That means a fully equipped cell can theoretically carry a maximum of about 60 calls. But some channels are set aside for overhead functions, specifically paging and access. The reverse channels paired with the paging channels are used by the phones to request service. When you dial a number and hit the SEND button, your phone sends a short digital message over the access channel corresponding to the paging channel it has been monitoring. Only now, with the introduction of digital cellular phones, are cryptographic authentication techniques being introduced to foil this attack.
Cryptographic authentication does nothing to protect the privacy of the communication itself.
Why The System Must Know Where You Are It should be fairly obvious by now why the cellular system must know your location, at least while you're in a call. As the call progresses, you may move from one cell to another. If this happens, the system must find the new cell and transfer the call to that cell. When another cell reports having found you, the system hands the call off to that new cell. So as long as you keep talking, the system can locate you to at least the nearest cell.