L2 HARQ feedback for downlink and uplink transmissions

Abstract

Systems and methods related to Layer 2 (L2) Hybrid Automatic Repeat Request (HARQ) feedback for uplink and downlink transmissions are disclosed In one embodiment, a method performed by a User Equipment (UE) comprises receiving a downlink transmission from a network node, the downlink transmission between associated to a certain HARQ process. The method further comprises determining whether the UE is able to successfully decode the downlink transmission. The method further comprises, upon determining that the UE is able to successfully decode the downlink transmission, determining whether to transmit HARQ feedback for the downlink transmission on a physical uplink shared channel based on whether the downlink transmission includes downlink data, first level HARQ feedback, or second level HARQ feedback and operating in accordance with a result of the determining whether to transmit HARQ feedback for the downlink transmission. In this manner, reliable HARQ-FB can be sent without causing ping pong issues.

Description

[0001] L2 HARQ FEEDBACK FOR DOWNLINK AND UPLINK TRANSMISSIONS RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 755,706, filed February 7, 2025, the disclosure of which is hereby incorporated herein by reference in its entirety.

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to a wireless communications system and, more specifically, to Hybrid Automatic Repeat Request (HARQ) feedback for downlink and uplink transmissions.

[0005] BACKGROUND

[0006] The 5thGeneration (5G) user-plane architecture and protocols defined in 3rdGeneration Partnership Project (3GPP) specifications are described with help of Figure 1. The User Equipment (UE) is connected over the air via the Uu protocol with the Radio Access Network (RAN) gNodeB (gNB). The gNB may be separated into a Distributed Unit (DU) and Centralized Unit (CU), connected via Fl interface. The gNB is connected to the Core Network (CN) including the User-Plane Function (UPF). Typically, Internet Protocol (IP) data is transported via UE-gNB-UPF. The RAN protocol stack between UE and gNB includes the Service Data Adaptation Protocol (SDAP) protocol for handling mapping of Quality of Service (QoS) flows as established by the UPF to Data Radio Bearers (DRBs) as established by the gNB. The Protocol Data Convergence Protocol (PDCP) is among others responsible for encryption / integrity protection and handover forwarding and retransmission. For handovers between gNBs, the Xn interface is employed. The Radio Link Control (RLC) is among others responsible for segmentation of higher layer PDCP / IP data to fitting the Transport Blocks (TBs) available for the lower layer over the air transmission. Also, retransmissions are based on Automatic Repeat Request (ARQ) in acknowledged mode of RLC. The Medium Access Control (MAC) protocol supports scheduling of transmissions over the air and entails the Hybrid Automated Repeat Request (HARQ) protocol. The physical layer (PHY) handles e.g. modulation and coding and the actual physical transmission.

[0007] In 3GPP RANs, e.g. 5G New Radio (NR), the HARQ protocol facilitates retransmissions of data in case of transmission errors over the air. A HARQ entity maintains multiple HARQ processes for data transmission.

[0008] In regarding to 5G HARQ, for downlink HARQ, the gNB provides downlink assignments in the Downlink Control Information (DCI), which is carried on the Physical Downlink Control Channel (PDCCH). The DL data is transmitted on the Physical Downlink Shared Channel(PDSCH). The UE responds with HARQ feedback (HARQ-FB), either a positive Acknowledgement (ACK) to confirm successful reception of the data, or if decoding failed, the UE sends a Negative Acknowledgement (NACK) to request a retransmission from the gNB. HARQ-FB is provided as part of the Uplink (UL) Control Information (UCI), which is carried on the Physical Uplink Control Channel (PUCCH) or alternatively mapped to Physical Uplink Shared Channel (PUSCH).

[0009] For uplink HARQ, the gNB can grant UL data transmission on a HARQ process via Dynamic Grants (DGs) contained in the DCI or semi-statically via Configured Grants (CGs) using Radio Resource Control (RRC) messages. Data is transmitted on the PUSCH. Typically, different Modulation and Coding Schemes (MCSs) are applied to PDCCH and PUSCH resulting in different error rates.

[0010] After the initial transmission based on DG or CG, HARQ retransmission(s) of a HARQ process is triggered upon request by gNB based on DCI on PDCCH. The HARQ process may alternatively be overridden by new data, either by dynamic grants with toggled New Data Indicator (NDI), or if a CG resource is used, after expiry of the ConfiguredGrantTimer, which disallows reuse of a HARQ process while running.

[0011] Due to inaccurate MCS selection, the HARQ protocol may result in residual errors. After a certain number of retransmissions, the gNB may decide to give up on / suspend a HARQ process, i.e. it would no longer grant UL retransmissions for that HARQ process, leading to data loss on HARQ. Furthermore, the UE may erroneously detect a false grant on PDCCH, even though the gNB didn’t send it, leading to undiscoverable HARQ process transmission for which data loss occurs as well.

[0012] For NR with access to shared spectrum (NR-U), the UE also starts the so-called CG-RetransmissionTimer for each UL transmission using the CG. The timer is stopped when the UE receives a HARQ-ACK in the Downlink Feedback Indicator (DFI) carried on PDCCH. If the timer expires, the UE uses the next CG opportunity for a HARQ retransmission.

[0013] In regard to a downlink (DL) HARQ candidate proposal for 6G, due to DL / UL scheduling dependencies, PUCCH complexity in general, data loss caused by HARQ NACK-to-ACK errors or inefficiencies caused by ACK-to-NACK errors, it is proposed to move UCI including the HARQ-FB from Layer 1 (LI), i.e. PUCCH or UCI on PUSCH, to Layer 2 (L2), i.e. UCI is conveyed in the PUSCH payload, comprising Cyclic Redundancy Check (CRC) and HARQ retransmissions, making HARQ-FB and thus DL HARQ reliable.

[0014] Furthermore, to counteract against potential DCI misdetection of DL assignments, the network may use a so-called RTX-TimerNW for each HARQ process. The timer is stopped whenHARQ-FB is received from the UE. At expiry, the network assumes NACK and triggers LI retransmission (same MCS and allowing soft combining).

[0015] In regard to RLC in 5G, the RLC protocol, which resides on top of the HARQ protocol, in acknowledged mode (AM), is able to detect and correct HARQ residual errors. Therefore, RLC maintains its own state of which data packets are already successfully received using sequence numbers. This is based on RLC status reporting from the receiver. Counters and timers are employed to poll, trigger and if needed retransmit RLC status reports and retransmit RLC data until reception success is ensured. RLC status reports are considered data in the HARQ protocol, meaning they undergo HARQ retransmissions in case of unsuccessful reception. The drawback of RLC retransmissions is increased latency.

[0016] In regard to HARQ-RLC interaction, after several DL transmission failures of the same HARQ process, the network may suspend the HARQ process and instead perform RLC retransmission, which allows for resegmentation and thus retransmission with a more robust MCS on HARQ, and any soft bits already received by the UE will be discarded for that HARQ process.

[0017] Another trigger for L2 retransmission is the use of a network internal LocalNACK-TimerNW, which gives the HARQ process a certain time window to convey the DL data, so the timer is stopped when a HARQ- ACK is received from the UE for the corresponding HARQ process. At expiry, a local NACK is triggered, implying a retransmission on L2 (RLC retransmission).

[0018] In regard to MAC Control Elements (CEs), in downlink, the MAC CE is used to convey control information which are CRC protected and subject to HARQ retransmissions.

[0019] Examples for such downlink control information is activation / deactivation commands for carrier aggregation.

[0020] Uplink control information comprises e.g. configured grant confirmation, recommended bit rate query, Beam Failure Reports (BFRs), Timing Advance Reports (TARs), Listen-Before-Talk (LBT) failure reports, and Channel State Information (CSI) reports.

[0021] SUMMARY

[0022] Systems and methods related to Layer 2 (L2) Hybrid Automatic Repeat Request (HARQ) feedback for uplink and downlink transmissions are disclosed. In one embodiment, a method performed by a User Equipment (UE) comprises receiving a downlink transmission from a network node, the downlink transmission between associated to a certain HARQ process. The method further comprises determining whether the UE is able to successfully decode the downlink transmission. The method further comprises, upon determining that the UE is able to successfullydecode the downlink transmission, determining whether to transmit HARQ feedback for the downlink transmission on a physical uplink shared channel based on whether the downlink transmission includes downlink data, first level HARQ feedback, or second level HARQ feedback and operating in accordance with a result of the determining whether to transmit HARQ feedback for the downlink transmission. In this manner, reliable HARQ-FB can be sent without causing ping pong issues.

[0023] In one embodiment, the method further comprises, upon determining that the UE is unable to successfully decode the downlink transmission, transmitting a HARQ Negative Acknowledgement (NACK) to the network node.

[0024] In one embodiment, determining whether to transmit HARQ feedback for the downlink transmission comprises determining whether the downlink transmission includes downlink data. In one embodiment, the UE determines to transmit a first level HARQ-ACK upon determining that the downlink transmission includes downlink data and, in response thereto, operating in accordance with a result of the determining whether to transmit HARQ feedback for the downlink transmission comprises transmitting a first level HARQ-ACK to the network node.

[0025] In another embodiment, determining whether to transmit HARQ feedback for the downlink transmission further comprises determining whether reliable transmission is configured for the UE and / or determining whether the data included in the downlink transmission exceeds a certain delay budget. In one embodiment, the UE determines to transmit a first level HARQ-ACK upon determining that the downlink transmission includes downlink data and either or both of: determining that reliable transmission is configured for the UE and / or determining that the data does not exceed the certain delay budget threshold and, in response thereto, operating in accordance with a result of the determining whether to transmit HARQ feedback for the downlink transmission comprises transmitting a first level HARQ-ACK to the network node (e.g., on PUSCH). In another embodiment, the UE determines to not transmit a first level HARQ-ACK upon determining that the downlink transmission includes downlink data and either or both of: determining that reliable transmission is not configured for the UE and / or determining that the data exceeds the certain delay budget threshold.

[0026] In one embodiment, the UE determines to transmit a second level HARQ-ACK upon determining that the downlink transmission does not include downlink data but does include a first level HARQ-ACK in response to a prior uplink data transmission and, in response thereto, operating in accordance with a result of the determining whether to transmit HARQ feedback for the downlink transmission comprises transmitting a second level HARQ-ACK to the network node.In one embodiment, the UE determines to not transmit a second level HARQ-ACK and to clear an associated HARQ process to be used for a new transmission upon determining that the downlink transmission does not include downlink data but does include a second level HARQ-ACK and, in response thereto, operating in accordance with a result of the determining whether to transmit HARQ feedback for the downlink transmission comprises clearing a HARQ process which is associated with the second level HARQ-ACK received from the network on a physical downlink shared channel and contains the associated first level HARQ-FB previously transmitted by the UE on a physical uplink shared channel to be used for a new transmission.

[0027] Corresponding embodiments of a UE are also disclosed. In one embodiment, a UE comprises a communication interface comprising a transmitter and a receiver. The UE further comprises processing circuitry associated with the communication interface. The processing circuitry is configured to cause the UE to receive a downlink transmission from a network node and determine whether the UE is able to successfully decode the downlink transmission. The processing circuitry is further configured to, upon determining that the UE is able to successfully decode the downlink transmission, determine whether to transmit HARQ feedback for the downlink transmission on a physical uplink shared channel, based on whether the downlink transmission includes downlink data, first level HARQ feedback, or second level HARQ feedback, and operate in accordance with a result of the determining whether to transmit HARQ feedback for the downlink transmission.

[0028] In another embodiment, a method performed by a UE comprises transmitting an uplink transmission to a network node, performing a first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK, and otherwise performing a second set of actions.

[0029] In one embodiment, performing the first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK comprises starting or restarting a first timer for triggering a Layer 2 (L2) retransmission upon expiry of the first timer and, upon expiry of the first timer without first receiving an acknowledgement (ACK) from the network node, performing a local negative acknowledgement (NACK) to thereby trigger a L2 retransmission. In one embodiment, performing the first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK further comprises, upon expiry of the first timer without first receiving an ACK from the network node, performing any one or more of the following, updating associated control information, discarding outdated control information, and discarding uplink data having an age that exceeds a certain age threshold.In one embodiment, performing the first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK further comprises stopping the first timer upon receiving an ACK from the network node before expiry of the first timer.

[0030] In one embodiment, performing the second set of actions comprises starting or restarting a second timer and, upon expiry of the second timer, discarding a HARQ-NACK or second level HARQ-ACK if included in the uplink transmission.

[0031] Corresponding embodiments of a UE are also disclosed. In one embodiment, a UE comprises a communication interface comprising a transmitter and a receiver. The UE further comprises processing circuitry associated with the communication interface. The processing circuitry is configured to cause the UE to transmit an uplink transmission to a network node, perform a first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK, and otherwise perform a second set of actions.

[0032] Embodiments of a method performed by a network node are also disclosed. In one embodiment, a method performed by a network node comprises receiving an uplink transmission from a UE and determining whether the network node is able to successfully decode the uplink transmission. The method further comprises, upon determining that the network node is able to successfully decode the uplink transmission, determining whether to transmit HARQ feedback for the uplink transmission on a physical downlink shared channel based on whether the uplink transmission includes uplink data, first level HARQ feedback, or second level HARQ feedback and operating in accordance with a result of the determining whether to transmit HARQ feedback for the uplink transmission.

[0033] In one embodiment, the method further comprises, upon determining that the network node is unable to successfully decode the uplink transmission, transmitting, to the UE, a grant for a retransmission and performing reception of the retransmission.

[0034] In one embodiment, determining whether to transmit HARQ feedback for the uplink transmission comprises determining whether the uplink transmission includes uplink data. In one embodiment, the network node determines to transmit a first level HARQ-ACK upon determining that the uplink transmission includes uplink data and, in response thereto, operating in accordance with a result of the determining whether to transmit HARQ feedback for the uplink transmission comprises transmitting a first level HARQ-ACK to the UE.

[0035] In one embodiment, determining whether to transmit HARQ feedback for the uplink transmission further comprises determining whether reliable transmission is configured for the UE and / or determining whether the data included in the uplink transmission exceeds a certain delay budget. In one embodiment, the network node determines to transmit a first level HARQ-ACKupon determining that the uplink transmission includes uplink data and either or both of: determining that reliable transmission is configured for the UE and / or determining that the data does not exceed the certain delay budget threshold. In response thereto, operating in accordance with a result of the determining whether to transmit HARQ feedback for the uplink transmission comprises transmitting a first level HARQ-ACK to the UE. In one embodiment, the network determines to not transmit a first level HARQ-ACK upon determining that the uplink transmission includes uplink data and either or both of: determining that reliable transmission is not configured for the UE and / or determining that the data exceeds the certain delay budget threshold.

[0036] In one embodiment, the network determines to transmit a second level HARQ-ACK upon determining that the downlink transmission does not include downlink data but does include a first level HARQ-ACK in response to a prior uplink data transmission. In response thereto, operating in accordance with a result of the determining whether to transmit HARQ feedback for the uplink transmission comprises transmitting a second level HARQ-ACK to the UE.

[0037] In one embodiment, the uplink transmission includes a second level HARQ feedback, and the method further comprises clearing an associated HARQ process such that it can be used for a new transmission if the second level HARQ feedback is a HARQ-ACK and retransmitting (434) a first level HARQ-ACK if the second level HARQ feedback is a HARQ-NACK.

[0038] Corresponding embodiments of a network node are also disclosed. In one embodiment, a network node comprises processing circuitry configured to cause the network node to receive an uplink transmission from a UE and determine whether the network node is able to successfully decode the uplink transmission. The processing circuitry is further configured to cause the network node to, upon determining that the network node is able to successfully decode the uplink transmission, determine whether to transmit HAR feedback for the uplink transmission on a physical downlink shared channel based on whether the uplink transmission includes uplink data, first level HARQ feedback, or second level HARQ feedback and operate in accordance with a result of the determining whether to transmit HARQ feedback for the uplink transmission.

[0039] In another embodiment, a method performed by a network node comprises transmitting a downlink transmission to a UE, performing a first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK, and otherwise performing a second set of actions.

[0040] Corresponding embodiments of a network node are also disclosed. In one embodiment, a network node comprises processing circuitry configured to cause the network node to transmit a downlink transmission to a UE, perform a first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK, and otherwise performing a second set of actions.BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0042] Figure 1 is an illustration of the 5thGeneration (5G) user-plane architecture and protocols defined in 3rdGeneration Partnership Project (3GPP) specifications.

[0043] Figure 2 illustrates a problem that exists with ping ponging Hybrid Automatic Repeat Request (HARQ) feedback.

[0044] Figure 3 is a flow chart that illustrates the operation of a User Equipment (UE), per HARQ Process (HP), when receiving a Physical Downlink Shared Channel (PDSCH), in accordance with an embodiment of the present disclosure.

[0045] Figure 4 is a flow chart that illustrates the operation of a network node for receiving a Physical Uplink Shared Channel (PUSCH), in accordance with an embodiment of the present disclosure.

[0046] Figure 5 is a flow chart that illustrates network node behavior for sending downlink data, in accordance with an embodiment of the present disclosure.

[0047] Figure 6 is a flow chart that illustrates the operation of the UE for transmitting UL data in accordance with an embodiment of the present disclosure.

[0048] Figures 7, 8, and 9 illustrate examples in accordance with embodiments of the present disclosure.

[0049] Figure 10 shows an example of a communication system in accordance with some embodiments.

[0050] Figure 11 is another example of a communication system according to some embodiments. Figure 12 shows a wireless device, which may be configured to operate in communication system of Figure 10 or in communication system of Figure 11.

[0051] Figure 13 shows a network node in accordance with some embodiments.

[0052] Figure 14 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized.

[0053] DETAILED DESCRIPTION

[0054] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled inthe art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0055] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art. Additional information may also be found in the document(s) provided in the Appendix.

[0056] There currently exist certain challenge(s). In current 3rdGeneration Partnership Project (3GG) 5thGeneration (5G) systems, there is no explicit Hybrid Automatic Repeat Request (HARQ)-Feedback (FB) for uplink (UL) transmissions. False grants may thus lead to unwanted data loss in the HARQ layer.

[0057] If HARQ-Acknowledgement (ACK) is transmitted on Physical Downlink Control Channel (PDCCH) for HARQ-FB transmitted on Physical Uplink Shared Channel (PUSCH), false detection, i.e. false ACKs, may occur, e.g. implicit by toggled New Data Indicator (NDI) bit.

[0058] For downlink (DL) data transmissions, the embodiments assume that a User Equipment (UE) transmits HARQ-FB on L2, i.e. on PUSCH as PUSCH payload (as discussed in the Background section regarding the downlink (DL) HARQ candidate proposal for 6G). If the network (NW) cannot decode the HARQ-FB on PUSCH, it would typically send a retransmission grant to the UE, and the UE performs an UL retransmission as in legacy. If the NW successfully decodes the PUSCH carrying the UE’s HARQ-FB and to avoid that the UE triggers local Negative Acknowledgement (NACK) for that PUSCH (if UE utilizes such mechanism), the NW would need to send a HARQ-ACK, and if reliable UL transmission is used or configured, the HARQ-ACK is sent on L2, i.e., in the Physical Downlink Shared Channel (PDSCH) payload, as a response to the UE’s HARQ-FB. However, the PDSCH payload would unnecessarily trigger another HARQ-FB transmission i.e. for the DL from the UE, leading to ping pong. The same applies to UL data transmissions.

[0059] Herein, i.e. to describe the abovementioned problem, a HARQ-FB in response to a data transmission (optionally multiplexed with HARQ-FB) is defined as a 1stlevel HARQ-FB, and HARQ-FB in response to a 1stlevel HARQ-FB is referred to as 2ndlevel HARQ-FB, and so on, as illustrated in Figure 2. The 2ndlevel HARQ-ACK is needed to prevent that the data receiver performs local NACK of the HARQ process containing the 1stlevel HARQ-FB. If all packets are successfully received, a HARQ-ACK on PDSCH would trigger a HARQ-ACK on PUSCH and vice versa. However, only the 1stlevel HARQ-FB needs to be acknowledged. Also note that, aswill be understood by one or ordinary skill in the art, when the description herein refers to HARQ-ACK or HARQ-NACK, the description typically refers to HARQ-FB for a given HARQ process.

[0060] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Embodiments of systems and methods are disclosed herein that solve the abovementioned issue of ping-pong HARQ FB transmission when HARQ FB on layer 2 (L2) is employed. By referring to reliable transmission in this context, we refer to reliable HARQ-FB transmission in UL and DL. Reliable UL transmission may additionally imply the use of the LocalNACK-TimerUE to ensure that the network node receives UL data and the 1stlevel HARQ-FB (to avoid loss due to falsely detecting an UL grant that was not provided by the network node).

[0061] At a NW receiver (i.e., a network node that receives an UL transmission (e.g., PUSCH) that includes UL data and / or HARQ-FB), if the NW receiver determines after successful PUSCH decoding that there is no UL data, the procedure ends here (no transmission (TX) of HARQ-ACK on PDSCH). If the NW receiver determines after successful PUSCH decoding that there is UL data multiplexed with the HARQ-ACK, it triggers TX of HARQ-ACK. If the PUSCH decoding fails, the NW decides whether to send a UL grant for Layer 1 (LI) HARQ Retransmission (RTX) (e.g., as in legacy) or local NACK request for legacy / enhanced L2 RTX.

[0062] At a UE transmitter (i.e., at a UE that transmits an UL transmission (e.g., PUSCH) that includes UL data and / or HARQ-FB):

[0063] • New LocalNACK-TimerUE, i.e. to trigger a L2 retransmission (RTX) upon expiry, is only started for HARQ processes carrying UL data and / or 1stlevel HARQ-FB (HARQ-FB in response to data).

[0064] • New FB-DiscardTimerUE is started for HARQ processes carrying HARQ-NACK or 2ndlevel HARQ-ACK on PUSCH. Upon timer expiry, the UE discards 2ndlevel HARQ-ACK. This timer gives time for the NW to provide UL (RTX) grants to be able to successfully receive the 2ndlevel HARQ-ACK.

[0065] In one embodiment, the NW receiver’ s behavior is dependent on the content of the received packets. The NW receiver will send HARQ-FB only if the UL packet contains data. Otherwise, if the UL packet contains HARQ-FB, the NW receiver acts upon HARQ ACK / NACK reception as in legacy.

[0066] In one embodiment, the UE transmitter’s behavior also depends on the content of the transmitted UL packet. If reliable reception of data and / or 1stlevel HARQ-FB is wanted, the UE uses the LocalNACK-TimerUE. Otherwise, if the UE is configured with reliable transmissions and the UL packet contains HARQ-NACK or 2ndlevel HARQ-ACK, the UE starts the FB-Discard-TimerUE. The NW chooses the duration of the FB-Discard-TimerUE to allow HARQretransmissions before it suspends the HARQ process, i.e., times out that UL transmission using e.g. the LocalNACK-TimerNW.

[0067] The transmitters / receivers distinguish between genuine data and 1stand 2ndlevel HARQ-FB. Before performing local NACK, the transmitter evaluates whether the payload contains outdated packets and, if so, it would discard those packets. Medium Access Control (MAC) Control Elements (CEs) carrying e.g. a Buffer Status Report (BSR) may instead be updated, i.e. the BSR is retransmitted, but with new / updated values.

[0068] Certain embodiments may provide one or more of the following technical advantage(s). By defining stop conditions, this solution allows sending reliable HARQ-FB in the DL packet (in PDSCH payload) and in the UL packet (PUSCH payload) without causing ping pong issues. By inspecting the payload before any retransmission, the transmitter may decide to discard packets to avoid unnecessary transmissions which would lower the spectral efficiency.

[0069] The teachings of certain embodiments may improve, e.g., the data rate, latency, and / or power consumption.

[0070] Now, a more detailed description of some exemplary embodiments of the present disclosure will be provided.

[0071] For any DL / UL transmission, the transmitter always knows whether a transmitted packet contains data or not. Any HARQ-FB received for packets containing data is referred to as 1stlevel HARQ-FB. A receiver, on the other hand, cannot detect control information carried in-band with the payload, and can only classify the content after successful decoding.

[0072] Figure 3 is a flow chart that illustrates the operation of a UE, per HARQ Process (HP), when receiving PDSCH in accordance with an embodiment of the present disclosure. Optional steps or actions are represented by dashed lines / boxes / diamonds. As illustrated, the UE receives a PDSCH (block 300). Decoding of the received PDSCH at the UE may fail or succeed. If PDSCH decoding at the UE fails (block 302, no), the UE transmits a HARQ-NACK (since the DL packet remains unknown, the UE does not know whether this is a 1stor 2ndlevel HARQ-NACK) (block 304). Conversely, if PDSCH decoding at the UE is successful (block 302, yes), the UE inspects the PDSCH payload (block 306) and, in this manner, the UE knows whether the PDSCH contains DL data or not. If the PDSCH contains data (block 308, yes), optionally reliable transmission is configured (block 310, yes), and optionally the data has not exceeded a delay budget if configured (block 312, no), the UE transmits a HARQ-ACK where this HARQ-ACK is a 1stlevel HARQ-ACK (block 314). Optionally, if the PDSCH contains data but either reliable TX is not configured (block 310, no) or the delay budget has been exceeded (block 312, yes), the UE stops the procedure (block 316).If the PDSCH does not contain DL data (block 308, no), the UE determines whether the PDSCH contains a 1stlevel HARQ-ACK (i.e., a HARQ-ACK in response to prior UL data transmission) (block 318). If so (block 318, yes), the UE transmits 2ndlevel HARQ-ACK on PUSCH (block 320). If not (block 318, no), the UE determines whether the PDSCH contains a 2ndlevel HARQ-ACK (HARQ-ACK but no prior UL data TX) (block 322). If so, the UE clears the HARQ process containing the associated 1stlevel HARQ-FB (block 324). In other words, the cleared HARQ process is the HARQ process which is associated with the second level HARQ-ACK received from the network on a PDSCH and contains the associated first level HARQ-FB previously transmitted by the UE on PDSCH.

[0073] This HARQ process can then be used by the UE for new data transmissions.

[0074] Figure 4 is a flow chart that illustrates the operation of a network (NW) node (e.g., a radio network node such as, e.g., a Radio Access Network (RAN) node, a base station, gNodeB (gNB), Distributed Unit (DU) of a RAN node (e.g., gNB-DU), a Central Unit (CU) of a RAN node (e.g., a gNB-CU), or the like) for receiving PUSCH, in accordance with an embodiment of the present disclosure. Optional actions or steps are represented by dashed lines / boxes / diamonds. For UL transmissions, a NW provides retransmission grants via PDCCH if the PUSCH cannot be decoded, and otherwise, the feedback is an explicit HARQ-ACK transmitted on PDSCH.

[0075] As illustrated in Figure 4, an HARQ Transmission Counter (HTC) is initialized (e.g., to 0 in this example) (block 400), and the NW node receives a PUSCH (block 402). There are two cases that define the NW behavior. Decoding of the PUSCH may be successful or fail. If the PUSCH decoding fails (block 404, no), the NW node increments the HTC (block 406), determines whether HTC is greater than a (e.g., defined or configured) threshold maxAttempts (block 408) and, if not, transmits an RTX grant to the UE (block 410) and performs PUSCH reception for the granted RTX (block 412).

[0076] Returning to block 404, if PUSCH decoding is successful (block 404, yes), the NW node inspects the PUSCH payload (block 414) and, in this manner, determines whether the PUSCH payload carries UL data or only HARQ-FB in response to a DL data transmission if any. If the PUSCH payload carries only UL data (block 416, yes), reliable TX is configured (block 418, yes), and the data has not exceeded the delay budget (if configured) (block 420, no), the NW node transmits a 1stlevel HARQ-ACK to the UE on PDSCH (block 422). If the PUSCH contains UL data but either reliable TX is not configured (block 418, no) or the delay budget has been exceeded (block 420, yes), the NW node stops the procedure (block 424).

[0077] Returning to step 416, if the PUSCH payload does not contain UL data (block 416, no) but does include a 1stlevel HARQ-FB (HARQ-FB in response to prior DL data TX (block 426, yes),the NW node determines whether the 1stlevel HARQ-FB is a 1stlevel HARQ-ACK (block 427). If so (block 427, yes), the NW node transmits 2ndlevel HARQ-ACK to the UE on PDSCH (block 428). Conversely, if the 1stlevel HARQ-FB is a 1stlevel HARQ-NACK (block 427, no), optionally, the NW node triggers a L2 TRX or L-NACK (L2 RTX) of the associated NACKed data on PUSCH (block 429).

[0078] If the PUSCH payload does not contain UL data (block 416, no) and does not contain 1stlevel HARQ-FB (block 426, no), but does include a 2ndlevel HARQ-FB (HARQ-FB with no prior DL data TX), if the 2ndlevel HARQ-FB is a 2ndlevel HARQ-ACK (block 430, ACK), the NW node clears the HARQ process such that the HARQ process can be used by a new transmission (block 432). Alternatively, if the 2ndlevel HARQ-FB is a 2ndlevel HARQ-NACK, the NW node retransmits the associated (1stlevel) HARQ-FB on PDSCH (block 434).

[0079] Note that (e.g., in accordance with the procedure of Figure 4), if the NW node receives PUSCH payload (CB or dynamically granted) without having performed any prior DL transmission, it knows that the PUSCH payload will not contain any HARQ-FB.

[0080] - PUSCH decoding failure: The NW can schedule UL retransmissions or decide to suspend the HARQ process.

[0081] - PUSCH decoding success: The NW sends a 1stlevel HARQ-ACK and expects 2ndlevel HARQ-FB from the UE.

[0082] Figure 5 is a flow chart that illustrates NW node behavior for sending downlink data, in accordance with an embodiment of the present disclosure. As illustrated, the NW node behavior for PDSCH transmission depends on the content of the payload. If the payload of the PDSCH contains DL data and / or a 1stlevel HARQ-ACK, the NW node will ensure that L1 / L2 retransmissions are triggered when no HARQ-ACK is received from the UE. This can be realized based on NW internal timers, such as a retransmission timer (R X-TimerNW), which triggers (LI) HARQ retransmissions upon expiry, and a local NACK timer (LocalNACK-TimerNW), which triggers L2 retransmissions upon expiry, allowing one or more DL HARQ transmission attempts. Here, a HARQ transmission counter (HTC) could for example be used, and if HTC is larger than a certain threshold, the NW suspends the HARQ process and optionally it could trigger a local NACK (and subsequent L2 retransmission). This is up to NW implementation. Alternatively, other decision criteria may be applied.

[0083] Also, instead of using a local NACK timer, the NW could solely use the HARQ transmission counter (HTC) to trigger local NACK, or alternatively, only the local NACK timer is used without using the HTC (the HTC could be implicitly considered where the timer wouldtake into account HARQ RTTs). In this example, though, both options are used complementary, e.g. whichever condition is fulfilled (or rather expires) first.

[0084] As an optimization, outdated control information could be discarded or updated, respectively, and higher layers, e.g. RLC, could decide to drop packets with exceeded age (longer than the delay budget).

[0085] A 2ndlevel HARQ-ACK is treated differently to avoid triggering unnecessary L1 / L2 retransmissions as the UE mechanism will ensure that 1stlevel HARQ-ACKs are reliably received by the NW, e.g. by performing local NACK to trigger L2 retransmissions. For 2ndlevel HARQ-ACK, LI retransmissions can be supported, but after expiry of the so-called ACK-DiscardTimerNW, the NW simply discards the HARQ-ACK, and the HARQ process can be used for new data transmissions.

[0086] Upon reception of HARQ-NACK from the UE, stopping the RTX-TimerNW and triggering a LI retransmission (which would then restart the RTX-TimerNW) could alternatively be referred to as triggering early expiry of the RTX-TimerNW, or in short, expiring the RTX-TimerNW. Similarly, stopping the LocalNACK-TimerNW and simultaneously triggering local NACK could be referred to as triggering early expiry of the LocalNACK-TimerNW.

[0087] More specifically, as illustrated in Figure 5, the NW node transmits PDSCH to a UE (block 500). If the payload of the PDSCH contains DL data and / or a 1stlevel HARQ-ACK (block 502, yes), the NW node starts or restarts a first timer referred to herein by the exemplary name LocalNACK-TimerNW (block 504), resets HTC to zero if NDI is toggled (block 505), and starts or restarts a second timer referred to herein by the exemplary nam RTX-TimerNW (block 506). Upon expiry of the LocalNACK-TimerNW timer without receiving an ACK on PUSCH (block 508), the NW node updates control information if applicable, discards outdated control information (CI), discards DL data with an age that exceeds a certain (e.g., defined or configured) age threshold, and stops the RTX-TimerNW (block 510) and performs local NACK (e.g., for more robust RTX) (block 512). Upon expiry of the RTX-TimerNW timer without receiving an ACK on PUSCH (block 514), the NW node determines whether to suspend the HARQ process (HP) (i.e., determines whether HTC is greater than a certain maximum threshold) (block 516). If not (block 516, no), the NW node performs an LI RTX (block 518), increments the HTC (block 520), and restarts the RTX-TimerNW (block 506). Conversely, if the NW determines in block 516 to suspend the HARQ process, the NW node determines whether to perform a Local NACK (L-NACK) (block 522) and, if so, proceeds to step 510.

[0088] Conversely, after transmitting the PDSCH, upon receiving an ACK on PUSCH before expiry of the LocalNACK-TimerNW timer or expiry of the RTX-TimerNW (block 524), the NWnode stops the LocalNACK-TimerNW timer and stops the RTX-TimerNW timer. After transmitting the PDSCH, if the NW node instead receives a NACK on PUSCH before expiry of the LocalNACK-TimerNW timer or expiry of the RTX-TimerNW (block 526), the NW node determines whether to perform a LI retransmission of the NACKed data (block 528). If not (block 528, no), the NW node determines whether to perform a L-NACK (block 522) and, if so, proceeds to step 510 for a L-NACK. If the NW node decides to perform a LI retransmission in block 528, the NW node triggers a LI retransmission.

[0089] Returning to step 502, if the PDSCH transmission instead includes a 2ndlevel HARQ-ACK (block 530, yes), the NW node starts a third timer referred to herein by the exemplary name ACK-DiscardTimerNW (block 532) and optionally performs one or more transmissions while the ACK-DiscardTimerNW timer is running (block 534). Upon expiry of the ACK-DiscardTimerNW timer (block 536), the NW node discards the 2ndlevel HARQ-ACK (block 538). If there is a failure, the UE performs local NACK for 1stlevel HARQ-FB. Thus, there is a relation between the LocalNACK-TimerUE and the ACK-DiscardTimerNW, and the network node chooses adequate configuration of the timer values when applicable.

[0090] Figure 6 is a flow chart that illustrates the operation of the UE for transmitting UL data in accordance with an embodiment of the present disclosure. For PUSCH transmission, if the PUSCH payload contains UL data and / or 1stlevel HARQ-ACK, the UE uses the local NACK timer, LocalNACK-TimerUE. Upon expiry, control information to be retransmitted on the PUSCH can be updated or discarded. Also, UL data with exceeded age can be discarded to avoid unnecessary L2 retransmission of data. While the timer is running, the NW can provide UL grants for HARQ retransmissions.

[0091] If the PUSCH payload contains HARQ-NACK or 2ndlevel HARQ-ACK, the UE will instead use the FB-DiscardTimerUE. This avoids unnecessary retransmissions and clearance of a HARQ process. If the UE’s 2ndlevel HARQ-ACK is not received in a given time window, the NW would perform local NACK, using e.g. the LocalNACK-TimerNW, for the 1stlevel HARQ-ACK of UL data and perform retransmission of the 1stlevel HARQ-ACK on different and / or more robust radio resources, which would trigger regeneration of the 2ndlevel HARQ-ACK. . Thus, there is a relation between the LocalNACK-TimerNW and the FB-DiscardTimerUE, and the network node chooses adequate configuration of the timer values when applicable.

[0092] If the PUSCH payload contains only HARQ-NACK, this means that the UE was not able to decode the DL transmission, which could contain DL data, 1stor 2ndlevel HARQ-ACK. HARQ-NACK for 2ndlevel HARQ-ACK is redundant as this means that the UE had already successfully received the DL data. For DL data or 1stlevel HARQ-ACK, the NW would at some point of timetrigger local NACK, so reliable transmission for those is ensured (by triggering L2 retransmission) and DL HARQ retransmissions are not essential to avoid any data / lstlevel HARQ-ACK loss.

[0093] More specifically, in the example of Figure 6, the UE transmits PUSCH (block 600). If the PUSCH transmission includes UL data and / or a 1stlevel HARQ-ACK (block 602, yes), the UE starts or restarts a first timer, LocalNACK-TimerUE (block 604). Upon expiry of the LocalNACK-TimerUE timer without receiving an ACK on PDSCH (block 606), the UE may update control information (e.g., HARQ-FB, BSR, etc.) if applicable, discard outdated control information, and discard UL data that has exceeded a certain (e.g., defined or configured) age threshold (block 608) and performs local NACK (for more robust RTX) (block 610). Conversely, if the UE receives an ACK on PDSCH before expiry of the LocalNACK-TimerUE timer (block 612), the UE stops the LocalNACK-TimerUE timer. If the UE receives a retransmission grant while the LocalNACK-TimerUE is running, the UE performs a LI retransmission on PUSCH.

[0094] If instead the PUSCH transmission includes a 2ndlevel HARQ-ACK or a HARQ-NACK (block 602, no), the UE starts a second timer, FB-DiscardTimerUE (block 614). Upon expiry of the FB-DiscardTimerUE timer (block 616), the UE discards the 2ndlevel HARQ-ACK (if applicable) (block 618). The NW node will perform L-NACK for the 1stlevel HARQ-ACK.

[0095] Local NACK enhancements related to Control information (e.g., in 5G carried in MAC CE): Instead of triggering L2 retransmission of the complete PDSCH / PUSCH payload, the local NACK procedure can be enhanced by updating or discarding outdated data and / or control information. Here, we list which control information could be simply retransmitted as in legacy, or alternatively updated or discarded, respectively.

[0096] - Retransmit same content: Activation / Deactivation, Indication, Confirmation; examples:

[0097] Configured Grant Confirmation, Recommended bit rate query

[0098] - Retransmit with updated values; examples: Beam Failure Report (BFR), Timing Advance Report (TAR), Listen-Before-Talk (LBT) failure, Channel State Information (CSI) Report - HARQ-FB for DL data: may or may not be retransmitted depending on radio bearer.

[0099] In the following, some examples are provided illustrating how the HARQ-FB mechanism works following the procedures described above, e.g. in case of a decoding failure of the data transmission or of the HARQ-FB.

[0100] Figure 7 illustrates an example for DL data TX and decoding failure of UE’s 1stlevel HARQ-ACK. In the example in Figure 7, the NW uses DL HP3 for data transmission and starts the RTX-TimerNW for DL HP3. Expecting HARQ-FB from the UE, the NW may provide an UL grant to the UE, e.g. for HP0. The UL grant and the PDSCH on DL HP3 are correctly decoded by the UE, and as a result, the UE responds with a 1stlevel HARQ-ACK, ACK3 (the numbercorresponds to the ACKed DL HP ID, i.e. DL HP3), transmitted as PUSCH payload using UL HPO and starts the localNACK-TimerUE for UL HPO. The reception of ACK3 on UL HPO fails, and thus, the NW sends a retransmission grant, RTX 0, to grant an UL retransmission for UL HPO. After receiving the UL RTX grant for UL HPO, the UE triggers retransmission of ACK3, which is then correctly decoded by the NW. The NW determines that the PUSCH payload in UL HPO contains an ACK for the DL data TX on DL HP3 and accordingly, stops the RTX-TimerNW for DL HP3. As ACK3 is not multiplexed with UL data, the NW classifies it as 1stlevel HARQ-ACK, triggers a 2ndlevel HARQ-ACK transmission on DL HP4 for UL HPO, ACKO, and starts the ACK-DiscardTimerNW for DL HP4. While the timer is running, the NW could receive HARQ-NACK from the UE and perform retransmissions. When the ACK-DiscardTimerNW expires, the NW clears DL HP4, i.e. discards ACKO. In the example, ACKO is successfully received by the UE, acknowledging the UE’s 1stlevel HARQ-ACK carried on UL HPO, and as a result, the UE stops the local NACK timer for UL HPO. Since there is no further data transmission, the procedure ends here.

[0101] A similar example is illustrated in Figure 8, i.e. the NW transmits downlink data on DL HP3 as in the previous example, but in this example, the UE fails to decode the DL transmission and thus responds with a HARQ-NACK for DL HP3, NACK3. Since it transmits HARQ-NACK on UL HPO, the UE starts the FB-DiscardTimerUE, which would upon expiry trigger the UE to clear UL HPO and discard NACK3. The NW correctly decodes UL HPO carrying NACK3 and determines that NACK3 is a 1stlevel HARQ-FB to data3, and sends a corresponding HARQ-ACK, ACKO, using another DL HP, HP4, as DL HP3 still contains non-acknowl edged data. After determining that UL HPO contains HARQ-NACK for DL HP3, the NW performs a retransmission of DL HP3, restarts the RTX-TimerNW for DL HP3, and also provides an UL grant so that the UE can send the corresponding HARQ-FB for DL HP3. The NW could in principle reuse DL HPO and toggle the NDI, or a cleaner variant would be to use a new HARQ process, e.g. UL HP1. The UE correctly receives the DL data in DL HP3, and as the HP contains DL data, the UE includes the 1stlevel HARQ-ACK in its PUSCH transmission using UL HP1 and starts the LocalNACK-TimerUE for UL HP1. The NW correctly receives the PUSCH transmission on UL HP1, and upon determining that this is a 1stlevel HARQ-ACK, the NW responds with a 2ndlevel HARQ-ACK using DL HP4, and starts a corresponding ACK-DiscardTimerNW. Upon timer expiry, the NW clears DL HP4, i.e. discards the 2ndlevel HARQ-ACK. Meanwhile, the UE correctly receives the HARQ-ACK for its 1stlevel HARQ-ACK, and it can thus clear the UL HP1 carrying the 1stlevel HARQ-ACK.Figure 9 shows an example where the UE also has UL data to transmit indicated by e.g. a scheduling request (SR) or buffer status report (BSR) that could have been transmitted on contention-based resource (no further details illustrated in this example). In other words, Figure 9 illustrates an example with DL data TX and 1stlevel HARQ-ACK multiplexed with UL data.

[0102] When the NW performs its DL transmission, in this example on DL HP3, the NW starts its timers for retransmission and local NACK, and simultaneously, it provides the UE with an UL grant that is sufficiently large such that the UE can multiplex its (1stlevel) HARQ-FB with its UL data into the granted PUSCH transmission. The UE successfully decodes the PDSCH on DL HP3 and responds with a 1stlevel HARQ-ACK, multiplexed with UL data, and for the data, it starts the local NACK timer.

[0103] The NW decodes the PUSCH on UL HP 0, and since it contains UL data, the NW sends a 1stlevel HARQ-ACK (rather than a 2ndlevel HARQ-ACK) on DL HP4 and starts the corresponding timers for DL HP4. The NW expects 2ndlevel HARQ-FB from the UE and would typically schedule UL resources, e.g. for UL HP1, for the UE. Furthermore, since the PUSCH received by the NW also contains a HARQ-ACK for DL HP3, the corresponding timers will be stopped.

[0104] When the UE successfully receives the 1stlevel HARQ-ACK for UL HPO contained in DL HP4, it stops the corresponding local NACK timer. Furthermore, it generates a 2ndlevel HARQ-ACK for DL HP4 to be carried by UL HP1 and starts the FB-DiscardTimerUE, and upon expiry, the UE would clear UL HP1, i.e. discard the HARQ-ACK for DL HP4 (ACK4).

[0105] Upon successful decoding of the PUSCH on UL HP1, the NW determines that it contained a HARQ-ACK for its 1stlevel HARQ-ACK on DL HP4, and as a result, it clears HP4 and stops the corresponding timers.

[0106] Figure 10 shows an example of a communication system 1000 in accordance with some embodiments.

[0107] In the example, the communication system 1000 includes a telecommunications network 1002 that includes an access network 1004, such as a radio access network (RAN), and a core network 1006, which includes one or more core network nodes 1008. The access network 1004 includes one or more access network nodes or base stations of various types, access network nodes 1010A and 1010B are depicted (which may be collectively referred to as network nodes 1010), or any other similar 3rdGeneration Partnership Project (3GPP) access nodes or non-3GPP access points (APs). Some embodiments of the access network 1004 may include more than one access network technology. The network nodes 1010 of access network 1004 facilitate direct or indirect connection of wireless devices, also referred to as user equipments (UEs), such as by connectingUEs 1012A, 1012B, 1012C, and 1012D (one or more of which may be generally referred to as UEs 1012) to the core network 1006 over one or more wireless connections.

[0108] Moreover, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunications network 1002 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a network node in the telecommunications network 1002 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other network nodes to implement one or more functionalities of any network node in the telecommunications network 1002, including one or more access network nodes 1010 and / or core network nodes 1008.

[0109] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). An ORAN network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN network node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies.

[0110] The network nodes 1010 facilitate direct or indirect connection of one or more UEs 1012 to the core network 1006 over one or more wireless connections. Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 1000 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired orwireless connections. The communication system 1000 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0111] The UEs 1012 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 1010 and other communication devices. Similarly, the network nodes 1008, 1010 are arranged, capable, configured, and / or operable to communicate directly or indirectly (e.g., via other devices of telecommunications network 1002) with the UEs 1012 and / or with other network nodes or equipment in the telecommunications network 1002 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunications network 1002. More specifically, UEs 1012 may send messages, data, and / or other signals to network nodes 1008, 1010 or other elements of the telecommunications network 1002 by transmitting such signals to the relevant device directly without the signals passing through any intervening devices or by transmitting such signals to the relevant device indirectly through an intervening device (or multiple intervening devices) that then transmit the signal to the relevant device. Similarly, network nodes 1008, 1010 may send messages, data, and other signals to UEs 10122, other network nodes 1008, 1010, and other devices in telecommunications network 1002 directly or indirectly. As one specific example, a core network node 108 may transmit a particular message to a UE 1012 by transmitting the message to an access network node 1010 that will then transmit the message to the intended UE 1012. Similarly, a core network node 108 may receive a particular message from a UE 1012 by receiving the message from an access network node 1010 that itself received the message from the UE 1012.

[0112] In the depicted example, the core network 1006 connects elements of the access network 1004 (e.g., one or more of the network nodes 1010) to one or more host computing systems, such as host 1016. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 1006 includes one or more core network nodes (e.g., core network node 1008) of various types, one or more of which may be generally referred to as network nodes 1008. Network nodes 1008 are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, access network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 1008. Example core network nodes provide functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function(SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0113] The host 1016 may be under the ownership or control of a service provider other than an operator or provider of the access network 1004 and / or the telecommunications network 1002. The host 1016 may be operated by the service provider or on behalf of the service provider. The host 1016 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0114] As a whole, the communication system 1000 of Figure 10 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 1000 may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (Wi-Fi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (Wi-Max), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, Li-Fi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox. Moreover, the communication system 1000 may be configured to support multiple different standards, protocols, or other rule sets, with individual components supporting all of the relevant rule sets or with different components or sub-systems within the communication system 1000 supporting different standards, protocols, or rule sets.

[0115] As one example, in certain embodiments, access network 1004 may contain some access network nodes 1010 that support 3 GPP radio access technologies (RAT), such as LTE or NR, while other access network nodes 1010 support (or the same access network nodes 1010 additionally support) non-3GPP RATs, such as Wi-Fi or a proprietary RAT. As another example, telecommunications network 1002 may support multiple generations of related communication standards (e.g., 4G and 5G 3GPP communication standards) and, as a result, may include an access network 104 and / or a core network 106 that supports multiple different standard generations ormay include multiple access networks 104 and / or multiple core networks 106 with individual networks 104, 106 supporting different standard generations.

[0116] Telecommunications network 1002 may support network slicing to provide different logical networks to different devices that are connected to the telecommunications network 1002. For example, the telecommunications network 1002 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0117] In some examples, one or more of the UEs 1012 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 1004 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 1004. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0118] In the example, the hub 1014 communicates with the access network 1004 to facilitate indirect communication between one or more UEs (e.g., UE 1012C and / or 1012D) and network nodes (e.g., network node 1010B). In some examples, the hub 1014 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 1014 may be a broadband router enabling access to the core network 1006 for the UEs. As another example, the hub 1014 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 1010, or by executable code, script, process, or other instructions in the hub 1014.

[0119] As another example, the hub 1014 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 1014 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 1014 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 1014 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 1014 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.The hub 1014 may have a constant / persistent or intermittent connection to the network node 1010B. The hub 1014 may also allow for a different communication scheme and / or schedule between the hub 1014 and UEs (e.g., UE 1012C and / or 1012D), and between the hub 1014 and the core network 1006. In other examples, the hub 1014 is connected to the core network 1006 and / or one or more UEs via a wired connection. Moreover, the hub 1014 may be configured to connect to an M2M service provider over the access network 1004 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 1010 while still connected via the hub 1014 via a wired or wireless connection. In some embodiments, the hub 1014 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 1010B. In other embodiments, the hub 1014 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1010B, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0120] Figure 11 is another example of a communication system 1100 according to some embodiments. As used herein, the communication system 1100 includes multiple access points (APs) 1110 (with four exemplary APs 1110A, 1110B, 1110C, and 1110D being depicted) and multiple wireless devices, referred to in the context of communication system 1100 as stations (STAs) 1112 (referred to individually as STA 1112A, ST A 1112B, STA 1112C, STA 1112D, and STA 1112E). STA 1112A is served by AP 1110A in a first basic service set (BSS) 1120A. STA 1110B and STA 1110C are served by AP 1110B in a second BSS, BSS 1120B. STA 1112D is served by AP 1110C in a third BSS, BSS 1120C. STA 1112E is served by AP 1 HOD in a fourth BSS, BSS 1120D. Stations 1112 may be non-AP STAs and correspond to various kinds of wireless devices, for example, user terminals, such as mobile or stationary computing devices like smartphones, laptop computers, desktop computers, tablet computers, gaming devices, headmounted displays (HMDs) for Augmented Reality (AR) or Virtual Reality (VR), or the like. Further, stations 1112 could, for example, correspond to other kinds of equipment like smart home devices, printers, multimedia devices, data storage devices, or the like.

[0121] Each of STAs 1112 may connect through a radio link to one of APs 1110. For example, depending on location or channel conditions experienced by a given STA 1112, the STA may select an appropriate AP and BSS for establishing the radio link. The radio link may be based on one or more orthogonal frequency-division multiplexing (OFDM) carriers from a frequency spectrum that is shared on the basis of a contention-based mechanism, e.g., an unlicensed or license exempt band like 2.4 GHz Industrial, Scientific, and Medical (ISM) band, the 5 GHz band, the 6 GHz band, or the 60 GHz band.Each AP 1110 may provide data connectivity to STAs 1112 connected to a particular AP 1110. As illustrated, APs 1110 may be connected to a data network 1130. In this way, APs 1110 may also provide data connectivity between STAs 1112 and other entities, e.g., to one or more servers, service providers, data sources, data sinks, user terminals, or the like. Accordingly, the radio link established between a given STA 1112 and its serving AP 1110 may be used for providing various kinds of services to STA 1112, e.g., a voice service, a multimedia service, or other data service. Such services may be based on applications that are executed on STA 1112 and / or on a device linked to STA 1112. By way of example, Figure 11 illustrates an application service platform 1132 provided in data network 1130. The application(s) executed on STA 1112 and / or on one or more other devices linked to STA 1112 may use the radio link for data communication with one or more other STA 1112 and / or the application service platform 1132, thereby enabling utilization of the corresponding service(s) at STA 1112.

[0122] Figure 12 shows a wireless device 1200, which may be configured to operate in communication system 1000 of Figure 10 or in communication system 1100 of Figure 11. The wireless device 1200 may be alternatively referred to as a UE 1200, like a UE 1012 within the context of communication system 1000, or as a station (STA) 1200 or as a non-access-point station (non-AP STA) 1200, like a STA 1112 within the context of the communication system 1100, in accordance with respective embodiments. As used herein, a wireless device refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other wireless devices. Examples of a wireless device include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, and wireless terminal. Other examples include any type of UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0123] A wireless device 1200 may support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, wireless device 1200 may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, wireless device 1200may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, wireless device 1200 may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0124] In particular embodiments, wireless device 1200 includes processing circuitry 1202 that is operatively coupled via a bus 1204 to an input / output interface 1206, a power source 1208, a memory 1210, a communication interface 1212, and / or any other component, or any combination thereof. Certain embodiments of wireless device 1200 may include all or a subset of the components shown in Figure 12. The level of integration between the components may vary from one embodiment of wireless device 1200 to another. In general, in a particular embodiment of wireless device 1200, processing circuitry 1202, input / output interface 1206, power source 1208, memory 1210, and communication interface 1212 may, in whole or in part, represent or include physical components common to or shared by one or more of the other elements of wireless device 1200. Further, certain embodiments of wireless devices 1200 may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0125] The processing circuitry 1202 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 1210. The processing circuitry 1202 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 1202 may include multiple central processing units (CPUs).

[0126] In the example, the input / output interface 1206 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into wireless device 1200. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor maybe, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0127] In some embodiments, the power source 1208 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used to supply power to circuitry or to charge an associated battery. The power source 1208 may further include power circuitry for delivering power from the power source 1208 itself, and / or an external power source, to the various parts of wireless device 1200 via input circuitry or an interface such as an electrical power cable. Power source 1208 may perform any formatting, converting, or other modification to make accessible power suitable for the respective components of the wireless device 1200 to which power is supplied.

[0128] The memory 1210 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 1210 includes one or more programs 1214, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1216. The memory 1210 may store, for use by wireless device 1200, any of a variety of various operating systems or combinations of operating systems.

[0129] The memory 1210 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 1210 may allow wireless device 1200 to access instructions, programs, and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, suchas one utilizing a communication system may be tangibly embodied as or in the memory 1210, which may be or comprise a device-readable storage medium.

[0130] The processing circuitry 1202 may be configured to communicate with an access network or other network via or using the communication interface 1212. The communication interface 1212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1222. The communication interface 1212 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another wireless device or a network node in an access network). Each transceiver may include a transmitter 1218 and / or a receiver 1220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 1218 and receiver 1220 may be coupled to one or more antennas (e.g., antenna 1222) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0131] In the illustrated embodiment, communication functions of the communication interface 1212 may include cellular communication, Wi-Fi communication (e.g., according to an IEEE 802.11 family standard), LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0132] In particular embodiments, wireless device 1200 may provide an output of data captured via a sensor, through its communication interface 1212, via a wireless connection to a network node, and / or in any appropriate manner. Data captured by sensors of a wireless device 1200 can be communicated through a wireless connection to a network node via another wireless device 1200. In particular embodiments, such output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).As another example, wireless device 1200 comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, wireless device 1200 may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0133] Wireless device 1200, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. In particular embodiments, wireless device 1200 represents an loT device that comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the example embodiment of wireless device 1200 shown in Figure 12.

[0134] As yet another specific example, in an loT scenario, wireless device 1200 may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another wireless device and / or a network node. Wireless device 1200 may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, wireless device 1200 may implement the 3 GPP NB-IoT standard. In other scenarios, wireless device 1200 may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0135] In practice, any number of wireless devices 1200 may be used together with respect to a single use case. For example, a first wireless device 1200 might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second wireless device 1200 that is a remote controller operating the drone. When a user makes changes from theremote controller, the first wireless device 1200 may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second wireless device 1200 can also include more than one of the functionalities described above. For example, wireless device 1200 might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0136] Figure 13 shows a network node 1300 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunications network. In accordance with respective embodiments, network node 1300 may be configured to operate in communication system 1000 of Figure 10, like network nodes 1008 or 1010, or in communication system 1100 of Figure 11, like an AP 1110 or a station 1112. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)), 0-RAN nodes or components of an 0-RAN node (e.g., O-RU, O-DU, O-CU).

[0137] Network nodes 1300 may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. Network node 1300 may be a relay node or a relay donor node controlling a relay. Network nodes 1300 may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0138] Other examples of network nodes 1300 include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0139] In particular embodiments, network node 1300 includes a processing circuitry 1302, a memory 1304, a communication interface 1306, and a power source 1308. In general, in a particular embodiment of network node 1300, processing circuitry 1302, memory 1304,communication interface 1306, and power source 1308 may, in whole or in part, represent or include physical components common to or shared by one or more of the other elements of network node 1300.

[0140] The network node 1300 may be composed of multiple distinct network entities (e.g., a NodeB entity and an RNC entity, or a BTS entity and a BSC entity, etc.), which may each have or utilize their own respective physical components. In certain scenarios in which the network node 1300 comprises multiple such entities (e.g., BTS and BSC), one or more of the separate entities may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 1300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memories 1304 or portions of memory 1304 for different RATs) and some components may be reused (e.g., a same antenna 1310 may be shared by different RATs). The network node 1300 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1300, for example GSM, WCDMA, LTE, NR, Wi-Fi (e.g., according to an IEEE 802.11 family standard), Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1300.

[0141] The processing circuitry 1302 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other components, such as the memory 1304, to provide network node 1300 functionality.

[0142] In some embodiments, the processing circuitry 1302 includes a system on a chip (SOC). In some embodiments, the processing circuitry 1302 includes one or more of radio frequency (RF) transceiver circuitry 1312 and baseband processing circuitry 1314. In some embodiments, the RF transceiver circuitry 1312 and the baseband processing circuitry 1314 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1312 and baseband processing circuitry 1314 may be on the same chip or set of chips, boards, or units.

[0143] The memory 1304 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mountedmemory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 1302. The memory 1304 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 1302 and utilized by the network node 1300. The memory 1304 may be used to store any calculations made by the processing circuitry 1302 and / or any data received via the communication interface 1306. In some embodiments, the processing circuitry 1302 and memory 1304 is integrated.

[0144] The communication interface 1306 is used in wired or wireless communication of signaling and / or data with UEs, other network nodes, and / or any other network equipment. In the illustrated embodiment, communication interface 1306 comprises port(s) / terminal(s) 1316 to send and receive data, for example to and from a network over a wired connection. In particular embodiments, network node 1200 may be capable of wireless communication and communication interface 1306 may also include radio front-end circuitry 1318 that may be coupled to, or in certain embodiments a part of, an antenna 1310. Particular embodiments of radio front-end circuitry 1318 include filter(s) 1320 and amplifier(s) 1322. The radio front-end circuitry 1318 may be connected to an antenna 1310 and processing circuitry 1302. The radio front-end circuitry may be configured to condition signals communicated between antenna 1310 and processing circuitry 1302. The radio front-end circuitry 1318 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 1318 may convert the digital data into a radio signal(s) having the appropriate channel and bandwidth parameters using a combination of filters 1320 and / or amplifiers 1322. The radio signal(s) may then be transmitted via the antenna 1310. Similarly, when receiving data, the antenna 1310 may collect radio signals which are then converted into digital data by the radio front-end circuitry 1318. The digital data may be passed to the processing circuitry 1302. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0145] In certain alternative embodiments, network node 1300 may be capable of wireless communication but does not include separate radio front-end circuitry 1318, instead, the processing circuitry 1302 includes radio front-end circuitry and is connected to the antenna 1310. Similarly, in some embodiments, all or some of the RF transceiver circuitry 1312 is part of the communication interface 1306. In still other embodiments, the communication interface 1306includes one or more ports or terminals 1316, the radio front-end circuitry 1318, and the RF transceiver circuitry 1312, as part of a radio unit (not shown), and the communication interface 1306 communicates with the baseband processing circuitry 1314, which is part of a digital unit (not shown).

[0146] The antenna 1310 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 1310 may be coupled to the radio front-end circuitry 1318 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 1310 is separate from the network node 1300 and connectable to the network node 1300 through one or more interfaces or ports.

[0147] The antenna 1310, communication interface 1306, and / or the processing circuitry 1302 may be configured to perform some or all of the receiving operations and / or obtaining operations described herein as being performed by the network node 1300. Any information, data, and / or signals may be received from a UE, another network node, and / or any other network equipment. Similarly, the antenna 1310, the communication interface 1306, and / or the processing circuitry 1302 may be configured to perform some or all of the transmitting or sending operations described herein as being performed by the network node 1300. Any information, data and / or signals may be transmitted to a UE, another network node, and / or any other network equipment.

[0148] The power source 1308 provides power to the various components of network node 1300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 1308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 1300 with power for performing the functionality described herein. For example, the network node 1300 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 1308. As a further example, the power source 1308 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0149] Embodiments of the network node 1300 may include additional components beyond those shown in Figure 13 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 1300 may include user interface equipment to allow input of information into the network node 1300 and to allow output ofinformation from the network node 1300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 1300.

[0150] Figure 14 is a block diagram illustrating a virtualization environment 1400 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1400 hosted by one or more of hardware nodes, such as a hardware computing device that operates as an access network node, UE, core network node, or host. Further, in embodiments in which a virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1400 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface.

[0151] Applications 1402 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1300 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0152] Hardware 1404 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1406 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VM 1408A and VM 1408B (which may be collectively referred to as VMs 1408), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 1406 may present a virtual operating platform that appears like networking hardware to one or more of the VMs 1408.

[0153] The VMs 1408 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by virtualization layer 1406. Different embodiments of the instance of a virtual appliance 1402 may be implemented on one or more of VMs 1408, and the implementations may be made in different ways. Virtualization of the hardware is in somecontexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0154] In the context of NFV, each of the VMs 1408 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 1408, and that part of hardware 1404 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more of the VMs 1408 on top of the hardware 1404 and corresponds to an application 1402.

[0155] Hardware 1404 may be implemented in a standalone network node with generic or specific components. Hardware 1404 may implement some functions via virtualization. Alternatively, hardware 1404 may be part of a larger cluster of hardware (e.g., such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1410, which, among others, oversees lifecycle management of applications 1402. In some embodiments, hardware 1404 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1412 which may alternatively be used for communication between hardware nodes and radio units.

[0156] Although the computing devices described herein (e.g., UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions, and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested withinmultiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0157] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

[0158] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

[0159] EMBODIMENTS

[0160] Group A Embodiments

[0161] Embodiment 1: A method performed by a User Equipment, UE, comprising any one or more of the following:

[0162] • receiving (300) a downlink transmission (e.g., a PDSCH transmission) from a network node;

[0163] • determining (302) whether the UE is able to successfully decode the downlink transmission;

[0164] • upon determining that the UE is able to successfully decode the downlink transmission (302, yes):

[0165] o determining (306-312; 318; 322) whether to transmit Hybrid Automatic RepeatRequest, HARQ, feedback for the downlink transmission, based on whether the downlink transmission includes downlink data, first level HARQ feedback, or second level HARQ feedback; and

[0166] o operating (314; 316; 320; 324) in accordance with a result of the determining (306- 312; 318; 322) whether to transmit HARQ feedback for the downlink transmission. Embodiment 2: The method of embodiment 1, further comprising, upon determining that the UE is unable to successfully decode the downlink transmission (302, no), transmitting (304) a HARQ Negative Acknowledgement, NACK, to the network node.

[0167] Embodiment 3: The method of embodiment 1, wherein determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises determining (306-308) whether the downlink transmission includes downlink data.

[0168] Embodiment 4: The method of embodiment 3, wherein: the UE determines to transmit a (first level) HARQ-ACK upon determining (308, yes) that the downlink transmission includes downlink data; and in response thereto, operating (314) in accordance with a result of the determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises transmitting (314) a (first level) HARQ-ACK to the network node (e.g., on PUSCH).

[0169] Embodiment 5: The method of embodiment 3, wherein determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission further comprises determining (310) whether reliable transmission is configured for the UE and / or determining (312) whether the data included in the downlink transmission exceeds a certain delay budget.

[0170] Embodiment 6: The method of embodiment 5, wherein: the UE determines to transmit a (first level) HARQ-ACK upon determining (308, yes) that the downlink transmission includes downlink data and either or both of: determining (310, yes) that reliable transmission is configured for the UE and / or determining (312, no) that the data does not exceed the certain delay budget threshold; and in response thereto, operating (314) in accordance with a result of the determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises transmitting (314) a (first level) HARQ-ACK to the network node (e.g., on PUSCH).

[0171] Embodiment 7: The method of embodiment 5, wherein: the UE determines to not transmit a (first level) HARQ-ACK upon determining (308, yes) that the downlink transmission includes downlink data and either or both of: determining (310, no) that reliable transmission is not configured for the UE and / or determining (312, yes) that the data exceeds the certain delay budget threshold.Embodiment 8: The method of embodiment 3, wherein: the UE determines to transmit a (second level) HARQ-ACK upon determining (308, no) that the downlink transmission does not include downlink data but does include a (first level) HARQ-ACK (e.g., in response to a prior uplink data transmission) (318, yes); and in response thereto, operating (320) in accordance with a result of the determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises transmitting (320) a (second level) HARQ-ACK to the network node (e.g., on PUSCH).

[0172] Embodiment 9: The method of embodiment 3, wherein: the UE determines to not transmit a (second level) HARQ-ACK (e.g., and to clear an associated HARQ process to be used for a new transmission) upon determining (308, no) that the downlink transmission does not include downlink data but does include a (second level) HARQ-ACK (e.g., in response to no prior uplink data transmission); and in response thereto, operating (324) in accordance with a result of the determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises clearing (324) an associated HARQ process to be used for a new transmission. More specifically, the cleared HARQ process is the HARQ process which is associated with the second level HARQ-ACK received from the network on a PDSCH and contains the associated first level HARQ-FB previously transmitted by the UE on PDSCH.

[0173] Embodiment 10: A method performed by a User Equipment, UE, comprising any one or more of the following: transmitting (600) an uplink transmission (e.g., a PUSCH transmission) to a network node; performing (604-612) a first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK; and otherwise (e.g., if the uplink transmission includes a second level HARQ-ACK or a HARQ-NACK) performing (614-618) a second set of actions.

[0174] Embodiment 11: The method of embodiment 10, wherein performing (604-612) the first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK comprises: starting or restarting (604) a first timer; and upon expiry (606) of the first timer without first receiving an ACK from the network node, performing (610) a local NACK.

[0175] Embodiment 12: The method of embodiment 11, wherein performing (604-612) the first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK further comprises, upon expiry (606) of the first timer without first receiving an ACK from the network node, performing any one or more of the following: updating associated control information (e.g., HARQ feedback, BSR, etc.); discarding outdated control information; discarding uplink data having an age that exceeds a certain age threshold.Embodiment 13: The method of embodiment 11 or 12, wherein performing (604-612) the first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK further comprises stopping the first timer upon receiving an ACK from the network node (e.g., on PDSCH) before expiry of the first timer.

[0176] Embodiment 14: The method of any of embodiments 10 to 13, wherein performing (614-618) the second set of actions (e.g., if the uplink transmission includes a second level HARQ-ACK or a HARQ-NACK) comprises: starting or restarting (614) a second timer; and upon expiry (616) of the second timer, discarding (618) the second level HARQ-ACK if included in the uplink transmission.

[0177] Embodiment 15: The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host via the transmission to the network node.

[0178] Group B Embodiments

[0179] Embodiment 16: A method performed by a network node, the method comprising any one or more of the following:

[0180] • receiving (402) an uplink transmission (e.g., a PUSCH transmission) from a User Equipment, UE;

[0181] • determining (404) whether the network node is able to successfully decode the uplink transmission;

[0182] • upon determining that the network node is able to successfully decode the uplink transmission (404, yes):

[0183] o determining (414-420; 426) whether to transmit Hybrid Automatic Repeat Request, HARQ, feedback for the uplink transmission, based on whether the uplink transmission includes uplink data, first level HARQ feedback, or second level HARQ feedback; and

[0184] o operating (422; 424; 428) in accordance with a result of the determining (414-420;

[0185] 426; 430) whether to transmit HARQ feedback for the uplink transmission.

[0186] Embodiment 17: The method of embodiment 16, further comprising, upon determining that the network node is unable to successfully decode the uplink transmission (404, no): transmitting (410), to the UE, a grant for a retransmission; and performing (412) reception of the retransmission.Embodiment 18: The method of embodiment 16, wherein determining (414-420; 426) whether to transmit HARQ feedback for the uplink transmission comprises determining (414-416) whether the uplink transmission includes uplink data.

[0187] Embodiment 19: The method of embodiment 18, wherein: the network node determines to transmit a (first level) HARQ-ACK upon determining (416, yes) that the uplink transmission includes uplink data; and in response thereto, operating (422) in accordance with a result of the determining (414-420; 426) whether to transmit HARQ feedback for the uplink transmission comprises transmitting (422) a (first level) HARQ-ACK to the UE (e.g., on PDSCH).

[0188] Embodiment 20: The method of embodiment 18, wherein determining (414-420; 426) whether to transmit HARQ feedback for the uplink transmission further comprises determining (418) whether reliable transmission is configured for the UE and / or determining (420) whether the data included in the uplink transmission exceeds a certain delay budget.

[0189] Embodiment 21 : The method of embodiment 20, wherein: the network node determines to transmit a (first level) HARQ-ACK upon determining (416, yes) that the uplink transmission includes uplink data and either or both of: determining (418, yes) that reliable transmission is configured for the UE and / or determining (420, no) that the data does not exceed the certain delay budget threshold (420, no); and in response thereto, operating (422) in accordance with a result of the determining (414-420; 426; 430) whether to transmit HARQ feedback for the uplink transmission comprises transmitting (422) a (first level) HARQ-ACK to the UE (e.g., on PDSCH).

[0190] Embodiment 22: The method of embodiment 20, wherein: the network determines to not transmit a (first level) HARQ-ACK upon determining (416, yes) that the uplink transmission includes uplink data and either or both of: determining (418, no) that reliable transmission is not configured for the UE and / or determining (420, yes) that the data exceeds the certain delay budget threshold.

[0191] Embodiment 23: The method of embodiment 18, wherein: the network determines to transmit a (second level) HARQ-ACK upon determining (416, no) that the downlink transmission does not include downlink data but does include a (first level) HARQ-ACK (e.g., in response to a prior uplink data transmission) (426, yes); and in response thereto, operating (428) in accordance with a result of the determining whether to transmit HARQ feedback for the uplink transmission comprises transmitting (428) a (second level) HARQ-ACK to the UE (e.g., on PDSCH).

[0192] Embodiment 24: The method of embodiment 18, wherein: the uplink transmission includes a second level HARQ feedback; and the method further comprises: clearing (432) an associated HARQ process such that it can be used for a new transmission if the second level HARQ feedbackis a HARQ-ACK; and retransmitting (434) a first level HARQ-ACK (e.g., on PDSCH) if the second level HARQ feedback is a HARQ-NACK.

[0193] Embodiment 25: A method performed by a network node, the method comprising any one or more of the following: transmitting (500) a downlink transmission (e.g., a PDSCH transmission) to a UE; performing (504-528) a first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK; and otherwise (e.g., if the downlink transmission includes a second level HARQ-ACK) performing (532-538) a second set of actions.

[0194] Embodiment 26: The method of embodiment 25, wherein performing (504-528) the first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK comprises: starting or restarting (504) a first timer; and upon expiry (508) of the first timer without first receiving an ACK from the UE, performing (512) a local NACK.

[0195] Embodiment 27: The method of embodiment 26, wherein performing (504-528) the first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK further comprises, upon expiry (508) of the first timer without first receiving an ACK from the UE, performing any one or more of the following: updating associated control information (e.g., HARQ feedback, BSR, etc.); discarding outdated control information; discarding downlink data having an age that exceeds a certain age threshold.

[0196] Embodiment 28: The method of embodiment 26 or 27, wherein performing (504-528) the first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK further comprises stopping the first timer upon receiving an ACK from the UE (e.g., on PUSCH) before expiry of the first timer.

[0197] Embodiment 29: The method of any of embodiments 26 to 28, wherein performing (504-528) the first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK comprises: starting or restarting (506) a second timer; and upon expiry (514) of the second timer without first receiving an ACK from the UE, performing (518) a Layer 1, LI, retransmission of the downlink transmission.

[0198] Embodiment 30: The method of any of embodiments 25 to 29, wherein performing (532-538) the second set of actions if the downlink transmission includes a second level HARQ-ACK comprises: starting or restarting (532) a third timer; and upon expiry (536) of the third timer, discarding (538) the second level HARQ-ACK.

[0199] Embodiment 31: The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host or a user equipment.Group C Embodiments

[0200] Embodiment 32: A wireless device, comprising: processing circuitry configured to perform any of the operations of any of the Group A embodiments; and a power source configured to supply power to the processing circuitry.

[0201] Embodiment 33: A network node comprising: processing circuitry configured to perform any of the operations of any of the Group B embodiments; a power source circuitry configured to supply power to the processing circuitry.

[0202] Embodiment 34: A wireless device comprising: one or more antennas; communication interface connected to the one or more antennas and to processing circuitry; the processing circuitry being configured to perform any of the operations of any of the Group A embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a power source connected to the processing circuitry and configured to supply power to the UE.

Claims

CLAIMS1. A method performed by a User Equipment, UE, comprising:• receiving (300) a downlink transmission from a network node, the downlink transmission between associated to a certain Hybrid Automatic Repeat Request, HARQ, process;• determining (302) whether the UE is able to successfully decode the downlink transmission;• upon determining that the UE is able to successfully decode the downlink transmission (302, yes):o determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission on a physical uplink shared channel, based on whether the downlink transmission includes downlink data, first level HARQ feedback, or second level HARQ feedback; ando operating (314; 316; 320; 324) in accordance with a result of the determining (306- 312; 318; 322) whether to transmit HARQ feedback for the downlink transmission.

2. The method of claim 1, further comprising, upon determining that the UE is unable to successfully decode the downlink transmission (302, no), transmitting (304) a HARQ Negative Acknowledgement, NACK, to the network node.

3. The method of claim 1, wherein determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises determining (306-308) whether the downlink transmission includes downlink data.

4. The method of claim 3, wherein:the UE determines to transmit a first level HARQ-ACK upon determining (308, yes) that the downlink transmission includes downlink data; andin response thereto, operating (314) in accordance with a result of the determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises transmitting (314) a first level HARQ-ACK to the network node.

5. The method of claim 3, wherein determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission further comprises determining (310) whether reliable transmission is configured for the UE and / or determining (312) whether the data included in the downlink transmission exceeds a certain delay budget.

6. The method of claim 5, wherein:the UE determines to transmit a first level HARQ-ACK upon determining (308, yes) that the downlink transmission includes downlink data and either or both of: determining (310, yes) that reliable transmission is configured for the UE and / or determining (312, no) that the data does not exceed the certain delay budget threshold; andin response thereto, operating (314) in accordance with a result of the determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises transmitting (314) a first level HARQ-ACK to the network node.

7. The method of claim 5, wherein:the UE determines to not transmit a first level HARQ-ACK upon determining (308, yes) that the downlink transmission includes downlink data and either or both of: determining (310, no) that reliable transmission is not configured for the UE and / or determining (312, yes) that the data exceeds the certain delay budget threshold.

8. The method of claim 3, wherein:the UE determines to transmit a second level HARQ-ACK upon determining (308, no) that the downlink transmission does not include downlink data but does include a first level HARQ-ACK in response to a prior uplink data transmission (318, yes); andin response thereto, operating (320) in accordance with a result of the determining (3 Ob-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises transmitting (320) a second level HARQ-ACK to the network node.

9. The method of claim 3, wherein:the UE determines to not transmit a second level HARQ-ACK and to clear an associated HARQ process to be used for a new transmission upon determining (308, no) that the downlink transmission does not include downlink data but does include a second level HARQ-ACK; and in response thereto, operating (324) in accordance with a result of the determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission comprises clearing (324) a HARQ process which is associated with the second level HARQ-ACK received from the network on a physical downlink shared channel and contains the associated first level HARQ-FB previously transmitted by the UE on a physical uplink shared channel to be used for a new transmission.

10. A User Equipment, UE, (1200) comprising:• a communication interface (1212) comprising a transmitter (1218) and a receiver (1220), the downlink transmission between associated to a certain Hybrid Automatic Repeat Request, HARQ, process; and• processing circuitry (1202) associated with the communication interface (1212), the processing circuitry (1202) configured to cause the UE (1200) to:o receive (300) a downlink transmission from a network node;o determine (302) whether the UE is able to successfully decode the downlink transmission;o upon determining that the UE is able to successfully decode the downlink transmission (302, yes):■ determine (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission on a physical uplink shared channel, based on whether the downlink transmission includes downlink data, first level HARQ feedback, or second level HARQ feedback; and■ operate (314; 316; 320; 324) in accordance with a result of the determining (306-312; 318; 322) whether to transmit HARQ feedback for the downlink transmission.

11. The UE of claim 10, wherein the processing circuitry is further configured to cause the UE to perform the method of any of claims 2 to 9.

12. A method performed by a User Equipment, UE, comprising:transmitting (600) an uplink transmission to a network node;performing (604-612) a first set of actions if the uplink transmission includes uplink data and / or a first level Hybrid Automatic Repeat Request Acknowledgement, HARQ-ACK; and otherwise performing (614-618) a second set of actions.

13. The method of claim 12, wherein performing (604-612) the first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK comprises:starting or restarting (604) a first timer for triggering a Layer 2, L2, retransmission upon expiry of the first timer; andupon expiry (606) of the first timer without first receiving an acknowledgement, ACK,from the network node, performing (610) a local negative acknowledgement, NACK, to thereby trigger a L2 retransmission.

14. The method of claim 13, wherein performing (604-612) the first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK further comprises, upon expiry (606) of the first timer without first receiving an ACK from the network node, performing any one or more of the following:updating associated control information;discarding outdated control information;discarding uplink data having an age that exceeds a certain age threshold.

15. The method of claim 13 or 14, wherein performing (604-612) the first set of actions if the uplink transmission includes uplink data and / or a first level HARQ-ACK further comprises stopping the first timer upon receiving an ACK from the network node before expiry of the first timer.

16. The method of any of claims 12 to 15, wherein performing (614-618) the second set of actions comprises:starting or restarting (614) a second timer; andupon expiry (616) of the second timer, discarding (618) a HARQ-NACK or second level HARQ-ACK if included in the uplink transmission.

17. A User Equipment, UE, comprising:a communication interface (1212) comprising a transmitter (1218) and a receiver (1220); andprocessing circuitry (1202) associated with the communication interface (1212), the processing circuitry (1202) configured to cause the UE (1200) to:transmit (600) an uplink transmission to a network node;perform (604-612) a first set of actions if the uplink transmission includes uplink data and / or a first level Hybrid Automatic Repeat Request Acknowledgement, HARQ- ACK; andotherwise perform (614-618) a second set of actions.

18. The UE of claim 17, wherein the processing circuitry is further configured to perform themethod of any of claims 13 to 16.

19. A method performed by a network node, the method comprising:• receiving (402) an uplink transmission from a User Equipment, UE;• determining (404) whether the network node is able to successfully decode the uplink transmission;• upon determining that the network node is able to successfully decode the uplink transmission (404, yes):o determining (414-420; 426) whether to transmit Hybrid Automatic Repeat Request, HARQ, feedback for the uplink transmission on a physical downlink shared channel, based on whether the uplink transmission includes uplink data, first level HARQ feedback, or second level HARQ feedback; ando operating (422; 424; 428) in accordance with a result of the determining (414-420;426; 430) whether to transmit HARQ feedback for the uplink transmission.

20. The method of claim 19, further comprising, upon determining that the network node is unable to successfully decode the uplink transmission (404, no):transmitting (410), to the UE, a grant for a retransmission; andperforming (412) reception of the retransmission.

21. The method of claim 19, wherein determining (414-420; 426) whether to transmit HARQ feedback for the uplink transmission comprises determining (414-416) whether the uplink transmission includes uplink data.

22. The method of claim 21, wherein:the network node determines to transmit a first level HARQ-ACK upon determining (416, yes) that the uplink transmission includes uplink data; andin response thereto, operating (422) in accordance with a result of the determining (414-420; 426) whether to transmit HARQ feedback for the uplink transmission comprises transmitting (422) a first level HARQ-ACK to the UE.

23. The method of claim 21, wherein determining (414-420; 426) whether to transmit HARQ feedback for the uplink transmission further comprises determining (418) whether reliable transmission is configured for the UE and / or determining (420) whether the data included in theuplink transmission exceeds a certain delay budget.

24. The method of claim 23, wherein:the network node determines to transmit a first level HARQ-ACK upon determining (416, yes) that the uplink transmission includes uplink data and either or both of determining (418, yes) that reliable transmission is configured for the UE and / or determining (420, no) that the data does not exceed the certain delay budget threshold (420, no); andin response thereto, operating (422) in accordance with a result of the determining (414-420; 426; 430) whether to transmit HARQ feedback for the uplink transmission comprises transmitting (422) a first level HARQ-ACK to the UE.

25. The method of claim 23, wherein:the network determines to not transmit a first level HARQ-ACK upon determining (416, yes) that the uplink transmission includes uplink data and either or both of: determining (418, no) that reliable transmission is not configured for the UE and / or determining (420, yes) that the data exceeds the certain delay budget threshold.

26. The method of claim 21, wherein:the network determines to transmit a second level HARQ-ACK upon determining (416, no) that the downlink transmission does not include downlink data but does include a first level HARQ-ACK in response to a prior uplink data transmission (426, yes); andin response thereto, operating (428) in accordance with a result of the determining whether to transmit HARQ feedback for the uplink transmission comprises transmitting (428) a second level HARQ-ACK to the UE.

27. The method of claim 21, wherein:the uplink transmission includes a second level HARQ feedback; andthe method further comprises:clearing (432) an associated HARQ process such that it can be used for a new transmission if the second level HARQ feedback is a HARQ-ACK; and retransmitting (434) a first level HARQ-ACK if the second level HARQ feedback is a HARQ-NACK.

28. A network node (1300) comprising processing circuitry (1302) configured to cause thenetwork node (1300) to:• receive (402) an uplink transmission from a User Equipment, UE;• determine (404) whether the network node is able to successfully decode the uplink transmission;• upon determining that the network node is able to successfully decode the uplink transmission (404, yes):o determine (414-420; 426) whether to transmit Hybrid Automatic Repeat Request, HARQ, feedback for the uplink transmission on a physical downlink shared channel, based on whether the uplink transmission includes uplink data, first level HARQ feedback, or second level HARQ feedback; ando operate (422; 424; 428) in accordance with a result of the determining (414-420;426; 430) whether to transmit HARQ feedback for the uplink transmission.

29. The network node of claim 28, wherein the processing circuitry is further configured to cause the network node to perform the method of any of claims 20 to 29.

30. A method performed by a network node, the method comprising:transmitting (500) a downlink transmission to a User Equipment, UE;performing (504-528) a first set of actions if the downlink transmission includes downlink data and / or a first level Hybrid Automatic Repeat Request Acknowledgement, HARQ-ACK; and otherwise performing (532-538) a second set of actions.

31. The method of claim 30, wherein performing (504-528) the first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK comprises:starting or restarting (504) a first timer; andupon expiry (508) of the first timer without first receiving an acknowledgement, ACK, from the UE, performing (512) a local negative acknowledgement, NACK, to thereby trigger a Layer 2, L2, retransmission.

32. The method of claim 31, wherein performing (504-528) the first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK further comprises, upon expiry (508) of the first timer without first receiving an ACK from the UE, performing any one or more of the following:updating associated control information;discarding outdated control information;discarding downlink data having an age that exceeds a certain age threshold.

33. The method of claim 31 or 32, wherein performing (504-528) the first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK further comprises stopping the first timer upon receiving an ACK from the UE before expiry of the first timer.

34. The method of any of claims 31 to 33, wherein performing (504-528) the first set of actions if the downlink transmission includes downlink data and / or a first level HARQ-ACK comprises:starting or restarting (506) a second timer; andupon expiry (514) of the second timer without first receiving an ACK from the UE, performing (518) a Layer 1, LI, retransmission of the downlink transmission.

35. The method of any of claims 30 to 34, wherein performing (532-538) the second set of actions if the downlink transmission includes a second level HARQ-ACK comprises:starting or restarting (532) a third timer; andupon expiry (536) of the third timer, discarding (538) the second level HARQ-ACK.

36. A network node (1300) comprising processing circuitry (1302) configured to cause the network node (1300) to:transmit (500) a downlink transmission to a User Equipment, UE;perform (504-528) a first set of actions if the downlink transmission includes downlink data and / or a first level Hybrid Automatic Repeat Request Acknowledgement, HARQ-ACK; and otherwise performing (532-538) a second set of actions.

37. The network node of claim 36, wherein the processing circuitry is further configured to cause the network node to perform the method of any of claims 31 to 35.

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