5G Fixed Wireless Access: Broadband Without a Phone Line
5G fixed wireless access (FWA) uses a 5G router as the broadband device for a home or business, replacing or supplementing a traditional fixed broadband service. Where a 5G signal is available, the performance is compelling – download speeds of 100-500 Mbps are common, with peak gigabit speeds achievable in strong signal conditions. For properties in suburban and urban areas without access to full-fibre broadband, 5G FWA is an increasingly credible primary broadband solution.
SimWise supplies 5G routers, SIM cards from all four UK networks, and external antennas for home and business 5G FWA installations across the UK.
How 5G Fixed Wireless Works
A 5G FWA router connects to the mobile network in the same way a 5G phone does, but it is a dedicated device designed to stay in one place and serve as a local Wi-Fi router. The router connects to the nearest 5G mast over the air and distributes the internet connection to devices in the property via Wi-Fi or wired Ethernet.
The key variables that determine performance are signal strength (measured as RSRP and SINR at the router) and the type of 5G spectrum available. Sub-6 GHz 5G (the most common type in the UK) provides good coverage with speeds typically 2-5x faster than 4G LTE. Millimetre wave 5G (mmWave, above 24 GHz) provides gigabit speeds but very limited range and is primarily a city centre technology.
Which Network for 5G FWA?
5G coverage varies significantly by network at any given UK address. EE was the first to deploy 5G and has the widest coverage as of 2025, particularly in suburban areas. Vodafone and Three have strong urban 5G networks. O2 has focused on sub-6 GHz 5G with broad geographic coverage.
For 5G FWA, checking all four networks at your specific address is essential before committing to a SIM. Coverage maps are indicative – actual indoor signal depends on building construction, window orientation, and proximity to the mast. SimWise can advise on which network is most likely to perform well at your address and supply the appropriate SIM.
Unlimited SIM Cards for 5G FWA: What You Need to Know
The major networks offer unlimited data tariffs suitable for 5G FWA use. These include EE Full Works, Vodafone Unlimited Max, O2 Unlimited, and Three Unlimited. All carry a fair use policy (FUP) rather than a truly unlimited commitment. Sustained heavy usage – particularly file-sharing or continuous 4K streaming on multiple devices – may be subject to speed management during peak periods. SimWise will discuss realistic usage expectations and recommend the most appropriate tariff. See: EE Unlimited, Vodafone Unlimited, Three Unlimited, O2 Unlimited.
External Antennas for 5G FWA
The internal antenna of a 5G FWA router is optimised for use inside a building but is limited by building attenuation. In strong signal areas this is not a problem. In areas with marginal 5G signal or where the property has heavy masonry walls, an external window-mount or wall-mount antenna can substantially improve signal quality and sustained throughput.
5G external antennas require wider band coverage than 4G antennas – specifically supporting the n78 (3.5 GHz) band used by all four UK networks for 5G, as well as the legacy LTE bands for fallback. Ensure any external antenna is specified for 5G n78 operation.
5G FWA vs Fibre Broadband
In areas with full-fibre (FTTP) broadband available, 5G FWA is typically not the primary recommendation – fibre provides a more consistent, lower-latency connection unaffected by RF conditions. Where full-fibre is unavailable or the connection speed is below 50 Mbps, 5G FWA is a compelling alternative that can deliver faster speeds at lower cost than waiting for fibre build-out.
5G FWA is also valuable as a backup to any fixed line connection – a 5G router with a data SIM activates automatically if the primary broadband fails, protecting against the trading interruptions that a broadband outage causes.
External Antennas: Do You Need One?
Every 4G and 5G router ships with stub antennas attached to the ports on the casing. In many installations these are perfectly adequate. In others – particularly inside metal-framed buildings, below ground level, or in rural areas far from the nearest mast – an external antenna can make a significant and measurable difference to both signal quality and sustained throughput.
Before purchasing an external antenna, we recommend working through a structured test process:
- Baseline test with supplied antennas in the intended location. Install the router where it will live in normal operation. Note the RSRP value from the router diagnostic page – this is a more reliable indicator than signal bars. Run a speed test and record the results.
- Try different positions within the same space. Cellular signal varies considerably within a single room. A window-mounted location can outperform a cabinet in the centre of the same space by 10-15 dB. Try several positions before concluding signal is poor.
- Test outdoors on a dry day. Take the router outside – clear of the building envelope – and run the same tests. Building fabric, particularly reinforced concrete, metal cladding, and low-emissivity glass, can attenuate signal by 20 dB or more. If outdoor results are substantially better, an externally-mounted antenna is the right solution.
- Test each network in turn. If you have a multi-network IoT SIM, lock the router to each available network and test each one. Coverage and performance vary significantly by network at any given location. EE frequently outperforms in rural areas; Three tends to be strongest in urban environments.
- Consider a directional antenna if signal is marginal. An omni-directional antenna captures signal from all directions but lacks gain. If you know the direction of the nearest mast, a directional or panel antenna aimed at the mast can provide 5-9 dBi additional gain over a standard stub – the equivalent of moving the router significantly closer to the mast.
Antenna Connection Note
Most 4G and 5G routers use SMA or TS9 connectors. Check your router specification before ordering an antenna and cable. For cable runs over five metres, use low-loss coaxial cable – standard RG58 introduces approximately 1.5 dB of loss per metre at LTE frequencies, which can negate the benefit of the antenna. Speak to SimWise before specifying a long cable run. Browse our antenna range.
Get a Quote for 5G Fixed Wireless Broadband
Tell us your postcode and whether you are looking at this as primary broadband or backup. We will check 5G coverage, recommend a router and SIM combination, and advise on whether an external antenna is likely to be needed.