[Johnythree]

You are confusing peak power with average power. The law of reciprocity says that nothing is to be gained if the base transmitter is more powerful than the mobile TX.

However because the base has multiple (hundreds) of low-power transmitters, it must cater for a very large instantaneous peak power when they momentarily add up.

And more importantly, excess Transmit power reduces the re-use ability of that frequency in nearby cells.

[flashdance]

> The law of reciprocity says that nothing is to be gained if the base transmitter is more powerful than the mobile TX.

Late response, but that assumes that the mobile RX is as good as the tower's RX, and I can assure you that's not the case.

The gear up on a tower has a way better low noise amplifier than a mobile phone, so it's able to "hear" the phone at a greater distance than you'd expect. That's why it's a-okay to have a base transmitter with a quite a bit more power than a mobile TX.

[Dylan16807]

> The law of reciprocity

The what? The only thing I can find about reciprocity is that antennas have the same characteristics in either direction. That doesn't mean your noise levels are the same, and you very often have different bandwidth requirements in each direction.