Browse Prior Art Database

TRANSMIT INHIBIT SIGNALING

IP.com Disclosure Number: IPCOM000005737D
Original Publication Date: 1988-Oct-01
Included in the Prior Art Database: 2001-Oct-31
Document File: 2 page(s) / 92K

Publishing Venue

Motorola

Related People

Brian K. A. Johnson: AUTHOR [+3]

Abstract

In acommunications system which uses distributed transceivers to communicate from phone line to por- table receivers it is essential to insure that only the active portable can steer the system. This is accomplished by having all the transmitters in the other inactive portables inhibited. This article describes avery simple and easy to implement method of signalling to accomplishing this.

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MOTOROLA Technical Developments Volume 8 October 1988

TRANSMIT INHIBIT SIGNALING

by Brian K. A. Johnson, Stelios Patsiokas, and Bill Braun

   In acommunications system which uses distributed transceivers to communicate from phone line to por- table receivers it is essential to insure that only the active portable can steer the system. This is accomplished by having all the transmitters in the other inactive portables inhibited. This article describes avery simple and easy to implement method of signalling to accomplishing this.

   The distributed transceiver sites are connected to a central controller which calls the portable in asimulcast mode, and on getting a response from the called portable, steers the message to the optimum transceiver for best communication. When there is no message activity on the system, each portable is capable of initiating a transmission in order to get access to the system, and originate a call. Once a request for communications has been received by the system from either a portable unit or from the phone line, the system needs a way to inhibit all the portable transmitters except the one that is being called, or the one making the call. After the activity has ended, the controller needs a way to enable all the portable transmitters that it previously inhibited. The signalling system described herein accomplishes both.

   At the central controller there is a circuit which when signalled by the logic at the beginning and the end of a message will simulcast a series of modulation bursts, consisting of full system deviation at 3000 Hz for 5 msec, followed by no modulation for 5 msec. Four bursts of modulation are simulcast for inhibit, before the called portable ID is simulcast, or the dial tone is sent to the requesting portable. Eight bursts are simulcast at the end of the message to enable all the portable...