5G Redcap and n28

5G RedCap and the n28 Band: A Practical Guide for UK Buyers

5G is not a single technology. It is a set of standards covering multiple frequency bands, device categories, and deployment models. Two of the most important for UK industrial and IoT buyers in 2026 are the n28 band (700MHz) and 5G RedCap. Both affect what router you should buy – and both directly affect how you should specify your antenna.

This guide explains what n28 and RedCap are, how UK networks use them, and what to look for when choosing an antenna. An incorrectly specified antenna is the most common reason a cellular deployment underperforms. Understanding the bands your router uses is the starting point for getting the specification right.

The n28 Band: 700MHz and Why It Matters

The n28 band operates at 700MHz. Before 2021, this slice of spectrum carried digital television (Freeview). Ofcom auctioned it to mobile operators to tackle two long-standing problems: poor indoor coverage and rural connectivity gaps.

The physics is straightforward. Lower frequencies travel further and pass through walls more effectively than higher frequencies. A single n28 mast covers significantly more ground than a mid-band 5G mast at 3.5GHz. That makes n28 the primary tool for the UK’s Shared Rural Network – the programme designed to eliminate mobile not-spots in Scotland, Wales, and other rural areas.

How UK operators use n28

• EE – uses n28 to extend 5G coverage into fringe and rural areas where mid-band cannot reach. If you see 5G on an EE SIM in a remote location, it is n28.
• O2 and Vodafone – rely on n28 for deep indoor coverage in dense urban centres. If you see 5G in a basement or inside a thick-walled building, it is almost certainly an n28 signal.
• Three – holds the most mid-band (n78) spectrum in the UK but uses n28 as the coverage layer for locations where 3.5GHz cannot penetrate.

The UK 5G Frequency Stack

5G in the UK operates across four frequency layers. A 5G router with carrier aggregation may use more than one simultaneously. Understanding each layer helps you specify an antenna that covers what your router actually needs.

For most industrial and IoT deployments in the UK, the relevant layers are n28/n20 for coverage and n78 for throughput. A quality 5G antenna should cover both – typically 700MHz to 3.8GHz.

What Is 5G RedCap?

5G RedCap (Reduced Capability) is a 3GPP Release 17 standard. It was created to fill the gap between low-power IoT protocols like NB-IoT and full-specification 5G. The aim is a cellular standard that delivers 5G network features – including network slicing and native 5G security – without the antenna count, processing power, and battery consumption of a full 5G device.

How RedCap differs from full 5G

Where RedCap is being used

RedCap is the target standard for the next generation of industrial IoT sensors, wearable health monitors, smart city infrastructure, and connected surveillance cameras. These devices need more bandwidth than NB-IoT provides but do not require gigabit throughput. Teltonika’s CALYX HAT+ module brings RedCap connectivity to Raspberry Pi-based industrial platforms – one of the first RedCap-capable modules available to UK developers.

For buyers specifying infrastructure today, RedCap is the direction the industry is heading. Deployments expected to run for five or more years should factor RedCap support into the evaluation.

Antenna Specification: Getting It Right for n28 and 5G

Antenna selection is where most cellular deployments are incorrectly specified. The router receives attention. The antenna is treated as an afterthought. Signal quality falls below what the hardware can deliver – and the cause is rarely obvious to someone who has not encountered it before.

The following sections cover each variable to check before ordering an antenna.

1. Frequency range: the most common mistake

An antenna datasheet states the frequency range it covers. Many antennas described as “4G” only cover 800MHz (Band 20) and above. The n28 band starts at 700MHz. If the antenna does not cover 700MHz, it will not support n28 connections. This matters most in rural locations and inside buildings – precisely the conditions where n28 is most likely to be the active band.

2. MIMO configuration: match to your router’s antenna ports

MIMO (Multiple-Input Multiple-Output) uses multiple antenna elements simultaneously to increase throughput and resilience. Most industrial 4G routers use 2×2 MIMO for cellular – two antenna ports, two antenna elements. Full 5G routers use 4×4 MIMO – four antenna ports. RedCap devices typically use 1×1 or 2×2 MIMO.

If your router has four cellular antenna ports, connect a 4×4 MIMO antenna. A 2×2 antenna connected to a 4×4 router leaves two ports either unconnected or connected to a separate single-element antenna. The throughput benefit of 4×4 MIMO is lost. Our 4×4 MIMO 5G antennas are specified for this purpose.

3. Gain and antenna pattern: omni versus directional

Antenna gain is measured in dBi. Higher gain means the antenna focuses signal energy more narrowly – it is more directional. A 5 dBi omni-directional antenna radiates in all directions with moderate gain. A 12 dBi directional antenna focuses toward a single point with significantly stronger gain in that direction.

Higher gain is not always the right choice. A directional antenna pointed accurately at a mast outperforms the same antenna pointed at open sky. For mobile or vehicle deployments, an omni-directional antenna maintains consistent signal regardless of orientation. For fixed deployments with a known mast location and weak signal, a directional antenna gives the best result. See our directional 4G antennas for fixed-site signal improvement options.

4. Cable length and signal loss

Coaxial cable introduces signal loss. The longer the cable run and the higher the frequency, the greater the loss. At 700MHz the loss per metre is relatively low. At 3.5GHz it is significantly higher. A 10-metre cable run on a mid-band 5G connection can cost several dB of effective gain – more than negating the benefit of adding an external antenna.

Keep cable runs as short as the installation allows. Use low-loss coaxial cable where longer runs are unavoidable. If you are unsure which cable suits your installation, call our UK-based technical support team on 0300 124 6181.

5. Connector type

Most Teltonika and Proroute routers use SMA Male connectors on the cellular antenna ports. Some compact or embedded devices use TS9 or SMA Female. Always check the antenna port specification in your router’s datasheet before ordering. Using the wrong connector requires an adapter, which introduces an additional point of signal loss and mechanical failure.

6. IP rating for outdoor installations

Outdoor antennas for permanent UK installations should carry a minimum IP65 rating. IP65 means dust-tight and protected against water jets from any direction. For exposed coastal or rooftop locations, IP67 (short-term immersion) provides additional protection. Our Fullband antenna range covers 700MHz to 3.8GHz, is rated for permanent outdoor use, and is stocked in the UK for next-day delivery.

Antenna Specification Checklist

Frequently Asked Questions

Does my 4G router support the n28 band?

It depends on the modem inside the router. Check the cellular connectivity section of the router’s datasheet for a band list. Look for Band 28 (4G) or n28 (5G NR). Most current Teltonika routers – including the RUT950, RUT955, RUT956, RUTX11, and RUTC40 – support Band 28. If you are unsure, contact us before ordering and we will confirm against the specific model.

Do I need a new antenna if I upgrade from 4G to a 5G router?

Possibly. An existing 2×2 MIMO antenna covering 700MHz to 2.7GHz will still handle the 4G bands on a 5G router. However, it will not cover n78 (3.5GHz) mid-band 5G, which is where the higher throughput comes from. A full 5G antenna covering 700MHz to 3.8GHz with 4×4 MIMO is the correct specification for a 5G router. View our 5G antennas for compatible options.

What is 5G Standalone and does it affect antenna choice?

5G Non-Standalone (NSA) uses the 4G LTE core to initiate connections, then adds 5G for data. 5G Standalone (SA) runs entirely on the 5G core without relying on 4G. SA enables network slicing and full RedCap support. However, the antenna specification is the same for both – the antenna cannot distinguish between SA and NSA. Band coverage and MIMO configuration are what determine antenna compatibility, not the core network architecture.

Is 5G RedCap the same as 5G?

RedCap is a subset of 5G New Radio. It uses the same frequency bands as full 5G – including n28 and n78 – and connects to the same 5G core network. The difference is the device specification: fewer antenna elements, lower maximum bandwidth, and lower peak speeds than full 5G hardware. A 5G RedCap device connecting on n28 uses the same network infrastructure as a full 5G router. To the network, it is a 5G connection.

What SIM card do I need for a 5G router?

A standard UK nano-SIM works in 5G routers. For fixed deployments requiring a static IP address for VPN tunnels, remote monitoring, or CCTV access, a fixed IP SIM card is the correct choice. For multi-site deployments across the UK and Europe, a roaming SIM connects automatically to the strongest available network. If your router supports eSIM, see our guide to eSIM routers.

Will n28 remain relevant as 5G networks develop?

Yes. n28 is the coverage foundation for all four UK networks and that will not change as mid-band 5G expands. As 2G approaches end of life and 3G has already been shut down by EE, Vodafone, and Three, n28 becomes the primary fallback band for any device outside mid-band coverage. Any router or antenna specified for a deployment with a multi-year lifespan should support n28.

Related Products and Further Reading

Browse our 5G antennas for options covering 700MHz to 3.8GHz with 2×2 and 4×4 MIMO configurations. For 4G deployments requiring n28 coverage, our 4G antennas include fullband options rated to 700MHz. The Fullband antenna range is stocked in the UK and built for permanent industrial outdoor use. For 5G router options, see our 5G routers including the Teltonika RUTX50, RUTM52, and Proroute H685 5G. If you need help matching an antenna to a specific router or deployment, call our UK-based technical team on 0300 124 6181.

Further reading: eSIM Routers Explained | VPN on Cellular Routers | What is Teltonika RMS?