4G/5G home internet: where should the router go?

With internet over the mobile network, the router is also the antenna. The best spot for one job is the worst for the other.

Published · 2 min read

In this guide
  1. Two jobs, two best positions
  2. Rule one: the mobile link comes first
  3. Rule two: extend the Wi-Fi, don't move the router
  4. If you have an outdoor antenna
  5. Measure the two things separately

More and more homes get their internet over the mobile network, with a router that takes a SIM or an outdoor antenna pointed at a mast. It works well where fibre doesn't reach. It also creates a placement problem that wired connections don't have.

Two jobs, two best positions

A normal router has one radio job: Wi-Fi for the house. A 4G/5G router has two:

  • Catching the mobile signal, which is strongest at a window, high up, on the side of the house facing the mast.
  • Serving Wi-Fi, which works best from the centre of the home: see where to put your router.

A window on an outside wall is about as far from "central" as you can get.

If the router hears the mast badly, everything behind it is slow, however good your Wi-Fi is. So place the router for the mobile signal, using its own signal indicator or app, and try more than one window. Height helps, and so does the upper floor.

One thing to watch: modern energy-saving glass often has a thin metallic coating that blocks mobile signal as well as heat. If a window gives a poor result, try another one, or compare with the window open: see Wi-Fi in new builds.

Rule two: extend the Wi-Fi, don't move the router

Once the router sits where the internet is best, bring Wi-Fi to the rest of the house separately:

  1. A cable from the router's network port to an access point in the middle of the home. This is the cleanest answer: see access point or mesh node.
  2. A mesh system, with the first node by the router and the next one towards the centre: see where to put a mesh node.
  3. Powerline or coax if a cable can't be run: see powerline adapters.

It's the same situation as internet line in the wrong corner, except that here the corner really can't be changed.

If you have an outdoor antenna

Some installations put the mobile antenna outside, on a wall or the roof, with a cable to an indoor router. Then the conflict disappears: the antenna handles the mast, and the indoor router can sit wherever that cable reaches.

Measure the two things separately

Speeds on a mobile connection change with the time of day, because you share the mast with the neighbourhood. That's not your Wi-Fi. To see your Wi-Fi on its own, map the house with WiFi Heatmap: it shows which rooms the window-side router reaches and where the second access point should go.