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Fibre, DSL, 4G, 5G, satellite: internet connection types explained

The speed you measure depends first on the technology that links your home to the internet. Each one has its strengths, limits and pitfalls: here is how to tell them apart.

Overview

TechnologyMediumTypical downloadUploadTypical latency
Fibre to the home (FTTH)Optical fibre300 Mbps to 8 GbpsOften symmetrical or high2 to 10 ms
Cable (DOCSIS 3.1)Cable TV network100 Mbps to 1 GbpsMuch lower10 to 25 ms
VDSL2Copper phone line15 to 100 Mbps5 to 40 Mbps10 to 25 ms
ADSL2+Copper phone line1 to 20 Mbpsunder 1 Mbps25 to 50 ms
4G home internetMobile network10 to 100 Mbps5 to 50 Mbps30 to 60 ms
5G home internetMobile network100 Mbps to 1 Gbps20 to 100 Mbps15 to 40 ms
Geostationary satelliteSatellite at 36,000 km20 to 100 Mbps3 to 10 Mbps550 to 700 ms
Low-orbit satelliteConstellation at ~550 km50 to 250 Mbps10 to 30 Mbps25 to 60 ms

These ranges are indicative: they vary by provider and country, and for copper and mobile, by your exact situation.

Fibre (FTTH)

Fibre carries light all the way to your home. Speed hardly depends on distance, latency is the lowest, and the connection copes well with many simultaneous uses. Watch the wording: some "fibre" plans stop at the building or the street cabinet and finish over coaxial cable or copper (FTTB, FTTC), in which case you get the performance of that last stretch.

With fast fibre, the bottleneck often moves inside your home: Wi-Fi, a network card limited to 1 Gbps, an old Category 5 Ethernet cable.

Copper: ADSL and VDSL

ADSL and VDSL reuse the phone line. Their speed drops with the length of the line to the exchange or street cabinet: within a few hundred metres, VDSL exceeds 50 Mbps; beyond one or two kilometres, it falls back to ADSL levels. Upload stays low, which hampers sending files and video calls. In many countries the copper network is gradually being switched off in favour of fibre.

Cable

Cable networks, originally built for television, now reach gigabit download speeds. Their weak points are the more limited upload and the fact that bandwidth is shared between subscribers in the same area, which can reduce performance at peak times.

4G and 5G home internet

A 4G or 5G router receives the internet over the mobile network, like a smartphone. It is quick to set up where fibre doesn't reach. Performance depends on coverage, distance to the mast and how many people use the same cell, so speed can vary a lot by time of day. Placing the router near a window facing the mast often makes all the difference. Some 4G or 5G home plans include a data cap or slow you down beyond a threshold: read the terms.

Satellite

Satellite covers the most remote areas. Geostationary satellites, 36,000 km up, impose latency of around 600 ms that makes online gaming and video calls painful. Low-orbit constellations, a few hundred kilometres up, offer latency close to ground connections, at the cost of dedicated equipment and an often higher subscription.

How to choose

  1. Check what's available at your address: provider websites and official coverage maps list the technologies on offer.
  2. Prefer fibre if you can get it: it's the best-performing and most future-proof option.
  3. Look at upload speed if you work from home, send large files or back up online.
  4. Look at latency if you game online: avoid geostationary satellite, and expect 4G to be irregular.
  5. Test before you commit when possible: a speed test on site with a smartphone on 4G or 5G gives an idea of real mobile coverage.

Once connected, measure your connection regularly, over Ethernet and at different times: it's the best way to check you're getting what you pay for.

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Frequently asked questions

Do I really need more than 1 Gbps?

For most households, no: 300 to 500 Mbps easily covers several 4K streams, video calls and downloads. Very high speeds mainly help with large file transfers, and only if your equipment can use them.

Can 5G home internet replace fibre?

Where 5G coverage is good, speeds can be comparable, but stability and latency remain less consistent than fibre, especially at busy times. It is an excellent alternative where fibre isn't available.

Why is my ADSL speed so low?

ADSL speed depends mostly on the length of the phone line to the exchange: beyond a few kilometres it drops sharply. Poor internal wiring or a bad phone socket can also degrade the signal.

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