Fibre vs fixed wireless: which business internet should you actually choose?

How fibre and fixed wireless actually work

The difference that drives everything else is physical: fibre is a sealed light-path all the way to your building, while fixed wireless is a radio link to the nearest mast.

Fibre runs a glass strand from the network into your premises and terminates at a small box (the ONT). Light carries the signal, so the link is fast, symmetric on business tiers and barely affected by weather or the neighbours’ usage. The catch is civils: if the cable has not been trenched to your building yet, someone has to dig.

Fixed wireless – whether LTE or 5G – puts a router or a rooftop unit (CPE) in your office that talks to a mobile mast. There is nothing to trench, so you can be live in days. But you are now sharing a radio cell with everyone else on that tower, and distance, obstructions and peak-hour congestion all move your speed and latency around.

Where each one wins, and where it does not

Put them side by side on the factors an office actually feels, and the trade-offs get clear fast.

What it means for your VoIP and video calls

If your team lives on calls, latency and jitter matter more than headline speed – and this is where the two technologies separate most.

Voice is surprisingly light on bandwidth. Under the ITU-T G.711 codec a single call uses only about 100 kbps once you count the packet overhead, so even a modest link carries plenty of concurrent calls. What voice cannot tolerate is delay and inconsistency. ITU-T G.114 sets the working ceiling at 150 ms of one-way latency before quality falls off, and clean calls also want jitter under 30 ms and packet loss under 1%.

Fibre sits comfortably inside all three limits and stays there. Fixed wireless can absolutely deliver call-grade quality on a strong, lightly loaded 5G cell – but its latency and jitter wander more, especially at peak times or when the signal is marginal. That is why call-heavy offices lean fibre, and why anyone running VoIP over wireless should size headroom and prioritise voice traffic deliberately.

What each one really costs

Sticker price is only half the story – the honest comparison is cost against the data and uptime your business actually uses.

In the South African business market, uncapped fibre runs from roughly R699 a month for an entry 10 Mbps line up to around R3,500 a month for 100 Mbps synchronous, with faster tiers and 10 Gbps in select metros quoted on request. Fixed wireless typically lands between about R599 and R1,299 a month. On paper wireless often looks cheaper, and for a light user it can be.

The picture flips for a data-heavy office. Once a wireless plan hits its fair-use ceiling and throttles, the “cheaper” line stops doing the job, whereas uncapped fibre keeps its speed no matter how hard you push it. Weigh the monthly figure against your real usage and the cost of downtime, not against the advertised headline alone.

How to choose in five questions

Work through these in order. The first two usually make the decision for you.

Why a hybrid setup beats picking just one

For any office that cannot afford to go dark, the strongest answer is not fibre or wireless – it is both, wired for automatic failover.

A hybrid setup uses fibre as the primary connection for everyday VoIP, video and cloud work, with fixed wireless or LTE on standby. A dual-WAN or failover router watches the primary link and switches over in seconds if fibre drops – a cut cable, a civils fault or a network outage no longer takes the whole office offline. Done well, this is how businesses reach the 99.9%-plus uptime that healthcare, fintech, e-commerce and remote-first teams depend on.

It also solves the multi-site problem elegantly: some branches may be fibre-ready while others are better served by wireless, and a failover-first strategy keeps every location on the same reliable footing. The two technologies are far more useful as partners than as rivals.

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