SUPERVISION OF PORTABLE RADIOTELEPHONES WITH VOICE-ACTUATED TRANSMISSION
Original Publication Date: 1982-Jan-01
Included in the Prior Art Database: 2001-Oct-10
High capacity radiotelephone systems such as the Motorola DYNATAC system require extensive supervision of the mobiles and portables in the system. The DYNATAC system (see U.S. Patent No. 3,906,166) divides the service area into cells. Service for a particular mobile or portable is transferred from cell to cell as the unit travels through the system. Periodic monitoring of signal strength is required to ac- complish this. This periodic monitoring becomes a problem with VOX (Voice Operated Transmission) because the portable is only transmitting when the user is talking. A "power up" digital command message could be sent to the portable, but every transmission of a digital message to the portable inter- rupts voice reception and is therefore not desirable unless absolutely necessary. The portable unit can be monitored only when the unit is VOXed-up, but this would leave gaps in the supervision during long periods of novoice activation at the portable.