5G Testing: A New Paradigm for Reliability and Performance

Charles Schroeder, Business and Technology Fellow at National Instruments, explains that 5G will revolutionize everything from enterprise communication to autonomous vehicles. To deliver the promised speed, ultra‑low latency, and massive connectivity, 5G devices are inherently more complex than previous generations, demanding a fundamentally different testing methodology.

Historically, test engineers relied on a well‑established suite of measurements and hardware‑cable methods to validate RF semiconductors, base stations, and mobile handsets at scale. With 5G’s expanded spectrum, sophisticated beamforming, and dense antenna arrays, those legacy techniques no longer suffice. Over‑the‑air (OTA) testing must now replace cabled approaches to accurately assess 5G performance in realistic operating conditions.

To meet the 5G goal of 10 Gbps per user, the standard introduces Multi‑User MIMO (MU‑MIMO) and expands into centimetre and millimetre‑wave (mmWave) bands. MU‑MIMO enables multiple users to share a single frequency band via beamforming, while mmWave frequencies provide the bandwidth needed for high data rates. However, mmWave signals attenuate more quickly, so antenna arrays and advanced beamforming are essential to extend range and power.

Implementing these technologies requires far more antenna elements than earlier generations. At mmWave frequencies, the antennas themselves are tiny, allowing them to be integrated into mobile devices using “antenna‑in‑package” (AiP) solutions. While AiP offers space savings, it also eliminates direct test points, making OTA testing the only viable option.

How OTA Addresses Emerging Challenges

For test engineers, the rise in frequency, new packaging, and antenna density introduces several hurdles. OTA testing introduces additional measurement uncertainty from antenna calibration, fixture tolerances, and signal reflections. Engineers must now incorporate anechoic chamber procedures, beam characterisation, optimal code‑book calculations, and antenna parameter profiling into test plans.

Moreover, the ever‑wider RF bandwidths increase the computational load for calibration and measurement, extending test times. Test managers must balance these technical demands against capital costs, operating expenses, time‑to‑market, and the physical footprint required for OTA chambers.

Despite these challenges, OTA testing brings unique advantages. It is the sole method capable of probing AiP‑based antenna arrays that cannot be accessed via cables. OTA enables system‑level evaluation of the entire array, potentially unlocking higher throughput and efficiency compared to serial or parallel individual‑element tests.

Industry experts have repeatedly demonstrated that robust testing frameworks can keep pace with advancing technology while controlling cost and schedule. With ongoing innovation in test instruments and methodologies—particularly OTA solutions—engineers worldwide are well positioned to ensure 5G’s commercial success.

The author is Charles Schroeder, Business and Technology Fellow, National Instruments