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07) Sub-system functional testing of Benetel 5G NR O-RU with VIAVI O-DU emulator

Companies Participating
in this Scenario

Benetel provided 5G NR pico O-RU.

VIAVI Solutions provided the 5G NR O-DU emulator

Rohde & Schwarz provided Vector Signal Generator and Vector Signal Analyser.

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Testbed setup

The connection details of the hardware in the lab are in the network topology diagram below.

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Device Under Test
Benetel 5G NR O-RU

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  • Radio: 5G NR TDD
  • Model: BNTL-RAN500
  • Antenna: NA
  • Output power: 20dBm per antenna port
  • Management plane: not supported
  • Fronthaul Interface: O-RAN 7-2x split (Cat A)
  • External Interface: NA
  • Channel Bandwidth: 40MHz; SCS: 30kHz
  • Frequency bands: n78 (FR1)
  • Frequency Synchronization: LLS-C4 synchronization topology (GPS)
  • Typical Power Consumption: 40W
    Modulation Schemes up to 256QAM
  • Dimensions: NA
  • The BNTL-RAN500 is a product family of 5G Remote Radio Units developed in compliance with the O-RAN WG4 Open fronthaul interface version 2.0 specification. This modular architecture is designed to support a 7-2x split fronthaul network implementation and equipped with a 10GbE fiber front haul transport option.
    The BNTL-RAN500 RU family is ideally suited for early adopters of an O-RAN network solution or those seeking to implement a small network deployment trial. This family of products offers a suite of radio choices that conform to the same form factor to ensure flexibility. In support of this, the Radio’s is encased in an IP22 rated indoor enclosure with accessible antenna ports, 10Gbe, GPS Antenna port, a 12V DC supply port, and a 1GbE (1000 Base-T) port for OAM support. The unit is designed for wall mount applications and for operation over a temperature range of 0 to +40°C.

Test scenarios introduction

  • Scenario 1, S-Plane test

O-RU synchronizing to GNSS (LLS-C4)

The purpose of this test is to validate that Benetel O-RU is correctly synchronizing to GPS antenna in LLS-C4
synchronization topology.

  • Scenario 2, U-Plane test

O-RU Scenario Class Compression
Static Format (SFM) Fixed-Point (FP)

The purpose of this test is to validate the correct encoding of IQ data under the following conditions.

• RU Static compression configurations
• Fixed point IQ data format 14bit
• Uplink/downlink

O-RU Scenario Class
DLM Downlink – Positive testing

This test case validates that the timing on the air interface is according to requirements specified in the CUS
Specification when the Control-Plane and the User-Plane messages are received within the O-RU’s reception
windows.

O-RU Scenario Class
DLM Uplink – Positive testing

This test case validates that the transmission of the U-Plane data in uplink direction is
transmitted correctly by the O-RU within its transmission window.

O-RU Scenario Class Base 3GPP DL

The purpose of this test is to ensure the radio can transmit
a basic 3GPP test frame using the default parameters.

O-RU Scenario
Class Extended 3GPP DL – Resource allocation

The purpose of this test is to ensure the radio can accurately transfer U-Plane data into the
correct resource blocks and transmit this data accurately in the downlink.

O-RU base class FDD test UL

The test validates that correct uplink operation of the O-RU using 3GPP Reference Sensitivity level definition (Section 7.2 TS 138.141-1) of the Conducted Receiver Characteristic Test section (Section 7 TS 138.141) and power Levels at least 30 dB above Reference Sensitivity power Level described in TS 138.141-1 Table 7.2.5-1. This is to improve the likelihood that all data will be received by radio correctly since we are not interested in testing receiver sensitivity but only the O-RAN protocol compliance.

5G NR Downlink Modulation Quality

The test validates Benetel O-RU DL Modulation Quality for a known IQ data sequence delivered
to the O-RU utilizing the Open FH interface. The test covers the case of no beamforming
(beamId=0x000) and with one spatial stream (single eAxC).

5G NR DL Occupied Bandwidth

The test validates that the emission at the antenna connector does not occupy an excessive bandwidth and the measurement of the bandwidth for the SCS specified and the number of RBs being transmitted in IQ data utilizing the Open FH interface.

Testing Results/Summary

IIn this test, Benetel O-RU connects to GPS antenna in LLS-C4 synchronization topology to do the clock synchronization and connects over O-RAN Open fronthaul 7-2x split to the VIAVI O-DU emulator. For the downlink, the performance of the Open FH interface to the O-RU is quantified at the RF interface using the Rohde & Schwarz VSA (Vector Signal Analyzer). For the uplink, a standard uplink RF signal is applied at the Benetel O-RU using the Rohde & Schwarz VSG (Vector Signal Generator) so that the performance of the Uplink Open FH interface can be verified based on analysis of I/Q data contained in the fronthaul packets received by the VIAVI O-DU Emulator.

Benetel test cases mainly do U/S Plane conformance tests with fixed 16 bit no beamforming configuration. Based on the logs from Benetel O-RU and the screenshots from the Rohde & Schwarz VSA output, the Radio KPI (EVM, MTIE, BER, etc.) achieved the criteria of both O-RAN and 3GPP specifications.

We validate Open FH performance, quantified by analysis of the IQ data in the U-plane payload, using similar metrics as for 5G NR radio performance as outlined in 3GPP TS 38.141-1. EVM has been measured for the multiple modulations (QPSK, 16QAM, 64QAM, 256QAM) and occupied bandwidth. Validated the 5G NR Radio Performance for DL and UL tests as outlined in TS 38.141-2.

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Benefits for the Industry

  • The validated LLS-C4 synchronization topology with a GPS antenna directly connected with the O-RU device.
  • The validated 10Gbps fiber physical connection in the case of O-RAN Open fronthaul 7-2x split.
  • The validated single-vendor O-RU solution with the Viavi emulators.
  • The validated Viavi emulator and R&S solution for O-RAN conformance test
  • The validated remote configuration with Benetel O-RU in the Berlin lab.
  • The validated remote integration in Berlin lab without on-site O-RU support team
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