Browse Prior Art Database

Unanswered Call Diverter

IP.com Disclosure Number: IPCOM000050794D
Original Publication Date: 1982-Dec-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 49K

Publishing Venue

IBM

Related People

Brady, RL: AUTHOR [+2]

Abstract

Newer electronic private automatic branch exchange (PABX) switching systems (ESS) have features and functions that are usually lacking on previously available PABXs. Of these new features, one of the most important is the ability to automatically forward or transfer an unanswered call to a second phone or to a voice message center.

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Unanswered Call Diverter

Newer electronic private automatic branch exchange (PABX) switching systems (ESS) have features and functions that are usually lacking on previously available PABXs. Of these new features, one of the most important is the ability to automatically forward or transfer an unanswered call to a second phone or to a voice message center.

The call diverter may be placed in series with the station (telephone) line and used to detect the lack of answer and cause a switching action to a voice message center or desired second telephone.

This is one of the most usable features for voice store and forward applications, such as the automatic voice message system shown in Fig. 1A. The system includes a PABX 1, a call diverter 2, and a telephone set 3. A small circuit (Fig. 2B) is introduced in the call diverter 2 in series with the telephone set 3. The circuit detects and counts the ringing impulses by use of circuit blocks 5-8.

The impulses are a low frequency AC signal (nominally 20 Hertz) at a level of about 100 volts, and are on for 2 seconds and off for 4 seconds. After a selected number of ring signals, a driver circuit 9 activates a relay 10 to enable the call to be forwarded to the voice message system, thereby allowing the caller to leave a message.

The call diverter can supply the CALLED number to the voice message system by special tones or by other special signals on an input port. This enhances the system and allows it to respond with a per...