Not very long ago, it took about $50 million to develop electromechanical central switches for the telephone system, and about 2,000 workers to produce them.

The phone numbers, he explains, connect to modems linked to the central switches that determine where electricity flows.

This contains complex electronics to accumulate telephone lines or data and route it to a central switch.

The third - the central switch - was in back of an improvised bar.

The office controller would be a central switch which would link users to applications and provide necessary services such as security.

In any city, a handful of central "switches" handle the work of routing local phone calls.

'The door operates from a central switch, and it's locked.'

After appropriate checks with the customer's bank, the transaction is forwarded to a central switch.

In conventional communications systems, calls are routed to a central switch, where the connection to the other telephone is made.

Under the system envisioned by Professor Acampora's group, the central switch would be eliminated.