Either system could be changed, although the Bell companies and other giant carriers have an interest in maintaining the pricing for the conventional network.

Nowadays, those kinds of jokes abound on even the most conventional network sitcoms.

With India and China together adding more than 12 million cellphone subscribers a month, the two countries are the fastest-growing markets for conventional networks.

And calls to parties outside the company often must still use the conventional public network for at least part of the call.

The call setup success rate in conventional (so-called land-line) networks is extremely high and is significantly above 99.9%.

For now, in any case, even calls placed by Internet phones are dependent on the conventional network.

That has to use some conventional network and IP addressing system.

The tricky part is sending images quickly over conventional, low-capacity networks.

A decentralized computer system has many benefits over a conventional centralized network.

Mr. Pitsch points out that tiny, wireless phones may have significant cost advantages over conventional wired networks.