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Intel ACC100 LDPC offload

Mon, 01 Jan 0001 00:00:00 +0000

Scope: hardware-accelerated LDPC encoding (PDSCH) and decoding (PUSCH) on Intel ACC100 vRAN accelerator cards, with full upper-PHY metrics instrumentation so operators can directly compare CPU-software and HW-offload performance in production logs.

Introduced in commit: aa6db7d066

Highlights

LDPC offload for both PDSCH and PUSCH the most CPU-heavy channel-coding steps move off the host and onto the accelerator.
Configuration-driven enable or disable via the DU YAML; no code changes.
Multi-VF scaling allowlisting additional ACC100 VFs automatically spreads load across them.
Unified metrics the same per-block PHY metric fields populate whether LDPC runs in software (AVX-512) or on the accelerator, enabling direct side-by-side comparison from one log format.
Measured gains on real traffic significantly lower PUSCH decode latency, tighter tail latency, higher processor throughput, and reduced upper-PHY uplink CPU (see §7).

1. Prerequisites

1.1 Hardware

Intel ACC100 PCIe card, SR-IOV capable; at least one VF exposed to the host.
x86-64 CPU with AVX2 (AVX-512 recommended for the software-fallback path).
≥ 2 GB of 2 MiB hugepages.
PCIe slot on the same NUMA node as the upper-PHY worker cores.

1.2 Software

Component	Minimum version	Notes
DPDK	22.11	Tested with 25.11; ACC100 PMD (`baseband_acc`) required.
Linux kernel	5.15+	IOMMU enabled (`intel_iommu=on iommu=pt`).
`pf_bb_config`	24.03+	PF configurator daemon; must run continuously.
DU build flags	`ENABLE_DPDK=True`, `ENABLE_PDSCH_HWACC=True`, `ENABLE_PUSCH_HWACC=True`	See §5.

1.3 Kernel and VFIO setup

# Kernel boot parameters (then update-grub + reboot):
intel_iommu=on iommu=pt hugepagesz=2M hugepages=1024

# Hugepage mount if not done by distro:
echo 1024 | sudo tee /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages

# Load VFIO modules:
sudo modprobe vfio-pci
echo 1 | sudo tee /sys/module/vfio_pci/parameters/enable_sriov # if kernel-builtin

# Create one SR-IOV VF and bind it to vfio-pci:
echo 1 | sudo tee /sys/bus/pci/devices/<ACC100_PF_BDF>/sriov_numvfs
sudo dpdk-devbind.py --bind=vfio-pci <ACC100_VF_BDF>

# Start pf_bb_config holding the PF group open with a VF token.
# The token (UUID) is required in the DU's EAL args.
sudo /opt/pf-bb-config/pf_bb_config ACC100 \
 -c /opt/pf-bb-config/acc100/acc100_config_vf_5g.cfg \
 -v <UUID> &

After setup, dpdk-test-bbdev should enumerate the VF as intel_acc100_vf.

Hardware-accelerated LDPC in OCUDU: ACC100 offload now available

Wed, 22 Apr 2026 00:00:00 +0000

Modern RAN stacks are expected to offload their heaviest DSP workloads LDPC channel coding chief among them to dedicated accelerators. Look-aside FEC cards, inline SoCs, and SmartNICs have been standard integration points in commercial vRAN for several years, and the open-source ecosystem has largely followed suit.

Until this release, OCUDU did not. The hardware-abstraction layer, the upper-PHY factory hooks, and the metric plumbing were present in the codebase, but the BBDEV backend required to dispatch LDPC operations to an Intel ACC100 was not implemented. Every deployment therefore executed LDPC encode and decode on the host CPU, consuming cycles that would otherwise be available to scheduling, MAC processing, or additional cells.

Mon, 01 Jan 0001 00:00:00 +0000

OCUDU 5G gNB Architecture

Target audience: RAN engineers. Scope: high-level architectural design of the OCUDU gNB layer responsibilities, inter-layer correlation, deployment topology, and the execution/async fabric that binds them. Deep algorithmic details (scheduling policies, PHY math, coroutine internals) are deliberately out of scope.

1. What OCUDU Is

OCUDU is a full 3GPP/O-RAN compliant 5G NR gNB implemented in C++17/C++20. It terminates every standardized RAN interface Uu toward the UE (via PHY/OFH/RU), F1-C/F1-U between CU and DU, E1 between CU-CP and CU-UP, N2/N3 toward the 5G Core (AMF/UPF), Xn between peer gNBs, and E2 toward the near-RT RIC. The codebase is functionally disaggregated so the same binaries can run co-located (gnb) or split across machines (cu_cp + cu_up + du, with optional du_low for an O-RAN Split-6 PHY).

About OCUDU India

Mon, 01 Jan 0001 00:00:00 +0000

About OCUDU India

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Mon, 01 Jan 0001 00:00:00 +0000