At the same time, advances in technology--better filters and digital compression--are allowing carriers to squeeze far more data onto each frequency.

FORBES: FCC could bring on too much air

The costs of starting new television channels are falling, and will drop faster as digital compression packs more into the same transmission capacity.

ECONOMIST: The comfort of strangers

Digital compression typically allows between eight and 12 channels to occupy the same capacity required by a single analogue channel.

ECONOMIST: A world view | The