With wireless connectivity evolving at breakneck speed, I recently had an opportunity to hit the pause button and take stock of 5G open radio access network (O-RAN) technology and what the future holds for O-RAN radio unit (O-RU) testing.

In my musings, I was joined by RCR Wireless News magazine editor-in-chief, Sean Kinney, who led a panel discussion on the evolution of O-RAN open innovation. Sean set the stage with a reminder that O-RAN is a movement founded by wireless operators seeking to diversify suppliers, increase flexibility, reduce costs and effectively “break apart” the RAN to expand its reach and appeal. In the past several years, that’s led to the release of more than 100 specifications covering everything from interfaces to platform orchestration.

O-RAN Trends to Watch

More recently, the O-RAN Alliance – and the industry at large – has championed cloud-based radio access as a means to conserve energy and enhance spectral efficiency. The ability to tie into the cloud is also spurring efforts to leverage AI to support shared O-RAN compute resources and edge-based services.

With 6G on the horizon, O-RAN is evolving beyond enhanced mobile broadband. Features like “mini-slot” scheduling allow for unencumbered data movement, because data no longer has to wait for the entire time slot to elapse before transmission can begin. This is important for time-sensitive technology like ultra-reliable low-latency communication (URLLC) in applications ranging from industrial automation to autonomous vehicles.

2025 is also shaping up to be a busy year on the integration front. O-RU designs are moving away from bulky FPGAs toward system-on-chip solutions as a means to significantly reduce power consumption and lower BOM costs. The bar is high in terms of cost cutting, but the goal is to make O-RUs as cost-effective as enterprise access points, which is critical for O-RAN to thrive in a competitive marketplace.

Interoperability Testing Ensures O-RAN Adoption at Scale

These exciting radio initiatives have a common trait: they depend heavily on smarter testing and integration. The O-RAN community has spent years promoting O-RU interoperability, for example, but it’s time to move past paper conformance and lean into real-world feedback to better manage vendor test strategies.

At LitePoint, RU testing is no longer just about verifying boxes on a checklist – it’s value is best appreciated when validating performance under pressure. For years, we focused on meeting front-haul and 3GPP conformance requirements, but now, with real carrier deployments underway, network operators are pushing testing into four key areas:

• Real-world scenarios that simulate traffic slicing, bursty data and mixed-service types
• Stress testing with full-bandwidth utilization, high modulation rates and peak-to-average power challenges to push the front-end modules to their limit.
• Multi-vendor compatibility that ensures radios adapt seamlessly to different distributed units.
• Proprietary features unique to specific carrier deployments.

MIMO Migrates to Parallel Antenna Testing 

Another area ripe for innovation is MIMO antenna testing. Traditional antenna-by-antenna (or chain-by-chain) testing offers only a narrow view of performance by focusing mainly on power measurements. More complete MIMO testing reveals how an entire system performs under real-world conditions.

A case in point is error vector magnitude (EVM) – a key metric that quantifies the difference between an ideal transmitted signal and the actual received signal. In real-world tests, MIMO measurements can uncover performance degradation that single-chain tests completely miss. Problems like crosstalk, PCB layout errors, front-end module limitations and potential issues with power supply bypass capacitors are uncovered only when multiple antennas operate in parallel, as they would in live deployments.

By measuring all chains simultaneously, parallel MIMO antenna chain testing can reduce costs by doubling test throughput and unit-per-hour test rates. As manufacturers prepare for large-scale production, MIMO testing is becoming the gold standard, not just for performance validation but for enabling scalable, cost-effective manufacturing.

Automation Is the Key to Scale

Automation is where O-RAN testing gets truly exciting. One of the beautiful things about O-RAN is the ability to take advantage of the M-plane, or fronthaul interface, that physically connects the O-RU and the distributed unit (O-DU).

Thanks to the O-RAN M-plane interface, we can now create a relatively generic automation framework that allows any vendor to simply drop in their specific M-plane XML file for the radio control. This makes it easy to automate radio testing from different vendors to validate performance, optimize through calibration and quickly scale to high-volume manufacturing.

O-RAN Reality Check

Despite the gloomy headlines about O-RAN’s commercial struggles, innovation hasn’t stopped. If anything, the push for lower costs, better interoperability and smarter test solutions is accelerating. The ecosystem remains vibrant, but success will depend on whether we can keep driving performance up and costs down while ensuring reliability in every real-world deployment.

To that end, every step of O-RAN radio development – from raw silicon to finished goods – relies on product-level testing. Isolated testing of RUs is no longer only practical; it’s the only way to capture and optimize key performance metrics while identifying failures early. As someone who’s deeply invested in RU testing, I can say this: the work we’re doing today is laying the groundwork for O-RAN’s next big leap.