The Delicate Balance of 5G OTA Testing Yields Big Biz Benefits

How far we’ve come from a relatively simple time when devices could be connected to cables for iron-clad testing and validation. Of course, in previous network generations, testing facilities were literal construction projects that took months and millions to complete.

Today, the real estate required for 5G device testing has been reduced to a couple of racks that can sit just about anywhere. But this convenience has come at the cost of overwhelming complexity. Establishing deterministic environments for over-the-air (OTA) 5G testing is now as much an art as a science and it has proven to be a delicate balance. Especially for those seeking to cut costs, move faster and streamline device testing processes.

Massive MIMO resulting in new testing realities

New massive MIMO technology found in 5G deployments impact how testing environments are designed. At the heart of successful testing is the ability to accurately emulate what happens to a signal as it travels from point A to B in a 5G wireless environment.

Once upon a time, a single antenna resulted in a donut-shaped signal that always experienced the same attenuation. As MIMO technology was introduced, the antenna became directive. So, if you put two elements close to each other, predictable patterns emerged with certain directions being more favorable than others. Suddenly, it mattered what direction signals were coming from, especially when there could be as many as 128 of them. Maybe in a perfect world, you’d have dozens of probe antennas to accommodate the new complexity, but this would be far too costly.

Now, testing effectively, efficiently and deterministically means having a complete understanding of how propagation parts arrive to UEs in a given environment – otherwise, it is impossible to properly locate probe antennas in testing chambers. If you didn’t understand channel models, you’d try to compensate by putting probes everywhere, resulting in wasted resources. But with deep expertise on channel modeling, an optimal set of probes can be installed, ultimately reducing costs.

A new day, and new way, for 5G device testing

Whereas device testing was previously a multi-vendor affair, vendors that have the technology, experience and expertise to offer a holistic, contained solution are addressing the technical challenges raised in this post. They are also creating compelling business cases for device makers eager to streamline testing requirements. Consider the critical business advantages of this approach:

• Testing doesn’t have to kick off with a construction project. Prior generation device testing necessitated substantial chambers resulting in entire buildings dedicated to testing. Where these structures were located, how they were staffed and maintained, and the time it took to build were all considerations that had to be weighed when spinning up testing efforts. Today, testing solutions can be placed virtually anywhere and moved with ease, occupying a small corner of the lab instead of costly commercial real estate.

• One vendor can provide end-to-end testing support. Device makers often found themselves in the unenviable position of managing a range of vendors. Chamber vendors, fader vendors, probe suppliers – you name it. When something inevitably went wrong, finger-pointing ensued. When one testing provider can offer a complete solution, any challenges that arise can be addressed with ease.

• Costs drop considerably. Despite the added technical complexity, costs can be reduced by as much as 3x – a welcome development in an era of perpetual cost-cutting initiatives. Financial fallout related to downtime is also mitigated as one single point of contact expedites trouble resolution, and removal of construction requirements reduces upfront time and expense requirements.

• Spin-up speeds accelerate. Time previously spent finding space for massive laboratories, building them and installing equipment can be redirected elsewhere as existing office space can now provide an ideal home for self-contained testing chambers.

Whether conducting R&D testing, prepping for a mass market launch, or conducting benchmark tests, how effective vendors can emulate massive MIMO environments and how cost-efficiently they can deliver solutions matters. Today, there are important technical and business cases to be considered.

Want more information? Learn more about Spirent's massive MIMO OTA test solution.