The growth trajectory of 5G cellular services is reshaping the communications landscape, with a new estimate from The Business Research Company forecasting global revenue of more than $355 billion in 2025, up from about $200 billion a year ago. As 5G momentum builds, the promise of 20 Gbps peak data rates tends to steal the limelight, but the focus on brute speed overshoots emerging opportunities in markets like industrial IoT, energy generation and connected healthcare that don’t necessarily require top-end data transfer speeds.

That’s where 5G New Radio Reduced Capability enters the picture. Standardized in 2022 as part of 3GGP Release 17, RedCap enables data rates as high as 230 Mbps. While that’s an order of magnitude slower than 5G, it’s still competitive with typical 4G LTE speeds and sufficient for use cases where performance is better served by throttling back data rates to better manage costs and extend battery life.

RedCap Technology Fills a 5G Performance Gap

Also known as 5G New Radio Light, or NR-Light, RedCap is a subset of the 5G air interface standard and supports lower-cost, less complex applications that typically have reduced bandwidth, fewer antennas and simpler processing requirements than standard 5G-enabled devices. By addressing what had been an underserved performance tier, RedCap enables broader adoption of IoT solutions in devices from smart industrial meters and video surveillance systems to wearable health trackers.

LitePoint is seeing early RedCap adoption by consumer, industrial and medical device manufacturers, particularly in Asia and North America, where China and the United States are leading the way. Research firm Omdia foresees nearly one billion RedCap connections by 2030, with a 66 percent compound annual growth rate contributing significantly to the overall surge in 5G IoT connections.

RedCap Fundamentals

RedCap is built on three underlying technologies that together reduce power and improve performance compared to existing 4G low-power WAN alternatives such as LTE Cat-M and narrowband IoT (NB-IoT). These foundational technologies are Bandwidth Part (BWP), Connected-Mode Discontinuous Reception (C-DRX) and Observed Time of Arrival (OTDOA).

The first, BWP, allows connected devices to use a smaller slice of available 5G network bandwidth. BWP reduces power by shrinking active bandwidth and receiver time, which improves network performance by making more efficient use of 5G spectrum. C-DRX further optimizes power use and performance by allowing 5G devices to switch to lower-power mode while remaining connected. The third feature, OTDOA, measures signal time differences from multiple base stations to improve data location accuracy and signal processing efficiency, which yields additional power savings.

Testing RedCap Across the Design Spectrum

For wireless device manufacturers to reap the full advantages of RedCap technology, LitePoint recommends a testing program at three stages – R&D, conformance and carrier acceptance – to ensure performance, interoperability and 3GPP standards compliance.

Testing during research and development provides early confirmation that RedCap devices work as designed and can maintain performance in low-power mode and under different operating conditions. Conformance testing using tools ensures devices adhere to RF and signaling protocols and comply with 3GPP standards, including standards updates. Finally, carrier acceptance testing assesses network compatibility and the user experience across different 5G service carriers.  

Parallel Testing of 4 RedCap 2×2 MIMO DUTs

Using tools like the LitePoint IQcell-5G, these tests are conducted sequentially but in sum comprise a broader regimen that companies should follow as they scale their test programs. Commercial manufacturing is often the Achilles heel for companies when they find their small batch testing processes are quickly overwhelmed as they shift from pilot to volume production.

Choosing the Right RedCap Test Tool

LitePoint’s IQcell-5G signaling callbox test solution is built for 5G NR signaling user experience validation across all RedCap devices. IQcell-5G supports RF parametric testing in addition to end-to-end application and conformance testing and features an intuitive web-based user interface and automated test sequences. The hardware platform features a multi-cell, multi-device architecture designed specifically to accommodate volume production scaling.

As 5G penetrates cellular networks globally, new technology advances will extend the benefits of RedCap as a power and performance enhancer. Network slicing is creating multiple virtual networks on a single physical network and allowing designers to more efficiently customize RedCap for different applications, while techniques such as enhanced C-DRX will further reduce power use and extend the battery life of portable devices. 

A comprehensive 5G RedCap test tool optimizes performance at a time when network operating environments are evolving rapidly and enables faster time-to-market by identifying and resolving issues early in the development cycle.