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US-12627418-B2 - Logical channel prioritization within configured grants

US12627418B2US 12627418 B2US12627418 B2US 12627418B2US-12627418-B2

Abstract

Embodiments include methods for a user equipment (UE) configured to operate in a radio access network (RAN). Such methods include obtaining data for transmission during a particular one of a plurality of periodic occasions during which the UE has been granted resources for uplink data transmission. The data includes first and second protocol data units (PDUs) associated with respective first and second hybrid ARQ (HARQ) processes. At least one of the first and second PDUs is for retransmission after failed transmission during an earlier one of the occasions. Such methods include selecting the first PDU or the second PDU for transmission during the particular occasion based on at least one of the following: priorities of logical channels with data included in the first and second PDUs. and whether one or both of the first and second PDUs are for retransmission. Other embodiments include complementary methods for a RAN node.

Inventors

  • Torsten Dudda
  • Zhenhua ZOU
  • Eda Genc

Assignees

  • TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

Dates

Publication Date
20260512
Application Date
20220401

Claims (20)

  1. 1 . A method for a user equipment (UE) configured to operate in a radio access network (RAN), the method comprising: obtaining data for transmission during a particular one of a plurality of periodic occasions during which the UE has been granted resources for uplink (UL) data transmission, wherein: the particular occasion is one of a first plurality of occasions associated with a first grant of resources and one of a second plurality of occasions associated with a second grant of resources; the data includes a first protocol data unit (PDU) associated with a first hybrid ARQ (HARQ) process and a second PDU associated with a second HARQ process, and the second PDU is for retransmission after a failed transmission during an earlier one of the plurality of occasions; selecting resources from the first grant or from the second grant, based on the HARQ process associated with the selected PDU; selecting the first PDU or the second PDU for transmission during the particular occasion based on priorities of logical channels (LCHs) with data included in the first and second PDUs, comprising selecting the second PDU when a highest priority of logical channels (LCHs) with data included in the first PDU is the same as a highest priority of LCHs with data included in the second PDU; and transmitting the selected PDU during the particular occasion using the selected resources.
  2. 2 . The method of claim 1 , wherein the first PDU is for initial transmission, and selecting the first PDU or the second PDU for transmission during the particular occasion comprises selecting a particular one of the first and second PDUs that includes data associated with a LCH having the highest of the priorities of the LCHs with data included in the first and second PDUs.
  3. 3 . The method of claim 1 , wherein: the first PDU is for initial transmission, and LCHs having one or more first types of medium access control (MAC) control elements (CEs) included in the second PDU are given higher priority than LCHs having data included in the first PDU.
  4. 4 . The method of claim 3 , wherein the first types of MAC CEs are associated with different priorities.
  5. 5 . The method of claim 1 , wherein: the first PDU is for initial transmission; a configured grant timer (CGT) and a configured grant retransmission timer (CGRT) associated with the first HARQ process are not running in the UE; the first HARQ process is not pending in the UE; a CGRT associated with the second HARQ process is not running in the UE; and one of the following applies: the second HARQ process is pending in the UE, or a CGT associated with the second HARQ process is running in the UE.
  6. 6 . The method of claim 5 , further comprising, when the first PDU is selected, extending an expiration time of the CGT associated with the second HARQ process by a period of the periodic occasions.
  7. 7 . The method of claim 6 , wherein extending the expiration time is based on one of the following: that the CGT associated with the second HARQ process is running in the UE, or that the second HARQ process is pending in the UE.
  8. 8 . The method of claim 1 , wherein: the first PDU is for retransmission after a failed transmission during an earlier one of the plurality of occasions; and selecting the first PDU or the second PDU further comprises one of the following: selecting the first PDU regardless of the priorities of LCHs with data included in the first and second PDUs; or selecting the second PDU regardless of the priorities of LCHs with data included in the first and second PDUs.
  9. 9 . The method of claim 8 , wherein: a configured grant timer (CGT) associated with the first HARQ process is running in the UE; a configured grant retransmission timer (CGRT) associated with the first HARQ process has expired in the UE; a CGRT and a CGT associated with the second HARQ process are not running in the UE; and the first HARQ process is not pending and the second HARQ process is pending in the UE.
  10. 10 . The method of claim 9 , further comprising performing a listen-before-talk (LBT) procedure in the granted resources during an earlier one of the occasions, wherein the second PDU is pending retransmission after failure of the LBT procedure.
  11. 11 . A method for a network node configured to operate in a radio access network (RAN), the method comprising: receiving data from a user equipment (UE) during a particular one of a plurality of periodic occasions during which the network node has granted resources to the UE for uplink (UL) data transmission, wherein: the particular occasion is one of a first plurality of occasions associated with a first grant of resources and one of a second plurality of occasions associated with a second grant of resources; the data includes either a first protocol data unit (PDU) associated with a first hybrid ARQ (HARQ) process or a second PDU associated with a second HARQ process, the second PDUs is for retransmission after a failed transmission during an earlier one of the plurality of occasions, the data includes the second PDU when a highest priority of logical channels (LCHs) with data included in the first PDU is the same as a highest priority of LCHs with data included in the second PDU, and the data is received during the particular occasion on resources from the first grant or from the second grant, depending on the HARQ process associated with the PDU included in the data.
  12. 12 . The method of claim 11 , wherein the first PDU is for initial transmission, and the data includes a particular one of the first and second PDUs that includes data associated with a LCH having the highest of the priorities of the LCHs.
  13. 13 . The method of claim 11 , wherein: the first PDU is for initial transmission, and LCHs having one or more first types of medium access control (MAC) control elements (CEs) included in the second PDU are given higher priority than LCHs having data included in the first PDU.
  14. 14 . The method of claim 13 , wherein the first types of MAC CEs are associated with different priorities.
  15. 15 . The method of claim 11 , wherein: the first PDU is for initial transmission; a configured grant timer (CGT) and a configured grant retransmission timer (CGRT) associated with the first HARQ process are not running in the UE; the first HARQ process is not pending in the UE; a CGRT associated with the second HARQ process is not running in the UE; and one of the following applies: the second HARQ process is pending in the UE, or a CGT associated with the second HARQ process is running in the UE.
  16. 16 . The method of claim 11 , wherein: the first PDU is for retransmission after a failed transmission during an earlier one of the plurality of occasions; and one of the following applies: the data includes the first PDU regardless of the priorities of LCHs with data included in the first and second PDUs; or the data includes the second PDU regardless of the priorities of LCHs with data included in the first and second PDUs.
  17. 17 . The method of claim 16 , wherein: a configured grant timer (CGT) associated with the first HARQ process is running in the UE; a configured grant retransmission timer (CGRT) associated with the first HARQ process has expired in the UE; a CGRT and a CGT associated with the second HARQ process are not running in the UE; and the first HARQ process is not pending and the second HARQ process is pending in the UE.
  18. 18 . The method of claim 17 , wherein the second PDU is pending retransmission after a failed listen-before-talk (LBT) procedure by the UE in the granted resources during an earlier one of the occasions.
  19. 19 . The method of claim 11 , further comprising sending the first grant and the second grant to the UE.
  20. 20 . A network node configured to operate in a radio access network (RAN), the network node comprising: radio network interface circuitry configured to communicate with user equipment (UEs); and processing circuitry operatively coupled to the radio network interface circuitry, whereby the processing circuitry and the radio network interface circuitry are configured to perform the method of claim 11 .

Description

TECHNICAL FIELD The present invention generally relates to wireless communication networks, and more specifically to techniques for prioritization between multiple types (or channels) of data that are available for transmission by a user equipment (UE) during one of a plurality of occasions in which the UE has been granted transmission resources by a wireless network. BACKGROUND Currently the fifth generation (“5G”) of cellular systems, also referred to as New Radio (NR), is being standardized within the Third-Generation Partnership Project (3GPP). NR is developed for maximum flexibility to support multiple and substantially different use cases. These include enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device-to-device (D2D), and several other use cases. NR was initially specified in 3GPP Release 15 (Rel-15) and continues to evolve through subsequent releases, such as Rel-16 and Rel-17. 5G/NR technology shares many similarities with fourth-generation Long-Term Evolution (LTE). For example, NR uses CP-OFDM (Cyclic Prefix Orthogonal Frequency Division Multiplexing) in the downlink (DL) from network to user equipment (UE), and both CP-OFDM and DFT-spread OFDM (DFT-S-OFDM) in the uplink (UL) from UE to network. As another example, NR DL and UL time-domain physical resources are organized into equal-sized 1-ms subframes. A subframe is further divided into multiple slots of equal duration, with each slot including multiple OFDM-based symbols. However, time-frequency resources can be configured much more flexibly for an NR cell than for an LTE cell. For example, rather than a fixed 15-kHz OFDM sub-carrier spacing (SCS) as in LTE, NR SCS can range from 15 to 240 kHz, with even greater SCS considered for future NR releases. In addition to providing coverage via cells as in LTE, NR networks also provide coverage via “beams.” In general, a downlink (DL, i.e., network to UE) “beam” is a coverage area of a network-transmitted reference signal (RS) that may be measured or monitored by a UE. In NR, for example, RS can include any of the following: synchronization signal/PBCH block (SSB), channel state information RS (CSI-RS), tertiary reference signals (or any other sync signal), positioning RS (PRS), demodulation RS (DMRS), phase-tracking reference signals (PTRS), etc. In general, SSB is available to all UEs regardless of the state of their connection with the network, while other RS (e.g., CSI-RS, DM-RS, PTRS) are associated with specific UEs that have a network connection. FIG. 1 shows an exemplary configuration of NR user plane (UP) and control plane (CP) protocol stacks between a UE, a gNodeB (gNB, e.g., base station), and an access and mobility management function (AMF) in the 5G core network (5GC). Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP) layers between the UE and the gNB are common to UP and CP. The PDCP layer provides ciphering/deciphering, integrity protection, sequence numbering, reordering, and duplicate detection for CP and UP. PDCP provides header compression and retransmission for UP data. On the UP side, Internet protocol (IP) packets arrive to the PDCP layer as service data units (SDUs), and PDCP creates protocol data units (PDUs) to deliver to RLC. In addition, the Service Data Adaptation Protocol (SDAP) layer handles quality-of-service (QOS) including mapping between QoS flows and Data Radio Bearers (DRBs) and marking QoS flow identifiers (QFI) in UL and DL packets. When each IP packet arrives, PDCP starts a discard timer. When this timer expires, PDCP discards the associated SDU and the corresponding PDU. If the PDU was delivered to RLC, PDCP also indicates the discard to RLC. The RLC layer transfers PDCP PDUs to the MAC through logical channels (LCH). RLC provides error detection/correction, concatenation, segmentation/reassembly, sequence numbering, reordering of data transferred to/from the upper layers. If RLC receives a discard indication from associated with a PDCP PDU, it will discard the corresponding RLC SDU (or any segment thereof) if it has not been sent to lower layers. The MAC layer provides mapping between LCHs and PHY transport channels, LCH prioritization, multiplexing into or demultiplexing from transport blocks (TBs), hybrid ARQ (HARQ) error correction, and dynamic scheduling (on gNB side). The PHY layer provides transport channel services to the MAC layer and handles transfer over the NR radio interface, e.g., via modulation, coding, antenna mapping, and beam forming. On CP side, the non-access stratum (NAS) layer is between UE and AMF and handles UE/gNB authentication, mobility management, and security control. The RRC layer sits below NAS in the UE but terminates in the gNB rather than the AMF. RRC controls communications between UE and gNB at the radio interface as well as the mobility of a UE between cells in the NG-RAN. R