Browse Prior Art Database

DIRECT MODE ON TRUNKING

IP.com Disclosure Number: IPCOM000007270D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2002-Mar-08
Document File: 1 page(s) / 48K

Publishing Venue

Motorola

Related People

Richard Comparey: AUTHOR

Abstract

Current Trunking does not allow for communi- cations in Direct Mode. Users cannot communicate to each other without broadcasting over a repeater.

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MO-LA Technical Developments Volume 23 October 1994

DIRECT MODE ON TRUNKING

by Richard Comparey

  Current Trunking does not allow for communi- cations in Direct Mode. Users cannot communicate to each other without broadcasting over a repeater.

  If Direct mode were available the subscriber gear will transmit on the trunking talkgroup's repeater transmit frequency. The difficulty is for the control- ler to know how long to leave the assigned repeat- er's frequencies assigned to the talkgroup.

To let the controller know that a Direct call is in progress, the trunking system could be supplemented

with Direct receivers (i.e. they are tuned for the repeater's transmit frequency).

  When a subscriber goes into direct mode a mes- sage to that effect is sent on the control channel. A handshake signal is sent to the direct receiver to inform the system that the DIR mode is being used. The Direct receiver for that talkgroup would pass on the data from the handshake signal to let the controller know that the Direct mode conversation is in progress.

working

channel

Notes:

1. Trunking system implemented with direct receivers.
2. Subscriber 1 makes a DIRECT CALL request.
3. Handshake on Working Channel identifies DIRECT MODE. (For Astro / APCO-25 this could be embedded.)
4. Direct receivers hear the DIRECT MODE indicator & notify the controller.

0 Motorola. inc. 1994 15

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