissions of the plurality of transmissions.

37. The apparatus of claim 31, wherein the processor and the memory configured to identify at least one transmission of a plurality of transmissions are further configured to identify that the at least one transmission of the plurality of transmissions has an acknowledgment-based feedback type.

38. The apparatus of claim 29, wherein the processor and the memory configured to discard at least one transmission of a plurality of transmissions or one or more TBs from being processed are further configured to: identifying all transmissions of the at least one transmission of the plurality of transmissions that satisfy one of the one or more rules; and All of the at least one of the plurality of transmissions or one or more TBs associated with all of the at least one of the plurality of transmissions are discarded from being processed based on the identification.

39. The apparatus of claim 29, wherein the processor and the memory configured to discard at least one transmission of a plurality of transmissions or one or more TBs from being processed are further configured to: identifying a first plurality of transmissions that satisfy a first rule of the one or more rules; After identifying the first plurality of transmissions, identifying a second group of transmissions in the first plurality of transmissions that satisfy a second rule of the one or more rules; and A second set of transmissions in the first plurality of transmissions or one or more TBs associated with the second set of transmissions in the first plurality of transmissions are discarded from being processed.

40. The apparatus of claim 29, wherein the processor and the memory are further configured to receive a plurality of transmissions from the one or more UEs via a sidelink channel.

41. The apparatus of claim 29, wherein the processor and the memory configured to process one or more remaining transmissions are further configured to decode the one or more remaining transmissions.

42. The apparatus of claim 29, wherein the processor and the memory configured to take one or more actions based on the processed one or more remaining transmissions are further configured to forward the one or more transmissions to at least one of a base station or a third UE.

43. The apparatus of claim 29, wherein the processor and the memory configured to take one or more actions based on the processed one or more remaining transmissions are further configured to send at least one of an acknowledgment (ACK) message or a negative acknowledgment (NACK) message to the one or more UEs or base stations.

44. An apparatus for wireless communication, comprising: Memory; a processor coupled to the memory, the processor and the memory being configured to: In response to a hybrid automatic repeat request (HARQ) budget being exceeded relative to the number of active HARQ processes, at least one transmission of a plurality of transmissions to one or more user equipment (UE) or one or more transport blocks (TBs) associated with the at least one transmission of the plurality of transmissions are discarded from being processed according to one or more rules, wherein The one or more rules are based at least in part on whether the at least one transmission of the plurality of transmissions is transmitted outside of a window of one or more time-domain resources associated with the plurality of transmissions; as well as A transmitter is configured to transmit one or more remaining transmissions of the plurality of transmissions to one or more UEs.

45. An apparatus as described in claim 44, wherein the processor and the memory configured to discard at least one transmission among a plurality of transmissions or one or more TBs so that they are not transmitted are further configured to determine that at least one of the number of the plurality of transmissions, the number of time domain resources associated with the plurality of transmissions, or the soft buffer capacity is equal to or greater than one or more thresholds, or a combination of the above.

46. ​​The apparatus of claim 44, wherein the processor and the memory configured to discard at least one transmission of a plurality of transmissions or one or more TBs from being transmitted are further configured to: identifying at least one transmission from among the plurality of transmissions that satisfies the one or more rules; and The at least one transmission of the plurality of transmissions or the one or more TBs are discarded from being transmitted based on the identification.

47. The apparatus of claim 46, wherein the one or more rules are further based on at least one of: the priority levels associated with multiple transfers, The delay budget associated with multiple transfers, The number of remaining retransmissions, a distance between the apparatus and the one or more UEs, The type of feedback associated with multiple transmissions, or Its combination.

48. The apparatus of claim 46, wherein the processor and the memory configured to identify at least one transmission of a plurality of transmissions are further configured to identify that the at least one transmission of the plurality of transmissions is to be transmitted prior to a time domain resource.

49. The apparatus of claim 46, wherein the processor and the memory configured to identify at least one of a plurality of transmissions are further configured to identify the at least one of the plurality of transmissions as having a lowest priority compared to priorities of other transmissions.

50. The apparatus of claim 46, wherein the processor and the memory configured to identify at least one of a plurality of transmissions are further configured to identify that the at least one of the plurality of transmissions has a packet delay budget that has a minimum amount of remaining time compared to delay budgets of other transmissions.

51. The apparatus of claim 46, wherein the processor and the memory configured to identify at least one of a plurality of transmissions are further configured to identify that at least one of the plurality of transmissions has a largest amount of remaining time in terms of a packet delay budget compared to delay budgets of other transmissions.

52. The apparatus of claim 46, wherein the processor and the memory configured to identify at least one of a plurality of transmissions are further configured to identify at least one of the one or more UEs as being farthest from the apparatus compared to other UEs of the one or more UEs.

53. The apparatus of claim 46, wherein the processor and the memory configured to identify at least one transmission of a plurality of transmissions are further configured to identify that the at least one transmission of the plurality of transmissions has an acknowledgment-based feedback type.

54. The apparatus of claim 44, wherein the processor and the memory configured to discard at least one transmission of a plurality of transmissions or one or more TBs from being transmitted are further configured to: identifying all transmissions of at least one transmission of the plurality of transmissions that satisfy one of the one or more rules; and All of the at least one of the plurality of transmissions or one or more TBs associated with all of the at least one of the plurality of transmissions are discarded from being transmitted based on the identification.

55. The apparatus of claim 44, wherein the processor and the memory configured to discard at least one transmission of a plurality of transmissions or one or more TBs from being transmitted are further configured to: identifying a first plurality of transmissions that satisfy a first rule of the one or more rules; After identifying the first plurality of transmissions, identifying a second group of transmissions in the first plurality of transmissions that satisfy a second rule of the one or more rules; and A second set of transmissions in the first plurality of transmissions or one or more TBs associated with the second set of transmissions in the first plurality of transmissions are discarded from being transmitted.

56. The apparatus of claim 44, wherein the processor and the memory are further configured to: transmitting at least one of an acknowledgement (ACK) message or a negative acknowledgement (NACK) message to a base station based on the at least one transmission of the plurality of transmissions or the one or more remaining transmissions; and The one or more remaining transmissions are transmitted to the one or more UEs via a sidelink channel.

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