Aug 25, 2021 · Configuration LLS-C3 (LLS-C3): In this setup, network timing distribution is done from PRTC/T-GM to O-RU between central sites and remote sites. One or more Ethernet switches are allowed in the...

A PTP Switch must provide a suitable transport solution for the different O-RAN Fronthaul topologies, in particular LLS-C2 and LLS-C3 where it is required to forward user traffic along with management and synchronization.

Jun 10, 2024 · Configuration LLS-C3: The O-DU is not part of the synchronization chain to the O-RU. Network timing is distributed directly from a PRTC/T-GM (Primary Reference Time Clock/Grandmaster Clock) to the O-RU, often from a central site.

May 12, 2022 · • Configuration LLS-C2: the O-DU is part of the synchronization chain towards the O-RU. Network timing is distributed from O-DU to O-RU between O-DU sites and O-RU sites. One or more Ethernet switches are allowed in the fronthaul network. • Configuration LLS-C3: the O-DU is not part of the synchronization chain towards the O-RU.

Note: Regarding the clock model and synchronization topology, configurations C1 and C3 of the connection between O-DU and O-RU are the only configurations supported in this release of the O-RAN implementation.

Apr 6, 2023 · Apart from LLS-C4 (which uses local GNSS receivers for synchronization), IEEE 1588 synchronizes the O-DU and O-RU units (the front haul network) together, either from a time source in the O-DU (LLS-C1,2) or in a switch within the fronthaul network (LLS-C3).

For LLS-C3/C4, O-DU does not act as synchronization master towards the fronthaul interface • Can select its own synchronization from local or remote PRTC like in LLS-C1/C2, but can also select the same synchronization master from the fronthaul as the O-RU (as a T-TSC)

Mar 3, 2023 · O-RAN ALLIANCE has defined four synchronization topologies— LLS-C1 , LLS-C2 , LLS-C3 and LLS-C4—to address different deployment topologies in telecom networks. The following figure shows a typical synchronization flow diagram with synchronization from PRTC flowing to end cell sites:

The LLS-C3 configuration enables the distribution of network timing between central sites and remote sites from PRTC/T-GM to RU. In simpler terms, it allows the synchronization of one or more PRTC/T-GM devices (serving as PTP master) in the fronthaul network to transmit network timing signals to DU and RU components as seen in the figure above.

Aug 22, 2024 · LLS-C3: This configuration can use PTP unaware switches for single hop counts, but a grandmaster clock must be connected. For multiple hop counts, CSR/DCSG type switches with embedded...

Functional test of O-DU + bridged network + O-RU using ITU-T G.8275.1 profile (LLS-C3) – 4. Performance test of O-DU + Two O-RUs using ITU-T G.8275.1 profile (LLS-C1)

Intel’s Accelerated vCSRs directly offload the data-path onto the Intel FPGA. The demo showcases a high-performance O-DU and O-RU system, including a PTP grandmaster providing O-RAN-compliant LLS-C3 timing synchronization.

ORAN LLS* Sync Architectures *LLS: “Lower Layer Split” –in effect, fronthaul 7

Aug 11, 2021 · The LLS-C3 configuration specifies that both O-RU and O-DU implement slave clocks and fronthaul switches connected to a grandmaster for clock source. The specification does not state whether the fronthaul switch should integrate boundary clock.

•Support all O-RAN LLS configuration (C1, C2, C3 and C4) •Extensive monitoring options (Timing and Transport) •Flexible and diverse Timing interfaces (Ethernet, Serial, 1PPS, 10MHz)

In LLS-C3, the T-GM and T-BC functions are assigned to the fronthaul network, and both O-DU and O-RU play the role of a telecom time slave clock (T-TSC). The PTP networks can support an ITU-T G.8275.1 (Full Timing Support) profile, or ITU-T G.8275.2 (Partial/Assisted Partial Timing Support) profile.

Jul 28, 2023 · When using the LLS-C3 PTP configuration and when the Cell Site Router (CSR) is rebooted the CSR reports an incorrect time of 1970 in its PTP packets with clock class 248, and for a brief duration with clock class 6, until the CSR GNNS receiver enters the phase locked state.

ITU-T G.8275.1 profile (LLS-C3) The purpose of this to validate that JMA O-DU is correctly synchronized to a timing reference delivering PTP using the ITU-T G.8275.1 profile and that the O-DU correctly collects the status based on the nominal synchronization conditions.

•LLS-C1: GM sync DU (BC) •LLS-C2: GM sync DU (BC) + PTP Aware Switch. 6 O-RAN Lower Layers Split 7.2 •LLS-C3: Inline GM + PTP Aware Switch •LLS-C4: GM sync RU + PTP Unaware Switch. 7 Industry 4.0 Campus Sync. 8 O-RAN xHaul Deployment Fronthaul RU DU Backhaul gNodeB 10GE 10GE 10GE 5G Core DU 2x25GE

This guide describes how to test an O-DU using Paragon-neo to ensure its behaviour meets the requirements specified in the CONF document for devices to be deployed in an LLS-C1, LLS-C2, LLS-C3 or LLC-C4 topology. Get your very own copy of the O-RAN O-DU Test Guide below.