Why Wi-Fi Is Worse In The Room Next To The Router

The router is one wall away and the connection is dreadful, while the far end of the flat works fine. Distance is only one of several things going on here.

The faster band trades reach for speed

Home equipment transmits on more than one frequency band. The higher band carries far more data and loses far more of its strength passing through solid material.

Longer wavelengths bend around obstacles and penetrate walls more readily. Shorter ones deliver the throughput everybody wants and then stop dead at a chimney breast.

A device that has latched onto the fast band in the next room may be far worse off than one sitting patiently on the slower band two rooms further away.

Walls are not all equal

Plasterboard is nearly transparent to radio. Brick, stone, tiled surfaces and anything containing metal are not, and the difference between them is enormous.

Foil-backed insulation board, common in modern renovation, behaves close to a mirror at these frequencies. So do large appliances, actual mirrors, and boilers full of pipework.

Water absorbs strongly, which is why a bathroom, an aquarium or a well-attended room behaves differently from an empty one of exactly the same dimensions.

The aerial pattern has holes in it

A typical rod aerial radiates in a doughnut shape around itself, strong outward and weak along its own axis. Directly above and below the aerial is the quiet zone.

A router standing upright on a shelf therefore serves its own floor well and the room directly overhead poorly, which is rarely how anybody thinks about positioning one.

Putting the box inside a cupboard, behind a television or on the floor beside a radiator removes signal before it has travelled anywhere at all.

Devices cling to a band after moving

Deciding when to switch bands or access points is left largely to the client device, and most are reluctant, holding a deteriorating connection rather than re-scanning.

A phone that connected to the fast band in the hallway will often stay on it in the kitchen, dragging along at a fraction of what the slower band would give it.

Turning the connection off and on again fixes exactly this, which is why that folk remedy keeps working while continuing to sound like superstition.

The neighbours are on your channel

The lower band has only a few genuinely non-overlapping channels, and in any dense building every one of them is occupied by several households at once.

Devices sharing a channel take turns, so a busy neighbour does not corrupt your signal, it simply makes you wait. Strong signal and slow speed coexist perfectly well.

Microwave ovens, older cordless phones and some baby monitors add interference in the same band, producing outages that track domestic routine rather than network load.