5G Redcap
5G Reduced Capability (RedCap) , also known as 5G NR-Light, is a version of 5G designed to cater to mid-tier use cases.
1. What is 5G RedCap?
- 5G RedCap is a new standard introduced by the 3rd Generation Partnership Project (3GPP). It aims to address use cases that fall between the high-speed Enhanced Mobile Broadband (eMBB), ultra-reliable low-latency communications (uRLLC), and low-throughput, battery-efficient Massive Machine-Type Communication (mMTC) technologies¹.
- Unlike regular 5G technology, which focuses on high performance, 5G RedCap strikes a balance between throughput, battery life, complexity, and device density. It provides a cost-effective solution for diverse use cases that don't require the full capabilities of standard 5G³.
Figure¹ : Illustration of technology positioning of RedCap in relation to eMBB, URLLC, and mMTC.
2. Use Cases for 5G RedCap
- Wearables: This includes devices like smartwatches, wearable medical devices, and AR/VR goggles.
- Industrial Wireless Sensors: These sensors play a crucial role in industrial automation and monitoring.
- Video Surveillance: 5G RedCap can enhance video surveillance systems, especially in scenarios where high performance isn't necessary¹.
Table¹: Requirements of wearables, industrial wireless sensors, and video surveillance use case
3. Release and Adoption
- RedCap doesn't have its own overall specification, but it is a feature that has a wide impact on existing specs, to allow new radio (NR) to accommodate RedCap as a bridge between support for low complexity and high performance use cases... bringing in 'middle of the range' devices.
- In Rel-17 the RedCap ecosystem and framework was defined, including principles of network awareness of device capabilities. However, not all aspects were completed and therefore some functionality was moved into Rel-18 for as enhancement.
4. Capabilities
Table¹: Device capabilities, Release 15 baseline NR devices versus Release 17 RedCap devices.
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Redcap frequency range
RedCap UE will be used in both Frequency range 1 (FR1) from 410 MHz - 7125 MHz. and Frequency range 2 (FR2) 24250 MHz - 52600 MHz - 71000 MHz.
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Maximum bandwidth
Maximum bandwidth of an FR1 RedCap UE during and after initial access is 20 MHz.
Maximum bandwidth of an FR2 RedCap UE during and after initial cess is 100 MHz.
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Number of Rx branches and DL MIMO layers
For frequency bands where legacy NR UE is required to be equipped with minimum of 2 RX antenna ports or with minimum of 4 Rx antenna ports, the minimum number of Rx branches supported for a RedCap UE is 1.
For a RedCap UE with 1 Rx branch, 1 DL MIMO layer is supported.
For a RedCap UE with 2 Rx branches, 2 DL MIMO layers are supported.
5. High Layer Features for UE Power Saving
There are also some higher layer features defined in Rel-17 that are optional for RedCap UEs, which can help with UE power consumption:
- Extended Discontinuous Reception (DRX) in The Radio Resource Control (RRC) idle/inactive state.
- Radio Resource Management (RRM) measurement relaxation for neighbour cells.
Source:
(1) What is reduced capability (RedCap) NR? - Ericsson.
https://www.ericsson.com/en/blog/2021/2/reduced-cap-nr.
(2) What is 5G RedCap? Exploring Benefits and Use Cases | Telenor IoT.
https://iot.telenor.com/technologies/connectivity/5g-redcap/.
(3) What is 5G RedCap? - everything RF.
https://www.everythingrf.com/community/what-is-5g-reduced-capability-or-5g-redcap.
(4) 5G NR-Light (RedCap): Revolutionizing IoT | Qualcomm.
Further read:
CMCC publication: GTI Technical Specification of 5G RedCap Lightweight Universal Modules