Standalone 5G: The Role of RedCap

Following earlier blogs on standalone 5G looking at connectivity models and the potential benefits for private mobile networks, I wanted to look at the role of Reduced Capability, or RedCap, in the next wave of 5G evolution.

Initial Internet of things (IoT) services allowed machines to communicate with one another, transmitting and receiving simple data messages over low-data-rate connections with relaxed quality-of-service requirements, driven by the notion of a sensor-type user experience-orientated network. Later deployments of IoT considered more sophisticated classifications, such as:

Massive IoT. This primarily consists of wide-area applications, connecting large numbers of low-complexity, low-cost devices that have long battery life and relatively low throughput. Commercial devices for massive IoT include various types of meters, sensors, trackers and wearables.

Broadband IoT. This mainly includes wide-area applications that require higher throughput, lower latency and larger data volumes than massive IoT technologies can support. LTE is already supporting many applications in this segment.

Critical IoT. This is used for time-critical communications in both wide- and local-area applications, requiring guaranteed data delivery with specified latency targets. Critical IoT will be introduced in 5G networks with the advanced time-critical communications capabilities of 5G. Typical uses include cloud-based virtual and augmented reality, cloud robotics, autonomous vehicles, advanced cloud gaming and real-time coordination and control of machines and processes.

RedCap, sometimes referred to as New Radio Light, is a reduced set of 5G capabilities intended to meet IoT device requirements: smaller, less complex and lower-cost RF solutions with better battery life than existing 5G products. This makes devices like wearables, sensors and low-cost hot spots much more viable.

RedCap targets IoT services needing a higher data rate than massive IoT services but lower data rates than 5G enhanced mobile broadband, and simultaneously reduces user experience complexity and improves power-saving aspects. This also enables smaller IoT devices, particularly helpful for gadgets like sensors.

Introduced with 3GPP Release 17, RedCap 5G is designed for devices currently served by LTE Cat M4, but provides equivalent or better performance, with 150 Mbps or higher downlink speeds (with optional capabilities), which should help reduce the complexity, cost and size of 5G devices.

Multiple factors drive the need for RedCap, including the desire to reduce device complexity, the need to reduce energy usage and the need for higher throughput machine-type communications in the uplink and the downlink. However, one of the primary aims is the full integration of IoT into 5G networks to benefit from overall system technologies like service-based architecture, network slicing and the flexible air interface capabilities of standalone 5G.

RedCap means that IoT technology can be integrated into the overall 5G system from its inception, so can take advantage of 5G technology. By enabling a reliable, low-latency and sufficiently high data-rate service, RedCap-based IoT can be attuned to quality-of-service requirements — including comparatively sophisticated management concepts such as network slicing, based on service-based architecture and 5G core network capabilities.

Uses driving the evolution of IoT devices include industrial wireless sensors for connected industries, video surveillance in smart cities and wearables — these are considered the first RedCap 5G end-point device priorities. These devices are characterized by a certain minimal set of quality-of-service flow requirements and a need for a higher data rate, especially in the uplink direction, underscoring the need for uplink-centric networks. They can differ in quality-of-service requirements like wireless data rate, latency, availability, size and battery life.

From CCS Insight’s recent conversations with solution providers such as Qualcomm, we expect that the RedCap device ecosystem will look something like Table 1.

Table 1. Possible RedCap 5G applications and device types

ApplicationDevicesData RatesLatencyDevices
WearablesSmartwatches, health monitors, smart glasses, virtual reality headsets5 Mbps to 50 Mbps downlink; 2 Mbps to 5 Mbps uplink (50 Mbps peak) One day to two weeks
Industrial sensorsTemperature, humidity, pressure, motion detection sensors, inventory and asset tagsUp to 4 MbpsLess than 100 millisecondsMore than three years
Video surveillanceCCTV cameras for smart city, healthcare, logistics and agriculture applicationsUp to 4 Mbps for basic applications; up to 25 Mbps for advanced applicationsLess than 500 millisecondsTypically not battery-based

RedCap 5G is imminent. For example, Ericsson has said that its RedCap solution would be commercially ready in November 2023 as a software addition to its standalone 5G-powered networks. The firm recently announced a radio access network software upgrade for standalone 5G New Radio systems which offers RedCap 5G features to lower hardware complexity, extend battery life and support a range of mostly IoT-based uses.

Several telecom operators have also been trialling RedCap 5G or assessing potential opportunities for enterprise customers. These include AT&T, BT, China Mobile, Optus, SK Telecom and Verizon. We expect that RedCap 5G will be an important technology to watch in 2024.