AT&T sees a significant role for a new internet of things (IoT) standard known as RedCap or NR Light. The company sees it as a sort of Goldilocks standard — not as complex as 5G NR but more versatile than LTE-M, making it suitable for wearables and low-cost hotspots. The company shared information about the technology in a blog post.
The company made clear that those other technologies will continue to be suitable for certain use cases. LTE-M will support low-power wide-area network (LPWA) use cases, AT&T said. On the other end of the spectrum is 5G, which will be used for more complex applications. RedCap will fill the space between them and provide 5G functionality to lower powered and smaller devices that could benefit from 5G bandwidth, according to AT&T.
The RedCap IoT Standard
The name RedCap is actually short for Reduced Capability to indicate that the technology is based on 5G but with a reduced set of capabilities.
AT&T said that it conducted the first 5G RedCap data call on July 19. The test utilized MediaTek’s RedCap platform and AT&T’s 5G SA network, which was built with Nokia’s AirScale.
RedCap, which is part of 3GPP Release 17, is aimed at devices now served by LTE Cat-4. It provides equivalent or better performance with a theoretical maximum downlink throughput of 150 Mbps, AT&T said. RedCap is designed to provide 5G connectivity to devices with lower battery consumption, costs and bandwidth requirements.
The sweet spot for RedCap will be wearables, smartwatches, augmented reality glasses, healthcare equipment, asset tracking, smart home systems, fleet management and similar devices, according to AT&T.
A key is that many IoT and wearables are small and don’t have room for complex antenna designs. This makes it impossible to get 5G and its benefits.
5G RedCap meets the challenge. Its core design has a maximum bandwidth of 20 MHz with a single carrier. There is no requirement that larger antennas with multiple carrier aggregation be accommodated. It enables one transmitter/two antenna designs that are more appropriate for smaller devices.
RedCap has eDRX allows control of interactions with the networks. This allows devices to “sleep” for longer periods of time and thus reduce energy consumption.
Among features being worked on for RedCap are wake-up signal (WUS), early paging indication (PEI), and PDCCH monitoring adaption, according to the AT&T blog post.