Although cellular telephones resemble walkie-talkies, they are actually portable radiotelephones that can make virtually any call made by a conventional telephone.

Some telecommunications experts think these wireless networks could eventually replace many conventional telephones.

Signalman Relay: For those who cannot hear the ring of a conventional telephone.

Most emergency dispatchers around the nation can already determine the location of a call made from a conventional telephone.

At the same time, the number of 411 calls from conventional telephones has been decreasing, several analysts said.

The customer can either speak through microphone and speakers or headset, text chat, or use a conventional telephone to communicate with the operator.

There has never been electricity, nor even conventional telephones, at Boland Brook.

That puts him in the same bind as many people around the country who want high-speed, or broadband, Internet access but no longer need a conventional telephone.

The phones are expected to be of use primarily to people who travel heavily in remote regions where conventional telephones are unavailable.

But like conventional telephone and postal service, E-mail will never fulfill its social and commercial promise until it is universal.