RLC HARQ receiver interaction for early gap detection

Abstract

Embodiments of a method performed by a network node for managing uplink traffic. The method comprises: receiving, from a user equipment (UE), one or more uplink hybrid automatic repeat request (HARQ) transmissions, each uplink HARQ transmission including a respective radio link control (RLC) sequence number (SN). A sequence number gap is detected in the respective RLC SNs of the received uplink HARQ transmissions. In response to detecting the sequence number gap: done or more missing sequence numbers are determined in the respective RLC SNs of the received uplink HARQ transmissions. Subsequently, transmission of an RLC early status report and / or a NACK message to the UE is triggered, indicating the RLC SN associated with the one or more missing sequence numbers.

Description

RLC HARQ Receiver Interaction For Early Gap Detection Technical Field

[0001] The present disclosure relates to management of uplink traffic, and in particular to RLC HARQ Receiver Interaction For Early Gap Detection.

[0002] Research on 6G as the next generation of mobile communication system is ongoing. This disclosure relates to technical components of 6G which are described utilizing existing definitions and descriptions according to 5G specifications.Background 5G user-plane protocols

[0003] The 5G user-plane architecture and protocols are described with help of FIG. 1. UE is connected over the air via the Uu protocol with the radio access network (RAN) gNB. The gNB may be separated into 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, 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 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. MAC protocol stands for medium access control and supports scheduling of transmissions over the air, and entails the hybrid automatic repeat request (HARQ) protocol. The physical layer (PHY) handles e.g. modulation and coding and the actual physical transmission.Background on HARQ

[0004] In 3GPP radio access networks, e.g. 5GNR, the hybrid automatic repeat request (HARQ) protocol facilitates retransmissions of data in case of transmission errors over the air. A HARQ entity maintains multiple HARQ processes for data transmission.

[0005] For uplink HARQ, data transmission on a HARQ process is granted by the gNB by downlink control information (DCI) carried on the physical downlink control channel(PDCCH) and data is transmitted on the physical uplink shared channel (PUSCH). Different encoding is applied to these channels resulting in different error rates.

[0006] HARQ retransmission of a HARQ process is triggered upon request by gNB based on DCI on PDCCH as well. The HARQ process may also be overridden to be used for new data also based on gNB indicating this via DCI.

[0007] The HARQ protocol may result in residual errors. After a certain number of retransmissions the gNB may give up on a HARQ process and not retransmit the data anymore, leading to data loss. Furthermore, the UE may erroneously detect a false grant / DCI on PDCCH, even though the gNB didn’t send it, leading to undiscoverable HARQ process transmission for which data loss occurs as well.Radio Link Control

[0008] The radio link control (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. 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.

[0009] There currently exist certain challenges. In current systems, recovery loops of residual HARQ errors by RLC layer are based on the RLC round trip time, which means long delays for retransmissions. Short latencies for time critical services can thus not be guaranteed. In particular, when it comes to failure or sequence number gap detection at the RLC receiver, the current algorithms do not take all information available at the receiver side into account to enable shorter recovery cycles.Summary

[0010] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges.

[0011] An aspect of the disclosure provides a method performed by a network node for managing uplink traffic. The method comprises: receiving, from a user equipment (UE), one or more uplink hybrid automatic repeat request (HARQ) transmissions, each uplink HARQ transmission including a respective radio link control (RLC) sequence number (SN). Asequence number gap is detected in the respective RLC SNs of the received uplink HARQ transmissions. In response to detecting the sequence number gap: done or more missing sequence numbers are determined in the respective RLC SNs of the received uplink HARQ transmissions. Subsequently, transmission of an RLC early status report and / or a NACK message to the UE is triggered, indicating the RLC SN associated with the one or more missing sequence numbers.

[0012] In some embodiments, detecting the sequence number gap comprises an RLC entity receiving (304) a HARQ process timeout indication from a HARQ entity of the network node.

[0013] In some embodiments, the method further comprises the HARQ process detecting (302) failure to receive an uplink HARQ transmission and the BS determining a timeout of the HARQ process, and forwarding the HARQ timeout indication for that HARQ process to the RLC entity.

[0014] In some embodiments, determining the one or more missing sequence number(s) comprises the RLC entity obtaining the RLC SN associated with the indicated HARQ process.

[0015] In some embodiments, the steps of determining the one or more missing sequence numbers and triggering transmission of the RLC early status report and / or a NACK message are performed immediately after detecting the one or more missing sequence number(s).

[0016] In some embodiments, the method further comprises receiving, from the UE, at least one later uplink transmission after the HARQ timeout indication, and wherein the steps of determining the one or more missing sequence numbers and triggering transmission of the RLC early status report and / or a NACK message are performed after successful HARQ decoding of the one or more later uplink transmissions.

[0017] In some embodiments, detecting the sequence number gap comprises: an RLC entity observing a discontinuous set of RLC SNs associated with received and successfully decoded uplink HARQ transmissions.

[0018] In some embodiments, the discontinuous set comprises a first set of one or more earlier received RLC SNs, and a second set of one or more later received RLC SNs, the RLC SNs of the second set being discontinuous with the RLC SNs of the first set, and wherein determining the one or more missing sequence numbers comprises: the RLC entityinteracting with a HARQ entity to identify at least one RLC SN lying between the first and second sets, and for which there are no pending or scheduled HARQ processes.

[0019] In some embodiments, the step of determining the one or more missing sequence number(s) comprises determining whether the each missing RLC SN is smaller than an RX NEXT STATUS TRIGGER,

[0020] In some embodiments, the step of determining the one or more missing sequence numbers comprises determining whether the missing RLC SN(s) are equal or higher than RX HIGHEST STATUS .

[0021] Embodiments of a base station, communication system, and a method in a communication system are also disclosed.

[0022] With this disclosure the receiver side sequence number (SN) gap detection is sped up on RLC layer by taking into account the reception status of the underlying HARQ layer. A detected HARQ failure at the HARQ receiver is indicated to the RLC receiver for expected RLC SNs in the failing HARQ transmission. Early RLC status reporting is triggered in this case, to inform the RLC transmitter of the failure and to issue a retransmission.

[0023] Aspects of this disclosure provide a method in a receiver, where a sequence number (SN) gap (e.g. RLC layer) is considered detected by indication from lower layers (e.g. HARQ layer) at the receiver side. The method comprises either one or both of:• Option 1 : Identifying the gap by observing: A HARQ process timeout, e.g. because it was scheduled and not received for a certain time, the HARQ process expected to carry data of an RLC entity. Ando Option a) optionally receiving the data for this same RLC entity in a later scheduled HARQ process, oro Option b) not waiting to receive data for this same RLC entity in a later scheduled HARQ process.• Option 2: Identifying the gap by observing: A HARQ process being received with RLC entity sequence numbers and a later HARQ process being received with RLC entity sequence numbers not consecutive to the first sequence numbers, while no further HARQ process is pending / was scheduled that could carry such RLC sequence numbers.

[0024] Certain embodiments may provide one or more of the following technical advantage(s). This disclosure helps to speed up error recovery, reducing tail latency. This in turn enables longer or even removal of t-Reassembly timers reducing overhead.Brief Description of the Drawings

[0025] 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 principles of the disclosure.

[0026] FIG. 1 schematically illustrates a 5G user-plane architecture known in the art.

[0027] FIG. 2 is a message flow diagram illustrating an a conventional method of gap detection and recovery.

[0028] FIGs. 3A-3C are message flow diagrams illustrating example methods according to some embodiments.

[0029] FIG. 4 is a message flow diagram illustrating an example method according to certain embodiments.

[0030] FIG. 5 shows an example of a communication system in accordance with some embodiments.

[0031] FIG. 6 shows a UE in accordance with some embodiments.

[0032] FIG. 7 shows a network node in accordance with some embodiments.

[0033] FIG. 8 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized.Detailed Description

[0034] 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 in the 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.

[0035] At least some of the following abbreviations and terms may be used in this disclosure.• 2D Two Dimensional3 GPP Third Generation Partnership Project 5G Fifth GenerationAAS Antenna Array SystemAM Acknowledged ModeAoA Angle of ArrivalAoD Angle of DepartureARI Acknowledgement Resource Indicator ASIC Application Specific Integrated Circuit BF BeamformingBLER Block Error RateBW Beam widthCBG Code Block GroupCE Control ElementCPU Central Processing UnitCSI Channel State InformationDAI Downlink Assignment IndexdB DecibelDCI Downlink Control InformationDFT Discrete Fourier TransformDSP Digital Signal ProcessoreNB Enhanced or Evolved Node BFIR Finite Impulse ResponseFPGA Field Programmable Gate ArraygNB New Radio Base StationHARQ Hybrid Automatic Repeat Request ICC Information Carrying CapacityIIR Infinite Impulse ResponseLTE Long Term EvolutionMAC Medium Access ControlMCS Modulation Coding SchemeMIMO Multiple Input Multiple Output MME Mobility Management Entity• MMSE Minimum Mean Square Error• MTC Machine Type Communication• NDI New Data Indicator• NR New Radio• OTT Over-the-Top• PBCH Physical Broadcast Channel• PDCCH Physical Downlink Control Channel• PDSCH Physical Downlink Shared Channel• PF PUCCH Format• P-GW Packet Data Network Gateway• PUCCH Physical Uplink Control Channel• PUSCH Physical Uplink Shared Channel• RAM Random Access Memory• RLC Radio Link Control• ROM Read Only Memory• RRC Radio Resource Control• RRH Remote Radio Head• SCEF Service Capability Exposure Function• SINR Signal to Interference plus Noise Ratio• TBS Transmission Block Size• UCI Uplink Control Information• UE User Equipment• ULA Uniform Linear Array• URA Uniform Rectangular Array

[0036] Radio Node: As used herein, a “radio node” is either a radio access node or a wireless device.

[0037] Radio Access Node: As used herein, a “radio access node” or “radio network node” is any node in a radio access network of a cellular communications network that operates to wirelessly transmit and / or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), and a relay node.

[0038] Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), or the like.

[0039] Wireless Device: As used herein, a “wireless device” is any type of device that has access to (i.e., is served by) a cellular communications network by wirelessly transmitting (and / or receiving) signals to (and / or from) a radio access node. Some examples of a wireless device include, but are not limited to, a User Equipment device (UE) in a 3GPP network and a Machine Type Communication (MTC) device.

[0040] Network Node: As used herein, a “network node” is any node that is either part of the radio access network or the core network of a cellular communications network / system.

[0041] Cell: As used herein, a “cell” is a combination of radio resources (such as, for example, antenna port allocation, time and frequency) that a wireless device may use to exchange radio signals with a radio access node, which may be referred to as a host node or a serving node of the cell. However, it is important to note that beams may be used instead of cells, particularly with respect to 5GNR. As such, it should be appreciated that the techniques described herein are equally applicable to both cells and beams.

[0042] Note that references in this disclosure to various technical standards (such as 3GPP TS 38.211 V15.1.0 (2018-03) and 3GPP TS 38.214 V15.1.0 (2018-03), for example) should be understood to refer to the specific version(s) of such standard(s) that is(were) current at the time the present application was filed.

[0043] The description herein focuses on a 3 GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.

[0044] Systems and methods are disclosed herein that provide

[0045] General, HAROdetection with RLC status

[0046] A main goal of this disclosure is to speed up the detection of a gap in the sequence of received data. In the RLC layer, this may be done by identifying missing sequence numbers (SNs) of service data units (SDUs), or missing segments of those data units (e.g. by SNs and segmentation offsets (SOs)). For RLC in 5G, one RLC SDU is mapped to one RLC protocol data unit (PDU), and thus, the SN also identifies an RLC PDU. While the following description refers to “SN gaps” or similar, it is also applicable to missing insequence data units or missing in-sequence segments of data units. Furthermore, when referring to one SN gap, it may also consider multiple SNs or SNs with missing segments. When referring to an RLC packet, we refer to RLC SDUs or RLC PDUs.

[0047] In current systems, the RLC layer employs a t-Reassembly timer for gap detection in acknowledged mode (AM). When SNs higher than the next in-order expected SN is received, the timer is started. The t-Reassembly timer is stopped when the SN for which the timer was started is received. Upon expiry of the t-Reassembly timer, the SN is considered as missing, which is to be indicated to the transmitter in the next RLC status report so that the RLC transmitter can retransmit it. The duration of the t-reassembly timer needs to encompass several HARQ round trip times (RTTs) to account for anticipated delays and potentially recover missing data. The RLC layer acts independent of the HARQ layer in current systems.

[0048] According to one embodiment, the RLC layer takes into account information about reception status of the HARQ layer to enable reduction of the t-Reassembly timer duration.

[0049] For example, in the uplink direction the network (NW) is aware of a future UL transmission (TX) as, it previously sent an UL grant to the UE for an initial TX or for a retransmission (RTX). Following reception of a TX or RTX packet, the HARQ layer will attempt to decode the received packet. However, this HARQ process may fail, for example due to that the employed TBS / MCS is not sufficiently robust for decoding. In this case, the NW may abort HARQ process, here referred to as HARQ timeout (which is not a fixed time, but rather dynamically decided by the NW).

[0050] In conventional systems, HARQ timeout leads to detection of an SN gap by the RLC receiver when the RLC receiver receives a subsequent RLC packet and starts the t-Reassembly timer. After expiry of the t-Reassembly timer, the RLC receiver then responds by triggering transmission of a RLC NACK indication to the UE. There may also be otherreasons for the network to abort a HARQ process without successfully decoding the received (R)TX, and schedule it for other UL data instead.

[0051] Instead of waiting for the SN gap to be detected by the RLC entity, according to one embodiment the HARQ entity may directly inform the RLC entity that the HARQ process was aborted. This enables the RLC entity to immediately trigger either a NACK indication or a status report, so that the RLC transmitter could retransmit the missing data with minimal delay.

[0052] In particular, for a given logical channel (i.e. RLC entity) HARQ process failure may be detected in the HARQ layer, and indicated to the affected RLC entity by either one of:

[0053] Option 1: HARQ timeout, as described above. In some embodiments, this step maya. include subsequently decoding subsequent RLC data in a later scheduled HARQ process so that the RLC entity can determine which RLC SNs are exactly missing.b. In other embodiments, the RLC entity may not wait to receive data in a later scheduled HARQ process and can typically only estimate the missing RLC SNs.

[0054] Option 2: observing two or more HARQ processes, but with non-consecutive RLC SNs. For example, a first HARQ process may be initiated for a first received (R)TX with a corresponding first RLC SN, and a second HARQ process may be initiated for a second (later) received (R)TX with a corresponding second RLC SN. If the first and second RLC SNs are non-consecutive, and there is / are no HARQ process(es) pending or scheduled that could carry the “missing” RLC SN(s), then the presence of an SN gap and a falsely detected UL grant can be inferred.

[0055] It will be appreciated that both of examples 1 and 2 above can be extended to cover embodiments in which there is a multiplicity of logical channels (i.e. RLC entities). The examples 1) and 2) are respectively illustrated in FIGs. 2 and 3 indicating the reduced gap detection delay compared to using a legacy t-Reassembly timer.

[0056] Referring to FIG. 2 there is shown a message flow diagram illustrating gap detection according to conventional methods . As may be seen in FIG. 2, a conventional method includes the following steps:

[0057] Step 1 (at 200): The UE performs an UL transmission (TX) to the Base station (BS), such as a gNB, for example in response to a Dynamic Grant (DG) received from the BS. The TX is associated with an RLC packet with sequence number (SN-1).

[0058] Step 2 (at 202): Upon receipt of the TX (SN-1), the HARQ receiver triggers a HARQ process to decode the received TX. In this case, HARQ decoding is successful and the HARQ process forwards the RLC packet to the RLC entity.

[0059] Step 3 (at 204): The UE transmits another UL transmission (TX) with an RLC sequence number (SN), for example in response to a Dynamic Grant (DG) received from the BS.

[0060] Step 4 (at 206): Upon receipt of the UL TX (SN), the HARQ receiver triggers HARQ decoding of the received TX. In this case, the decoding of the received TX (SN) associated with a HARQ process fails and the HARQ receiver of the BS decides to timeout the HARQ process (this may happen after several transmission attempts, repeating steps 1-4).

[0061] Step 5 (at 208) The UE transmits another UL transmission (TX), with an RLC sequence number (SN+1), for example in response to a Dynamic Grant (DG) received from the BS.

[0062] Step 6 (at 210): Upon receipt of the TX (SN+1), the HARQ receiver triggers a HARQ process to decode the received TX. In this case, HARQ decoding is successful and the HARQ process forwards the RLC packet to the RLC entity.

[0063] Step 7 (at 212): Following receipt of the RLC packet (SN+1), the RLC entity determines that there is an SN gap (i.e. SN is missing between (SN-1) and (SN+1)). Upon gap detection, the BS starts the t-Reassembly timer.

[0064] Step 8 (at 214): The t-Reassembly timer expires without successfully receiving the missing RLC packet (SN), for example because the BS decided to perform a HARQ timeout of that process. The BS RLC receiver triggers transmission of a status report and / or a NACK message to the UE.

[0065] Step 9 (at 216): Following receipt of the status report and / or NACK message, the UE sends a retransmission (RTX) with the same RLC sequence number (SN).

[0066] In the example of FIG. 2, the HARQ entity failed to decode the received HARQ TX carrying the RLC packet (SN) at Step 4 (206), leading to detection of an SN gap following receipt of a later TX with SN+1 in the RLC receiver. An alternative failure can occur wherein the UE transmits (at 204) the UL HARQ TX carrying the RLC packet (SN) based on a falsely detected Uplink Grant. For example, the UE may falsely interpret noise as an UL grant. In this case, the UL transmission will not be received, because the BS did not actually send an UL grant, and consequently the HARQ entity for decoding the HARQ TX (RLC SN) will not be started. In this case, the SN gap will still be detected at Step 7, when the later TX with SN+1 is received and decoded.

[0067] In contrast to the conventional method described above, FIG. 3 A shows a message flow diagram illustrating gap detection according to Option 1 above. As may be seen in FIG. 3 A, the illustrated embodiment includes the following steps:

[0068] Step 1 (at 300): The UE performs an UL transmission (TX) to the Base station (BS), for example in response to a Dynamic Grant (DG) received from the BS. The TX is associated with an RLC packet with sequence number (SN).

[0069] Step 2 (at 302): Upon receipt of the TX, the HARQ receiver triggers HARQ decoding of the received TX. In this case, the HARQ decoding of the received TX (SN) fails and the HARQ receiver of the BS decides to timeout the HARQ process. This timeout is indicated to the RLC entity.

[0070] Step 3 (at 304): In response to the HARQ-Timeout indication, the RLC entity obtains the RLC SN(s) associated with the discarded HARQ process to generate the early status report.

[0071] Step 4 (at 306): The RLC entity triggers transmission of an RLC early status report and / or a NACK message to the UE indicating the RLC SN (SN) associated with the failed HARQ process.

[0072] Step 5 (at 308): Following receipt of the early status report and / or NACK message, the UE sends a retransmission (RTX) of the RLC packet identified by the indicated RLC sequence number (SN). Upon receipt of the UL retransmission (RTX), the receiver triggers a HARQ decoding attempt of the received RTX, repeating from step 2 (at 306) above.

[0073] As may be seen in FIGs. 2 and 3 A, the transmission of the early status report / NACK message at 306, results in a significant reduction of the recovery delay due tonot waiting for RLC SN gap detection following reception of a later RLC TX (e.g. with SN+1) , which triggers the start of the t-Reassembly timer, and subsequent expiry of the t-Reassembly timer.

[0074] FIG. 3B shows an alternative embodiment that operates on the same principle as FIG. 3A, but instead of triggering steps 3 and 4 (at 304-306) immediately after the HARQ timeout (at 302), the network waits for a further HARQ / RLC transmission 310 to be received (at 312) and successfully decoded so that the RLC entity receives at least one subsequent RLC packet, before detecting an SN gap (at 314) and triggering the early status report and / or NACK message (at 306). In this embodiment, the BS waits for gap detection, but it does not start the t-Reassembly timer and wait for subsequent expiry of the t-Reassembly timer before triggering the status report and / or NACK (at 214).

[0075] FIG. 3C is a message flow diagram illustrating gap detection according to Option 2 above, which relates to the case of the UE transmitting an TX in response to a falsely detected uplink grant.. In the example of FIG. 3C, the method includes the following steps:

[0076] Step 1 (at 200): The UE performs an UL transmission (TX) to the Base station (BS), such as a gNB, for example in response to a Dynamic Grant (DG) received from the BS. The TX is associated with an RLC packet with sequence number (SN-1).

[0077] Step 2 (at 202): Upon receipt of the TX (SN-1), the HARQ receiver triggers a HARQ process to decode the received TX. In this case, HARQ decoding is successful and the HARQ process forwards the RLC packet to the RLC entity.

[0078] Step 3 (at 316): The UE transmits a second UL transmission (TX) with an RLC sequence number (SN) based on a falsely detected grant. For example, the UE may falsely interpret noise as an UL grant.

[0079] Step 4 (At 318): The UL transmission (carrying RLC SN) is not received by the BS, because it is not associated with an actual DG. Consequently a HARQ decoding process associated with SN is not started

[0080] Step 5 (at 320): The UE transmits a further UL transmission (TX) with an RLC sequence number (SN+1), in response to a DG received from the BS.

[0081] Step 6 (at 322): Upon receipt of the UL transmission (TX (SN+1)), the HARQ receiver triggers HARQ decoding of the received TX. The decoding in the HARQ entity is successful and the packet with SN+1 is forwarded to the RLC entity.

[0082] Step 7 (at 324): The SN is recognized as missing by the RLC entity as it has received two discontinuous RLC sequence numbers (in this case SN-1 and SN 3).

[0083] Step 8 (at 326): Upon the SN gap detection, the RLC entity interacts with the HARQ layer to determine whether there are ongoing HARQ processes indicating HARQ data potentially carrying RLC service data unit with SN. In this case, the HARQ layer indicates that there are no HARQ processes in use (i.e. no HARQ processes pending or scheduled, and thus no HARQ data in flight).

[0084] Step 9 (at 328): In response to determining there are no HARQ processes in use that could carry the RLC packet with sequence number SN, the RLC entity triggers transmission of an early status report and / or a NACK message to the UE, without starting the t-Reassembly timer to avoid unnecessary transmission of RLC status reports.

[0085] Step 10 (at 308): Following receipt of the early status report and / or NACK message, the UE sends a retransmission (RTX) with the same RLC sequence number (SN). Upon receipt of the UL retransmission (RTX), the receiver triggers a HARQ decoding attempt of the received RTX, repeating from step 2 (at 202) above..Details, how to consider identified gap in RLC specification

[0086] In the current RLC standard, only one t-Reassembly timer is employed in total, i.e. when a gap in the SN sequence is identified it is started. Upon expiry, if there is further SN gap, it is started again. According to the RLC standard, data units are therein considering received or not received yet. There is no third state differentiating between not received and identified as failed. Introducing the indication from HARQ to RLC about failed RLC receptions however provides the information of “identified as failed” to RLC and RLC could then differentiate between identified as failed and pending.

[0087] RLC maintains the variable RX HIGHEST STATUS to limit the status reporting to be about the reception gaps for which t-Reassembly already expired. Further gaps afterwards are not reported (until t-Reassembly also expired for them). T-Reassembly timer runs are associated with the state variable RX NEXT STATUS TRIGGER, the SN received after a gap. RX HIGHEST STATUS is updated to this variable after expiry.Example 1 for a simple case:a) RLC0 is received, RX HIGHEST STATUS is set to 1.b) RLC2 is received, t-Reassembly starts, RX NEXT STATUS TRIGGER is set to 2.c) Embodiment: upon indication of failure of RLC 1, t-Reassembly, is expired (meaning that it is shortcut and actions upon expiry are triggered). T- Reassembly is only expired if failure is indicated for SN < RX NEXT STATUS TRIGGER, i.e. if the timer had been started due to this SN missing. RX HIGHEST STATUS is set to 3 in this case.Example2 for the case of FIG. 4:

[0088] In a different example for the Figure 2-4 a case where two SNs are missing is shown. No gap is identified for RLC1. Thus, the t-Reassembly timer started when RLC2 was received after RLCO.

[0089] According to current RLC specification, RLC would in this case not have updated RX HIGHEST STATUS beyond 1. RLC still waits (correctly) for the missing RLC1 some time, before indicating its failure.

[0090] Later, RLC4 is received and RLC3 is indicated as failed according to this disclosure.

[0091] It is important that according this disclosure, not any failure indication leads to t-Reassembly expiry, but only failure indications of SNs that triggered the timer. As explained above, t-Reassembly is only expired if failed indicated SN <RX NEXT STATUS TRIGGER. In this example the failure indication is RLC3 while RX NEXT STATUS TRIGGER is 2. The t-reassembly timer is thus not expired. Otherwise even though RLC1 was not indicated as failed, the RLC receiver would have not waited for it long enough before considering it also failed.

[0092] With current specification, RLC status reporting would thus not be able to indicate the identified failure RLC3. The failure indication according to this disclosure would not lead to any sped-up status reporting or retransmission.

[0093] So, another embodiment is introduced: RLC status reporting should also allow indicating RLC SNs that are indicated as failed, which may go beyondRX HIGHEST STATUS. The RLC SNs may be explicitly marked as identified as failed or as not received (NACK). When RLC status report size is limited, inclusion of these RLC SNs may be prioritized over other information in the RLC status report. For the example in above Figure 2-4 ACK would be 0 and NACK 3.to Unacknowledged mode (UM).

[0094] Furthermore, if no retransmission scheme is employed in RLC, i.e. unacknowledged mode (UM) of operation, the identified gap on HARQ could further be indicated to PDCP layer, i.e. to consider a PDCP PDU SN as discarded and skip the related reorderingTimer. The reorderingTimer defines a waiting time for missing SNs before delivering subsequent SNs, in order to maintain their original sequence. When it is identified at HARQ layer though that certain SNs are not going to be received anymore, the reordering procedure can be skipped.

[0095] Figure 5 shows an example of a communication system 500 in accordance with some embodiments.

[0096] In the example, the communication system 500 includes a telecommunication network 502 that includes an access network 504, such as a radio access network (RAN), and a core network 506, which includes one or more core network nodes 508. The access network 504 includes one or more access network nodes, such as network nodes 510a and 510b (one or more of which may be generally referred to as network nodes 510), or any other similar 3rdGeneration Partnership Project (3GPP) access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, 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 telecommunication network 502 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 502 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 nodes to implement one or more functionalities of any node in the telecommunication network 502, including one or more network nodes 510 and / or core network nodes 508.

[0097] 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). The network node may support a specification by, for example, supporting an interfacedefined 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 access 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 0-2 interface defined by the O-RAN Alliance or comparable technologies. The network nodes 510 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 512a, 512b, 512c, and 512d (one or more of which may be generally referred to as UEs 512) to the core network 506 over one or more wireless connections.

[0098] 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 500 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 or wireless connections. The communication system 500 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0099] The UEs 512 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 510 and other communication devices. Similarly, the network nodes 510 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 512 and / or with other network nodes or equipment in the telecommunication network 502 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 502.

[0100] In the depicted example, the core network 506 connects the network nodes 510 to one or more host computing systems, such as host 516. 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 506 includes one more core network nodes (e.g., core network node 508) that are structured with hardware and software components. Features of these components may be substantially similar to those describedwith respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 508.Example core network nodes include 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).

[0101] The host 516 may be under the ownership or control of a service provider other than an operator or provider of the access network 504 and / or the telecommunication network 502. The host 516 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.

[0102] As a whole, the communication system 500 of Figure 5 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 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 (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0103] In some examples, the telecommunication network 502 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 502 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 502. For example, the telecommunications network 502 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.

[0104] In some examples, the UEs 512 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 504 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 504.Additionally, a UE may be configured for operating in single- or multi-RAT or multistandard 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).

[0105] In the example, the hub 514 communicates with the access network 504 to facilitate indirect communication between one or more UEs (e.g., UE 512c and / or 512d) and network nodes (e.g., network node 510b). In some examples, the hub 514 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 514 may be a broadband router enabling access to the core network 506 for the UEs. As another example, the hub 514 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 510, or by executable code, script, process, or other instructions in the hub 514. As another example, the hub 514 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 514 may be a content source. For example, for a UE that is a VR device, display, loudspeaker, or other media delivery device, the hub 514 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 514 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 514 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0106] The hub 514 may have a constant / persistent or intermittent connection to the network node 510b. The hub 514 may also allow for a different communication scheme and / or schedule between the hub 514 and UEs (e.g., UE 512c and / or 512d), and between the hub 514 and the core network 506. In other examples, the hub 514 is connected to the corenetwork 506 and / or one or more UEs via a wired connection. Moreover, the hub 514 may be configured to connect to an M2M service provider over the access network 504 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 510 while still connected via the hub 514 via a wired or wireless connection. In some embodiments, the hub 514 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 510b. In other embodiments, the hub 514 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 510b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0107] Figure 6 shows a UE 600 in accordance with some embodiments. The UE 600 presents additional details of some embodiments of the UE 512 of Figure 1. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE 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 / playback device, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), an Augmented Reality (AR) or Virtual Reality (VR) device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-loT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0108] A UE 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, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may 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, a UE 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).

[0109] The UE 600 includes processing circuitry 602 that is operatively coupled via a bus 604 to an input / output interface 606, a power source 608, a memory 610, a communication interface 612, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 6. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0110] The processing circuitry 602 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 610. The processing circuitry 602 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 602 may include multiple central processing units (CPUs).[OHl] In the example, the input / output interface 606 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 the UE 600. 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 may be, 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.

[0112] In some embodiments, the power source 608 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricityoutlet), photovoltaic device, or power cell, may be used. The power source 608 may further include power circuitry for delivering power from the power source 608 itself, and / or an external power source, to the various parts of the UE 600 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 608. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 608 to make the power suitable for the respective components of the UE 600 to which power is supplied.

[0113] The memory 610 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 610 includes one or more application programs 614, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 616. The memory 610 may store, for use by the UE 600, any of a variety of various operating systems or combinations of operating systems.

[0114] The memory 610 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 610 may allow the UE 600 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 610, which may be or comprise a device-readable storage medium.

[0115] The processing circuitry 602 may be configured to communicate with an access network or other network using the communication interface 612. The communicationinterface 612 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 622. The communication interface 612 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 UE or a network node in an access network). Each transceiver may include a transmitter 618 and / or a receiver 620 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 618 and receiver 620 may be coupled to one or more antennas (e.g., antenna 622) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0116] In the illustrated embodiment, communication functions of the communication interface 612 may include cellular communication, Wi-Fi communication, 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 in 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 / intemet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0117] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 612, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The 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).

[0118] As another example, a UE 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, the UE may comprise a motor that adjusts thecontrol 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.

[0119] A UE, 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, city 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. A UE in the form of an loT device 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 UE 600 shown in Figure 6.

[0120] As yet another specific example, in an loT scenario, a UE 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 UE and / or a network node. The UE 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, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE 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.

[0121] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE 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 UE can also include more than one ofthe functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0122] Figure 7 shows a network node 700 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 telecommunication network. 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., 0-RU, 0-DU, O-CU).

[0123] Base stations 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. A base station may be a relay node or a relay donor node controlling a relay. A network node 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 0-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).

[0124] Other examples of network nodes 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).

[0125] The network node 700 includes a processing circuitry 702, a memory 704, a communication interface 706, and a power source 708. The network node 700 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 700 comprisesmultiple separate components (e.g., BTS and BSC components), one or more of the separate components 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 700 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 704 for different RATs) and some components may be reused (e.g., a same antenna 710 may be shared by different RATs). The network node 700 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 700, for example GSM, WCDMA, LTE, NR, WiFi, 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 700.

[0126] The processing circuitry 702 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 network node 700 components, such as the memory 704, to provide network node 700 functionality.

[0127] In some embodiments, the processing circuitry 702 includes a system on a chip (SOC). In some embodiments, the processing circuitry 702 includes one or more of radio frequency (RF) transceiver circuitry 712 and baseband processing circuitry 714. In some embodiments, the radio frequency (RF) transceiver circuitry 712 and the baseband processing circuitry 714 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 712 and baseband processing circuitry 714 may be on the same chip or set of chips, boards, or units.

[0128] The memory 704 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, 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 computerexecutable memory devices that store information, data, and / or instructions that may be usedby the processing circuitry 702. The memory 704 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 702 and utilized by the network node 700. The memory 704 may be used to store any calculations made by the processing circuitry 702 and / or any data received via the communication interface 706. In some embodiments, the processing circuitry 702 and memory 704 is integrated.

[0129] The communication interface 706 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 706 comprises port(s) / terminal(s) 716 to send and receive data, for example to and from a network over a wired connection. The communication interface 706 also includes radio front-end circuitry 718 that may be coupled to, or in certain embodiments a part of, the antenna 710. Radio front-end circuitry 718 comprises filters 720 and amplifiers 722. The radio front-end circuitry 718 may be connected to an antenna 710 and processing circuitry 702. The radio front-end circuitry may be configured to condition signals communicated between antenna 710 and processing circuitry 702. The radio front-end circuitry 718 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 718 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 720 and / or amplifiers 722. The radio signal may then be transmitted via the antenna 710. Similarly, when receiving data, the antenna 710 may collect radio signals which are then converted into digital data by the radio front-end circuitry 718. The digital data may be passed to the processing circuitry 702. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0130] In certain alternative embodiments, the network node 700 does not include separate radio front-end circuitry 718, instead, the processing circuitry 702 includes radio front-end circuitry and is connected to the antenna 710. Similarly, in some embodiments, all or some of the RF transceiver circuitry 712 is part of the communication interface 706. In still other embodiments, the communication interface 706 includes one or more ports or terminals 716, the radio front-end circuitry 718, and the RF transceiver circuitry 712, as part of a radio unit (not shown), and the communication interface 706 communicates with the baseband processing circuitry 714, which is part of a digital unit (not shown).

[0131] The antenna 710 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 710 may be coupled to the radio frontend circuitry 718 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 710 is separate from the network node 700 and connectable to the network node 700 through an interface or port.

[0132] The antenna 710, communication interface 706, and / or the processing circuitry 702 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 710, the communication interface 706, and / or the processing circuitry 702 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0133] The power source 708 provides power to the various components of network node 700 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 708 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 700 with power for performing the functionality described herein. For example, the network node 700 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 708. As a further example, the power source 708 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.

[0134] Embodiments of the network node 700 may include additional components beyond those shown in Figure 7 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 700 may include user interface equipment to allow input of information into the network node 700 and to allow output of information from the network node 700. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 700. In some embodiments providing a core network node, such as core network node108 of FIG. 5, some components, such as the radio front-end circuitry 718 and the RF transceiver circuitry 712 may be omitted.

[0135] Figure 8 is a block diagram illustrating a virtualization environment 800 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 800 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the 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 800 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. Virtualization may facilitate distributed implementations of a network node, UE, core network node, or host.

[0136] Applications 802 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0137] Hardware 804 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 806 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 808a and 808b (one or more of which may be generally referred to as VMs 808), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 806 may present a virtual operating platform that appears like networking hardware to the VMs 808.

[0138] The VMs 808 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 806. Different embodiments of the instance of a virtual appliance 802 may be implemented on one or more of VMs 808, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts 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.

[0139] In the context of NFV, a VM 808 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 808, and that part of hardware 804 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 VMs 808 on top of the hardware 804 and corresponds to the application 802.

[0140] Hardware 804 may be implemented in a standalone network node with generic or specific components. Hardware 804 may implement some functions via virtualization.Alternatively, hardware 804 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 810, which, among others, oversees lifecycle management of applications 802. In some embodiments, hardware 804 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 812 which may alternatively be used for communication between hardware nodes and radio units.

[0141] Although the computing devices described herein (e.g., UEs, network nodes) 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 disclosedherein. 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 within multiple 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.

[0142] 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.

Claims

ClaimsWhat is claimed is:

1. A method performed by a network node for managing uplink traffic, the method comprising:receiving (302, 318, 322), from a user equipment (UE), one or more uplink hybrid automatic repeat request (HARQ) transmissions, each uplink HARQ transmission including a respective radio link control (RLC) sequence number (SN);detecting (304, 314, 324) a sequence number gap in the respective RLC SNs of the received uplink HARQ transmissions; andin response to detecting the sequence number gap:determining (306, 326) one or more missing sequence numbers in the respective RLC SNs of the received uplink HARQ transmissions; and subsequently triggering (306, 328) transmission of an RLC early status report and / or a NACK message to the UE indicating the RLC SN associated with the missing sequence numbers.

2. The method of claim 1, wherein detecting the sequence number gap comprises an RLC entity receiving (304) a HARQ process timeout indication from a HARQ entity of the network node.

3. The method of claim 2, further comprising the HARQ process detecting (302) failure to receive an uplink HARQ transmission and the BS determining a timeout of the HARQ process, and forwarding the HARQ timeout indication for that HARQ process to the RLC entity.

4. The method of claim 2, wherein determining the one or more missing sequence number(s) comprises the RLC entity obtaining the RLC SN associated with the indicated HARQ process.

5. The method of claim 2, wherein the steps of determining the one or more missing sequence numbers and triggering transmission of the RLC early status report and / ora NACK message are performed immediately after detecting the one or more missing sequence number(s).

6. The method of claim 2, further comprising receiving (312), from the UE, at least one later uplink transmission after the HARQ timeout indication, and wherein the steps of determining the one or more missing sequence numbers and triggering transmission of the RLC early status report and / or a NACK message are performed after successful HARQ decoding of the one or more later uplink transmissions.

7. The method of claim 1, wherein detecting the sequence number gap comprises:an RLC entity observing a discontinuous set of RLC SNs associated with received and successfully decoded uplink HARQ transmissions.

8. The method of claim 7, wherein the discontinuous set comprises a first set of one or more earlier received RLC SNs, and a second set of one or more later received RLC SNs, the RLC SNs of the second set being discontinuous with the RLC SNs of the first set, and wherein determining the one or more missing sequence numbers comprises:the RLC entity interacting with a HARQ entity to identify at least one RLC SN lying between the first and second sets, and for which there are no pending or scheduled HARQ processes.

9. The method of claim 7, wherein the steps of determining the one or more missing sequence number(s) comprises determining whether the each missing RLC SN is smaller than an RX NEXT STATUS TRIGGER,10. The method of claim 7, wherein the step of determining the one or more missing sequence numbers comprises determining whether the missing RLC SN(s) are equal or higher than RX HIGHEST STATUS .

11. A network node for managing uplink traffic, the network node comprising:processing circuitry configured to perform any of the steps of any of claims 1 - 8;

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