Why your signal is bad — seven reasons that have nothing to do with the nearest tower

People come to sites like this one looking for a tower, on the assumption that finding the nearest one explains their coverage. It rarely does. Distance matters, but it is one variable among several, and usually not the dominant one.

Here is what else is going on.

1. The tower near you may not carry your carrier

More than half of registered structures belong to tower companies rather than to networks. A tower company leases space to whoever wants it. That means the mast at the end of your road might carry three carriers, or one, or none of the ones you use.

Nothing in the public registration data tells you which. The structure is registered; the radios on it are licensed separately, and those licences are not linked to the structure record in any way you can look up quickly. So “there is a tower nearby” and “my carrier has equipment nearby” are genuinely different statements.

2. Antennas point somewhere

A cell site is not a light bulb. Panel antennas are directional, typically arranged in three sectors covering 120 degrees each, and they are downtilted — aimed at the ground within a planned radius rather than at the horizon.

Directly underneath a tower is often a weak spot, because you are below the main beam. People are frequently surprised to find better signal a few hundred metres away than at the base of the mast.

3. Frequency decides how far it goes and what it goes through

This is the big one, and it is invisible in any structure database.

Low-band spectrum (600–900 MHz) travels a long way and penetrates buildings well. Mid-band (1.7–2.5 GHz) carries more data but does not reach as far. C-band (3.7–3.98 GHz) carries a great deal more and reaches meaningfully less. Millimetre wave (24 GHz and up) delivers enormous capacity over a couple of hundred metres and is stopped by a window.

A tower a mile away transmitting low-band may serve you better indoors than one 200 metres away transmitting C-band. Both are on the map. Only one is helping.

4. Buildings, and specifically your building

Signal loses roughly 10–20 dB passing into a typical building — sometimes far more. Concrete and steel frames are worse than timber. Foil-backed insulation is very effective at keeping radio out, which is not what it was designed for but is what it does. Modern low-emissivity window glass has a metallic coating that attenuates radio significantly.

Energy-efficient buildings are frequently terrible for mobile signal, and the better insulated the building, the worse it tends to be.

5. Terrain, and specifically what is between you

Radio at these frequencies travels in something close to a straight line. A hill between you and the site does not attenuate the signal so much as block it. Being in a valley, a cutting, or the wrong side of a ridge can eliminate a site that is nominally close.

This is why the coverage estimates on this site are labelled as theoretical maxima. The formula gives the distance to the radio horizon over flat, unobstructed ground. Real terrain is neither.

6. Congestion, not coverage

Bars measure signal strength. They do not measure whether there is any capacity left.

A stadium after a match, a motorway at rush hour, a town centre on a Saturday — the signal is fine and the data is unusable, because a few hundred other people are sharing the same sector. This is the failure mode most often misdiagnosed as poor coverage, and no amount of tower-hunting explains it.

7. Your phone, and where you are holding it

Handsets vary in antenna performance more than manufacturers like to discuss. Cases with metallic elements attenuate. Holding a phone so your hand covers the antenna band costs real signal — the effect is measurable and was once a public scandal.

And a phone at the edge of coverage transmits at higher power to stay connected, which is why the battery drains fastest exactly where the signal is worst.

What actually helps

If you want better indoor coverage, in rough order of effectiveness:

Wi-Fi calling. Most carriers support it and it bypasses the radio path entirely. If you have broadband, this solves the problem completely for voice.

Move nearer a window. A single wall can be worth 10 dB. Windows with metallic coatings are the exception, but most homes have at least one window that is better than the rest.

A femtocell or signal booster. Carriers sometimes provide the former; the latter is sold commercially. Both work, and both are a bigger lever than knowing where the nearest mast is.

Change carrier. Coverage differs substantially between networks at any given address, and the carriers’ own coverage maps — for all their optimism — are more useful for this than a structure database.

What this site is for, then

Knowing where registered structures are is genuinely useful: for understanding infrastructure density, for checking what is near a property before you buy, for satisfying curiosity about the tall thing on the hill. It is a poor tool for diagnosing why your phone is slow indoors, and we would rather say so than pretend otherwise.