O-RAN RU, DU, CU

Test. Improve. Repeat.

High stakes in 5G means more focus on pre-service testing

5G is being deployed across the globe putting mobile operators under pressure to deliver. According to GSMA Intelligence, mobile operators plan to invest $620 billion in their networks between 2022 and 2025, and 85% of this will be 5G related. There is little room for error or delays.

The number of Radio Units (RUs) required for 5G is far greater than to 4G, meaning 5G RAN will account for a higher proportion of overall deployment costs than in the past. This is causing some mobile operators to consider sharing RAN costs.

To ensure they can meet Service Level Agreement (SLA) requirements when sharing RAN investments, mobile operators must exhaustively test their RAN solutions before deployment to guarantee performance and resilience.

Vendors of 5G chips, equipment and solutions need to prove their products can meet the demands of 5G mobile operators. Impairment solutions let them test products under extreme scenarios before they are deployed.

Preparing for extreme 5G O-RAN scenarios with impairment testing

5G needs to support a broad variety of services with individual Quality of Service (QoS) requirements. Ultra-low latency requirements are a particular challenge as strict timing and synchronization performance are critical.

As shown below, 5G O-RAN allows virtualized Central Units (CUs) and Distributed Units (DUs) to be deployed either closer to the core for efficiency or closer to the edge for latency-sensitive services. This results in a highly dynamic environment but requires also multiple potential scenarios to be tested.

O-RAN specifies using network emulators

O-RAN Alliance’s  specifications (O-RAN.TIFG.E2E-Test.0-v03.00 and O-RAN.WG5.IOT.0-v05.00) specifically mention network emulators for effective testing.

Some of the test cases in O-RAN.TIFG.E2E-Test.0-v03.00 using impairment testing are:

  • 5.11 Impact of fronthaul latency on downlink peak throughput
  • 5.12 Impact of fronthaul latency on uplink peak throughput
  • 5.13 Impact of mid-haul latency on downlink peak throughput
  • 5.14 Impact of mid-haul latency on uplink peak throughput

These directly relate to latency testing of the Open Fronthaul interface between the O-RU to O-DU and the mid-haul interface between the O-DU and O-CU. These test cases determine the impact on network throughput as the network delay increases. The test system increases the network delay to find when the throughput drops to 30% of the peak throughput.

5G O-RAN impairment testing with E100 Chimera

Xena’s solution for impairment testing of 5G O-RAN networks is called E100 Chimera. Flexible, easy to use and cost-efficient, E100 Chimera is available as a stand-alone impairment tool or as a test module that integrates seamlessly with Xena Traffic Generators. This is a unique feature that lets you speed up your workflow by using the same test system to both generate and impair Ethernet traffic.

E100 Chimera supports true wire-speed impairment at 10, 25, 40, 50 and 100Gbps. It also provides the highest port density in the industry – up to 48 ports in one chassis. Plus it allows test engineers to reserve individual port-pairs without blocking access to other ports.

E100 Chimera makes it easy to add a broad range of impairments to incoming traffic to emulate various conditions. Each traffic flow is prioritized and processed in order of priority.

Also included with the E100 Chimera is a Command Line Interface (CLI) for automated scripting supporting multiple concurrent sessions. In addition to CLI, Xena OpenAutomation (XOA) provides native support for 5G O-RAN test cases, enabling easy integration into third party test systems or automated test environments.

E100 Chimera ideal for O-RAN test cases

E100 Chimera supports a broad range of 5G O-RAN test cases that can be automated for concurrent testing. The test system creates network impairments so test engineers can monitor how the network equipment or applications perform and respond. This can be used to test virtual functions, like CUs and DUs, and their performance under various conditions.

E100q Chimera Product Details

E100 Chimera (P/N E100q Chimera) is available as a 2-slot test module for a XenaBay chassis (P/N B2400). Or as a quiet desktop-sized standalone chassis called the E100 Chimera Compact (P/N C-E100q Chimera)

Chimera Traffic Emulator Module
Chimera ChimeraCompact
XenaBay 2020

Xena’s test solutions for O-RAN

Broad range of test modules

Xena offers a selection of test modules for testing all Ethernet speeds from 10Mbps to 800Gbps.

When testing 5G O-RAN, we recommend the E100q Chimera network emulation test modules for impairment, paired with either our Z10 Odin or Z100 Loki Ethernet Traffic Generation & Analysis (TGA) test modules. Xena’s Z10 Odin test modules support Ethernet TGA up 10Gbps while Z100 Loki can be used for testing speeds from 10Gbps up to 100Gbps.

Learn more about Z10 Odin and Z100 Loki test modules.

Easy-to-use software

Xena’s test solutions include feature-rich software for generating Ethernet traffic and analyzing the result. The primary tool is XenaManager.

There are also test suites for running standard tests such as RFC2544, RFC2889, RFC3918 and Y.1564, and specialized AN/LT tests along with a comprehensive range of powerful scripting and test automation options such as Xena OpenAutomation (XOA), an open-source test automation framework featuring a Python API that runs on any OS.

Robust chassis choices

Choose between the robust scalable 4U XenaBay with space for up to 12 test modules, or the small, easy-to-transport 1U XenaCompact with just one test module.

Exceptional value

All our solutions include the Xena Value Pack which consists of 3 years’ SW updates, 3 years’ HW warranty, free online/email support for the lifetime of the product and free product training.

Together with our low port-pricing, this represents significant savings on the TCO of your Ethernet traffic generation and analysis solutions.

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