Small cell testing

What is small cell technology?

For 5G networks, an infrastructure combining macro cells and small cells, known as disaggregated RAN, is essential to emerging applications, such as IoT and autonomous vehicles. They are also critical for enabling 5G services in offices, stadiums and other indoor locations where coverage is typically weak.

The main purpose of small cell technology is to improve network performance by offloading traffic from congested macro cell networks and providing better coverage and capacity in high-demand areas. By bringing the network closer to users, small cells help reduce interference, increase data rates and enhance overall user experience.

In order to meet the complex challenge of modern networks, small cell manufacturers require reliable, high-performance test equipment during their R&D and production processes.

Rohde & Schwarz provides comprehensive solutions that cover the complete 5G small cell testing cycle - from component characterization and design validation all the way to mass production.

Master your small cell testing challenges

There are numerous challenges associated with testing small cells, regardless of operating frequency range. Small cells use advanced technologies, such as beamforming and massive MIMO, to enhance network performance. Specialized equipment that can accurately capture and analyze complex radio signals is necessary to properly test these features.

Additionally, small cell networks must adhere to the latest standards, such as 3GPP specifications, to ensure effective network operation. This means that testing equipment must also be compatible with these standards to ensure accurate testing.

Testing small cells operating in the 5G NR FR2 frequency range face added challenges. Small cell testing for FR2 must be performed over the air (OTA) because conducted testing is practically impossible for mmWave frequencies, and these measurements are highly susceptible to thermal changes and other environmental factors. The issue is further complicated because small cell networks are deployed in various environments, and each environment comes with its own set of challenges, such as humidity and physical obstacles.

In some countries, FR1 small cells operate in the same frequency bands as other wireless technologies, such as Wi-Fi. This can result in signal interference, which affects network performance and makes it difficult to isolate and diagnose issues.

Discover the best small cell testing solution for you

High-performance solutions for the complete small cell test and operation cycle

Browse our portfolio and discover:

• Signal generator and signal and spectrum analyzer combo to verify the proper implementation of digital pre-distortion (DPD) and enhance the linearity of the power amplifiers used in a small cell
• Vector network analyzers (VNA) to characterize the antenna arrays of a small cell
• High-performance oscilloscopes with multiple channels that enable phase coherent acquisition of small cell output streams for accurate demodulation and MIMO signal analysis
• A wide portfolio of probe to complement the oscilloscopes when testing the signal and power integrity of a small cell in the early digital design phase
• Multi-channel power supplies with built-in measurements to gauge power consumption of the modules (unit testing) as well as the small cell as a system
• OTA test chambers that support thermal measurements to test, for example, the Antenna in Package (AiP) modules used in small cell across a wide range of temperatures, from -40^oC to +85^oC

Small cell testing in FR1 and FR2

5G NR supports operation in two frequency ranges: FR1 (below 7125 MHz) and FR2 or millimeterwave bands (between 24.25 and 52.6 GHz). The Rohde & Schwarz portfolio offers solutions for both.

Traditional FR1 cells can be tested with a cable, but FR2 small cells require OTA testing. This is also the case for FR1 small cells that use advanced technologies such as massive MIMO and beamforming. OTA testing comes with unique challenges, such as significant path loss, sensitivity to DUT alignment and the need for highly accurate setup calibration.

The R&S®PVT360A is a VSG/VSA single-box vector tester optimized for small cell testing in FR1. It has two independent signal generators and analyzers to enable fast parallelized measurements, as well as a frequency range of up to 8 GHz, flexible bandwidth configuration and an optional second TRX channel. Most importantly, it supports standard-complaint 5G NR signal generation and analysis in all FR1 frequency bands and comes with preconfigured test routines in line with 3GPP requirements.

For small cell testing in FR2, we offer the R&S®CMPQ compact solution, which is designed to make 5G FR2 OTA testing as reliable and efficient as testing in the FR1 range. The R&S®CMPQ is a three-part testing solution based on the R&S®CMP200 radio communication tester , R&S®CMPHEAD30 remote radio head (RRH) and R&S®CMQ200 shielding cube .