5G Reduced Capability (RedCap)

What is 5G RedCap?

When introducing 5G devices, it is crucial to have the right balance between features, market readiness, and cost-effectiveness – particularly when the devices must be designed to meet specific requirements and constraints. This is especially important for IoT devices such as smart cameras, wearables, and industrial sensors. The 5G Release 17 brings everything together.

Introduced in 5G Release 17, 5G Reduced Capability (5G RedCap for short), also known as 5G NR-light, enhances IoT applications by supporting various types of devices in different price categories.

5G RedCap serves two main markets:

  • Consumer IoT such as wearables, extended reality, and health monitoring
  • Industrial IoT fueling smart factories such as surveillance cameras and different kinds of robots.

5G RedCap devices offer reduced features and operate on 5G standalone networks only. This results in greater reliability, lower latency, and improved performance and efficiency.

Asia (led by China) and North America are already making significant progress in adopting RedCap devices for various use cases. The installed base of cellular IoT connections is expected to grow substantially worldwide.

5G RedCap explained
5G RedCap explained

Cellular IoT evolution with 5G RedCap

Cellular IoT is a fast-growing use case.

While 4G IoT technology is on the rise, the market is already preparing for the next generation of IoT technologies within 5G. Various categories have been specified to facilitate a smooth transition from LTE to 5G, e.g.

  • 5G RedCap, specified in Release 17, will replace LTE Cat 4 devices
  • 5G Release 18 introduces a RedCap device with lower bandwidth (5 MHz) to replace the LTE Cat 1 device

RedCap devices have a power consumption comparable to LTE Cat 4 devices and offer features which are not supported by LTE IoT technologies, such as network slicing. This 5G feature enables more use cases, as well as optimized services with quality of service (QoS) features.

Moreover, 5G RedCap devices support:

  • 5G LAN or Ethernet PDU capabilities, simplifying routing and connectivity between enterprises (e.g. on factory floors)
  • Voice over NR (VoNR) for enhanced voice quality
  • Non-Terrestrial Networks (NTN) to ensure continuous global coverage, depending on the use case

Power saving with 5G RedCap devices

Power saving is crucial for IoT devices. The mechanisms defined in 3GPP Releases 15 and 16 are complemented by the logic of Release 17, ensuring that RedCap devices can utilize a power-saving cluster based on three pillars:

  • Enhanced mechanisms and innovations, e.g. wake-up signals, relaxed measurements and adaptive bandwidth
  • Hardware restrictions and reduced capabilities, e.g. lower power class, single antenna, half-duplex operation, and bandwidth restrictions
  • Operational enhancements, e.g. discontinuous reception (DRX), sleep mode, power saving mode (PSM), signaling reduction and cross-slot scheduling

RedCap benefits

The main benefits of these reduced capabilities are reduced complexity and therefore lower device costs, longer battery life and faster testing.

5G RedCap Device Testing Challenges

The compact design of RedCap devices demands rigorous testing to address key challenges: How does the device handle limited bandwidth, fewer antennas, and various modulation schemes? Can the network efficiently identify and manage devices to provide precise access control tailored to their capabilities?

A 5G RedCap device needs protocol efficiency requiring a detailed evaluation of optimized signaling flow, shorter sequence numbering, and power-efficient transmission strategies.

Even seemingly small details require careful consideration, e.g. disabled frequency hopping and multi-band connectivity. By effectively addressing these signaling challenges, we unleash the full potential of RedCap devices, ensuring their seamless integration into the 5G ecosystem while maintaining overall network efficiency.

The performance of RedCap devices is also essential. Throughput measurements are necessary in different deployment scenarios – including dense urban areas, nomadic / mobile settings, industrial environments, and rural locations – to ensure compliance with performance standards.

Early RedCap devices will use LTE fallback when a 5G standalone (SA) network is unavailable. Therefore, to ensure reliability, LTE fallback must be considered into all test setups. Test solutions should replicate customer scenarios as closely as possible to simulate real-world usage.

The Rohde & Schwarz solution for 5G RedCap testing and measurement

The R&S®CMX500 one box signaling tester (OBT) is designed with a simplified setup, specifically tailored to meet the needs of customers conducting RedCap device testing during research and development (R&D) phases and type approval processes.

It is the perfect solution for testing and measuring 5G RedCap. The OBT facilitates the verification of various RedCap aspects as defined in 3GPP 5G Release 17 during the R&D phase, including network access restrictions, bandwidth parts (BWP), BWP switching, energy efficiency/power consumption, and other RedCap-specific protocol signaling procedures.

Moreover, the R&S®CMX500 OBT reduces time to market and supports all early R&D design phases – from RF parameter testing to end-to-end application testing (including throughput testing and signaling protocol testing), and from conformity tests for type approval to sample production testing.

R&S®CMX500 OBT Lite
R&S®CMX500 OBT Lite

R&S®CMX500 5G one-box signaling tester

The lite version of our flagship R&S®CMX500 5G one-box signaling tester (OBT) supports testing and simulation of different RedCap network conditions.

Benefits of our 5G RedCap test solution

The R&S®CMX500 5G one-box signaling tester provides a comprehensive testing solution for all stages of 5G device production. It supports a wide range of radio access technologies (RATs), including Wi-Fi, LTE and 5G frequencies up to 50 GHz, making it suitable for current and future LTE and 5G 3GPP band configurations.

R&S®CMX500 is designed to assist in both 5G standalone and 5G non-standalone operational modes. With its forward-looking hardware architecture, the solution can be easily customized to meet evolving testing needs, ensuring its longevity and value.

A 5G RedCap cell can effortlessly be integrated from the list of predefined networks in R&S®CMsquares, allowing the immediate examination of cell barring, bandwidth parts, and other RedCap-related features. The user-friendly web-based R&S®CMsquares interface provides convenient access to perform RF tests, functional tests, application tests, and protocol tests.

Want to discuss your RedCap test cases with our experts?

Discover our 5G RedCap white papers, webinars and more

Webinar: RedCap device testing made easy

This webinar provides an overview of the 5G RedCap technology, market trends, use cases, related test requirements and challenges while developing RedCap devices. A RedCap device testing solution is demonstrated for R&D, conformance, and carrier acceptance based on the R&S CMX500 radio communication tester. A vendor case study is moreover provided.

More information

Video: 3GPP 5G Release 17 RedCap device testing

The R&S CMX500 OBT comes with a streamlined configuration that perfectly serves customers’ need to test RedCap devices in R&D and type approval.

Watch Video

White paper: Reduced capabilities (RedCap) – A new class of 5G devices

This white paper provides a concise overview of RedCap and describes the impact on the UE design and operation within a 5G network.

More information

5G RedCap FAQs

What is 5G RedCap?

5G Reduced Capability (RedCap), also known as 5G NR-Light, is a variant of 5G designed for applications that do not require the high-performance attributes of conventional 5G technology. It is intended as the first 5G standard for the vast and expanding Internet of Things (IoT) landscape. RedCap aims to meet the requirements of IoT devices for smaller, less complex and lower cost RF solutions with enhanced battery life compared to existing 5G products. This concept was introduced in 3GPP Release 17 for 5G NR.

Previously, all devices connected to a 5G network shared the same bandwidth. To allocate reduced resources and bandwidth to RedCap devices, the network can utilize specific bandwidth parts. This approach involves assigning higher bandwidth to advanced devices and lower bandwidth to those with reduced capabilities, thus optimizing network efficiency.

What are the benefits of RedCap?

The main benefits of the streamlined capabilities of RedCap devices are reduced complexity leading to lower device costs, longer battery life, and faster testing.

What are RedCap use cases?

5G RedCap offers a wide range of use cases depending on the type of device, its throughput, and mobility.

For consumer IoT, wearables like fitness trackers, smartwatches, and health monitors use RedCap for efficient data transmission, allowing the tracking of vital signs, sleep patterns, and activity levels, without excessive battery power consumption. In the realm of Extended Reality (XR), low-end AR/VR glasses can leverage RedCap's capabilities to handle moderate data streams for applications such as navigation and information overlays.

In industrial IoT, smart factories can greatly benefit from RedCap technology by connecting various sensors within the factory. This enables real-time monitoring of temperature, vibration, and production line efficiency without the need for high-bandwidth connections for each sensor. Additionally, surveillance cameras equipped with RedCap can efficiently transmit essential video data for monitoring purposes while optimizing battery life for long-term deployments. Looking towards the future, various types of robots can use RedCap for basic communication and data exchange, facilitating efficient sharing of sensor data and control commands.

What is 5G NR Light?

In most 3GPP documentation, the 5G NR Light term is standardized to 5G NR RedCap. 5G NR Light is now officially referred to as Reduced Capability (RedCap) in 3GPP NR Release 17.

3GPP introduced the concept of RedCap to enhance user experience by taking advantage of 5G NR deployments, while leveraging fewer 5G NR capabilities to balance cost and power consumption.

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