In this article, I want to review the 5G Reduced Capability (RedCap) device category that have been specified as RedCap / eRedCap in 3GPP Rel. 17 and Rel. 18 technical specifications and explain why these provide a compelling and future-proof radio option for device manufacturers.
This article complements one of my previous articles that was reviewing regulatory compliance testing for radio enabled IoT devices using pre-certified radio modules.
As stated, device manufacturers integrate radio modules to benefit from a wireless connection to the internet enabling and enhancing advanced applications provided by their device. In most cases, the mobility of the device in use is another important requirement making cellular radio technologies a good fit.
The cellular radio technologies covered in the above referred article were 3GPP specified Low-Power Wide-Area (LPWA) technologies NB-IoT and eMTC in addition to broadband LTE and 5G NR. Together these technologies, specified in 3GPP Releases up to Rel. 16, have been accepted as IMT-2020 technologies, aka 5G, by the ITU-R.
eRedCap is part of 5G Advanced, an evolutionary step beyond the initial 5G standard, enhancing 5G capabilities and preparing the way for 6G.
5G RedCap Devices and Market Developments for IoT |
5G Reduced Capability (5G RedCap for short), also known as 5G NR-light, is a 5G technology designed for the Internet of Things (IoT). The technology is intended to provide a cost-effective and energy-efficient solution for IoT devices that don’t require the full capabilities of standard 5G. RedCap balances performance with lower complexity, smaller size, and longer battery life for IoT devices compared to traditional 5G.
To recap, the usage scenarios that were defined for IMT-2020, a framework for 5G technologies, are enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communication (URLLC) and massive Machine Type Communication (mMTC).
5G public networks and devices have prioritised the consumer-focused eMBB usage scenario with the smartphone being a dominant device example using NR chipsets/modems.
The URLLC usage scenario has been specified to enable connected industries in a digitized world with the goal to improve flexibility, enhance productivity and efficiency, reduce maintenance costs, and improve operational safety.
Industrial 5G adoption is still lagging behind initial expectations. WURLLC-enabled devices based on NR chipsets/modems are not yet widely available and the technology is still developing.
The mMTC radio technologies NB-IoT and eMTC (LTE-M) can be used, where low device cost and high battery efficiency are a focus and limitations on achievable data rate, latency and reliability are acceptable. These LPWA technologies are in use on a massive scale.
In 2022, the industry requested a cost-optimised NR variant which provides sufficient performance for use cases that fall in between the initial IMT-2020 service categories primarily serving communication needs of industrial wireless sensors, security and surveillance equipment and wearables.
Figure 1: Use cases requested to be served by a new 5G NR radio category
In response 3GPP specified the NR Reduced Capability (RedCap) radio category yielding good battery efficiency at moderate cost while providing higher data rates and lower latency than NB-IoT and eMTC can offer.
The following simplified illustration depicts the IMT-2020 triangle of usage scenarios with RedCap (Rel. 17) added.
Figure 2: 3GPP radio technologies for IMT-2020 aka 5G usage scenarios
RedCap simplifications compared to the eMBB / URLLC NR radios are:
Due to the reduced complexity, smaller form factors and longer battery lives can be supported by RedCap compared to legacy NR (eMBB & URLLC). Additional Rel-17 enhancements for Uplink Coverage and Power Savings are part of the RedCap specifications.
Focusing on peak data rate and device cost, RedCap (Rel. 17) can be seen as a replacement for lower LTE UE categories 2, 3 and 4 providing peak data rates of 85-150 Mbps in the downlink and 50 Mbps in the uplink and at similar chipset/modem cost.
Figure 3: NB-IoT, eMTC (LTE-M), RedCap and eRedCap
To further expand the market for use cases yielding even lower device cost and longer battery life 3GPP has specified eRedCap in Rel. 18 (June 2024). It was decided that a peak data rate of 10 Mbps is sufficient for eRedCap.
Additional simplifications / enhancements of eRedCap compared to RedCap:
Again, in view of peak data rate and device cost, eRedCap works well as a replacement for low-cost LTE UE categories 1/1bis while avoiding an overlap with the LWPA solutions NB-IoT and eMTC.
The following table provides key performance parameters for the different radio technologies discussed allowing a comparison of NR based RedCap / eRedCap to LTE, NB-IoT and eMTC.
Figure 4: Key performance parameters for the different radio technologies.
RedCap / eRedCap are based on the 5G Standalone (SA) architecture. The connection to the 5G SA core is mandatory to realise the full potential of advanced 5G features such as network slicing and 5G LAN and allows the control of network services via API.
5G network slicing, allows operators to allocate dedicated network resources for specific uses, which enhances performance, security and efficiency. This makes RedCap technology ideal for applications that require guaranteed service quality, such as mission-critical communications.
While most 5G public networks (PLMNs - Public Land Mobile Networks) started operation in Non-Standalone (NSA) mode, more and more network operators are switching to SA mode. Currently about 70 out of 340 commercial 5G service providers have launched 5G SA 1. LTE networks will gradually be migrated, with 5G expected to overtake LTE as the dominant mobile access technology by subscription in 2027 1.
Since radio modem hardware requirements between RedCap (Rel. 17) and LTE category 2, 3 and 4 are very similar, modem manufacturers today offer dual-mode modems supporting both radio technologies. On a global scale the roaming framework for RedCap still needs to be put in place by network operators. The dual-mode radio implementation, supporting RedCap as well as lower LTE UE categories helps migration. Until wide 5G SA coverage is achieved the dual-mode capability also provides LTE fallback to maintain connectivity.
Private networks, also called Non-Public Networks (NPNs), are seen as a connectivity solution that will help unlock business innovation, including AI and 5G IoT. Large-scale enterprises running warehouses and manufacturing facilities and hospitals have implemented 5G NPNs to provide dedicated bandwidth for their most critical devices 2. These 5G NPNs usually operate in SA mode from the start to provide the highest level of reliable and resilient connectivity. RedCap / eRedCap devices serve many use cases in these environments.
A review of the chipset and ecosystem reveals that there is a choice of 5 chipset vendors and 17 radio module manufacturers with commercial RedCap products on the market 3.
eRedCap devices are expected to be commercially available in 2027, becoming an important stepping stone to move subscribers from 4G to 5G networks before 6G begins taking off.
For the industrial IoT domain the substantial longer equipment life cycles of the OT industry compared to the ICT industry should be considered. Industrial equipment is often required to last 20 years or even longer. Device implementations for the industrial IoT should also note that the telecom industry is expecting an LTE sunset around 2032.
Finally, the 5G NR design of physical channels has since the start of 5G allowed NB-IoT and eMTC radio transmissions to be placed into the NR carrier bandwidth (in-band). Thus, these radios will be allowed to coexist alongside NR radios including RedCap / eRedCap.
At TÜV SÜD, we provide regulatory (FCC/ISED & RED) testing services for all above-mentioned cellular radio technologies including RedCap with a focus on testing devices using pre-certified radio modules.
Please contact us to discuss your project requirements or find out more about Federal Communications Commission (FCC) Telecommunications Certification Body (TCB), Innovation, Science and Economic Development (ISED) Canada and the Radio Equipment Directive (RED) CE Mark.
[1] Ericsson Mobility Report June 2025
[2] Ericsson: The State of Enterprise Connectivity United States 2025
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