5G RedCap: what it is and where it fits
Short answer: 5G RedCap (Reduced Capability, also called NR-Light) is a slimmed-down class of 5G device defined in 3GPP Release 17. A RedCap device uses at most 20 MHz of bandwidth, one or two receive antennas and one transmit antenna, so its modem is smaller, cheaper and less power-hungry than a full 5G phone modem, with peak speeds in the same class as mid-range 4G. It is meant for wearables, video cameras, industrial sensors and routers that need more than LTE-M offers but far less than a phone. It works only on standalone 5G networks.
5G RedCap explained: what Reduced Capability 5G cuts from full 5G, how it compares with LTE-M, NB-IoT and Cat 1 bis, eRedCap, and which devices should use it.
This article covers what RedCap is and why 3GPP created it, what it removes from full 5G, speed and battery life in plain terms, the standalone 5G requirement, how it compares with NB-IoT, LTE-M, LTE Cat 1 bis and full 5G, eRedCap from Release 18, which devices suit it, and what to check before choosing a RedCap module. It does not cover the 5G radio layer in detail, coverage maps or prices for particular operators, or reviews of individual modules and routers.
5G RedCap is the version of 5G built for devices that are not phones. Full 5G modems are designed for peak speed: wide channels, four antennas, constant high data rates. A smartwatch, a security camera or a sensor on a factory line needs none of that and pays for it in size, cost and battery. RedCap, short for Reduced Capability, trims the modem down to what these devices use. It was specified by 3GPP in Release 17, completed in 2022, and operators began switching it on in 2024 and 2025. This guide explains what it removes, what it keeps and how it fits with the cellular IoT options already covered in the connectivity hub, especially NB-IoT and LTE-M.
Why RedCap exists
Before RedCap, cellular devices had two broad choices. At the low end sat NB-IoT and LTE-M, built for small, infrequent messages and years on a battery. At the top sat full 4G and 5G, built for phones and routers. The middle was covered by older 4G categories, mainly LTE Cat 1, Cat 1 bis and Cat 4.
As operators shut down 2G and 3G and plan for the day they reduce 4G, device makers want a mid-range option that belongs to 5G and will be supported for a long time. RedCap is that option. It gives mid-range devices a 5G modem with a cost and power draw much closer to a 4G one.
What RedCap removes from full 5G
The savings come from a handful of hardware limits written into the standard.
Narrower bandwidth. A RedCap device handles at most 20 MHz of spectrum in the bands below 6 GHz, against up to 100 MHz for a full 5G device. (In the millimeter-wave bands the limit is 100 MHz, against 400 MHz.) Less bandwidth means simpler, cheaper signal processing.
Fewer antennas. One or two receive antennas instead of four, and one transmit antenna. Every antenna removed saves a radio chain, board space and power, which matters a lot inside a watch or a small sensor.
Fewer data streams. At most two downlink streams instead of four, which follows from having fewer antennas.
Half duplex allowed. On paired spectrum, a RedCap device may transmit and receive at different moments rather than at once, which removes a costly filter called a duplexer.
Longer sleep. RedCap adds extended discontinuous reception (eDRX) and relaxed measurement rules for devices that do not move, so a device can sleep longer between checks with the network. That is what makes multi-day battery life practical on a wearable, and longer on a sensor that reports occasionally.
What it keeps is just as important: 5G security, network slicing, the 5G core’s management features, and lower latency than the older IoT technologies.
How fast is RedCap?
The 3GPP specifications set limits on hardware, not a single speed. In practice, a two-antenna RedCap device on a 20 MHz channel reaches peak rates in the same class as LTE Cat 4, the mid-range 4G category used in many routers and cameras for years. That means well above what LTE-M or Cat 1 bis can do, enough for HD video, quick firmware updates and a router that backs up a small office line, and far below a 5G phone.
As with any cellular link, real speed depends on signal strength, how busy the cell is and how the operator has configured it.
RedCap needs standalone 5G
This is the catch to check first. RedCap works only on standalone (SA) 5G, where the operator runs a full 5G core network. Much early 5G was non-standalone, using 5G radio with a 4G core, and RedCap devices cannot use that.
So a RedCap device is only as useful as its operator’s standalone 5G coverage. Several operators, including T-Mobile and AT&T in the United States, have launched RedCap on their standalone networks, but coverage varies a lot by country and operator. Many RedCap modules fall back to LTE when there is no standalone 5G, which protects you while coverage grows. Check whether a module you are considering has that fallback, and on which LTE categories.
RedCap compared with the other cellular IoT options
| NB-IoT | LTE-M | LTE Cat 1 bis | 5G RedCap | Full 5G | |
|---|---|---|---|---|---|
| Generation | 4G family, carried into 5G | 4G family, carried into 5G | 4G | 5G | 5G |
| Data | Small, infrequent messages | Moderate | Several Mbit/s | Similar to mid-range 4G | Highest |
| Battery | Years | Years | Months to years, depending on use | Days on a wearable, longer on a sensor | Charged daily |
| Moves while connected | Poorly | Yes | Yes | Yes | Yes |
| Network needed | NB-IoT enabled LTE | LTE-M enabled LTE | Any LTE | Standalone 5G | 5G |
| Typical devices | Meters, fixed sensors | Trackers, alarms, wearables | Point of sale, trackers, telematics | Cameras, wearables, routers, industrial devices | Phones, home broadband |
Against NB-IoT and LTE-M. These remain the right choice for small battery devices that send little. RedCap does not replace them; 3GPP treats them as the low-power part of 5G and they will run for many years. Choose RedCap when the device needs video, large updates or quick responses that LTE-M cannot give. The NB-IoT vs LTE-M guide covers the low end in detail.
Against LTE Cat 1 bis. Cat 1 bis is the single-antenna version of LTE Cat 1, popular for its low module cost and the fact that it works on almost any 4G network today. For most devices shipping now, it is the safe mid-range choice. RedCap is the option with the longer future and more speed, and it makes sense where standalone 5G coverage is good or where the product will be sold for many years.
Against full 5G. If a device needs gigabit speeds, such as a home broadband router, it needs a full 5G modem. Everything below that is a candidate for RedCap.
eRedCap: the smaller version in Release 18
3GPP went further in Release 18 with enhanced RedCap (eRedCap). It cuts the device’s data processing bandwidth to 5 MHz and brings peak speeds down to around the level of LTE Cat 1 bis, with a matching drop in cost and power. It is aimed at the devices that use Cat 1 and Cat 1 bis today, so that they have a 5G path when 4G networks eventually shrink. Expect eRedCap modules and network support to arrive some time after RedCap.
Which devices suit RedCap
- Wearables: smartwatches and health devices that need a cellular link and days of battery.
- Video: security cameras, body cameras and dashcams that upload clips over cellular.
- Routers and backup links: small routers that keep a shop or office online when the fixed line fails, or that serve a site with no wired connection. The IoT gateway guide explains where these sit in an industrial system.
- Industrial devices: sensors and controllers that send more than small readings, such as vibration data or images for inspection.
- Point of sale and kiosks: where Cat 1 bis is the usual choice today and a longer runway is wanted.
Poor fits are tiny battery sensors that report a few bytes a day, which belong on NB-IoT or LTE-M, and anything installed where the operator has no standalone 5G and no plans to build it.
Before you choose a RedCap module
- Check standalone 5G coverage from your operator where the devices will actually sit, not just a national map.
- Check LTE fallback in the module, so devices keep working outside standalone coverage.
- Check the SIM and plan. Your SIM and data plan must allow RedCap and standalone 5G. The IoT SIM card guide and the MNO vs MVNO guide explain what to ask a provider.
- Check certification with the operators and countries you plan to sell in, which can take time for a new module category.
- Test in place. As with every cellular technology, test the real module in the real location before ordering in volume.
For the rest of the cellular picture, read the NB-IoT vs LTE-M comparison, the IMEI and IMSI explainers, and the other connectivity guides.
Written by the IoT Crest editorial team. Facts in this article follow the editorial policy: only well-established behavior is stated and no figures are invented.