Search

WO-2026096714-A1 - OPTIMIZING INTER-DU DOWNLINK RADIO RESOURCE MANAGEMENT IN O-RAN NETWORKS

WO2026096714A1WO 2026096714 A1WO2026096714 A1WO 2026096714A1WO-2026096714-A1

Abstract

In a system for implementing optimized coordinated multi-point transmission (CoMP) in an Open Radio Access Network (O-RAN) wireless system including at least one centralized unit (CU) of the O-RAN; a first distributed unit (DU) of the O-RAN; and a second DU of the O-RAN, optimized CoMP is implemented based on information provided by at least one of the CU, the first DU and the second DU regarding at least one of i) interference experienced by a user equipment (UE) in a first serving cell of the first DU from a neighbor cell of the first serving cell, and ii) interference experienced in a second serving cell of the second DU from a neighbor cell of the second serving cell. Coordination of the optimized CoMP is implemented by at least one of the first DU, the second DU and a near-real time radio intelligent controller (near-RT RIC).

Inventors

  • MIDDE, SUNIL KUMAR SHETTY
  • KAIMALETTU, SUNIL
  • TANEJA, MUKESH

Assignees

  • MAVENIR SYSTEMS, INC.

Dates

Publication Date
20260507
Application Date
20251030
Priority Date
20241030

Claims (20)

  1. CLAIMS:
  2. 1. A method for implementing optimized coordinated multi-point transmission (CoMP) in an Open Radio Access Network (O-RAN) wireless system, comprising:
  3. providing at least one centralized unit (CU) of the O-RAN;
  4. providing a first distributed unit (DU) of the O-RAN;
  5. providing a second DU of the O-RAN; and
  6. implementing the optimized CoMP based on information provided by at least one of the CU, the first DU and the second DU regarding at least one of i) interference experienced by a user equipment (UE) in a first serving cell of the first DU from a neighbor cell of the first serving cell, and ii) interference experienced in a second serving cell of the second DU from a neighbor cell of the second serving cell, wherein coordination of the optimized CoMP is implemented by at least one of the first DU, the second DU and a near-real time radio intelligent controller (near-RT RIC).
  7. 2. The method of claim 1, wherein:
  8. the first DU and the second DU are communicatively connected via D2 application protocol (D2-AP) connection; and
  9. the optimized CoMP comprises the first DU sending a message to the second DU requesting to blank at least one physical resource block (PRB) in at least one cell served by the second DU, and said message to the second DU comprises per-cell information of cells served by second DU.
  10. 3. The method of claim 2, wherein:
  11. the at least one CU is communicatively connected to the first DU via a first Fl application protocol (Fl-AP) connection;
  12. the at least one CU is communicatively connected to the second DU via a second Fl-AP connection; and the first Fl-AP connection and the second Fl-AP connection are enhanced for measurement report triggering and reporting.
  13. 4. The method of claim 2, further comprising:
  14. providing a second CU;
  15. wherein the first CU is communicatively connected to the first DU via a first Fl application protocol (Fl-AP) connection;
  16. wherein the second CU is communicatively connected to the second DU via a second Fl-AP connection; and
  17. wherein the first Fl-AP connection and the second Fl-AP connection are enhanced for measurement report triggering and reporting.
  18. 5. The method of claim 4, wherein:
  19. the first CU and the second CU are communicatively connected to each other via Xn control plane (Xn-C) interface.
  20. 6. The method of claim 1, further comprising:

Description

Optimizing Inter-DU Downlink Radio Resource Management in O-RAN Networks BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure [0001] The present disclosure relates to Open Radio Access Network (O-RAN) systems, and relates more particularly to optimization of inter-DU downlink radio resource management in O-RAN systems. 2. Description of Related Art [0002] In the following sections, an overview of Next Generation Radio Access Network (NG-RAN) architecture and 5GNew Radio (NR) stacks will be presented. 5GNew Radio (NR) user and control plane functions with monolithic gNB (gNodeB) are shown in FIGS. 1a, 1b and 2. For the user plane (shown in FIG. 1a, which is in accordance with 3GPP TS 38.300), physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP) and Service Data Adaptation Protocol (SDAP) sublayers originate in the UE 101 and are terminated in the gNB 102 on the network side. [0003] As shown in FIG. 1b, which is a block diagram illustrating the user plane protocols stacks for a PDU session, in accordance with 3GPP TS 23.501, PDU layer 9010 corresponds to the PDU carried between the UE 101 and the data network (DN) 9011 over the PDU session. As shown in FIG. 1b, UE 101 is connected to the 5G access network (AN) 902, which AN 902 is in turn connected via the N3 interface to the Intermediate UPF (I-UPF) 903a portion of the UPF 903, which I-UPF 903a is in turn connected via the N9 interface to the PDU session anchor 903b portion of the UPF 903, and which PDU session anchor 903b is connected to the DN 9011. The PDU session can correspond to IPv4, IPv6, or both types of IP packets, when the PDU session is of type IPv4, IPv6 or IPv4v6, respectively. GTP-U shown in FIG. 1b supports tunnelling user plane data over N3 and N9 interfaces and provides encapsulation of end user PDUs for N3 and N9 interfaces. [0004] For the control plane (shown in FIG. 2, which is in accordance with 3GPP TS 38.300), Radio Resource Control (RRC), PDCP, RLC, MAC and PHY sublayers originate in the UE 101 and are terminated in the gNB 102 on the network side, and Non- Access Stratum (NAS) originate in the UE 101 and is terminated in the Access & Mobility Function (AMF) 103 on the network side. [0005] NG-Radio Access Network (NG-RAN) architecture from 3GPP TS 38.401 is shown in FIGS. 3-4. As shown in FIG. 3, the NG-RAN 301 consists of a set of gNBs 302 connected to the 5GC 303 through the NG interface. Each gNB comprises gNB-CU 304 and one or more gNB-DU 305 (see FIG. 3). As shown in FIG. 4 (which illustrates separation of CU-Control Plane (CU-CP) and CU-User Plane (CU-UP)), El is the interface between gNB-CU-CP 304a and gNB-CU-UP 304b, Fl-C is the interface between gNB-CU-CP 304a and gNB-DU 305, and Fl-U is the interface between gNB- CU-UP 304b and gNB-DU 305. As shown in FIG. 4, gNB 302 can consist of a gNB-CU- CP 304a, multiple gNB-CU-UPs (or gNB-CU-UP instances) 304b and multiple gNB- DUs (or gNB-DU instances) 305. One gNB-DU 305 is connected to only one gNB-CU- CP 304a, and one gNB-CU-UP 304b is connected to only one gNB-CU-CP 304a. Note that F1-Application Protocol (F1-AP) running on F1-C is specified in 3GPP TS38.473 version 18.1.0, and NR User Plane (NR-U) running on F1-U is specified in 3GPP TS38.425 version 18.0.0. [0006] In this section, an overview of Layer 2 (L2) of 5G NR will be provided in connection with FIG. 5. L2 of 5G NR is split into the following sublayers (in accordance with 3GPP TS 38.300): 1) Medium Access Control (MAC) 501 in FIGS. 5: Logical Channels (LCs) are Service Access Points (SAPs) between the MAC and RLC layers. This layer runs a MAC scheduler to schedule radio resources across different LCs (and their associated radio bearers). For the downlink direction, the MAC layer processes and sends RLC PDUs received on LCs to the Physical layer as Transport Blocks (TBs). For the uplink direction, it receives transport blocks (TBs) from the physical layer, processes these and sends to the RLC layer using the LCs. 2) Radio Link Control (RLC) 502 in FIG. 5: The RLC sublayer presents RLC channels to the Packet Data Convergence Protocol (PDCP) sublayer. The RLC sublayer supports three transmission modes: RLC-Transparent Mode (RLC-TM), RLC-Unacknowledged Mode (RLC-UM) and RLC-Acknowledgement Mode (RLC-AM). RLC configuration is per logical channel. It hosts Automatic Repeat Request (ARQ) protocol for RLC-AM mode. 3) Packet Data Convergence Protocol (PDCP) 503 in FIG. 5: The PDCP sublayer presents Radio Bearers (RBs) to the SDAP sublayer. There are two types of Radio Bearers: Data Radio Bearers (DRBs) for data and Signaling Radio Bearers (SRBs) for control plane. 4) Service Data Adaptation Protocol (SDAP) 504 in FIG. 5: The SDAP maps QoS flows within a PDU session to a specific Data Radio Bearer. FIG. 5 is a block diagram illustrating DL L2 structure, in accordance with 3GPP TS 38.300. [0007] Open Radio Access Network (O-RAN) is based on disaggregated components