When an extender is the wrong answer

An extender moves the edge of usable coverage outward, at a cost in speed. It does nothing else. If the complaint is about speed rather than reach, about a room that has a signal but a slow one, about drops that happen everywhere in the house, or about an evening when everyone is online at once, the cause lies somewhere an extender cannot touch.

Nothing wireless can exceed the speed of the connection entering the house. A home on a slow or congested line experiences that slowness in every room, near the router and far from it alike, and an extender adds a relay to a bottleneck that sits upstream of everything. The tell is that the experience is the same beside the router as it is in the far room. Whatever the wireless equipment shows, the line is what is being used up.

The same applies to a line that is fast on paper and slow in the evening. That is contention on the provider’s side, shared with the neighbours, and it comes and goes with the time of day rather than the room.

The router is the only source of signal in the house, and a source badly placed wastes coverage that no repeater can recover. A router on the floor behind a television, inside a cupboard, in a metal cabinet, or at the end of the house furthest from where people sit is starting every signal at a disadvantage. Moving it a few metres into the open, or a floor up, often does more than any extender, and often makes the extender unnecessary.

Where the line enters the house is a constraint, but a less rigid one than it seems: a longer cable between the wall socket and the router is cheap, and providers’ own documentation generally describes what is permitted on their line.

A household of many devices, several of them streaming video at once, can exhaust a router’s wireless capacity in a room where the signal is excellent. The symptom is a network that is fine at noon and slow at nine in the evening, in every room at once. An extender shares the same channel as the router and takes its own turn on the air for every relayed frame, so it adds to the congestion rather than relieving it.

Capacity problems belong to the router: its generation, how many simultaneous streams it can carry, the band and channel width it is using, and how many devices are on the crowded 2.4 GHz band when they could be on 5 GHz. Those are matters for the router’s own documentation.

An extender needs a socket where the router’s signal remains strong, between the router and the rooms without one. In a house with solid masonry internal walls, a modern one with foil-faced insulation throughout, or a flat with reinforced concrete floors, there may be no such socket: the signal fades within a wall or two of the router, and every candidate position is already in the shadow. What actually blocks a wireless signal explains why, and four ways compared sets out the approaches that carry a network through walls radio cannot cross.

In a block of flats, dozens of networks can share the same few channels. Every one of them takes turns on the air with every other, and a room with a strong signal can still be slow because the channel is busy with the neighbours’ traffic. An extender adds another transmitter to the same channel and worsens the queue. The variables that matter are the channel and the band the router uses, and the width of the channel, all of which are set on the router.

The case for an extender is specific and common. The line is adequate. The router is reasonably placed. The house is large enough, or its walls ordinary enough, that the signal fades before it reaches a bedroom, a conservatory or a garden room, while remaining strong at a socket somewhere between. In that house an extender at that socket moves the edge of coverage into the room that lacked it, at a price that makes the halving irrelevant against the speed of the line. Where an extender belongs describes how to find the socket.