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EP-4646901-B1 - SIGNAL-TO-INTERFERENCE-PLUS-NOISE RATIO REPORT FOR OPEN RADIO ACCESS NETWORK OPEN FRONTHAUL INTERFACE

EP4646901B1EP 4646901 B1EP4646901 B1EP 4646901B1EP-4646901-B1

Inventors

  • LU, CHENGUANG
  • HUANG, Yezi
  • HUSS, FREDRIK
  • TESSIER, Stéphane
  • VDOVIN, Lev
  • HENNERT, LARS
  • KARLSSON, JONAS
  • BERG, MIGUEL
  • POHLMAN, Björn
  • SUN, LOUISE

Dates

Publication Date
20260513
Application Date
20241219

Claims (19)

  1. A method of operating a network node in a communications network, the network node configured to provide a radio unit, RU, the method comprising: determining (1240) a symbol pattern that the RU is capable of using to transmit a signal-to-interference-plus-noise, SINR, report to a distributed unit, DU; transmitting (1250) an indication to the DU of the symbol pattern that the RU is capable of using to transmit the SINR report to the DU; and transmitting (1260) the SINR report to the DU using the symbol pattern.
  2. The method of Claim 1, wherein determining the symbol pattern that the RU is capable of using to transmit the SINR report to the DU comprises determining the symbol pattern to be used for transmitting the SINR report to the DU, and wherein transmitting the indication to the DU of the symbol pattern that the RU is capable of using to transmit the SINR report to the DU comprises transmitting an indication to the DU of the symbol pattern to be used for transmitting the SINR report to the DU.
  3. The method of Claim 2, wherein the SINR report is a first SINR report of a plurality of SINR reports, wherein determining the symbol pattern to be used for transmitting the SINR report to the DU comprises determining the symbol pattern to be used for transmitting the plurality of SINR reports to the DU, and wherein transmitting the indication to the DU of the symbol pattern to be used for transmitting the SINR report comprises transmitting the indication to the DU of the symbol pattern to be used for transmitting the plurality of SINR reports to the DU.
  4. The method of Claim 3, wherein the SINR report is a first SINR of the plurality of SINR reports, wherein transmitting the SINR report to the DU using the symbol pattern comprises: transmitting the first SINR report of the plurality of SINR reports within a first number of symbols associated with the symbol pattern; and transmitting a second SINR report of the plurality of SINR reports within a second number of symbols associated with the symbol pattern.
  5. The method of Claim 4, wherein the first number of symbols associated with the symbol pattern is different than the second number of symbols associated with the symbol pattern.
  6. The method of any of Claims 2-5, wherein transmitting the indication to the DU of the symbol pattern to be used for transmitting the SINR report to the DU comprises transmitting a Section Type 9, ST9, message via a control plane, C-plane, to the DU, the ST9 message including the indication of the symbol pattern to be used for transmitting the SINR report to the DU.
  7. The method of any of Claims 1-6, wherein transmitting the SINR report to the DU comprises transmitting SINR data within a slot, and wherein the indication of the symbol pattern comprises an indication of a symbol mask that indicates a position of the SINR report within the slot.
  8. The method of any of Claims 1-7, wherein the communications network comprises an open radio access network, O-RAN, wherein the RU comprises an O-RAN RU, O-RU, and wherein the DU comprises an O-RAN DU, O-DU.
  9. A method of operating a network node in a communications network, the network node configured to provide a distributed unit, DU, the method comprising: receiving (1540) an indication from a radio unit, RU, of a symbol pattern that the RU is capable of using to transmit a signal-to-interference-plus-noise, SINR, report to the DU; and receiving (1550) the SINR report from the RU using the symbol pattern.
  10. The method of Claim 9, wherein receiving the indication from the RU of the symbol pattern that the RU is capable of using to transmit the SINR report to the DU comprises receiving an indication from the RU that the symbol pattern will be used for transmitting the SINR report to the DU.
  11. The method of Claim 10, wherein the SINR report is a first SINR report of a plurality of SINR reports, and wherein receiving the indication from the RU that the symbol pattern will be used for transmitting the SINR report comprises receiving the indication from the DU that the symbol pattern will be used for transmitting the plurality of SINR reports to the DU.
  12. The method of Claim 11, wherein the SINR report is a first SINR of the plurality of SINR reports, wherein receiving the SINR report from the RU using the symbol pattern comprises: receiving the first SINR report of the plurality of SINR reports within a first number of symbols associated with the symbol pattern; and receiving a second SINR report of the plurality of SINR reports within a second number of symbols associated with the symbol pattern.
  13. The method of Claim 12, wherein the first number of symbols associated with the symbol pattern is different than the second number of symbols associated with the symbol pattern.
  14. The method of any of Claims 10-13, wherein receiving the indication from the RU that the symbol pattern will be used for transmitting the SINR report to the DU comprises receiving a Section Type 9, ST9, message via a control plane, C-plane, from the RU, the ST9 message including the indication that the symbol pattern will be used for transmitting the SINR report to the DU.
  15. The method of any of Claims 9-14, wherein receiving the SINR report from the RU comprises receiving SINR data within a slot, and wherein the indication of the symbol pattern comprises an indication of a symbol mask that indicates a position of the SINR report within the slot.
  16. The method of any of Claims 10-15, further comprising: prior to receiving the indication from the RU of the symbol pattern that the RU will be using to transmit the SINR report to the DU, receiving (1610) an indication from the RU, via a management plane, M-plane, of a plurality of symbol patterns that the RU is capable of using to transmit the SINR report to the DU.
  17. The method of any of Claims 9-16, wherein the communications network comprises an open radio access network, O-RAN, wherein the RU comprises an O-RAN RU, O-RU, and wherein the DU comprises an O-RAN DU, O-DU.
  18. A network node (2000) in a communications network, the network node adapted to perform the method of any of the claims 1-17.
  19. A computer program comprising program code to be executed by processing circuitry (2002) of a network node (2000) in a communications network, whereby execution of the program code causes the network node to perform the method of any of the claims 1-17.

Description

TECHNICAL FIELD The present disclosure is related to wireless communication systems and more particularly to efficient and flexible signal-to-interference-plus-noise ratio ("SINR") report for open radio access network ("O-RAN") open fronthaul interface. BACKGROUND The present disclosure is related to wireless communication systems and more particularly to efficient and flexible signal-to-interference-plus-noise ratio ("SINR") report for open radio access network ("O-RAN") open fronthaul interface. FIG. 1 illustrates an example of a new radio ("NR") network (e.g., a 5th Generation ("5G") network) including a 5G core ("5GC") network 130, network nodes 120a-b (e.g., 5G base station ("gNB")), multiple communication devices 110 (also referred to as user equipment ("UE")). Massive multiple-input-multiple-output ("MIMO") techniques have been first adopted to practice in long term evolution ("LTE"). In 5G, it becomes a key technology component, which can be deployed in a much larger scale than in LTE. It features a large number of antennas used on the base-station side, where the number of antennas is typically much larger than the number of user-layers, for example, 64 antennas serving 8 or 16 user-layers in frequency range 1 ("FR1"), which includes sub-6 GHz frequency bands, and 256/512 antennas serving 2 or 4 layers in frequency range 2 ("FR2"), which includes frequency bands from 24.25 GHz to 52.6 GHz. A user layer can be used herein to refer to an independent downlink or uplink data stream intended for one user. One user or UE may have one or multiple user layers. A user layer can also be referred to as a layer in the 3rd generation partnership project ("3GPP") terminology. Massive MIMO can also be referred to as massive beamforming, which is able to form narrow beams focusing on different directions to counteract against the increased path loss at higher frequency bands. It also benefits multi-user MIMO which allows for transmissions from/to multiple users simultaneously over separate spatial channels resolved by the massive MIMO technologies, while keeping high capacity for each user. Therefore, it can significantly increase the spectrum efficiency and cell capacity. At the base-station side, the interface between the distributed unit ("DU") and the radio unit (RU) is the fronthaul interface, as shown in FIG. 2. The great benefits of massive MIMO at the air-interface also introduce new challenges at the base-station side. The legacy common public radio interface ("CPRI")-type fronthaul transports time-domain in-phase and quadrature ("IQ") samples per antenna branch. As the number of antennas scales up in massive MIMO systems, the required fronthaul capacity also increases proportionally, which significantly drives up the fronthaul costs. To address this challenge, the fronthaul interface evolves from CPRI to enhance CPRI ("eCPRI"), a packet-based fronthaul interface. In eCPRI, other functional split options between a distributed unit ("DU") and a radio unit ("RU") are supported, referred to as different lower-layer split ("LLS") options. In the eCPRI standard specification, the terms eCPRI Radio Equipment Control ("eREC") and (eCPRI Radio Equipment ("eRE") are used instead of DU and RU. The basic idea is to move the frequency-domain beamforming function from DU to RU so that frequency samples or data of user-layers are transported over the fronthaul interface. Note that the frequency-domain beamforming is sometimes also referred to as precoding in the downlink ("DL") direction and equalizing or pre-equalizing in uplink ("UL") direction. By doing this, the required fronthaul capacity and thereby the fronthaul costs are significantly reduced, as the number of user layers is typically much fewer than the number of antennas in massive MIMO. In open radio access network ("O-RAN"), DU is referred to as O-DU while RU is referred to as O-RU. WO 2023/152180 A1 discloses transmitting post-equalization SNIR values from O-RU to O-DU where SNIR is per time and frequency unit over a PUSCH allocation for each layer and user. Time resolution may be configured, i.e. that SNIR is averaged over a configured number of OFDM symbols. US 2023/155864 A1 discloses various O-RAN functional splits, among these an UL functional split with O-RU Cat C2 wherein the O-RU performs the "DM-RS based Channel Estimation" and "Equalization" in the UL, and the O-DU performs demodulation. ETSI Draft; MSG(24)000003, "ETSI TS 103 859 V12.0.0 (2024-01)", "Publicly Available Specification (PAS); O-RAN Fronthaul Control, User and Synchronization Plane Specification v12.00; (O-RAN.WG4.CUS.0-R003-v12.00)", European Telecommunications Standards Institute (ETSI), 650, route des Lucioles ; F-06921 Sophia-Antipolis ; France discloses O-RAN functional split options and fronthaul section types. SUMMARY The invention is set out in the claims. A first aspect of the invention comprises a method of operating a network node in a communications network as set forth