CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Patent Application Number 63/329,250 entitled “CONFIGURING A PRIORITIZED HARQ-NACK TIMING INDICATOR” and fded on 8 April 2022 for Razvan-Andrei Stoica, Hossein Bagheri, and Vijay Nangia, which application is incorporated herein by reference.

FIELD

[0002] The subject matter disclosed herein relates generally to wireless communications and more particularly relates to configuring a prioritized Hybrid Automatic Repeat Request Negative Acknowledgement (“HARQ-NACK”) timing indicator, e.g., for opportunistic feedback prioritization.

BACKGROUND

[0003] A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an evolved NodeB (“eNB”), a next-generation NodeB (“gNB”), or other suitable terminology. Each network communication devices, such as a base station may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (“UE”), or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers). Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (“3G”) Radio Access Technology (“RAT”), fourth generation (“4G”) RAT, fifth generation (“5G”) RAT, among other suitable RATs beyond 5G (e.g., sixth generation (“6G”)).

[0004] The wireless communication system may utilize Hybrid Automatic Repeat Request (“HARQ”) procedures for error control, whereby a receiving device informs a transmitting device whether a transmission was correctly received and decoded at the receiver.

BRIEF SUMMARY [0005] The present disclosure relates to methods, apparatuses, and systems that support techniques for configuring a prioritized HARQ-NACK timing indicator, e.g., for opportunistic HARQ-NACK feedback prioritization. Said techniques may be implemented by apparatus, systems, methods, or computer program products.

[0006] One method at a receiving device, such as a UE, includes identifying a prioritized HARQ-NACK timing indicator corresponding to a prioritized slot offset timing delay associated with a scheduled transport block (‘TB”) and identifying a default HARQ timing indicator corresponding to a default slot offset timing delay associated with the scheduled TB. The method includes receiving the scheduled TB and determining whether the scheduled TB was successfully decoded. The method includes selecting a slot offset timing delay based at least in part on the prioritized HARQ-NACK timing indicator, the default HARQ timing indicator, and whether the scheduled TB was successfully decoded, wherein the selected slot offset timing delay corresponds to the prioritized slot offset timing delay or the default slot offset timing delay. The method includes transmitting, based on the selected slot offset timing delay, a HARQ feedback report associated with the received TB.

[0007] One method at a transmitting device, such as a radio access network (“RAN”) node, includes determining a prioritized HARQ-NACK timing indicator corresponding to a prioritized slot offset timing delay associated with a scheduled TB. The method includes configuring a receiving device with the prioritized HARQ-NACK timing indicator and with a default HARQ timing indicator corresponding to a default slot offset timing delay associated with the scheduled TB. The method includes transmitting the scheduled TB and receiving, based on the prioritized slot offset timing delay or the default slot offset timing delay, a HARQ feedback report associated with the scheduled TB. The method includes retransmitting, to the receiving device, the scheduled TB based on the HARQ feedback report indicating that the transmission of the scheduled TB was unsuccessful.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 illustrates an example of a wireless communication system that supports techniques for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure;

[0009] Figure 2 illustrates an example of a Third Generation Partnership Project (“3GPP”) New Radio (“NR”) protocol stack that supports different protocol layers in the UE and network, in accordance with aspects of the present disclosure; [0010] Figure 3 illustrates an example of a network architecture for extended reality (“XR”) that supports content rendering and delivery, in accordance with aspects of the present disclosure;

[0011] Figure 4 illustrates an example of payload size distribution for XR services, in accordance with aspects of the present disclosure;

[0012] Figure 5 illustrates an example of a communication system architecture for XR services, in accordance with aspects of the present disclosure;

[0013] Figure 6 illustrates an example of a timing diagram for HARQ feedback, in accordance with aspects of the present disclosure;

[0014] Figure 7 illustrates an example of a procedure for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure;

[0015] Figure 8 illustrates an example of a downlink/uplink (“DL/UL”) traffic model that supports delivery of XR application traffic, in accordance with aspects of the present disclosure;

[0016] Figure 9 illustrates an example of a first timing diagram of opportunistic HARQ- NACK prioritization, in accordance with aspects of the present disclosure;

[0017] Figure 10 illustrates an example of a second timing diagram of opportunistic HARQ-NACK prioritization, in accordance with aspects of the present disclosure;

[0018] Figure 11 illustrates an example of a third timing diagram of opportunistic HARQ- NACK prioritization, in accordance with aspects of the present disclosure;

[0019] Figure 12 illustrates an example of a fourth timing diagram of opportunistic HARQ- NACK prioritization, in accordance with aspects of the present disclosure;

[0020] Figure 13 illustrates an example of a fifth timing diagram of opportunistic HARQ- NACK prioritization, in accordance with aspects of the present disclosure;

[0021] Figure 14 illustrates an example of a sixth timing diagram of opportunistic HARQ- NACK prioritization, in accordance with aspects of the present disclosure;

[0022] Figure 15 illustrates an example of a seventh timing diagram of opportunistic HARQ-NACK prioritization, in accordance with aspects of the present disclosure;

[0023] Figure 16 illustrates an example of an eighth timing diagram of opportunistic HARQ-NACK prioritization, in accordance with aspects of the present disclosure;

[0024] Figure 17 illustrates an example of a UE apparatus that supports techniques for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure;

[0025] Figure 18 illustrates an example of a network equipment (“NE”) apparatus that supports techniques for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure; [0026] Figure 19 illustrates a flowchart of one method that supports techniques for HARQ- NACK feedback prioritization, in accordance with aspects of the present disclosure; and

[0027] Figure 20 illustrates a flowchart of another method that supports techniques for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

[0028] The present disclosure describes systems, methods, and apparatus that supports techniques for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. In certain embodiments, the methods may be performed using computer code embedded on a computer-readable medium. In certain embodiments, an apparatus or system may include a computer-readable medium containing computer-readable code which, when executed by a processor, causes the apparatus or system to perform at least a portion of the below described solutions.

[0029] A service-oriented design considering XR traffic characteristics (e.g., (a) bursty quasi-periodic packets coming at 30-120 frames/second with some jitter, (b) packets having variable and large packet size, (c) B/P-frames being dependent on I-frames, (d) presence of multiple traffic/data flows such as pose (i.e., user orientation/position) and video scene in uplink, (e) various degrees of importance between I/P/B-frames in contributing to the end-to-end quality of user experience) can enable more efficient (e.g., in terms of satisfying XR service requirements for a greater number of UEs, in terms of UE power saving, or in terms of XR traffic reliability and rendering robustness against wireless networks transmissions effects) XR service delivery.

[0030] According to 3GPP Technical Report (“TR”) 26.928, XR is an umbrella term for different types of realities including: Virtual Reality (“VR”), Augmented Reality (“AR”), and Mixed Reality (“MR”).

[0031] VR is a rendered version of a delivered visual and audio scene. The rendering is designed to mimic the visual and audio sensory stimuli of the real world as naturally as possible to an observer or user as they move within the limits defined by the application. VR usually, but not necessarily, requires a user to wear a head mounted display (‘HMD”), to completely replace the user's field of view with a simulated visual component, and to wear headphones, to provide the user with the accompanying audio. Some form of head and motion tracking of the user in VR is usually also necessary to allow the simulated visual and audio components to be updated to ensure that, from the user's perspective, items and sound sources remain consistent with the user's movements. Additional means to interact with the VR simulation may be provided but are not strictly necessary. [0032] AR is when a user is provided with additional information or artificially generated items, or content overlaid upon their current environment. Such additional information or content will usually be visual and/or audible and their observation of their current environment may be direct, with no intermediate sensing, processing, and rendering, or indirect, where their perception of their environment is relayed via sensors and may be enhanced or processed.

[0033] MR is an advanced form of AR where some virtual elements are inserted into the physical scene with the intent to provide the illusion that these elements are part of the real scene.

[0034] XR refers to all real-and-virtual combined environments and human-machine interactions generated by computer technology and wearables. It includes representative forms such as AR, MR and VR and the areas interpolated among them. The levels of virtuality range from partially sensory inputs to fully immersive VR. A key aspect of XR is the extension of human experiences especially relating to the senses of existence (represented by VR) and the acquisition of cognition (represented by AR).

[0035] The Quality of Service (“QoS”) requirements of XR downlink traffic in terms of delay budget (e.g., 15-20 ms per packet delay budget) and reliability (e.g., 10 ^-4 packet error rate) constrain the number of retransmissions for XR packets to at most 1 -2 possible retransmissions in practical deployment scenarios (e.g., multiple UEs system load, varying Signal-to-Noise Ratios (“SNRs”), etc.), given XR traffic characteristics. This is predominant especially for packets forming application data units of higher importance, such as I-frames or I-slices. As such, early feedback of HARQ non-acknowledgement indications is essential in recovering from transmission errors. However, an aggressive feedback resource timing allocation, despite reducing feedback latency, will considerably increase energy consumption, especially as the frequency of HARQ- NACK occurrences is expected to be reduced under the 10 ^-4 packet error rate service requirement. Mechanisms and configuration tools to provide energy-efficient low-latency feedback of HARQ non-acknowledgements indications are therefore required for the network to exploit dynamically.

[0036] In the following, solutions are described to provide mechanisms and configuration tools for energy-efficient low-latency feedback of HARQ non-acknowledgements indications based on opportunistically prioritized HARQ-NACK indications.

[0037] Described herein is a new timing indicator, referred to herein as “Kl-NACK”, which indicates a prioritized Physical Downlink Shared Channel (“PDSCH”) to HARQ-NACK feedback timing, e.g., an earliest slot offset for reporting the HARQ-NACK feedback of a PDSCH transmission. The Kl-NACK timing indicator supports techniques for HARQ-NACK feedback prioritization, as described in further detail below. As used herein, the Kl-NACK timing indicator may also be referred to as the “Kl-NACK parameter,” the Kl-NACK indicator,” and the “prioritized Kl-NACK timing indicator.”

[0038] Also described herein are procedures that support opportunistic HARQ-NACK feedback prioritization for HARQ-NACK feedback of a PDSCH transmission. In various embodiments, the procedures for opportunistic HARQ-NACK feedback prioritization combine low latency HARQ-NACK feedback with increased energy efficiency of multiple TB HARQ- ACK codebook multiplexing based on the newly introduced Kl-NACK timing indicator and the KI timing indicator (i.e., used to indicate (non-prioritized) PDSCH-to-HARQ feedback timing). As used herein, the KI timing indicator may also be referred to as the “KI parameter,” the “KI indicator,” and the “default KI timing indicator.”

[0039] Figure 1 illustrates an example of a wireless communication system 100 supporting HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as a Long- Term Evolution (“LTE”) network or an LTE-Advanced (“LTE-A”) network. In some other implementations, the wireless communications system 100 may be a 5G network, such as an NR network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (“IEEE”) 802.11 (i.e., Wi-Fi), IEEE 802. 16 (i.e., WiMAX), IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (“TDMA”), frequency division multiple access (“FDMA”), or code division multiple access (“CDMA”), etc.

[0040] In one embodiment, the wireless communication system 100 includes at least one remote unit 105, a RAN 120, and a mobile core network 140. The RAN 120 and the mobile core network 140 form a mobile communication network. The RAN 120 may be composed of at least one base station unit 121 with which the remote unit 105 communicates using wireless communication links 123. Even though a specific number of remote units 105, RANs 120, base station units 121, wireless communication links 123, and mobile core networks 140 are depicted in Figure 1, one of skill in the art will recognize that any number of remote units 105, RANs 120, base station units 121, wireless communication links 123, and mobile core networks 140 may be included in the wireless communication system 100. [0041] In one implementation, the RAN 120 is compliant with the 5G cellular system specified in the 3GPP specifications. For example, the RAN 120 may be a Next Generation Radio Access Network (“NG-RAN”), implementing NR Radio Access Technology (“RAT”) and/or LTE RAT. In another example, the RAN 120 may include non-3GPP RAT (e.g., Wi-Fi® or IEEE 802. 11 -family compliant wireless local area network (“WLAN”)). In another implementation, the RAN 120 is compliant with the LTE system specified in the 3GPP specifications. More generally, however, the wireless communication system 100 may implement some other open or proprietary communication network, for example, the Worldwide Interoperability for Microwave Access (“WiMAX”) or IEEE 802.16-family standards, among other networks. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0042] In one embodiment, the remote units 105 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), smart appliances (e.g., appliances connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, modems), or the like. In some embodiments, the remote units 105 include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the remote units 105 may be referred to as the UEs, subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, user terminals, wireless transmit/receive unit (“WTRU”), a device, or by other terminology used in the art. In various embodiments, the remote unit 105 includes a subscriber identity and/or identification module (“SIM”) and the mobile equipment (“ME”) providing mobile termination functions (e.g., radio transmission, handover, speech encoding and decoding, error detection and correction, signaling and access to the SIM). In certain embodiments, the remote unit 105 may include a terminal equipment (“TE”) and/or be embedded in an appliance or device (e.g., a computing device, as described above).

[0043] The remote units 105 may communicate directly with one or more of the base station units 121 in the RAN 120 via uplink (“UL”) and downlink (“DL”) communication signals. Furthermore, the UL and DL communication signals may be carried over the wireless communication links 123. Furthermore, the UL communication signals may comprise one or more UL channels, such as the Physical Uplink Control Channel (“PUCCH”) and/or Physical Uplink Shared Channel (“PUSCH”), while the DL communication signals may comprise one or more DL channels, such as the Physical Downlink Control Channel (“PDCCH”) and/or PDSCH. Here, the RAN 120 is an intermediate network that provides the remote units 105 with access to the mobile core network 140.

[0044] In various embodiments, the remote unit 105 is configured with one or more HARQ timing indicators 125. The remote unit 105 identifies a prioritized HARQ-NACK timing indicator, KI -NACK, of a prioritized slot offset timing delay corresponding to a scheduled TB and identifies a default HARQ timing indicator, KI, of a default slot offset timing delay corresponding to the scheduled TB.

[0045] The remote unit 105 receives the scheduled TB and the processor determines whether the scheduled TB was successfully decoded. The processor selects a slot offset timing delay corresponding to the prioritized K 1 -NACK timing indicator or the K 1 timing indicator based at least in part on whether the scheduled TB was successfully decoded (e.g., selects KI -NACK if unsuccessful) and applies the selected slot offset timing delay to report HARQ feedback 127 for the received TB.

[0046] In various embodiments, the remote units 105 may communicate directly with each other (e.g., device -to-de vice communication) using sidelink (“SL”) communication 113. The SL communication 113 may comprise one or more SL channels, such as the Physical Side link Control Channel (“PSCCH”), the Physical Sidelink Shared Channel (“PSSCH”) and/or the Physical Sidelink Feedback Channel (“PSFCH”). Here, SL transmissions may occur on SL resources. A remote unit 105 may be provided with different SL communication resources according to different allocation modes. For example, in 3GPP systems, allocation Mode-1 corresponds to a NR-based network-scheduled SL communication mode, wherein the in-coverage RAN 120 indicates resources for use in SL operation, including resources of one or more resource pools. Allocation Mode-2 corresponds to a NR-based UE-scheduled SL communication mode (i.e., UE- autonomous selection), where the remote unit 105 selects a resource pools and resources therein from a set of candidate pools. Allocation Mode-3 corresponds to an LTE-based network- scheduled SL communication mode. Allocation Mode-4 corresponds to an LTE-based UE- scheduled SL communication mode (i.e., UE -autonomous selection).

[0047] As used herein, a “resource pool” refers to a set of resources assigned for SL operation. A resource pool consists of a set of RBs (i.e., Physical Resource Blocks (“PRBs”)) over one or more time units (e.g., subframe, slots, Orthogonal Frequency Division Multiplexing (“OFDM”) symbols). In some embodiments, the set of RBs comprises contiguous PRBs in the frequency domain. A Physical Resource Block (“PRB”), as used herein, consists of twelve consecutive subcarriers in the frequency domain. [0048] In some embodiments, the remote units 105 communicate with an application server 151 via a network connection with the mobile core network 140. For example, an application 107 (e.g., web browser, media client, telephone and/or Voice-over-Intemet-Protocol (“VoIP”) application) in a remote unit 105 may trigger the remote unit 105 to establish a protocol data unit (“PDU”) session (or Packet Data Network (“PDN”) connection) with the mobile core network 140 via the RAN 120. The PDU session represents a logical connection between the remote unit 105 and the User Plane Function (“UPF”) 141. The mobile core network 140 then relays traffic between the remote unit 105 and the application server 151 in the packet data network 150 using the PDU session (or other data connection).

[0049] In order to establish the PDU session (or PDN connection), the remote unit 105 must be registered with the mobile core network 140 (also referred to as “attached to the mobile core network” in the context of a Fourth Generation (“4G”) system). Note that the remote unit 105 may establish one or more PDU sessions (or other data connections) with the mobile core network 140. As such, the remote unit 105 may have at least one PDU session for communicating with the packet data network 150. The remote unit 105 may establish additional PDU sessions for communicating with other data networks and/or other communication peers.

[0050] In the context of a 5G system (“5GS”), the term “PDU Session” refers to a data connection that provides end-to-end (“E2E”) user plane (“UP”) connectivity between the remote unit 105 and a specific Data Network (“DN”) through the UPF 141. A PDU Session supports one or more Quality of Service (“QoS”) Flows. In certain embodiments, there may be a one-to-one mapping between a QoS Flow and a QoS profile, such that all packets belonging to a specific QoS Flow have the same 5G QoS Identifier (“5QI”).

[0051] In the context of a 4G/LTE system, such as the Evolved Packet System (“EPS”), a PDN connection (also referred to as EPS session) provides E2E UP connectivity between the remote unit and a PDN. The PDN connectivity procedure establishes an EPS Bearer, i.e., a tunnel between the remote unit 105 and a PDN Gateway (“PGW”) (not shown in Figure 1) in the mobile core network 140. In certain embodiments, there is a one-to-one mapping between an EPS Bearer and a QoS profile, such that all packets belonging to a specific EPS Bearer have the same QoS Class Identifier (“QCI”).

[0052] The base station units 121 may be distributed over a geographic region. In certain embodiments, a base station unit 121 may also be referred to as an access terminal, an access point, a base, a base station, a Node-B (“NB”), an Evolved Node B (abbreviated as eNodeB or “eNB,” also known as Evolved Universal Terrestrial Radio Access Network (“E-UTRAN”) Node B), a 5G/NRNode B (“gNB”), a Home Node-B, a relay node, a RAN node, or by any other terminology used in the art. The base station units 121 are generally part of a RAN, such as the RAN 120, that may include one or more controllers communicably coupled to one or more corresponding base station units 121. These and other elements of radio access network are not illustrated but are well known generally by those having ordinary skill in the art. The base station units 121 connect to the mobile core network 140 via the RAN 120.

[0053] The base station units 121 may serve a number of remote units 105 within a serving area, for example, a cell or a cell sector, via a wireless communication link 123. The base station units 121 may communicate directly with one or more of the remote units 105 via communication signals. Generally, the base station units 121 transmit DL communication signals to serve the remote units 105 in the time, frequency, and/or spatial domain. Furthermore, the DL communication signals may be carried over the wireless communication links 123. The wireless communication links 123 may be any suitable carrier in licensed or unlicensed radio spectrum. The wireless communication links 123 facilitate communication between one or more of the remote units 105 and/or one or more of the base station units 121.

[0054] Note that during NR operation on unlicensed spectrum (referred to as “NR-U”), the base station unit 121 and the remote unit 105 communicate over unlicensed (i.e., shared) radio spectrum. Similarly, during LTE operation on unlicensed spectrum (referred to as “LTE-U”), the base station unit 121 and the remote unit 105 also communicate over unlicensed (i.e., shared) radio spectrum.

[0055] In one embodiment, the mobile core network 140 is a 5G Core network (“5GC”) or an Evolved Packet Core (“EPC”), which may be coupled to a packet data network 150, like the Internet and private data networks, among other data networks. A remote unit 105 may have a subscription or other account with the mobile core network 140. In various embodiments, each mobile core network 140 belongs to a single mobile network operator (“MNO”) and/or Public Land Mobile Network (“PLMN”). The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0056] The mobile core network 140 includes several network functions (“NFs”). As depicted, the mobile core network 140 includes at least one UPF 141. The mobile core network 140 also includes multiple control plane (“CP”) functions including, but not limited to, an Access and Mobility Management Function (“AMF”) 143 that serves the RAN 120, a Session Management Function (“SMF”) 145, a Policy Control Function (“PCF”) 147, a Unified Data Management function (“UDM”) and a User Data Repository (“UDR”). In some embodiments, the UDM is co-located with the UDR, depicted as combined entity “UDM/UDR” 149. Although specific numbers and types of network functions are depicted in Figure 1, one of skill in the art will recognize that any number and type of network functions may be included in the mobile core network 140.

[0057] The UPF(s) 141 is/are responsible for packet routing and forwarding, packet inspection, QoS handling, and external PDU session for interconnecting Data Network (“DN”), in the 5G architecture. The AMF 143 is responsible for termination of Non-Access Stratum (“NAS”) signaling, NAS ciphering and integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The SMF 145 is responsible for session management (i.e., session establishment, modification, release), remote unit (i.e., UE) Internet Protocol (“IP”) address allocation and management, DL data notification, and traffic steering configuration of the UPF 141 for proper traffic routing.

[0058] The PCF 147 is responsible for unified policy framework, providing policy rules to CP functions, access subscription information for policy decisions in UDR. The UDM is responsible for generation of Authentication and Key Agreement (“AKA”) credentials, user identification handling, access authorization, subscription management. The UDR is a repository of subscriber information and may be used to service a number of network functions. For example, the UDR may store subscription data, policy-related data, subscriber-related data that is permitted to be exposed to third party applications, and the like.

[0059] In various embodiments, the mobile core network 140 may also include a Network Repository Function (“NRF”) (which provides Network Function (“NF”) service registration and discovery, enabling NFs to identify appropriate services in one another and communicate with each other over Application Programming Interfaces (“APIs”)), a Network Exposure Function (“NEF”) (which is responsible for making network data and resources easily accessible to customers and network partners), an Authentication Server Function (“AUSF”), or other NFs defined for the 5GC. When present, the AUSF may act as an authentication server and/or authentication proxy, thereby allowing the AMF 143 to authenticate a remote unit 105. In certain embodiments, the mobile core network 140 may include an authentication, authorization, and accounting (“AAA”) server.

[0060] In various embodiments, the mobile core network 140 supports different types of mobile data connections and different types of network slices, wherein each mobile data connection utilizes a specific network slice. Here, a “network slice” refers to a portion of the mobile core network 140 optimized for a certain traffic type or communication service. For example, one or more network slices may be optimized for enhanced mobile broadband (“eMBB”) service. As another example, one or more network slices may be optimized for ultra-reliable low- latency communication (“URLLC”) service. In other examples, a network slice may be optimized for machine-type communication (“MTC”) service, massive MTC (“mMTC”) service, Intemet- of-Things (“loT”) service. In yet other examples, a network slice may be deployed for a specific application service, a vertical service, a specific use case, etc.

[0061] A network slice instance may be identified by a single-network slice selection assistance information (“S-NSSAI”) while a set of network slices for which the remote unit 105 is authorized to use is identified by network slice selection assistance information (“NSSAI”). Here, “NSSAI” refers to a vector value including one or more S-NSSAI values. In certain embodiments, the various network slices may include separate instances of network functions, such as the SMF 145 and UPF 141. In some embodiments, the different network slices may share some common network functions, such as the AMF 143. The different network slices are not shown in Figure 1 for ease of illustration, but their support is assumed.

[0062] While Figure 1 illustrates components of a 5G RAN and a 5G core network, the described embodiments for HARQ-NACK feedback prioritization apply to other types of communication networks and RATs, including IEEE 802.11 variants, Global System for Mobile Communications (“GSM”) (i.e., a 2G digital cellular network), General Packet Radio Service (“GPRS”), Universal Mobile Telecommunications System (“UMTS”), LTE variants, CDMA2000, Bluetooth, ZigBee, Sigfox, and the like.

[0063] Moreover, in an LTE variant where the mobile core network 140 is an EPC, the depicted network functions may be replaced with appropriate EPC entities, such as a Mobility Management Entity (“MME”), a Serving Gateway (“SGW”), a PGW, a Home Subscriber Server (“HSS”), and the like. For example, the AMF 143 may be mapped to an MME, the SMF 145 may be mapped to a control plane portion of a PGW and/or to an MME, the UPF 141 may be mapped to an SGW and a user plane portion of the PGW, the UDM/UDR 149 may be mapped to an HSS, etc.

[0064] In the following descriptions, the term “RAN node” is used for the base station/ base station unit, but it is replaceable by any other radio access node or entity, e.g., gNB, ng-eNB, eNB, Base Station (“BS”), Access Point (“AP”), NR BS, 5G NB, Transmission and Reception Point (“TRP”), base unit, etc. Additionally, the term “UE” is used for the mobile station/ remote unit, but it is replaceable by any other remote device, e.g., remote unit, MS, ME, etc. Further, the operations are described mainly in the context of 5G NR. However, the below described solutions/methods are also equally applicable to other mobile communication systems for HARQ- NACK feedback prioritization. [0065] In the following, instead of “slot,” the terms “mini-slot,” “subslot,” or “aggregated slots” can also be used, wherein the notion of slot/mini-slot/sub-slot/aggregated slots can be described as defined in 3GPP Technical Specification (“TS”) 38.211, TS 38.213, and/or TS 38.214.

[0066] Several solutions to provide HARQ-NACK feedback prioritization are described below. According to a possible embodiment, one or more elements or features from one or more of the described solutions may be combined.

[0067] Figure 2 illustrates an example of an NR protocol stack 200, in accordance with aspects of the present disclosure. While Figure 2 shows the UE 205, the RAN node 210 and an AMF 215, e.g., in a 5GC, these are representatives of a set of remote units 105 interacting with a base station unit 121 and a mobile core network 140. As depicted, the NR protocol stack 200 comprises a User Plane protocol stack 201 and a Control Plane protocol stack 203. The User Plane protocol stack 201 includes a physical (“PHY”) layer 220, a Medium Access Control (“MAC”) sublayer 225, the Radio Eink Control (“RLC”) sublayer 230, a Packet Data Convergence Protocol (“PDCP”) sublayer 235, and Service Data Adaptation Protocol (“SDAP”) sublayer 240. The Control Plane protocol stack 203 includes a PHY layer 220, a MAC sublayer 225, an RLC sublayer 230, and a PDCP sublayer 235. The Control Plane protocol stack 203 also includes an RRC layer 245 and a NAS layer 250.

[0068] The Access Stratum (“AS”) layer 255 (also referred to as “AS protocol stack”) for the User Plane protocol stack 201 is comprised by at least SDAP, PDCP, RLC and MAC sublayers, and the PHY layer 220. The AS layer 260 for the Control Plane protocol stack 203 is comprised of at least the RRC, PDCP, RLC and MAC sublayers, and the PHY layer 220. The Layer-1 (“LI”) comprises the PHY layer 220. The Layer-2 (“L2”) is split into the SDAP sublayer 240, PDCP sublayer 235, RLC sublayer 230, and MAC sublayer 225. The Layer-3 (“L3”) includes the RRC layer 245 and the NAS layer 250 for the control plane and includes, e.g., an IP layer and/or PDU Layer (not shown in Figure 1) for the user plane. LI and L2 are referred to as “lower layers,” while L3 and above (e.g., transport layer, application layer) are referred to as “higher layers” or “upper layers.”

[0069] The PHY layer 220 offers transport channels to the MAC sublayer 225. The PHY layer 220 may perform a Clear Channel Assessment (“CCA”) and/or Listen-Before-Talk (“LBT”) procedure using energy detection thresholds. In certain embodiments, the PHY layer 220 may send an indication of beam failure to a MAC entity at the MAC sublayer 225. In certain embodiments, the PHY layer 220 may send a notification of Listen-Before-Talk (“LBT”) failure to a MAC entity at the MAC sublayer 235. The MAC sublayer 225 offers logical channels to the RLC sublayer 230. The RLC sublayer 230 offers RLC channels to the PDCP sublayer 235. The PDCP sublayer 235 offers radio bearers to the SDAP sublayer 240 and/or RRC layer 245. The SDAP sublayer 240 offers QoS flows to the core network (e.g., 5GC). The RRC layer 245 provides functions for the addition, modification, and release of Carrier Aggregation and/or Dual Connectivity. The RRC layer 245 also manages the establishment, configuration, maintenance, and release of Signaling Radio Bearers (“SRBs”) and Data Radio Bearers (“DRBs”).

[0070] The NAS layer 250 is between the UE 205 and an AMF 215 in the 5GC. NAS messages are passed transparently through the RAN. The NAS layer 250 is used to manage the establishment of communication sessions and for maintaining continuous communications with the UE 205 as it moves between different cells of the RAN. In contrast, the AS layers 255 and 260 are between the UE 205 and the RAN (i.e., RAN node 210) and carry information over the wireless portion of the network. While not depicted in Figure 2, the IP layer exists above the NAS layer 250, a transport layer exists above the IP layer, and an application layer exists above the transport layer.

[0071] The MAC sublayer 225 is the lowest sublayer in the L2 architecture of the NR protocol stack. Its connection to the PHY layer 220 below is through transport channels, and the connection to the RLC sublayer 230 above is through logical channels. The MAC sublayer 225 therefore performs multiplexing and demultiplexing between logical channels and transport channels: the MAC sublayer 225 in the transmitting side constructs MAC PDUs (also known as transport blocks (“TBs”)) from MAC Service Data Units (“SDUs”) received through logical channels, and the MAC sublayer 225 in the receiving side recovers MAC SDUs from MAC PDUs received through transport channels.

[0072] The MAC sublayer 225 provides a data transfer service for the RLC sublayer 230 through logical channels, which are either control logical channels which carry control data (e.g., RRC signaling) or traffic logical channels which carry user plane data. On the other hand, the data from the MAC sublayer 225 is exchanged with the PHY layer 220 through transport channels, which are classified as UL or DL. Data is multiplexed into transport channels depending on how it is transmitted over the air.

[0073] The PHY layer 220 is responsible for the actual transmission of data and control information via the air interface, i.e., the PHY layer 220 carries all information from the MAC transport channels over the air interface on the transmission side. Some of the important functions performed by the PHY layer 220 include coding and modulation, link adaptation (e.g., Adaptive Modulation and Coding (“AMC”)), power control, cell search and random access (for initial synchronization and handover purposes) and other measurements (inside the 3GPP system (i.e., NR and/or LTE system) and between systems) for the RRC layer 245. The PHY layer 220 performs transmissions based on transmission parameters, such as the modulation scheme, the coding rate (i.e., the modulation and coding scheme (“MCS”)), the number of Physical Resource Blocks (“PRBs ”), etc.

[0074] In some embodiments, the UE 205 may support an LTE protocol stack. Note that an LTE protocol stack comprises similar structure to the NR protocol stack 200, with the differences that the LTE protocol stack lacks the SDAP sublayer 240 in the AS layer 255 and that the NAS layer 250 is between the UE 205 and an MME in the EPC.

[0075] Figure 3 illustrates a split-rendering architecture 300 for mobile networks based on an edge/cloud video application server 301 and an XR UE device 303 (e.g., an embodiment of the remote unit 105 and/or UE 205). The XR UE device 303 is connected to a RAN 305 which is in turn connected to the application server 301 via a core network 307. The application server 301 may deliver XR media traffic and metadata 309 based on local XR processed content 311 or on remote XR processed content 313. The said processing may account for and/or further process tracking and sensing information 315 as uplinked by the XRUE device 303. The application server 301 streams the XR multimedia content via a content delivery gateway 317 to which the XR UE device 303 is connected via any real-time transport protocol. The XR UE device 303, after decoding the XR content received from the application server 301, may use its XR engine 319 and additional local hardware/software capabilities and/or XR pre-rendered content, and XR associated XR metadata to locally render the XR content on a display 321.

[0076] The split-rendering architecture 300 is one example of a setup adopted at the 3GPP level for immersive XR and high-performance video content transmissions and relies on the concept of split (i.e., distributed) rendering. Note that the application server 301 may be located at the edge and connected to a core network (“CN”) 307. The application server performs “prerendering” of XR content (e.g., video and/or audio), encodes the application video/audio content, and transfers the content to a RAN”) 305 for mobile communications. In exchange, the RAN 305 communicates with a connected XR UE device 303 which may use additional hardware/software processing to render the video/audio content to match a user’s pose/inputs/control state.

[0077] The video application server 301 is used therefore to process/encode/transcode and serve local or remote video content pertaining to an XR and/or cloud gaming (“XR/CGM”) application session to the XR UE device 303. The video application server 301 may, as a result, encode/transcode and control the video viewport content and transmit it in downlink to the RAN 305 based on UE -specific parameters, configurations and sensing inputs that may affect the rendering perspective, rate, quality, panning, etc. The architecture 300 is expected to leverage the advantages of various compute and network domains (e.g., cloud, edge, smart handsets/headsets) to enable scalable XR/CGM applications and use cases with low-latency, high rate, and efficient energy usage. The architecture 300 is as such universally applicable both to split rendering with asynchronous time warping devices, i.e., where the video application server encodes a rasterized pre-processed viewport representation to aid the XR UE devices 303, or to split rendering with viewport rendering at the device side, i.e., where the video viewport may be completely or partially rendered at the device side given the media encoded video content and its corresponding metadata available.

[0078] The XR DL traffic is generically characterized by a quasi -periodic, jitter-affected packet arrival rate determined by the XR application frame generation rate periodicity, e.g., 30/60/90/120 frame s-per-second (“fps”). As such, the average packet arrival periodicity is obtained as the reciprocal ofthe application frame rate, e.g., 16.67ms = 1/60 fps. Thus, the periodic arrival time without jitter at the gNB of XR packets indexed by k = 1,2,3, ... is 1000 [ms], Equation 1 where F denotes the XR application video frame generation rate (per second).

[0079] This periodic packet arrival model implicitly assumes fixed delay contributed from network side including fixed video encoding time, fixed network transfer delay, etc.

[0080] However, in a real system, the varying frame encoding delay and network transfer time introduces stochastic jitter in packet arrival time at the gNB. Generically, the jitter is modelled as a truncated Gaussian random process resulting into a random variable added on top of periodic arrivals. The jitter contribution to the packet arrival time thus generates an additive truncated Gaussian distribution to the inherent ideal periodicity of the XR DL traffic with statistical parameters according to 3GPP TR 38.838 (vl.0.1) displayed in Table 1, below.

Table 1: Statistical parameters for jitter of XR DL traffic

[0081] Given the jitter model considered in 3GPP RAN for 5G and beyond, even for high frame generation rates, e.g., 120 fps, the combined realistic XR DL traffic model ensures in-order packet arrivals (i.e., arrival time of a next packet is always larger than that of the previous packet). Concretely, the XR DL traffic model of periodic arrival with jitter for an arrival time of a video frame packet with index k = 1,2,3, ... is summarized by fc

T _k = offset + - • 1000 + J [ms], Equation 2 where F is the given frame generation rates (per second) and J is the jitter specific random variable following the model of Table 1, and respectively, the offset represents an arbitrary UE specific shift in packet arrival timing.

[0082] In addition, the quasi-periodic, jittery XR DL video traffic presents another characteristic of high peak-to-average throughput requirements. This effect is a consequence of the video encoded packets which form groups of pictures (“GoPs”) according to some codec configuration. This happens since I-frames/I-slices which are intra-coded (more important) have higher payloads than their P/B frames/slices counterparts (less important, depending on I-frames/I- slices).

[0083] In a concrete example, a high definition (“HD”) resolution VR stream of left eye output is encoded with a real-time low-complexity configuration of the H.265 codec as a stream of a plurality of 8 GoPs formed of 1 1-frame and 7 P-frames each containing 2 slices.

[0084] Figure 4 illustrates exemplary variations between distributions of I-slice payload size 400 and P-slice payload size 410 in an HD VR stream encoded with a H.265 low-complexity real-time codec configuration of 8 GoPs (i.e., 1 I-frame, 7-P frames), in accordance with aspects of the present disclosure. It can be clearly seen in the depicted the size distribution of the I/P slices forming the video frames that the application data units (“ADUs”) corresponding to the I-slices have considerably larger payloads than those of the P-slices. This leads to XR DL traffic to be formed of quasi-periodic, jittery bursts of various payloads with considerable high-rate and low- latency requirements (e.g., up to 10-20ms over-the-air latency with a packet error rate of 10 ^-4 , according to 5G QoS Identifier (“5QI”) discussed in 3GPP TR 26.926).

[0085] In the UL direction, the XR/CGM traffic is similarly generically characterized by user inputs, control metadata, pose updates, panning information, and the like, and according to 3GPP TR 38.838 (vl.0. 1), the latter is modelled by an UL pose/control stream traffic model where packets arrive at the UE 205 periodically with parameters tabulated reproduced in Table 2.

Table 2: Statistical parameters for the UL XR/CGM pose/control traffic model

[0086] Figure 5 illustrates an exemplary communication system architecture 500 for XR services, in accordance with aspects of the present disclosure. The architecture 500 includes a source application server 501 connected (possibly at the edge) to a CN 503 (e.g., one embodiment of the mobile core network 140) which in terms is connected to a RAN 505 (e.g., one embodiment of the RAN 120) serving one or more subscribed and connected XR UE devices, for example, a wearable XR-capable UE device 507 and/or a handheld XR-capable UE device 509, each of which may be embodiments of the remote unit 105, the UE 205, and/or the XR UE device 303.

[0087] The protocol data units (“PDUs”) associated with an XR application session of an application server 501 connected to a CN 503 are transferred via the CN UPF (e.g., over IP) to the RAN 505. The multimedia traffic may be further supported by a real-time multimedia transport protocol, such as a Real-time Transport Protocol (“RTP”) or the like, to handle jitter, packet loss and out-of-order deliveries that may occur within a typical IP network setup.

[0088] The QoS associated with IP packets of the XR traffic is handled by the CN via QoS flows 511 generated at the UPF within the established PDU session. This procedure is opaque to the RAN 505 which only manages the mapping of QoS flows 511 associated with the received IP packets to their corresponding DRBs given the QoS profile associated with the indicators of each QoS flow 511. In the 5GS, for instance, the QoS flows 511 will be characterized by the 5QI, e.g., as described in 3GPP TS 38.323 (vl6.6.0).

[0089] This latter mapping of QoS flows 511 to DRBs is performed within the RAN 505 by the SDAP sublayer 240. The SDAP PDU is then processed by the PDCP sublayer 235 where among others header compression and ciphering are performed and the outputs further processed by the RLC layer 230. The RLC layer 230 may perform segmentation of the PDCP PDUs and implements the automatic request response (“ARQ”) repetition retransmissions.

[0090] The RLC PDUs are then processed over the logical channels’ interfaces by the MAC sublayer 225 which handles the logical channels multiplexing, HARQ, scheduling and scheduling retransmission functions. Lastly, the MAC PDUs are combined over the transport channel into TBs at the level of the PHY layer 220. The PHY layer 220 handles the coding/decoding, rate matching, modulation/demodulation, radio resource mapping, multiantenna mapping and other typical radio low-level functions.

[0091] The PHY TBs, which are appended with their own Cyclic Redundancy Check (“CRC”) of 16 or 24 bits blocks for detection of errors, are further partitioned into same-sized coding blocks (“CBs”). The CBs are appended as well by 24 bits CRC for error detection and following this operation they are forward error correction (“FEC”) encoded by the PHY layer 220. The HARQ procedure within 5G NR ensures incremental redundancy retransmissions of an entire TB in case any of the CBs or TB CRC checks fails thus effectively ensuring reliability over the wireless link.

[0092] In addition, given the increasing size of TBs, 5GNR also introduced a code block group (“CBG”) construct to group one or more CBs into CBGs. The CBGs, if configured appropriately via the Radio Resource Control (“RRC”) layer 217, support independent HARQ via Downlink Control Information (“DCI”) signaling primarily via CBG Transmit Indicator (“CBGTI”) and CBG Flush Indicator (“CBGFI”) within the same HARQ process as the enclosing TB.

[0093] As such, some mechanisms for versatile retransmissions are present in 5G NR to reduce retransmissions delays and resource utilization, applicable also to high-rate low-latency traffic such as immersive XR/CGM media applications. Yet these procedures are purely based on traditional FEC mechanisms, applied at a bit-level unaware of XR ADUs (i.e., the smallest unit of data that can be processed independently by an XR application, e.g., a video frame, a slice of a video frame etc.) and XR traffic characteristics.

[0094] 5QI QoS characteristics for XR traffic are summarized in Table 3, below:

Table 3: Standardized 5QI to QoS characteristics mapping

[0095] Generically HARQ feedback is binary in the form of ACK/NACK with reporting done per instance of HARQ process corresponding to 1 TB or 2 TBs (in case of spatial multiplexing with more than 4 layers). The HARQ procedure is controlled by a HARQ process within the HARQ entity of a ServiceCell as part of the MAC entity. According to 3GPP TS 38.321 (vl6.7.0), Clause 5.3.2, the following procedure follows:

[0096] The MAC entity includes a HARQ entity for each Serving Cell, which maintains a number of parallel HARQ processes. Each HARQ process is associated with a HARQ process identifier. The HARQ entity directs HARQ information and associated TBs received on the Downlink Shared Channel (“DL-SCH”) to the corresponding HARQ processes (see clause 5.3.2.2 of 3GPP TS 38.321).

[0097] The number of parallel DL HARQ processes per HARQ entity is specified in 3 GPP TS 38.214. The dedicated broadcast HARQ process is used for the Broadcast Control Channel (“BCCH”). The HARQ process supports one TB when the PHY layer 220 is not configured for downlink spatial multiplexing. The HARQ process supports one or two TBs when the PHY layer 220 is configured for downlink spatial multiplexing.

[0098] When the MAC entity is configured with the parameter pdsch-AggregationFactor having a value greater than 1, the parameter pdsch-AggregationFactor provides the number of transmissions of a TB within a bundle of the downlink assignment. Bundling operation relies on the HARQ entity for invoking the same HARQ process for each transmission that is part of the same bundle. After the initial transmission, (pdsch-AggregationFactor - 1) HARQ retransmissions follow within a bundle.

[0099] If a downlink assignment has been indicated, then the MAC entity shall allocate the TB(s) received from the PHY layer 220 and the associated HARQ information to the HARQ process indicated by the associated HARQ information. If a downlink assignment has been indicated for the broadcast HARQ process, then the MAC entity shall allocate the received TB to the broadcast HARQ process. [0100] When a transmission takes place for the HARQ process, one or two (in case of downlink spatial multiplexing) TBs and the associated HARQ information are received from the HARQ entity.

[0101] For each received TB and associated HARQ information, if the New Data Indicator (“NDI”) (when provided) has been toggled compared to the value of the previous received transmission corresponding to this TB, or if the HARQ process is equal to the broadcast process, and this is the first received transmission for the TB according to the system information schedule indicated by RRC, or if this is the very first received transmission for this TB (i.e., there is no previous NDI for this TB), then the HARQ process shall consider this transmission to be a new transmission. Otherwise, the HARQ process shall consider this transmission to be a retransmission.

[0102] If the transmission is (or is considered to be) a new transmission, then the MAC entity shall attempt to decode the received data. Else, if this is a retransmission, then if the data for this TB has not yet been successfully decoded, then the MAC entity shall instruct the PHY layer 220 to combine the received data with the data currently in the soft buffer for this TB and attempt to decode the combined data.

[0103] If the data which the MAC entity attempted to decode was successfully decoded for this TB, or if the data for this TB was successfully decoded before, then if the HARQ process is equal to the broadcast process, then the MAC entity shall deliver the decoded MAC PDU to upper layers.

[0104] If the data which the MAC entity attempted to decode was successfully decoded for this TB, or if the data for this TB was successfully decoded before, then if this is the first successful decoding of the data for this TB, then the MAC entity shall deliver the decoded MAC PDU to the disassembly and demultiplexing entity.

[0105] Otherwise, if the data which the MAC entity attempted to decode was not successfully decoded for this TB and if the data for this TB was not successfully decoded before, then the MAC entity shall instruct the PHY layer 220 to replace the data in the soft buffer for this TB with the data which the MAC entity attempted to decode.

[0106] If the HARQ process is associated with a transmission indicated with a Temporary Cell-Radio Network Temporary Identifier (“C-RNTI”) and the Contention Resolution is not yet successful (see clause 5.1.5 of 3GPP TS 38.321), or if the HARQ process is associated with a transmission indicated with a MsgB-RNTI and the Random Access procedure is not yet successfully completed (see clause 5.1.4a of 3GPP TS 38.321), or if the HARQ process is equal to the broadcast process, or if the parameter timeAlignmentTimer, associated with the Timing Advance Group (“TAG”) containing the Serving Cell on which the HARQ feedback is to be transmitted, is stopped or expired, then the MAC entity shall not instruct the PHY layer 220 to generate acknowledgement s) of the data in this TB. Otherwise, the MAC entity shall instruct the PHY layer 220 to generate acknowledgements) of the data in this TB.

[0107] The MAC entity shall ignore NDI received in all downlink assignments on PDCCH for its Temporary C-RNTI when determining if NDI on PDCCH for its C-RNTI has been toggled compared to the value in the previous transmission. Note that if the MAC entity receives a retransmission with a TB size different from the last TB size signaled for this TB, the UE behavior is left up to UE implementation.

[0108] In various embodiments of the protocol stack of LTE/5GNR RAN retransmissions are inherently embedded to ensure reliability over wireless media. Three levels of protection are available across the stack at different layers with varying characteristics of reliability, latency, and overall role, as follows at the PDCP sublayer 235 (e.g., as described in 3GPP TS 38.323), at the RLC layer 230 (e.g., as described in 3GPP TS 38.322), and at the PHY layer 220 (e.g., as described in 3 GPP TS 38.213).

[0109] At the PDCP sublayer 235, PDCP retransmissions are used for acknowledged mode (“AM”) configurations in case of handovers or whenever necessary to ensure in-order delivery of PDUs based on configured PDCP status reports. PDCP duplication is the main redundancy mechanism at this layer relying on simple repetition coding. PDCP retransmissions delays may vary between 50-150 ms depending on the data radio bearer air interface configuration, including subcarrier spacing (“SCS”) and MCS.

[0110] At the RLC layer 230, RLC retransmissions are used only for AM configurations to ensure reliable delivery of RLC PDUs. RLC relies on ARQ (i.e., simple repetition-based retransmissions) as redundancy mechanism upon receival of status reports from the peer receiving protocol. RLC retransmission delays may vary between 10-50 ms based on the infrequent status reports feedback and air interface configuration, including SCS and MCS.

[0111] At the PHY layer 220, physical retransmissions rely on HARQ mechanism with soft combining embedding PEC channel coding with ARQ retransmissions for a highly robust and adaptive retransmission scheme ensuring high reliability. PHY retransmissions are controlled by individual HARQ processes within a HARQ entity as part of the MAC and are scheduled accordingly by the latter given the HARQ feedback indication of a receiver of nonacknowledgement (i.e., NACK) (or equivalently HARQ-NACK). PHY retransmission delays may vary between 2-10 ms based on the scheduling, SCS and MCS configurations. [0112] HARQ feedback is generically binary in the form of ACK/NACK with reporting done per instance of HARQ process corresponding to 1 TB or 2 TBs (in case of spatial multiplexing with more than 4 layers). The HARQ procedure is controlled by a HARQ process within the HARQ entity of a ServiceCell as part of the MAC entity. HARQ-ACK reporting for DL transmissions is multiplexed over Uplink Control Information (“UCI”) and transported over PUCCH or PUSCH. As used herein, ‘HARQ-ACK” may represent collectively the Positive Acknowledgement (“ACK”) and the Negative Acknowledgement (“NACK”). ACK means that a TB is correctly received while NACK (also referred to as “HARQ-NACK”) means a TB is erroneously received.

[0113] The encoding of HARQ ACK/NACK is further organized in codebooks determined according to 3GPP TS 38.213 (vl6.8.0). The respective codebooks include the Type-1 HARQ- ACK codebook (i.e., semi-static codebook), the Type-2 HARQ-ACK codebook (i.e., dynamic codebook), the Type-3 HARQ-ACK codebook (i.e., OneShotReporting), and the CBG-based HARQ-ACK codebook.

[0114] Regarding the Type-1 HARQ-ACK codebook, the semi-static codebook is determined by the RRC configuration of HARQ timing offset, CBG-based HARQ, Component Carriers (“CCs”) or simultaneous TBs in transit and dynamic scheduling decisions. The number of bits to send in an ACK/NACK report is thus fixed and could be potentially large. If many component carriers are configured for instance but only a few are scheduled, this can be inefficient.

[0115] Regarding the Type-2 HARQ-ACK codebook, the dynamic codebook (or enhanced dynamic codebook in 3GPP Release 16 (“Rel-16”) and onwards) is optimized to reduce multiplexed feedback size since a UE 205 sends feedback only for the scheduled carriers. As in low Signal-to-Interference-Plus-Noise Ratio (“SINR”) channel conditions, the UE 205 may wrongly infer the number of carriers that were scheduled, Downlink Assignment Index (“DAI”) as a tuple of a counter DAI (“cDAI”) and a total DAI (“tDAI”), i.e., (cDAI, tDAI), is used as part of DCI scheduling to aid the UE 205 to determine and form the dynamic HARQ feedback codebook. The procedure is detailed in 3GPP TS 38.213.

[0116] Regarding one -shot reporting (i.e., Type 3 HARQ-ACK codebook), a UE 205 sends ACK/NACK report for all HARQ processes, and all CCs configured in the PUCCH group in a semi-static manner given RRC configuration and parameters, as described in 3GPP TS 38.213.

[0117] Regarding CBG-level reporting, the UE 205 performs this reporting on a per CBG level as part of the TB given an RRC configured HARQ-ACK/HARQ-NACK CBG-based feedback; as such one bit per CBG is to be reported as per 3GPP TS 38.213. [0118] In some embodiments, NR with Rel-16 supports out-of-order HARQ-ACK reporting for an URLLC UE and dynamic downlink scheduling, on the active bandwidth part (“BWP”) of a given serving cell. In such embodiments, the HARQ-ACK associated with the second PDSCH with HARQ process ID x received after the first PDSCH with HARQ process ID y (where x y) can be sent before the HARQ-ACK of the first PDSCH.

[0119] The timing resource allocation of HARQ feedback is determined for DL transmissions based on the KI and N1 timing parameters. According to Clause 5.3 of 3GPP TS 38.213 (vl6.8.0), if the first uplink symbol of the PUCCH, which carries the HARQ-ACK information, as defined by the assigned HARQ-ACK timing KI and the PUCCH resource to be used and including the effect of the timing advance, starts no earlier than Equation 3 after the end of the last symbol of the PDSCH carrying the TB being acknowledged, then the UE 205 provides a valid HARQ-ACK message.

[0120] Consequently, KI defines the gap in terms of slots for the time delay between a slot receiving PDSCH transmission and a slot providing an UCI resource (e.g., PUCCH or PUSCH) for UL HARQ feedback. The KI indication of PDSCH-to-HARQ-feedbackTiminglndicator within a DCI format l_x of a PDSCH specifies thus an index in a semi-statically signaled RRC parameter table of possible KI values determined by the parameter dl-DataToUL-ACK under PUCCH-Config within a RRC Reconfig message. The selection of the KI value is further constrained to satisfy a minimum processing time of the PDSCH channel (i.e., channel estimation, demodulation, decoding) for the determination of the HARQ feedback, and respectively, a UL preparation of the UCI for transmission of the feedback.

[0121] The PDSCH processing time of a UE 205 is mainly determined by the N 1 parameter according to Equation 3, as specified in Clause 5.3 of 3GPP TS 38.214. The parameter N1 is based on the SCS factor, ., for UE capability #1 (default), for UE capability #2 (optional), where fJ. corresponds to the one of (UPDCCH , dposcii- -UL) resulting with the largest T _{proc l} , where the UPDCCH corresponds to the SCS of the PDCCH scheduling the PDSCH, the -PDSCH corresponds to the SCS of the scheduled PDSCH, and . _UL corresponds to the SCS of the uplink channel (i.e., PUCCH or PUSCH) with which the HARQ-ACK is to be transmitted. Values for N1 are defined in 3GPP TS 38.214, see, e.g., Table 5.3.1 and Table 5.3.2 of 3GPP TS 38.214. [0122] Note that the values K, T _C are constants according to Clause 4 of 3GPP TS 38.211, whereas the values of T _ext , d _{l lt} d _{1 2} are conditional, rule-based constants according to Clause 5.3 of 3GPP TS 38.214.

[0123] Figure 6 illustrates an exemplary timing diagram 600 showing the relationship between a DCI scheduling of a PDSCH transmission, the PDSCH transmission processing, an associated UCI HARQ feedback, and parameters KI and Nl. Note that the KI values may be selected from Table 620.

[0124] Figure 7 illustrates an exemplary procedure 700 for HARQ-NACK feedback prioritization, according to embodiments of the first solution. The procedure 700 involves a UE 205 and a RAN node 210 in a mobile communication network. Here, the UE 205 may be an embodiment of the remote unit 105, while the RAN node 210 may be an embodiment of the base station unit 121.

[0125] At Step 1, the RAN node 210 configures the UE 205 with one or more timing indicators (see messaging 705).

[0126] At Step 2, the UE 205 identifies a prioritized HARQ-NACK timing indicator, denoted “KI -NACK”, of a prioritized slot offset timing delay corresponding to a scheduled TB (see block 710).

[0127] At Step 3, the UE 205 identifies a default HARQ timing indicator, denoted “KI”, of a default (i.e., non-prioritized) slot offset timing delay corresponding to the scheduled TB (see block 715).

[0128] At Step 4, the RAN node 210 transmits the scheduled TB to the UE 205 (see messaging 720).

[0129] At Step 5, the UE 205 receives and attempts to decode the scheduled TB. The UE 205 determines HARQ feedback for the scheduled TB (see block 725). If the TB is successfully received and decoded, then the UE 205 determines to report positive feedback (i.e., ACK) for the scheduled TB. However, if the TB is not successfully received and decoded, then the UE 205 determines to report negative feedback (i.e., NACK) for the scheduled TB.

[0130] At Step 6, the UE 205 selects a slot offset timing delay based on the identified timing indicators Kl-NACK and KI and based on the determined HARQ feedback (see block 710). In one embodiment, the UE 205 selects the slot offset timing delay corresponding to the prioritized Kl-NACK timing indicator when the HARQ feedback is NACK. In another embodiment, the UE 205 selects the slot offset timing delay corresponding to the default (nonprioritized) KI timing indicator when the HARQ feedback is ACK. [0131] At Step 7, the UE 205 reports the determined HARQ feedback for the schedule TB by applying the selected slot offset timing delay (see messaging 735). Concurrently, the RAN node 210 applies the slot offset delays corresponding to KI and Kl-NACK to process the HARQ feedback received from the UE 205.

[0132] At Step 8, if the UE 205 reported NACK (i.e., indicating that the transmission of the scheduled TB was not successful), the RAN node 210 retransmits the TB to the UE 205 (see messaging 740).

[0133] The following solutions detail mechanisms and configuration tools to provide energy-efficient low-latency feedback of HARQ non-acknowledgements indications based on opportunistically prioritized HARQ-NACK indications. Various solutions extend the KI timing indicator by a second indicator Kl-NACK, i.e., forming the tuple (Kl-NACK, KI) for indication of the occurrence of a PDSCH HARQ feedback UCI over a PUCCH or a PUSCH. The Kl-NACK indicator may be in some embodiments determined dynamically by the network, e.g., by DCI indication, or based on some semi-static rule-based determination given KI dynamic indication.

[0134] The solution consists thus in leveraging Kl-NACK of the tuple (Kl-NACK, KI), with the value of Kl-NACK being less than or equal to KI, as a network indication of the earliest available UCI resource, as PUCCH or PUSCH, for reporting NACK feedback for a TB. In case of ACK feedback for a TB, the reporting shall be performed under the KI indication for the transmission timing of the HARQ-ACK codebook in UL.

[0135] Given the DL and UL periodicity for XR/CGM traffic, as detailed previously, the embodiments and examples in the following assume the basic scenario where XR video coded frames and associated codec metadata are mainly transported over the air interface over the 1

PDSCH in DL at a periodicity of with the stochastic jitter model previously described. In UL, the user pose, inputs, and associated application metadata are transported over the PUSCH.

[0136] Figure 8 illustrates exemplary DL/UL traffic model 800, e.g., for XR application traffic with differing DL and UL periodicities, in accordance with aspects of the present disclosure. The example of Figure 8 considers a video codec frame rate at 120fps, i.e., corresponding to PDSCH periodicity of 8.33ms, whereas the UL pose update is considered at 4ms. In the depicted embodiment, the UE 205 transmits periodic PUSCH with pose updates 803. The UE 205 is configured with configured grant (“CG”) PUSCH resources 805 for pose updates at 4ms intervals. During successive PDSCH transmissions, the UE 205 receives a first DL ADU packet (denoted “DL ADU Pkt #1”), a second DL ADU packet (denoted “DL ADU Pkt #2”), a third DL ADU packet (denoted “DL ADU Pkt #3”), a fourth DL ADU packet (denoted “DL ADU Pkt #4”), a fifth DL ADU packet (denoted “DL ADU Pkt #5”), and a sixth DL ADU packet (denoted “DL ADU Pkt #6”).

[0137] As used herein, a “configured grant” refers to a semi-persistent allocation of wireless resources. A CG configuration may pre-allocate (e.g., configure, schedule, assign) one or more resources of the wireless communications system for wireless communication by the UE 205 during a CG occasion. For example, a UE 205 may be configured with multiple CG configurations for uplink communications (e.g., uplink transmissions). A CG occasion may include one or more time and frequency resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) configured for wireless communication. The CG configuration may configure multiple CG occasions, e.g., having a certain periodicity between each CG occasion.

[0138] In various embodiments, the demanding QoS requirements of XR downlink traffic in terms ofdelay budget (e.g., 15-20 ms per packet delay budget) and reliability (e.g., 10 ^-4 packet error rate) constrain the number of retransmissions for XR packets to at most 1-2 possible retransmissions in practical deployment scenarios (e.g., considering multiple UEs system load, varying SNRs, realistic video streams for XR/CGM etc.), given XR traffic characteristics. This is predominant especially for packets forming ADUs of higher importance, such as I-frames or I- slices. In such embodiments, the early feedback of HARQ-NACK indications is thus essential in recovering from transmission errors without violating the PDB, and inherently corrupting the video stream ADU leading to decrease both in QoS but also in the quality of experience of a user.

[0139] One option to support XR traffic in 5G NR is to dedicate more aggressively explicit PUCCH resources for faster feedback of each TB of a plurality of TBs forming an ADU. Another option is to leverage CG PUSCH resources reserved for pose UL transmissions to multiplex HARQ UCI feedback. This is possible as the UCI multiplexing in PUSCH is supported when UCI and PUSCH transmissions coincide in time, either due to transmission of an Uplink Shared Channel (“UL-SCH”) TB or due to triggering of aperiodic Channel State Information (“CSI”) transmission without UL-SCH TB, and are associated with the same priority (high/low) whereby the multiplexing procedure of the control UCI and UL-SCH data over PUSCH is specified according to Clause 6.2.7 of 3GPP TS 38.300 (vl6.8.0).

[0140] However, the current state-of-art for 5G NR comes with some drawbacks that may impact primarily UE energy-efficiency and latency of HARQ feedback, especially in the case of more critical HARQ-NACK reports. In the case of more aggressive explicit PUCCH resource allocation, many PUCCH resources need to be allocated for the HARQ feedback of the plurality of TBs forming an ADU. This leads to a potential waste of resources and low energy efficiency (i.e., due to energy wasted for each HARQ UCI transmission of one or more TB over PUCCH) due to the high fragmentation of the HARQ feedback for the entire ADU. In summary, the gains in lower latency for UL feedback are paid in energy efficiency.

[0141] On the other hand, aligning KI to meet the CG of UL pose PUSCH transmissions and thus multiplexing HARQ UCI with the UL pose PUSCH will lower the energy consumption as the UL transmissions were any way scheduled by the pose CG but may incur higher delays as the pose frequency is of at least 4 ms frequency.

[0142] In some embodiments, the pose may be filtered by a UE 205 and as a result some pose updates may be skipped due to insufficient new data or delta with respect to previous pose updates. In such embodiments this latter result of multiplexing HARQ with PUSCH pose occurrences may impact UE energy efficiency by preventing the device to go to sleep or a low energy state.

[0143] In other embodiments, multiplexing the UCI HARQ feedback may impact the reliability of the PUSCH pose data due to the pruning operation required at rate matching for accommodating the extra UCI HARQ information bits within an already allocated resource of the PUSCH occurrence. This results in pruning some of the PUSCH data bits (for UCI containing 1 or 2 bits) or by rate matching PU SCH data bits (for UCI containing more than 2 bits) and increasing its coding rate, thus lowering its reliability against wireless media effects. In summary, the energy efficiency gained by this result trades off in terms of latency of the HARQ reporting, and potentially in reliability of the UL PUSCH data.

[0144] Accordingly, the above options present the same drawback of treating the HARQ- ACK and HARQ-NACK feedback indications equally. In various embodiments, however, the HARQ-NACK occurs less frequently than the HARQ-ACK feedback given the stringent QoS reliability requirements associated with DL immersive data traffic of 10 ^-4 under a latency budget of 15-20 ms, according to Table 5.7.4-1 of 3GPP TS 23.501. A HARQ-NACK occurrence should nonetheless be reported with higher priority than a HARQ-ACK in UL to the RAN node 210 (e.g., gNB) to allow for enough time budget PDB to schedule, process and acknowledge sufficient retransmissions to correct for any potential errors within the tight time constraints of the XR.

[0145] Note that the following embodiments, albeit described in the context of XR traffic, are generally applicable to any kind of traffic bursts modelled similarly in DL by fixed periodicity with stochastic jitter with high-rate and low-latency requirements, and respectively, in UL by periodic traffic bursts.

[0146] Note that in some of the embodiments the indications “Kl_x,” “KI,” “KINACK x,” and “KI -NACK” are utilized implicitly as slot offset values with respect to a relative slot in which a corresponding PDSCH transmission was received. In some embodiments this requires an intermediate semi-static table mapping of said indications to slot values, which is hereby implicitly considered for brevity when the terms “Kl_x slots”, “KI slots”, “Kl-NACK_x slots”, “Kl-NACK slots” are utilized. In other embodiments, the distinction between the indications and the slots offset value mapping is explicitly considered and detailed. One skilled in the art should be therefore able to infer in all following embodiments the procedures detailed as a holistic concept and not in isolation of the brevity of the language.

[0147] According to embodiments of a first solution, a receiving device, e.g., a UE (such as the UE 205), is configured with at least one or more HARQ timing indications Kl-NACK, KI corresponding to one or more TBs of an ADU scheduled by a transmitting device, e.g., the RAN node 210, a 5G NR gNB, or the like.

[0148] In one embodiment of the first solution, for each (i.e., of one or more) TBs received scheduled by the transmitting device (e.g., RAN node 210) and received/detected by the receiving device (e.g., UE 205), the receiving device applies the configured HARQ timing indication tuple (Kl-NACK, KI) to opportunistically prioritize and report a HARQ-NACK feedback indication to the transmitting device at an earliest available UCI resource as at least Kl-NACK-determined slots after receiving the TB up to KI -determined slots after receiving the TB.

[0149] In another embodiment of the first solution, upon correctly receiving a TB of the one or more TBs, the receiving device (e.g., the UE 205) applies the received HARQ timing indication tuple (Kl-NACK, KI) to report the determined HARQ-ACK feedback (i.e., an ACK indication) of the received TB to the transmitting device. Optionally, the ACK indication may be multiplexed as part of a dynamic HARQ codebook, e.g., 5G NR Type-2 HARQ codebook together with other (i.e., zero or more) HARQ feedback indications over a UCI resource at KI slots after receiving the TB.

[0150] In other embodiments of the first solution, the ACK indication of a first correctly received TB, i.e., associated with a first configured tuple (K1-NACK_1, Kl_l), is multiplexed as part of a dynamic HARQ codebook, e.g., 5G NR Type-2 HARQ codebook, according to Clause 9.1.3 of 3GPP TS 38.214 (vl6.8.0), together with at least one other NACK indication belonging to a second TB, i.e., associated with a second configured tuple (K1-NACK_2, Kl_2), over a UCI resource, whereby the second TB was erroneously received after the first correctly received TB.

[0151] In one embodiment implementing the opportunistic HARQ-NACK feedback prioritization, the UCI resource carrying the HARQ codebook is signaled in UL to the transmitting device at K1-NACK_2 slots after the receiving of the second TB and comprises at least of the HARQ codebook ‘ 10’, indicating ACK for the first TB and NACK for the second TB. In such embodiments, the time instance of K1-NACK_2 slots after the receiving of the second TB is, at most, equal in absolute timing to the time instance of Kl_l slots after the receiving of the first TB.

[0152] Therefore, in an example, if the first TB is received successfully at slot ‘nl’ and second TB is received erroneously at slot ‘n2’ then the following relations hold for the slots’ absolute timings: nl < n2 and (n2 + K1-NACK_2) < (nl + KI). In some embodiments, between the first TB and the second TB zero or more TBs can be received belonging to the same ADU. As such, the rule applies generally to two or more TBs belonging to the same ADU.

[0153] In some embodiments, the opportunistic HARQ-NACK feedback prioritization is combined with CBG-based retransmissions to enable a higher granularity, lower latency and increased spectral efficiency of the necessary retransmissions than for the embodiments where CBG-based retransmissions are disabled. In such embodiments, the CBG-based retransmissions are enabled by means of RRC messaging parameter codeBlockGroupTransmission for PDSCHs and the TB is split into M number of CBGs, where

M = min(A,C), Equation 4 where N is the parameter maxCodeBlockGroupsPerTransportBlock signaled by higher layers, and C is the number of CBs as determined by typical 5G NR TB CB segmentation procedure, e.g., as defined in Clause 7.2.3 of 3GPP TS 38.212.

[0154] The opportunistic HARQ-NACK feedback prioritization follows as previously detailed whereby the multiplexing of HARQ feedback of one or more TBs is now performed by dynamic HARQ codebook, e.g., 5G NR Type-2 HARQ codebook, such that for each TB the HARQ codeword is determined by a CBG-based HARQ codebook, e.g., the 5G NR CBG-based HARQ-ACK codebook, and as such for each TB one bit per CBG is to be reported.

[0155] In embodiments with CBG-based retransmissions, upon opportunistic HARQ- NACK feedback prioritization only the incorrectly received CBGs are scheduled for retransmissions. In an example, the RAN node 210 schedules such a retransmission of a CBG of a TB within the same HARQ process as of the comprising TB by leveraging the DCI parameters NDI, CBGTI, and CBGFI. In this example, the parameter NDI represents a toggle bit indicating new data or retransmission for a HARQ process, the parameter CBGTI indicates which CBG within the TB is being retransmitted, whereas the parameter CBGFI determines whether soft combining should be performed by the HARQ process at the receiver, or the receive buffer should be flushed.

[0156] In various embodiments, the value of KI -NACK is to be determined such that KINACK < KI. An additional constraint is related to allowing a receiving device, e.g., the UE 205, enough processing time, i.e., Tproc, l, to be able to decode the PDSCH DL transmission of a TB. In an embodiment applicable to 5G NR, this processing time, Tproc,l, relates to the signal processing at the receiver PHY layer 220 in performing channel estimation, processing of demodulation reference signal (“DM-RS”), signal demodulation, FEC decoding, and associated UL preparation processing (e.g., UCI HARQ codeword determination, channel coding, modulation and multiplexing, layer mapping, physical/virtual resources mapping) for transmission of UCI over PUSCH or PUCCH resources.

[0157] According to Equation 3, in a 5G NR embodiment the value Tproc,l is mainly determined by the parameter N 1 and UE capabilities, whereby the parameter N 1 indicates the number of symbols necessary for UEs of different capabilities to process a PDSCH transmission given various SCS configurations used for the transmission.

[0158] In one example of 5G NR, Table 4 outlines the minimum possible PDSCH processing times Tproc, l and corresponding integer slot duration for UE default capability (UE capability #1). The Tproc, l conversion to integer slot durations given the individual SCSs, i.e., Equation 5 is motivated by the fact that in various embodiments the bursty quasi -periodic, and jittery XR DL traffic characteristics are better served in DL over PDSCHs transmitted over heavily oriented DL slot formats, i.e., no self-contained slots are assumed.

Table 4: An example of minimum processing time of PDSCH and UL transmission of UCI containing HARQ-ACK over PUCCH resource for 5G NR UEs of default capability. [0159] It follows therefore that the additional constraint on the value determination of KINACK is given by the fact that S 1 < Kl-NACK, such that:

S 1 < K 1 -NACK < K 1 Equation 6

[0160] For brevity, the latter constraint implicitly assumes Kl-NACK and KI as the mapped values to slots of the indications their represent.

[0161] In various embodiments, the Kl-NACK timing indicator may be dynamically signaled by the network. In some embodiments, a value of the Kl-NACK index mapped to slots may be determined by an extended signaling of the IdbS -io-HARQ feedback Ammg indicator in DCI to encoding the tuple (Kl-NACK, KI), whereby Kl-NACK has the same bit length as KI, i.e., 1, 2 or 3 bits, depending on the DCI format (e.g., 1 0, I I or 1 2) and the corresponding dl-DataToUL-ACK table indicated by upper layer RRC PUCCH-Config messages. The extended signaling of the IdbS -io-HARQ feedback Ammg indicator is thus determined in an embodiment by additionally selecting to KI a Kl-NACK indicator whose index into the corresponding table dl-DataToUL-ACK returns a value of slots fulfilling the constraints of Equation 7:

S 1 < dl-DataToUL-ACK[Kl-NACK] < dl-DataToUL-ACK[Kl] Equation 7

[0162] In other embodiments, an indication of the Kl-NACK timing indicator is signaled alone as a field corresponding to a PDSCH-to-HARQ NACK Jeedback timing indicator. In some embodiments the PDSCH-to-HARQ NACK feedback timing indicator signals an index into a corresponding table of dl-DataToUL-ACK values, e.g., the parameter dl-DataToUL-ACK, or the parameter dl-DataToUL-ACK-r!6 for DCI formats 1 0, I I, and the parameter dl-DataToUL- ACK-DCI-1-2 for DCI formats 1 2, such that the mapped value of slots returned by the index indication fulfills the constraints of Equation 7.

[0163] In various embodiments, the transmitter-selected Kl-NACK indicator is determined additionally based on a configuration of PUCCH configured resource sets and resources, a configuration of a scheduled PUSCH transmission, a semi-static configuration of a CG Type-1 of periodic PUSCH transmissions, a dynamically enabled/disabled CG Type-2 configuration of PUSCH transmissions, a configuration of timing processing a PDSCH given a SCS, and a MCS of the physical transport layer, or any combination thereof.

[0164] Therefore, the transmitting device (e.g., RAN node 210 or gNB) uses its available network configuration to determine an earliest available UCI resource for the receiving device to report (i.e., to feed back) a potential HARQ-NACK occurrence of the scheduled PDSCH transmission by the DCI carrying the Kl-NACK configuration. As such, in some embodiments, the earliest available UCI resource to be opportunistically used by the receiving device to prioritize HARQ-NACK feedback is a physical channel in the form of a PUCCH configured resource within a PUCCH resource set, or a PUSCH transmission scheduled by means of either a dynamic grant or active CG configuration.

[0165] In other embodiments, the transmitting entity (i.e., the RAN node 210 or gNB) transmits DCI indicating a Kl-NACK index of a PDSCH for determining the slot where the potential PDSCH HARQ-NACK feedback could be prioritized by the receiving entity (i.e., the UE 205), serving as an indication to the UE 205 that any UCI resource available at least within the determined slot, or later, up to the slot indicated by the KI index value can be used to opportunistically prioritize the HARQ-NACK feedback. In this context, the available UCI resource comprises at least one of a PUCCH configured resource sets and a PUCCH resource therein, a scheduled PUSCH transmission, a semi-static configured CG Type-1 periodic PUSCH transmissions, and a dynamically enabled CG Type-2 configuration of PUSCH transmissions. Note that in CG Type-1, the uplink resources are both configured and (semi-statically) enabled by RRC signaling. In CG Type-2, the uplink resources are configured by RRC signaling, but (dynamically) enabled/disabled by DCI.

[0166] Thus, in some embodiments the PDSCH -to-HARQ^feedback timing indicator tuple (Kl-NACK, KI) or the PDSCH-to-HARQ NACK Jeedback timing indicator Kl-NACK field is signaled dynamically by a dynamic PDCCH DCI scheduling of one or more PDSCH transmissions, a dynamic PDCCH DCI scheduling of a PDSCH transmission group, or any combination thereof.

[0167] In various embodiments, the enablement or disablement of the opportunistic prioritization of HARQ-NACK feedback occurrence for one or more PDSCHs is signaled by means of at least one of a semi-static RRC indication field, a dynamic DCI indication field for a DCI scheduling one or more PDSCH transmissions, a dynamic DCI indication field for a DCI scheduling a group of PDSCH transmissions. In some embodiments, the enablement/disablement indication field carries a single bit of information encoding the enabled or disabled state of the opportunistic prioritization procedure of HARQ-NACK feedback. In an example, an indication of ‘ I ’ encodes the enabled state, and an indication of ‘0’ encodes the disabled state, respectively.

[0168] In various embodiments, typical DL transmissions of XR video coded data may lead on average to large data bursts of ADU payloads going up to 100 - 140 kBytes for 2 eye buffered streams at 2K resolution with H.265 encoding. This is easy to observe based on the distributions illustrated in Figure 4 for a 1 eye channel stream with HD resolution, where I-slices (or similarly I-frames) have a long-tailed distribution reaching even 100 kBytes. In practical deployments, it is expected therefore that some of XR DL ADUs, predominantly those containing I -slices and/or I-frames are going to span multiplex TBs over the PHY layer transmissions.

[0169] In one example of 5GNR, assuming 120 kBytes I-frame ADU within a stream with 120 • 10 ³ • 8

120 fps, it follows that this payload is split over at least 12 = — _8Q6Q7 TBS considering a PHY transmission configuration containing: A) a 60 kHz SCS, corresponding to /r = 2 ; B) a transmission bandwidth of 100 MHz corresponding to 135 physical resource blocks; C) a singular transmission layer; D) a MCS scheme corresponding to 64-QAM modulation and 0.75 Low- Density Parity-Check (“LDPC”) FEC coding rate; and E) a typical DL-oriented slot format containing at least 12 OFDM symbols dedicated to DL PDSCH and same slot (K0=0) dynamic DCI scheduling over PDCCH.

[0170] Note that the above number of TBs is obtained using Equation 8 to determine the number of information bits, determining the TB size with a frontloaded only DM-RS.

N_info = Nsymb * 12 * Nprb x Qm * v x R Equation 8

[0171] In the above example, the value of N_info is calculated to be 80,607 bits.

[0172] For the XR application traffic periodicity of 8.33 ms, the radio configuration has available at most 33 slots for the PDCCH DL/UL transmissions configuration, the PDSCH XRDL traffic, the PUSCH UL XR periodic traffic, as well as the other DL/UL traffic pertaining to other served applications for the UE 205 or other UEs in the cell. In addition, for a PDB of 15 ms, it follows that the example radio configuration provides at most 60 slots for the successful transmission of all TBs belonging to the ADU.

[0173] The detailed example configuration represents the best 5G NR MCS, SCS and bandwidth combination for frequency range 1 (“FR1”) and a middle-ground MCS, SCS and bandwidth combination for frequency range (“FR2”) in transmitting such demanding data bursts like XR DL traffic with low latency.

[0174] It follows therefore that in many embodiments, the opportunities for recovering from retransmissions of TBs belonging to XR traffic are very tight and at most 1-2 retransmission possibilities are possible in practice. However, given the target QoS error rate 10 ^-4 such errors are in most embodiments infrequent, yet they need to be reported as early as possible to the RAN node 210 for appropriate retransmission procedures to correct emergent errors. In contrast to the feedback options previously detailed, the below described procedures for opportunistic HARQ- NACK prioritization provide tools for the RAN node 210 to achieve these objectives, while maintaining UE energy consumption as low as possible and providing low latency signaling configuration to exploit for informing the RAN node 210 of the receive failures of XR ADU TBs.

[0175] The following examples outline at a high-level the attributes, configuration, and techniques of the proposed opportunistic HARQ-NACK feedback for the various embodiments described above.

[0176] Figure 9 illustrates an exemplary timing diagram 900 of opportunistic HARQ- NACK prioritized on PUCCH resources, in accordance with aspects of the present disclosure. Here, the opportunistic HARQ-NACK prioritization is presented for a first ADU formed of at least 3 TBs followed by a second ADU formed of at least 2 TBs. The two ADUs represent a partial timing of XR DE traffic with video frame periodicity of 120 fps, i.e., a XR DL traffic periodicity of 8.33 ms. According to the depicted embodiment, the first ADU may comprise an I-frame and the second ADU may comprise a P-frame. The TBs are indicated dynamically and scheduled upon their arrival at the RAN node 210 by DCI over PDCCH. The TBs are then transmitted over PDSCH to the UE 205.

[0177] According to the exemplary timing diagram 900, it is assumed that the second TB of the first ADU, e.g., TB#2, is erroneously received and the HARQ-ACK codebook of at least the first 3 TBs of the first ADU is configured (by means of KI indication) to be multiplexed together over a UCI resource, e.g., UCI#2. This UCI resource may be a configured PUCCH resource as part of some common or configured PUCCH resource set, or a PUSCH transmission occurrence. In some examples, the UCI#2 may be aligned for instance with a CG PUSCH pose transmission of UL XR traffic to reduce the energy consumption at the UE side by avoiding transmissions of additional PUCCH resources.

[0178] As such, in some examples, the multiplexing of the HARQ-ACK codebook is performed after a significant number of slots, e.g., 12, after the receiving of a group of one or more TBs belonging to an ADU, to provide energy savings at the UE 205. This leads to undesired delays regarding the HARQ feedback, which in case of HARQ-NACK indications for any of the TBs increases the PDB of the negatively acknowledged TB and - depending on cell traffic, system load or SINR - may lead to missing the PDB target of the TB and dropping the ADU, missing the QoS targets and affecting the user Quality of Experience (“QoE”).

[0179] In certain embodiments, the above situation may be avoided by the aggressive scheduling of PUCCH resources out of a common or configured PUCCH resource set for HARQ- ACK codebook reporting of XR DL traffic. This results in lower latency at the price of increased energy consumption due to the aggressive PUCCH UCI transmission policy. [0180] In contrast, an enabled opportunistic HARQ-NACK prioritization is illustrated in Figure 9 as follows. Each of the at least 3 TBs, TB#1 (received at slot nl), TB#2 (received at slot n2), TB#3 (received at slot n3), belonging to the first ADU has its own Kl-NACK, KI configuration, such that nl + Kl_l = n2 + Kl_2 = n3 + Kl_3 and nl + K1-NACK_1 = n2 + Kl- NACK_2 < n3 + K1-NACK_3 <= n3 + Kl_3. This configuration corresponds to the RAN node 210 (e.g., gNB) informing the UE 205 that the UE 205 can opportunistically use the configured PUCCH resource at slot n2 + K1-NACK_2 for transmitting UCI#1 in case a HARQ-NACK indication is indicated for any of TB#1 or TB#2, whereas for TB#3 any PUCCH or PUSCH resource between slots n3 + K1-NACK_3 and n3 + Kl_3 can be used for opportunistic HARQ- NACK prioritized feedback indication in case TB#3 is erroneously received.

[0181] In the depicted embodiment, the erroneous TB#2 HARQ-NACK is reported thus in UL of UCI#1 together with the HARQ-ACK of TB#1 by the standard Type-2 HARQ-ACK codebook multiplexing procedure, yielding the HARQ codeword ‘ 10’ to be sent in UL over the PDCCH resource available. As TB#3 was scheduled and received but did not finish processing at the UE 205, by n2 + K1-NACK_2 < n3 + K1-NACK_3, it follows that the TB#3 HARQ-ACK codebook is not multiplexed with TB# 1 and TB#2, respectively, as expected by the RAN node 210.

[0182] As a result of the HARQ-NACK prioritization depicted in Figure 9, the RAN node 210 (e.g., gNB) gets notified earlier than UCI#2 of the occurrence of the HARQ-NACK of TB#2 and is thus capable of earlier retransmission of the TB as ReTB#2 which is now received correctly. In the example of Figure 9, the feedback timing of the retransmitted TB (ReTB#2) is configured to coincide with the original UCI#2 resource where TB#3 was to be also multiplexed upon successful reception. Consequently, as ReTB#2 and TB#3 were both successfully received UCI#2 yields the codework ‘ 11 ’ by applying the dynamic HARQ-ACK codebook multiplexing procedure and the reception of the at least 3 TBs of the first ADU is successfully completed and the corresponding HARQ processes of TB#2 and TB#3 are released.

[0183] Figure 10 illustrates an exemplary timing diagram 1000 of opportunistic HARQ- NACK prioritized on PUCCH resources, in accordance with aspects of the present disclosure. Here, the opportunistic HARQ-NACK prioritized feedback configuration of the at least 3 TBs of the first ADU is such that nl + Kl_l = n2 + Kl_2 = n3 + Kl_3 and nl + Kl-NACK 1 = n2 + Kl- NACK_2 = n3 + K1-NACK_3 <= n3 + Kl_3, indicating that in turn the processing of the PDSCH comprising TB#3 is finalized by the UE 205 by n2 + K1-NACK_2 and is thus included in the dynamic HARQ codebook multiplexing over UCI#1 transmitted by the configured PUCCH resource. In the example of Figure 10, this results in the dynamic HARQ-ACK codebook multiplexing leading to the HARQ codeword ‘ 101’ standing for the HARQ-ACK of TB#1, HARQ-NACK of TB#2, and HARQ-ACK of TB#3.

[0184] Again, the opportunistic HARQ-NACK prioritized feedback of TB#2 triggers an early reporting of a HARQ codebook containing at least one HARQ-NACK occurrence over UCI#1 and informs the RAN node 210 (e.g., gNB) with low latency of the TB failure. In effect the RAN node 210 (e.g., gNB) schedules the retransmission of TB#2 as ReTB#2 by dynamic DCI toggling the NDI bit. As shown in Figure 10, the ReTB#2 is received correctly and its HARQ feedback report is configured to be sent in UL over the UCI#2 resource, forming the dynamic HARQ-ACK codebook ‘ 1 ’ .

[0185] Note that in the examples depicted in Figure 9 and Figure 10, if the TB#2 is correctly received, then the UCI#1 UL transmission is skipped as there is no need for HARQ- NACK opportunistic prioritization by K1-NACK_2. As such, only the UCI#2 resource would be used to multiplex the at least 3 TBs HARQ-ACK codebook as ‘ 111’ outlining the acknowledgements of all the TBs. Beneficially, this results in energy savings, whereas the detailed HARQ-NACK opportunistic prioritization represents a low latency HARQ feedback enhancement.

[0186] Figure 11 illustrates an exemplary timing diagram 1100 of opportunistic HARQ- NACK prioritized on a CG PUSCH resource, in accordance with aspects of the present disclosure. The timing diagram 1100 outlines another example derived from the timing diagram 900, whereby the UCI#1 available resource is a PUSCH UL transmission as UCI multiplexing in PUSCH is supported when UCI and PUSCH transmissions coincide in time.

[0187] In the illustrated embodiment, the error in TB#2 triggers the opportunistic HARQ- NACK prioritization on top of a CG PUSCH transmission corresponding to a pose occurrence of UL XR. As such the UCI# 1 resource becomes an instance of the UL XR pose whereby the UCI# 1 HARQ-ACK codebook is multiplexed according to typical 5G NR procedures described earlier.

[0188] As the time of the PUSCH CG available instance is before processing of the TB#3 PDSCH, the UCI#1 HARQ-ACK dynamic HARQ-ACK codebook multiplexes just TB#1 and TB#2 HARQ feedback as ‘ 10’. Like the timing diagram 900, the opportunistic HARQ-NACK feedback prioritization lets the RAN node 210 (e.g., gNB) know early ofthe TB#2 decoding failure and successful retransmission leads to a UCI#2 indication confirming the successful reception of both TB#2 (upon retransmission) and TB#3 as a dynamic HARQ-ACK codebook ‘ 11 ’.

[0189] Figure 12 illustrates an exemplary timing diagram 1200 of opportunistic HARQ- NACK prioritized on dynamically scheduled PUSCH resource, in accordance with aspects of the present disclosure. Here, the PUSCH resource leveraged by the opportunistic HARQ-NACK feedback prioritization does not necessarily need to be part of a CG, but instead can be a dynamically scheduled grant by means of DCI format O x indication over PDCCH. Accordingly, in the timing diagram 1200, the UCI#1 indication UL resource is a dynamically scheduled PUSCH.

[0190] In an example, the PUSCH is configured by a DCI Format 0 0 indicator received at slot n with PUSCH-TimeDomainResourceAllocation parameter K2 and a Start and Length Indicator Value (“SLIV”) configuration such that n + K2 > n2 + K1-NACK_2. As a result, the UCI#1 yields the same HARQ-ACK dynamic codebook of ‘ 10’ as for the previous example of Figure 11.

[0191] Note that in the examples depicted in Figure 11 and Figure 12, if TB#2 is correct, then the UCI#1 multiplexing over PUSCH is skipped as no HARQ-NACK occurrence would require prioritization.

[0192] In some embodiments a non-necessary opportunistic HARQ-NACK prioritization results in no multiplexing of the control channel alongside the UL-SCH channel in the PUSCH. In such embodiments, the UCI HARQ-ACK codebook bits are simply missing from the PUSCH. However, this does not impact the capability of recovering the UL-SCH data bits of the PUSCH by applying the legacy procedures of UCI multiplexing over PUSCH, i.e., for up to 2 bits of HARQ-ACK codebook 2 bits of UL-SCH data are pruned, whereas for more than 2 bits of HARQ- ACK codebook the UL-SCH bits are rate matched.

[0193] Figure 13 illustrates an exemplary timing diagram 1300 of opportunistic HARQ- NACK prioritization with CBG-based retransmission, in accordance with aspects of the present disclosure. The timing diagram 1300 may be an extension of the timing diagram 900, described above, having an RRC enabled CBG-based retransmissions configuration with 2 CBGs per TB. The timing diagram 1300 exemplifies the case where both TB# 1 and TB#2 are received with errors due to each containing 1 erroneous CBG. In the depicted embodiments, it is assumed that the second CBG of TB# 1 and the first CBG of TB#2 are erroneously received at the receiving device (i.e., UE).

[0194] Due to the erroneous reception of at least one CBG, the receiving device (i.e., UE) applies opportunistic HARQ-NACK feedback prioritization to transmit a HARQ feedback report over the available UCI#1 PUCCH resource. However, in the depicted embodiment, given the enabled CBG-based retransmissions, the UCI# I HARQ-ACK dynamic codebook is ‘ 1001 ’ by means of each of the TBs CBG-based HARQ-ACK codebook. Following successful retransmission of both erroneous CBGs, the receiving device (i.e., UE) transmits a second HARQ feedback report over the available UCI#2 resource, where the second HARQ report multiplexes the feedback of all TBs as the HARQ-ACK dynamic codebook ‘ 111111 ’ by means of each of the TBs CBG-based HARQ-ACK codebook configuration. Note here that the second HARQ report provides feedback for all CBGs of TB# 1 and TB#2, even though only one CBG was retransmitted for each of these TBs.

[0195] The opportunistic HARQ-NACK feedback prioritization procedure benefits of the KI -NACK and KI parameters configuration which provides a dynamically configurable and opportunistically adaptive toolset in combining low-latency HARQ-NACK feedback reporting necessary for quick transmission errors recovery with increased energy efficiency of the multiplexing and joint reporting of a plurality of TBs. These benefits enhance the HARQ procedure in supporting high-rate, low-latency, bursty, and quasi-periodic traffic, such as the XR DL traffic discussed as an example.

[0196] In certain embodiments of the first solution, the value of KI -NACK is semi- statically determined by a receiving device, i.e., the UE 205, configured to enable the opportunistic prioritization of HARQ-NACK reporting for one or more TBs over PDSCH. In such embodiments, the UE 205 uses a rule-based determination of Kl-NACK for a DCI scheduled TB transmitted over a PDSCH instance based on a processing timing lower bound of the PDSCH, a DCI configured PDSCH-to-HARQJeedback timing indicator, a dl-DataToUL-ACK timing table mapping, a scheduling information of UCI carrying resource available as PUSCH or PUCCH, or a combination thereof. In various embodiments the rule-based used for determination of Kl- NACK is common to both the receiving device (e.g., the UE 205), and the transmitting device (e.g., the RAN node 210). Here, the common rule (i.e., transceiver-receive-common rule) allows for synchronization of Kl-NACK values between the UE 205 and the RAN node 210.

[0197] An example of rule-based determination from the side of the UE 205 of default capability is as follows: Consider a DL XR transmission received over PDSCH at slot n, indicated by a dynamic DCI configuring the regular HARQ feedback after 12 slots according to signaled PDSCH-to-HARQ^feedback timing indicator KI and an RRC-configured dl-DataToUL-ACK table. The PDSCH transmission occurs with SCS . = 2, i.e., 60kHz, and frontloaded DM-RS only, i.e., dmrs-AdditionalPosition == 0. In such an example, the UE 205 may process and decode the PDSCH after 0.30 ms, according to Table 4. With a slot duration of 0.25 ms for the 60kHz SCS, the UE 205 would be able at earliest to feedback any HARQ indication in 2 slots upon receiving the PDSCH, whereas the UL PUCCH or PUSCH transmission cannot start at the beginning of the second slot, i.e., slot n+2, as at least 0.05 ms are necessary for the UE 205 to complete processing.

[0198] Figure 14 illustrates an exemplary timing diagram 1400 of a determination of Kl- NACK at a receiving device based on UE capabilities, SCS configuration and PDSCH processing time, in accordance with aspects of the present disclosure. The timing diagram 1400 may be an extension of the timing diagram 600 described above with reference to Figure 6.

[0199] In the example depicted in Figure 14, a guard slot is assumed by the UE 205 to account for any partial compute requirements during a slot, in this case the slot n+2, for completing decoding PDSCH. Consequently, in the timing diagram 1400, the UE 205 determines that KINACK 3 slots for the earliest slot duration where HARQ feedback is possible. By applying the same rule (i.e., transmitter-receiver-common rule), the RAN node 210 (e.g., gNB) would be able to determine the same KI -NACK 3 slots based on the configuration of the N1 PDSCH processing parameter, SCS and reported UE capabilities.

[0200] Figure 15 illustrates another exemplary timing diagram 1500 of a determination of KI -NACK at a receiving device based on UE capabilities, SCS configuration, PDSCH processing time, and RRC dl-DataToUL-ACK configuration, in accordance with aspects of the present disclosure. In a further example, the UE 205 is configured by RRC with the parameter dl- DataToUL-ACKiWustiaiQA in table 1520 of Figure 15, to be in synchronization with the RAN node 210 (e.g., gNB). Therefore, the UE 205 selects a value mapping available in the configured table. As such, from the table 1520, the UE 205 selects the minimum value greater than or equal to the earliest slot duration determined, e.g., in this case 4 > 3, which constitutes the Kl-NACK 4. By applying the same rule (i.e., transmitter-receiver-common rule), the RAN node 210 (e.g., gNB) has all the necessary information to similarly determine Kl-NACK 4 slots. It yields therefore that the opportunistic HARQ-NACK prioritization can proceed with configuration Kl-NACK 4 slots and KI >-> 8 slots.

[0201] Figure 16 illustrates another exemplary timing diagram 1600 of a determination of Kl-NACK at a receiving device based on UE capabilities, SCS configuration, PDSCH processing time, RRC dl-DataToUL-ACK configuration, and available UCI resources (hereby a configured PUCCH resource), in accordance with aspects of the present disclosure. In a follow-up example, in determining Kl-NACK, the UE 205 may further take into account any available scheduled UCI resources as either configured PUCCH resources out of a configured PUCCH resource set or scheduled PUSCH resources (either dynamically scheduled or by means of a CG). For example, having a configured PUCCH resource in slot n+5, the UE 205 determines that the UCI containing a HARQ-NACK indication for the received PDSCH at slot n will occur over PUCCH at slot n+5.

[0202] As this occurs after the Kl-NACK >-> 4 slots determination based on the processing time and the parameter dl-DataToUL-A CK illustrated in table 1620 of Figure 16, the opportunistic signaling of HARQ-NACK at slot n+5 over PUCCH corresponds to the constraints and embodiments discussed above. As such, upon opportunistically signaling HARQ-NACK at slot n+5 over PUCCH the KI -NACK virtually becomes KI -NACK 5 slots. In the timing diagram 1600, the RAN (e.g., gNB) again has all the relevant information and the upon this rule-based approach is synchronized with the UE 205 signaling general strategy and procedure.

[0203] Figure 17 illustrates an example of a UE apparatus 1700 that may be used for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. In various embodiments, the UE apparatus 1700 is used to implement one or more of the solutions described above. The UE apparatus 1700 may be an example of a user endpoint, such as the remote unit 105 and/or the UE 205, as described above. Furthermore, the UE apparatus 1700 may include a processor 1705, a memory 1710, an input device 1715, an output device 1720, and a transceiver 1725.

[0204] In some embodiments, the input device 1715 and the output device 1720 are combined into a single device, such as a touchscreen. In certain embodiments, the UE apparatus 1700 may not include any input device 1715 and/or output device 1720. In various embodiments, the UE apparatus 1700 may include one or more of: the processor 1705, the memory 1710, and the transceiver 1725, and may not include the input device 1715 and/or the output device 1720.

[0205] As depicted, the transceiver 1725 includes at least one transmitter 1730 and at least one receiver 1735. In some embodiments, the transceiver 1725 communicates with one or more cells (or wireless coverage areas) supported by one or more base station units 121. In various embodiments, the transceiver 1725 is operable on unlicensed spectrum. Moreover, the transceiver 1725 may include multiple UE panels supporting one or more beams. Additionally, the transceiver 1725 may support at least one network interface 1740 and/or application interface 1745. The application interface(s) 1745 may support one or more APIs. The network interface(s) 1740 may support 3GPP reference points, such as Uu, Nl, PC5, etc. Other network interfaces 1740 may be supported, as understood by one of ordinary skill in the art.

[0206] The processor 1705, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor 1705 may be a microcontroller, a microprocessor, a central processing unit (“CPU”), a graphics processing unit (“GPU”), an auxiliary processing unit, a field programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, the processor 1705 executes instructions stored in the memory 1710 to perform the methods and routines described herein. The processor 1705 is communicatively coupled to the memory 1710, the input device 1715, the output device 1720, and the transceiver 1725.

[0207] In various embodiments, the processor 1705 controls the UE apparatus 1700 to implement the above-described UE behaviors. In certain embodiments, the processor 1705 may include an application processor (also known as “main processor”) which manages applicationdomain and operating system (“OS”) functions and a baseband processor (also known as “baseband radio processor”) which manages radio functions.

[0208] In various embodiments, the processor 1705 identifies a prioritized HARQ-NACK timing indicator (i.e., KI -NACK) of a prioritized slot offset timing delay corresponding to a scheduled TB to be transmitted by a transmitting device (e.g., eNB/gNB) and identifies a default HARQ timing indicator (i.e., KI) of a default slot offset timing delay corresponding to the scheduled TB. Via the transceiver 1725, the processor 1705 receives the scheduled TB from the transmitting device and determines whether the received TB was successfully decoded. The processor 1705 selects a slot offset timing delay based at least in part on the KI -NACK timing indicator, the KI timing indicator, and whether the received TB was successfully decoded. In certain embodiments, the selected slot offset timing delay corresponds to the prioritized slot offset timing delay associated with the KI -NACK timing indicator or corresponds to the default slot offset timing delay associated with the KI timing indicator. For example, the processor 1705 selects the slot offset timing delay based on the KI -NACK timing indicator if the TB was not successfully decoded. The processor 1705 applies the selected slot offset timing delay to report a HARQ feedback corresponding to the received TB and controls the transceiver 1725 to transmit, to the transmitting device and based on the selected slot offset timing delay, a HARQ feedback report for the received TB.

[0209] In some embodiments, the prioritized slot offset timing delay (i.e., corresponding to the prioritized KI -NACK timing indicator) is less than or equal to the default slot offset timing delay (i.e., corresponding to the KI timing indicator). In some embodiments, the selected slot offset timing delay is selected, by the processor 1705, from available UCI resources over a window occurring between the prioritized slot offset timing delay (i.e., corresponding to the prioritized KINACK timing indicator) and the default slot offset timing delay (i.e., corresponding to the KI timing indicator).

[0210] In some embodiments, the prioritized Kl-NACK timing indicator and the KI timing indicator represent indexed indications into a semi-static table configured by higher layers, said table mapping a respective timing indicator to a respective slot offset timing delay. In some embodiments, at least the prioritized slot offset timing delay (i.e., corresponding to the prioritized Kl-NACK timing indicator) is greater than or equal to a TB processing delay of the received TB.

[0211] In some embodiments, the processor 1705 selects the slot offset timing delay by selecting the default slot offset timing delay (i.e., corresponding to the KI timing indicator) when the received TB is correctly decoded. In such embodiments, the HARQ feedback reported to the transmitting device includes a positive feedback (i.e., ACK) based on the received TB being correctly decoded.

[0212] In some embodiments, the processor 1705 selects the slot offset timing delay by selecting the prioritized slot offset timing delay (i.e., corresponding to the prioritized Kl-NACK timing indicator) when the received TB is not correctly decoded. In such embodiments, the HARQ feedback reported to the transmitting device includes a negative feedback (i.e., NACK) based on the received TB not being correctly decoded. In certain embodiments, the processor 1705 further multiplexes the negative feedback with additional HARQ feedback for at least one second (i.e., additional) received TB.

[0213] In certain embodiments, the multiplexing of the negative feedback (i.e., NACK) with HARQ feedback for at least one second received TB is performed by a dynamic Type-2 HARQ-ACK codebook. In certain embodiments, each second received TB has a respective second prioritized HARQ-NACK timing indicator. In such embodiments, the slot offset timing delays associated with the respective second prioritized HARQ-NACK timing indicators are less than or equal to the selected slot offset timing delay (i.e., the prioritized slot offset timing delay corresponding to the prioritized Kl-NACK timing indicator) for the received TB that was not correctly decoded. Note here that the at least one second received TB may be received before or after the received TB that was not correctly decoded, so long as the aforementioned slot offset timing delay constraint is met.

[0214] In some embodiments, the processor 1705 further receives an indication that CBG- based retransmission is supported, where the HARQ feedback reported to the transmitting device for the received TB is formed of a CBG-based HARQ-ACK codebook. In such embodiments, the received TB includes a plurality of CBGs, where the HARQ feedback for the received TB reports as HARQ-NACK at least one CBG in the received TB.

[0215] In some embodiments, identifying the prioritized Kl-NACK timing indicator and the KI timing indicator includes receiving a bit field indication over DCI scheduling of one or more TBs over PDSCH, said bit field including an indication of the prioritized Kl-NACK timing indicator and/or the KI timing indicator. In some embodiments, identifying the prioritized Kl- NACK timing indicator includes the processor 1705 determining a value for the prioritized Kl- NACK timing indicator by means of a transmitter-receiver-common rule.

[0216] In some embodiments, the report to the transmitting device of the HARQ feedback for the received TB is transmitted over an UCI physical channel resource using one of: A) a PUCCH configured resource; B) a dynamically scheduled PUSCH transmission resource; and C) a configured PUSCH transmission resource (e.g., a resource of either a semi-static CG Type-1 or a dynamic CG Type-2).

[0217] In some embodiments, the processor 1705 is further configured to dynamically enable or disable selecting a slot offset timing delay using the prioritized KI -NACK timing indicator. In certain embodiments, the configuration to dynamically enable or disable selecting a slot offset timing delay using the prioritized Kl-NACK timing indicator includes at least one of: A) a 1-bit indication dynamically signaled over DCI; and B) a 1-bit indication semi-statically signaled using RRC messaging.

[0218] In some embodiments, identifying the prioritized Kl-NACK timing indicator includes determining a value for the Kl-NACK timing indicator based on: A) a configuration of PUCCH configured resource sets and resources; B) a configuration of a dynamically scheduled PUSCH transmission; C) a configuration of periodic PUSCH transmissions (e.g., either as semistatic CG Type-1 or as dynamic CG Type-2); D) a configuration of timing processing a PDSCH given a SCS; E) the identified KI timing indicator; F) a HARQ timing table mapping configured by higher layer signaling; or G) any combination thereof.

[0219] The memory 1710, in one embodiment, is a computer readable storage medium. In some embodiments, the memory 1710 includes volatile computer storage media. For example, the memory 1710 may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory 1710 includes non-volatile computer storage media. For example, the memory 1710 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 1710 includes both volatile and non-volatile computer storage media.

[0220] In some embodiments, the memory 1710 stores data related to HARQ-NACK feedback prioritization and/or mobile operation. For example, the memory 1710 may store various parameters, panel/beam configurations, resource assignments, policies, and the like as described above. In certain embodiments, the memory 1710 also stores program code and related data, such as an operating system or other controller algorithms operating on the UE apparatus 1700.

[0221] The input device 1715, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device 1715 may be integrated with the output device 1720, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, the input device 1715 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device 1715 includes two or more different devices, such as a keyboard and a touch panel. [0222] The output device 1720, in one embodiment, is designed to output visual, audible, and/or haptic signals. In some embodiments, the output device 1720 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, the output device 1720 may include, but is not limited to, a Liquid Crystal Display (“LCD”), a Light- Emitting Diode (“LED”) display, an Organic LED (“OLED”) display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting, example, the output device 1720 may include a wearable display separate from, but communicatively coupled to, the rest of the UE apparatus 1700, such as a smart watch, smart glasses, a heads-up display, or the like. Further, the output device 1720 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

[0223] In certain embodiments, the output device 1720 includes one or more speakers for producing sound. For example, the output device 1720 may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 1720 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all or portions of the output device 1720 may be integrated with the input device 1715. For example, the input device 1715 and output device 1720 may form a touchscreen or similar touch-sensitive display. In other embodiments, the output device 1720 may be located near the input device 1715.

[0224] The transceiver 1725 communicates with one or more network functions of a mobile communication network via one or more access networks. The transceiver 1725 operates under the control of the processor 1705 to transmit messages, data, and other signals and also to receive messages, data, and other signals. For example, the processor 1705 may selectively activate the transceiver 1725 (or portions thereof) at particular times in order to send and receive messages.

[0225] The transceiver 1725 includes at least one transmitter 1730 and at least one receiver 1735. One or more transmitters 1730 may be used to provide UL communication signals to a base station unit 121, such as the UL transmissions described herein. Similarly, one or more receivers 1735 may be used to receive DL communication signals from the base station unit 121, as described herein. Although only one transmitter 1730 and one receiver 1735 are illustrated, the UE apparatus 1700 may have any suitable number of transmitters 1730 and receivers 1735. Further, the transmitter(s) 1730 and the receiver(s) 1735 may be any suitable type of transmitters and receivers. In one embodiment, the transceiver 1725 includes a first transmitter/ receiver pair used to communicate with a mobile communication network over licensed radio spectrum and a second transmitter/receiver pair used to communicate with a mobile communication network over unlicensed radio spectrum.

[0226] In certain embodiments, the first transmitter/receiver pair used to communicate with a mobile communication network over licensed radio spectrum and the second transmitter/receiver pair used to communicate with a mobile communication network over unlicensed radio spectrum may be combined into a single transceiver unit, for example, a single chip performing functions for use with both licensed and unlicensed radio spectrum. In some embodiments, the first transmitter/receiver pair and the second transmitter/receiver pair may share one ormore hardware components. For example, certain transceivers 1725, transmitters 1730, and receivers 1735 may be implemented as physically separate components that access a shared hardware resource and/or software resource, such as for example, the network interface 1740.

[0227] In various embodiments, one or more transmitters 1730 and/or one or more receivers 1735 may be implemented and/or integrated into a single hardware component, such as a multi-transceiver chip, a system-on-a-chip, an Application-Specific Integrated Circuit (“ASIC”), or other type of hardware component. In certain embodiments, one or more transmitters 1730 and/or one ormore receivers 1735 may be implemented and/or integrated into a multi-chip module. In some embodiments, other components such as the network interface 1740 or other hardware components/circuits may be integrated with any number of transmitters 1730 and/or receivers 1735 into a single chip. In such embodiment, the transmitters 1730 and receivers 1735 may be logically configured as a transceiver 1725 that uses one or more common control signals or as modular transmitters 1730 and receivers 1735 implemented in the same hardware chip or in a multi-chip module.

[0228] Figure 18 illustrates an example of a NE apparatus 1800 that may be used for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. In one embodiment, the NE apparatus 1800 may be one implementation of a network endpoint, such as the base station unit 121 and/or RAN node 210, as described above. Furthermore, the NE apparatus 1800 may include a processor 1805, a memory 1810, an input device 1815, an output device 1820, and a transceiver 1825.

[0229] In some embodiments, the input device 1815 and the output device 1820 are combined into a single device, such as a touchscreen. In certain embodiments, the NE apparatus 1800 may not include any input device 1815 and/or output device 1820. In various embodiments, the NE apparatus 1800 may include one or more of: the processor 1805, the memory 1810, and the transceiver 1825, and may not include the input device 1815 and/or the output device 1820. [0230] As depicted, the transceiver 1825 includes at least one transmitter 1830 and at least one receiver 1835. Here, the transceiver 1825 communicates with one or more remote units 105. Additionally, the transceiver 1825 may support at least one network interface 1840 and/or application interface 1845. The application interface(s) 1845 may support one or more APIs. The network interface(s) 1840 may support 3GPP reference points, such as Uu, N1 , N2 and N3. Other network interfaces 1840 may be supported, as understood by one of ordinary skill in the art.

[0231] The processor 1805, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor 1805 may be a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or similar programmable controller. In some embodiments, the processor 1805 executes instructions stored in the memory 1810 to perform the methods and routines described herein. The processor 1805 is communicatively coupled to the memory 1810, the input device 1815, the output device 1820, and the transceiver 1825.

[0232] In various embodiments, the NE apparatus 1800 is a radio access entity (e.g., gNB) that communicates with one or more UEs and one or more NFs, as described herein. In such embodiments, the processor 1805 controls the NE apparatus 1800 to perform the above-described RAN behaviors. When operating as a radio access entity, the processor 1805 may include an application processor (also known as “main processor”) which manages application-domain and operating system (“OS”) functions and a baseband processor (also known as “baseband radio processor”) which manages radio functions.

[0233] In various embodiments, the processor 1805 determines a prioritized HARQ- NACK timing indicator (i.e., Kl-NACK) corresponding to a prioritized slot offset timing delay corresponding to a scheduled TB to be transmitted to a receiving device (e.g., a UE) and, via the transceiver 1825, configures the receiving device with at least the determined Kl-NACK timing indicator and a default HARQ timing indicator (i.e., KI) corresponding to a default slot offset timing delay for the scheduled TB. Via the transceiver 1825, the processor 1805 transmits the scheduled TB to the receiving device and receives, from the receiving device, a HARQ feedback report for the transmitted TB. The processor 1805 applies at least the prioritized slot offset timing delay (i.e., corresponding to the prioritized Kl-NACK timing indicator) and the default slot offset timing delay (i.e., corresponding to the KI timing indicator) to process a HARQ-NACK feedback report. Via the transceiver 1825, the processor 1805 retransmits the TB to the receiving device (e.g., for error recovery) when the HARQ-NACK feedback from the receiving device indicates that the transmission of the scheduled TB was unsuccessful (i.e., was not correctly decoded). [0234] In some embodiments, the prioritized slot offset timing delay (i.e., corresponding to the prioritized KI -NACK timing indicator) is less than or equal to the default slot offset timing delay (i.e., corresponding to the KI timing indicator). In some embodiments, the prioritized KINACK timing indicator and the KI timing indicator represent indexed indications into a semistatic table configured by higher layers, said table mapping a respective timing indicator to a respective slot offset timing delay. In some embodiments, at least the prioritized slot offset timing delay (i.e., corresponding to the prioritized Kl-NACK timing indicator) is greater than or equal to a TB processing delay of the receiving device.

[0235] In some embodiments, the HARQ-NACK feedback from the receiving device is multiplexed with additional HARQ feedback for at least one second received TB. In certain embodiments, the multiplexing of the negative acknowledgement feedback (i.e., HARQ-NACK) with the additional HARQ feedback for at least one second received TB is performed by a dynamic Type-2 HARQ-ACK codebook. In certain embodiments, each second received TB has a respective second prioritized HARQ-NACK timing indicator, where the slot offset timing delays associated with the respective second prioritized HARQ-NACK timing indicators are less than or equal to the selected slot offset timing delay for the received TB that was not correctly decoded.

[0236] In some embodiments, the transceiver 1825 further transmits an indication that CBG-based retransmission is supported, where the HARQ feedback reported by the receiving device for the transmitted TB is formed of a CBG-based HARQ-ACK codebook. In such embodiments, the transmitted TB includes a plurality of CBGs and where the HARQ feedback for the transmitted TB reports as HARQ-NACK at least one CBG in the received TB.

[0237] In some embodiments, configuring the receiving device with the prioritized Kl- NACK timing indicator and with the KI timing indicator includes transmitting a bit field indication over DCI scheduling of one or more TBs over PDSCH, said bit field including an indication of the prioritized Kl-NACK timing indicator and/or the KI timing indicator. In some embodiments, determining the prioritized Kl-NACK timing indicator includes determining a value for the Kl- NACK timing indicator by means of a transmitter-receiver-common rule.

[0238] In some embodiments, the HARQ-NACK feedback report from the receiving device is received over an UCI physical channel resource using one of: A) a PUCCH configured resource; B) a dynamically scheduled PUSCH transmission resource; and C) a configured PUSCH transmission resource (e.g., a resource of either a semi-static CG Type-1 or a dynamic CG Type- 2).

[0239] In some embodiments, the processor 1805 further configures the receiving device to dynamically enable or disable selecting a slot offset timing delay using the prioritized KI- NACK timing indicator. In certain embodiments, the configuration to dynamically enable or disable selecting a slot offset timing delay using the prioritized KI -NACK timing indicator includes at least one of: A) a 1-bit indication dynamically signaled over DCI; and B) a 1-bit indication semi-statically signaled using RRC messaging.

[0240] In some embodiments, determining the prioritized KI -NACK timing indicator includes determining a value for the Kl-NACK timing indicator based on: A) a configuration of PUCCH configured resource sets and resources; B) a configuration of a dynamically scheduled PUSCH transmission; C) a configuration of periodic PUSCH transmissions (e.g., either as semistatic CG Type-1 or as dynamic CG Type-2); D) a configuration of timing processing a PDSCH given a SCS; E) the configured KI timing indicator; F) a HARQ timing table mapping configured by higher layer signaling; or G) any combination thereof.

[0241] The memory 1810, in one embodiment, is a computer readable storage medium. In some embodiments, the memory 1810 includes volatile computer storage media. For example, the memory 1810 may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory 1810 includes non-volatile computer storage media. For example, the memory 1810 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 1810 includes both volatile and non-volatile computer storage media.

[0242] In some embodiments, the memory 1810 stores data related to HARQ-NACK feedback prioritization and/or mobile operation. For example, the memory 1810 may store parameters, configurations, resource assignments, policies, and the like, as described above. In certain embodiments, the memory 1810 also stores program code and related data, such as an operating system or other controller algorithms operating on the NE apparatus 1800.

[0243] The input device 1815, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device 1815 may be integrated with the output device 1820, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, the input device 1815 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device 1815 includes two or more different devices, such as a keyboard and a touch panel.

[0244] The output device 1820, in one embodiment, is designed to output visual, audible, and/or haptic signals. In some embodiments, the output device 1820 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, the output device 1820 may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non -limiting, example, the output device 1820 may include a wearable display separate from, but communicatively coupled to, the rest of the NE apparatus 1800, such as a smart watch, smart glasses, a heads-up display, or the like. Further, the output device 1820 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

[0245] In certain embodiments, the output device 1820 includes one or more speakers for producing sound. For example, the output device 1820 may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 1820 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all or portions of the output device 1820 may be integrated with the input device 1815. For example, the input device 1815 and output device 1820 may form a touchscreen or similar touch-sensitive display . In other embodiments, the output device 1820 may be located near the input device 1815.

[0246] The transceiver 1825 includes at least one transmitter 1830 and at least one receiver 1835. One or more transmitters 1830 may be used to communicate with the UE 205, as described herein. Similarly, one or more receivers 1835 may be used to communicate with network functions in the PLMN and/or RAN, as described herein. Although only one transmitter 1830 and one receiver 1835 are illustrated, the NE apparatus 1800 may have any suitable number of transmitters 1830 and receivers 1835. Further, the transmitter(s) 1830 and the receiver(s) 1835 may be any suitable type of transmitters and receivers.

[0247] Figure 19 illustrates a flowchart of a method 1900 for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. The operations of the method 1900 may be implemented by a receiving entity, such as the remote unit 105, the UE 205, and/or the UE apparatus 1700 (or components thereof), as described herein. Additionally, or alternatively, the operations of the method 1900 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0248] The method 1900 begins and identifies 1905 a Kl-NACK timing indicator (i.e., prioritized HARQ-NACK timing indicator) corresponding to a prioritized slot offset timing delay associated with a scheduled TB. The method 1900 includes identifying 1910 a KI timing indicator (i.e., default HARQ timing indicator) corresponding to a default slot offset timing delay associated with the scheduled TB. The method 1900 includes receiving 1915 the scheduled TB. The method 1900 includes determining 1920 whether the scheduled TB was successfully decoded. The method 1900 includes selecting 1925 a slot offset timing delay based at least in part on the Kl-NACK timing indicator, the KI timing indicator, and whether the scheduled TB was successfully decoded, wherein the selected slot offset timing delay corresponds to the prioritized slot offset timing delay or the default slot offset timing delay. The method 1900 includes transmitting 1930, based on the selected slot offset timing delay, a HARQ feedback report associated with the scheduled TB. The method 1900 ends.

[0249] Figure 20 illustrates a flowchart of a method 2000 for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. The operations of the method 2000 may be implemented by a transmitting entity, such as a base station unit 121, the RAN node 210, and/or the NE apparatus 1800 (or components thereof), as described herein. Additionally, or alternatively, the operations of the method 2000 may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0250] The method 2000 begins and determines 2005 a Kl-NACK timing indicator (i.e., a prioritized HARQ-NACK timing indicator) corresponding to a prioritized slot offset timing delay associated with a scheduled TB. The method 2000 includes configuring 2010 a receiving device with the Kl-NACK timing indicator and with a KI timing indicator (i.e., a default HARQ timing indicator) corresponding to a default slot offset timing delay associated with the scheduled TB. The method 2000 includes transmitting 2015 the scheduled TB. The method 2000 includes receive 2020, based on the prioritized slot offset timing delay or the default slot offset timing delay, a HARQ feedback report associated with the scheduled TB. The method 2000 includes retransmitting 2025, to the receiving device, the scheduled TB based on the HARQ feedback report indicating that the transmission of the scheduled TB was unsuccessful. The method 2000 ends.

[0251] Disclosed herein is a first apparatus for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. The first apparatus may be implemented by a receiving device, such as the remote unit 105, the UE 205, and/orthe UE apparatus 1700, described above. The first apparatus includes a processor coupled to a memory storing instructions executable by the processor to cause the first apparatus to: A) identify a prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator) corresponding to a prioritized slot offset timing delay associated with a scheduled TB; B) identify a default HARQ timing indicator (i.e., KI timing indicator) corresponding to a default slot offset timing delay associated with the scheduled TB; C) receive the scheduled TB; D) determine whether the scheduled TB was successfully decoded; E) select a slot offset timing delay based at least in part on the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator), the default HARQ timing indicator (i.e., KI timing indicator), and whether the scheduled TB was successfully decoded, wherein the selected slot offset timing delay corresponds to the prioritized slot offset timing delay or the default slot offset timing delay; and F) transmit, based on the selected slot offset timing delay, a HARQ feedback report associated with the scheduled TB.

[0252] In some embodiments, the default slot offset timing delay (i.e., corresponding to the KI timing indicator) is less than or equal to the default slot offset timing delay (i.e., corresponding to the KI timing indicator). In some embodiments, at least the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) is greater than or equal to a TB processing delay associated with the scheduled TB.

[0253] In some embodiments, the selected slot offset timing delay corresponds to an offset from a range between the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) and the default slot offset timing delay (i.e., corresponding to the KI timing indicator).

[0254] In some embodiments, the prioritized HARQ-NACK timing indicator (i.e., Kl- NACK timing indicator) and the default HARQ timing indicator (i.e., KI timing indicator) comprise indexed indications of a semi-static table configured by higher layers, where the semistatic table maps a respective timing indicator to a respective slot offset timing delay.

[0255] In some embodiments, to select the slot offset timing delay, the instructions are executable by the processor to cause the first apparatus to select the default slot offset timing delay (i.e., corresponding to the KI timing indicator) when the received TB is correctly decoded. In such embodiments, the HARQ feedback reported to the transmitting device includes an ACK based on the received TB being correctly decoded.

[0256] In some embodiments, to select the slot offset timing delay, the instructions are executable by the processor to cause the first apparatus to select the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) based on the received TB being not correctly decoded. In such embodiments, the HARQ feedback reported to the transmitting device includes a NACK based on the received TB being not correctly decoded. In certain embodiments, the instructions are executable by the processor to cause the first apparatus to multiplex the NACK with additional HARQ feedback for at least one second received TB.

[0257] In certain embodiments, to multiplex the NACK with the additional HARQ feedback for the at least one second received TB, the instructions are executable by the processor to cause the first apparatus to use a dynamic Type-2 HARQ-ACK codebook. In certain embodiments, each second received TB has a respective second prioritized HARQ-NACK timing indicator. In such embodiments, a second slot offset timing delay associated with the respective second timing indicator is less than or equal to the selected slot offset timing delay based on the received TB not being correctly decoded.

[0258] In some embodiments, the instructions are executable by the processor to cause the first apparatus to receive an indication that CBG-based retransmission is supported. In such embodiments, the HARQ feedback reported to the transmitting device for the received TB is formed of a CBG-based HARQ-ACK codebook. In certain embodiments, the received TB includes a plurality of CBGs, where the HARQ feedback for the received TB reports a NACK for at least one CBG in the received TB.

[0259] In some embodiments, the instructions are executable by the processor to cause the apparatus to receive a bit field over DCI scheduling of one or more TBs over PDSCH, wherein the bit field indicates the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator), the default HARQ timing indicator (i.e., KI timing indicator), or both. In some embodiments, to identify the prioritized HARQ-NACK timing indicator, the instructions are executable by the processor to cause the first apparatus to determine a value for the prioritized HARQ-NACK timing indicator by means of a transmitter-receiver-common rule.

[0260] In some embodiments, to transmit the HARQ feedback report, the instructions are executable by the processor to cause the first apparatus to transmit UCI using one of: A) a PUCCH configured resource; B) a dynamically scheduled PUSCH transmission resource; and C) a configured PUSCH transmission resource (e.g., a resource of either a semi-static CG Type-1 or a dynamic CG Type-2).

[0261] In some embodiments, the instructions are executable by the processor to cause the first apparatus to receive a configuration for dynamically enabling or disabling the selection of the slot offset timing delay using the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator). In certain embodiments, the configuration for dynamically enabling or disabling the selection of the slot offset timing delay using the prioritized HARQ-NACK timing indicator includes at least one of: A) a dynamic indication (e.g., a 1 -bit flag) signaled over DCI; B) a semistatic indication (e.g., a 1 -bit flag) signaled using RRC messaging; or C) a combination thereof.

[0262] In some embodiments, the instructions are executable by the processor to cause the first apparatus to determine a value of the prioritized HARQ-NACK timing indicator (i.e., Kl- NACK timing indicator) based on: A) a configuration of PUCCH configured resource sets and resources; B) a configuration of a dynamically scheduled PUSCH transmission; C) a configuration of periodic PUSCH transmissions (e.g., either as semi-static CG Type-1 or as dynamic CG Type- 2); D) a configuration of timing processing a PDSCH given a SCS; E) the default HARQ timing indicator (i.e., KI timing indicator); F) a HARQ timing table mapping configured by higher layer signaling; or G) any combination thereof.

[0263] Disclosed herein is a first method for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. The first method may be performed by a receiving device, such as the remote unit 105, the UE 205, and/orthe UE apparatus 1700, described above. The first method includes identifying identify a prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator) corresponding to a prioritized slot offset timing delay associated with a scheduled TB and identifying a default HARQ timing indicator (i.e., KI timing indicator), corresponding to a default slot offset timing delay associated with the scheduled TB.

[0264] The first method includes receiving the scheduled TB and determining whether the scheduled TB was successfully decoded. The first method includes selecting a slot offset timing delay based at least in part on the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator), the default HARQ timing indicator (i.e., KI timing indicator), and whether the scheduled TB was successfully decoded, where the selected slot offset timing delay corresponds to the prioritized slot offset timing delay or the default slot offset timing delay. The first method includes transmitting, based on the selected slot offset timing delay, a HARQ feedback report associated with the scheduled TB.

[0265] In some embodiments, the default slot offset timing delay (i.e., corresponding to the KI timing indicator) is less than or equal to the default slot offset timing delay (i.e., corresponding to the KI timing indicator). In some embodiments, at least the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) is greater than or equal to a TB processing delay associated with the scheduled TB.

[0266] In some embodiments, the selected slot offset timing delay corresponds to a timing delay selected from a range between the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) and the default slot offset timing delay (i.e., corresponding to the KI timing indicator).

[0267] In some embodiments, the prioritized HARQ-NACK timing indicator (i.e., Kl- NACK timing indicator) and the default HARQ timing indicator (i.e., KI timing indicator) comprise indexed indications of a semi-static table configured by higher layers, where the semistatic table maps a respective timing indicator to a respective slot offset timing delay.

[0268] In some embodiments, selecting the slot offset timing delay includes selecting the default slot offset timing delay (i.e., corresponding to the KI timing indicator) when the received TB is correctly decoded. In such embodiments, the HARQ feedback reported to the transmitting device includes an ACK based on the received TB being correctly decoded. [0269] In some embodiments, selecting the slot offset timing delay includes selecting the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) based on the received TB being not correctly decoded. In such embodiments, the HARQ feedback reported to the transmitting device includes a NACK based on the received TB being not correctly decoded. In certain embodiments, the first method includes multiplexing the NACK with additional HARQ feedback for at least one second received TB.

[0270] In certain embodiments, multiplexing the NACK with the additional HARQ feedback for the at least one second received TB includes using a dynamic Type-2 HARQ-ACK codebook. In certain embodiments, each second received TB has a respective second prioritized HARQ-NACK timing indicator. In such embodiments, a second slot offset timing delay associated with the respective second timing indicator is less than or equal to the selected slot offset timing delay based on the received TB not being correctly decoded.

[0271] In some embodiments, the first method includes receiving an indication that CBG- based retransmission is supported. In such embodiments, the HARQ feedback reported to the transmitting device for the received TB is formed of a CBG-based HARQ-ACK codebook. In certain embodiments, the received TB includes a plurality of CBGs, where the HARQ feedback for the received TB reports a NACK for at least one CBG in the received TB.

[0272] In some embodiments, the first method includes receiving a bit field over DCI scheduling of one or more TBs over PDSCH, wherein the bit field indicates the prioritized HARQ- NACK timing indicator (i.e., Kl-NACK timing indicator), the default HARQ timing indicator (i.e., KI timing indicator), or both. In some embodiments, identifying the prioritized HARQ- NACK timing indicator includes determining a value for the prioritized HARQ-NACK timing indicator by means of a transmitter-receiver-common rule.

[0273] In some embodiments, transmitting the HARQ feedback report includes transmitting UCI using one of: A) a PUCCH configured resource; B) a dynamically scheduled PUSCH transmission resource; and C) a configured PUSCH transmission resource (e.g., a resource of either a semi-static CG Type-1 or a dynamic CG Type-2).

[0274] In some embodiments, the first method includes receiving a configuration for dynamically enabling or disabling the selection of the slot offset timing delay using the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator). In certain embodiments, the configuration for dynamically enabling or disabling the selection of the slot offset timing delay using the prioritized HARQ-NACK timing indicator includes at least one of: A) a dynamic indication (e.g., a 1-bit flag) signaled over DCI; B) a semi-static indication (e.g., a 1-bit flag) signaled using RRC messaging; or C) a combination thereof. [0275] In some embodiments, the first method includes determining a value of the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator) based on: A) a configuration of PUCCH configured resource sets and resources; B) a configuration of a dynamically scheduled PUSCH transmission; C) a configuration of periodic PUSCH transmissions (e.g., either as semi-static CG Type-1 or as dynamic CG Type-2); D) a configuration of timing processing a PDSCH given a SCS; E) the default HARQ timing indicator (“KI timing indicator”); F) a HARQ timing table mapping configured by higher layer signaling; or G) any combination thereof.

[0276] Disclosed herein is a second apparatus for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. The second apparatus may be implemented by a transmitting entity, such as the base station unit 121, the RAN node 210, and/or the NE apparatus 1800, described above. The second apparatus includes a processor coupled to a memory storing instructions executable by the processor to cause the second apparatus to: A) determine a prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator) corresponding to a prioritized slot offset timing delay associated with a scheduled TB; B) configure a receiving device with the prioritized HARQ-NACK timing indicator and with a default HARQ timing indicator (i.e., KI timing indicator) corresponding to a default slot offset timing delay associated with the scheduled TB; C) transmit the scheduled TB; D) receive, based on the prioritized slot offset timing delay or the default slot offset timing delay, a HARQ feedback report associated with the scheduled TB; and E) retransmit, to the receiving device, the scheduled TB based on the HARQ feedback report indicating that the transmission ofthe scheduled TB was unsuccessful (i.e., was not correctly decoded).

[0277] In some embodiments, the default slot offset timing delay (i.e., corresponding to the KI timing indicator) is less than or equal to the default slot offset timing delay (i.e., corresponding to the KI timing indicator). In some embodiments, at least the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) is greater than or equal to a TB processing delay associated with the scheduled TB.

[0278] In some embodiments, the selected slot offset timing delay corresponds to an offset selected from a range between the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) and the default slot offset timing delay (i.e., corresponding to the KI timing indicator).

[0279] In some embodiments, the prioritized HARQ-NACK timing indicator (i.e., Kl- NACK timing indicator) and the default HARQ timing indicator (i.e., KI timing indicator) comprise indexed indications of a semi-static table configured by higher layers, where the semistatic table maps a respective timing indicator to a respective slot offset timing delay.

[0280] In some embodiments, a NACK feedback corresponding to the transmitted TB is multiplexed with additional HARQ feedback for at least one second transmitted TB. In certain embodiments, the multiplexing of the NACK with the additional HARQ feedback for at least one second received TB is performed by a dynamic Type-2 HARQ-ACK codebook. In certain embodiments, each second transmitted TB has a respective second prioritized HARQ-NACK timing indicator, where a second slot offset timing delays associated with the respective second timing indicator is less than or equal to the slot offset timing delay associated with the scheduled TB that was not correctly decoded.

[0281] In some embodiments, the instructions are executable by the processor to cause the second apparatus to transmit an indication that CBG-based retransmission is supported. In such embodiments, the received HARQ feedback report is formed of a CBG-based HARQ-ACK codebook. In such embodiments, the transmitted TB includes a plurality of CBGs and where the HARQ feedback report associated with the scheduled TB reports a NACK for at least one CBG in the received TB.

[0282] In some embodiments, to configure the receiving device with the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator) and with the default HARQ timing indicator (i.e., KI timing indicator), the instructions are executable by the processor to cause the second apparatus to transmit a bit field indication over DCI scheduling of one or more TBs over PDSCH, where the bit field indicates the prioritized HARQ-NACK timing indicator and/or the default HARQ timing indicator. In some embodiments, to determine the prioritized HARQ-NACK timing indicator, the instructions are executable by the processor to cause the second apparatus to determine a value for the prioritized HARQ-NACK timing indicator by means of a transmitter-receiver-common rule.

[0283] In some embodiments, to receive the HARQ-NACK feedback report the instructions are executable by the processor to cause the second apparatus to receive UCI using one of: A) a PUCCH configured resource; B) a dynamically scheduled PUSCH transmission resource; and C) a configured PUSCH transmission resource (e.g., a resource of either a semistatic CG Type-1 or a dynamic CG Type-2).

[0284] In some embodiments, the instructions are executable by the processor to cause the second apparatus to transmit a configuration for dynamically enabling or disabling the selection of a slot offset timing delay using the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator). In certain embodiments, the configuration for dynamically enabling or disabling the selection of the slot offset timing delay using the prioritized HARQ-NACK timing indicator includes at least one of: A) a dynamic indication (e.g., a 1 -bit flag) signaled over DCI; B) a semistatic indication (e.g., a 1 -bit flag) signaled using RRC messaging; or C) a combination thereof.

[0285] In some embodiments, the instructions are executable by the processor to cause the second apparatus to determine a value of the prioritized HARQ-NACK timing indicator (i.e., KINACK timing indicator) based on: A) a configuration of PUCCH configured resource sets and resources; B) a configuration of a dynamically scheduled PUSCH transmission; C) a configuration of periodic PUSCH transmissions (e.g., either as semi-static CG Type-1 or as dynamic CG Type- 2); D) a configuration of timing processing a PDSCH given a SCS; E) the default HARQ timing indicator (i.e., KI timing indicator); F) a HARQ timing table mapping configured by higher layer signaling; or G) any combination thereof.

[0286] Disclosed herein is a second method for HARQ-NACK feedback prioritization, in accordance with aspects of the present disclosure. The second method may be performed by a transmitting entity, such as the base station unit 121, the RAN node 210, and/or the NE apparatus 1800, described above. The second method includes determining a prioritized HARQ-NACK timing indicator (i.e., KI -NACK timing indicator) corresponding to a prioritized slot offset timing delay associated with a scheduled TB and configuring a receiving device with the prioritized HARQ-NACK timing indicator and with a default HARQ timing indicator (i.e., KI timing indicator), corresponding to a default slot offset timing delay associated with the scheduled TB.

[0287] The second method includes transmitting the scheduled TB and receiving, based on the prioritized slot offset timing delay or the default slot offset timing delay, a HARQ feedback report associated with the scheduled TB. The second method includes retransmitting, to the receiving device, the scheduled TB based on the HARQ feedback report indicating that the transmission of the scheduled TB was unsuccessful (i.e., was not correctly decoded).

[0288] In some embodiments, the default slot offset timing delay (i.e., corresponding to the KI timing indicator) is less than or equal to the default slot offset timing delay (i.e., corresponding to the KI timing indicator). In some embodiments, at least the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) is greater than or equal to a TB processing delay associated with the scheduled TB.

[0289] In some embodiments, the selected slot offset timing delay corresponds to a timing delay selected from a range between the prioritized slot offset timing delay (i.e., corresponding to the Kl-NACK timing indicator) and the default slot offset timing delay (i.e., corresponding to the KI timing indicator). [0290] In some embodiments, the prioritized HARQ-NACK timing indicator (i.e., KINACK timing indicator) and the default HARQ timing indicator (i.e., KI timing indicator) comprise indexed indications of a semi-static table configured by higher layers, where the semistatic table maps a respective timing indicator to a respective slot offset timing delay.

[0291] In some embodiments, a NACK feedback corresponding to the transmitted TB is multiplexed with additional HARQ feedback for at least one second transmitted TB. In certain embodiments, the multiplexing of the NACK with the additional HARQ feedback for at least one second received TB is performed by a dynamic Type-2 HARQ-ACK codebook. In certain embodiments, each second transmitted TB has a respective second prioritized HARQ-NACK timing indicator, where a second slot offset timing delays associated with the respective second timing indicator is less than or equal to the slot offset timing delay associated with the scheduled TB that was not correctly decoded.

[0292] In some embodiments, the second method includes transmitting an indication that CBG-based retransmission is supported. In such embodiments, the received HARQ feedback report is formed of a CBG-based HARQ-ACK codebook. In such embodiments, the transmitted TB includes a plurality of CBGs and where the HARQ feedback report associated with the scheduled TB reports a NACK for at least one CBG in the received TB.

[0293] In some embodiments, configuring the receiving device with the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator) and with the default HARQ timing indicator (i.e., KI timing indicator) includes transmitting a bit field indication over DCI scheduling of one or more TBs over PDSCH, where the bit field indicates the prioritized HARQ- NACK timing indicator and/or the default HARQ timing indicator. In some embodiments, determining the prioritized HARQ-NACK timing indicator includes determining a value for the prioritized HARQ-NACK timing indicator by means of a transmitter-receiver-common rule.

[0294] In some embodiments, receiving the HARQ-NACK feedback report includes receiving UCI using one of: A) a PUCCH configured resource; B) a dynamically scheduled PUSCH transmission resource; and C) a configured PUSCH transmission resource (e.g., a resource of either a semi-static CG Type-1 or a dynamic CG Type-2).

[0295] In some embodiments, the second method includes transmitting a configuration for dynamically enabling or disabling the selection of a slot offset timing delay using the prioritized HARQ-NACK timing indicator (i.e., Kl-NACK timing indicator). In certain embodiments, the configuration for dynamically enabling or disabling the selection of the slot offset timing delay using the prioritized HARQ-NACK timing indicator includes at least one of: A) a dynamic indication (e.g., a 1-bit flag) signaled over DCI; B) a semi-static indication (e.g., a 1-bit flag) signaled using RRC messaging; or C) a combination thereof.

[0296] In some embodiments, the second method includes determining a value of the KINACK timing indicator based on: A) a configuration of PUCCH configured resource sets and resources; B) a configuration of a dynamically scheduled PUSCH transmission; C) a configuration of periodic PUSCH transmissions (e.g., either as semi-static CG Type-1 or as dynamic CG Type- 2); D) a configuration of timing processing a PDSCH given a SCS; E) the default HARQ timing indicator (i.e., KI timing indicator); F) a HARQ timing table mapping configured by higher layer signaling; or G) any combination thereof.

[0297] Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

[0298] As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects.

[0299] For example, the disclosed embodiments may be implemented as a hardware circuit comprising custom very-large-scale integration (“VLSI”) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. The disclosed embodiments may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, or the like. As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function.

[0300] Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine readable code, computer readable code, and/or program code, referred hereafter as code. The storage devices may be tangible, non- transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.

[0301] Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0302] More specific examples (a non-exhaustive list) of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a RAM, a read-only memory (“ROM”), an erasable programmable read-only memory (“EPROM”), an electronically erasable programmable read-only memory (“EEPROM”), a Flash memory, a portable compact disc read-only memory (“CD-ROM”), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0303] Code for carrying out operations for embodiments may be any number of lines and may be written in any combination of one or more programming languages including an object- oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the “C” programming language, or the like, and/or machine languages such as assembly languages. The code may execute entirely on the user’s computer, partly on the user’s computer, as a stand-alone software package, partly on the user’s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user’s computer through any type of network, including a local area network (“LAN”), WLAN, or a wide area network (“WAN”), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider (“ISP”)).

[0304] Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of an embodiment.

[0305] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.

[0306] As used herein, a list with a conjunction of “and/or” includes any single item in the list or a combination of items in the list. For example, a list of A, B and/or C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C. As used herein, a list using the terminology “one or more of’ includes any single item in the list or a combination of items in the list. For example, one or more of A, B and C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C. As used herein, a list using the terminology “one of’ includes one and only one of any single item in the list. For example, “one of A, B and C” includes only A, only B or only C and excludes combinations of A, B and C. As used herein, “at least one of A, B and C” includes only A, only B, only C, a combination of A and

B, a combination of B and C, a combination of A and C or a combination of A, B and C. As used herein, “a member selected from the group consisting of A, B, and C,” includes one and only one of A, B, or C, and excludes combinations of A, B, and C. As used herein, “a member selected from the group consisting of A, B, and C and combinations thereof’ includes only A, only B, only

C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C.

[0307] Aspects of the embodiments are described above with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by code. This code may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the fimctions/acts specified in the flowchart diagrams and/or block diagrams. [0308] The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function/act specified in the flowchart diagrams and/or block diagrams.

[0309] The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other devices to produce a computer implemented process such that the code which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart diagrams and/or block diagrams.

[0310] The call-flow diagrams, flowchart diagrams and/or block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods, and program products according to various embodiments. In this regard, each block in the flowchart diagrams and/or block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function(s).

[0311] It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, of the illustrated Figures.

[0312] Although various arrow types and line types may be employed in the call-flow, flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and code.

[0313] The description of elements in each figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements.