GENERATOR FOR DIGITAL PULSE SIGNALS REPRESENTATIVE OF ANALOG SIGNAL PAIRS

• US 3,706,855 A
• Filed: 10/02/1970
• Issued: 12/19/1972
• Est. Priority Date: 10/02/1970
• Status: Expired due to Term

• Current Assignee: AG Communication Systems Corp. (Nokia Corporation)
• Original Assignee: Bernard J. Rekiere, Satyan G. Pitroda
• Inventors: Pitroda, Satyan G., Rekiere, Bernard J.
• Primary Examiner(s): Brown, T. W.
• Application Number:
  US05/077,487
• Time in Patent Office: 809 Days
• Field of Search: 179/15BY,18J,18ES,15AT
• US Class Current: 379/283
• CPC Class Codes: H04Q 1/4575 which are transmitted in digital form
• CPC Class Codes: H04Q 11/04 for time-division multiplexing H04Q11/0001 takes precedence

Abstract

A technique of multifrequency pulsing consisting of transmitting a digitally valid number over pulse code modulated carrier from a time division multiplex office. The signals generated thereby after passing through a conventional carrier channel bank would be accepted by conventional analog multifrequency receivers as utilized in the telephone industry.

Claims

1. Means for generating a plurality of different digital signals, each representative of a different analog tone signal pair, for use in signaling iN a telephone system, comprising:

common equipment, including counting means having a circuit connection to said telephone system central processing unit, operated in response to receipt of pulses from said central processing unit to count sequentially in a first direction to produce a numerical sequence of output pulses;

a plurality of digital tone generators each connected to said common equipment and each including a non-destructive readout memory having circuit connections to said counting means and to said central processing unit, each operated in response to a specific particular count produced by said counting means in combination with a signal from said central processing unit, to produce a digital readout signal representative of a particular tone signal pair corresponding to a particular signal used in a telephone system; and

said digital signal generators each further including a plurality of gating circuits connected to said memories operated to control the digital signal outputs of said memories.

2. Apparatus as claimed in claim 1 wherein:

said counting means comprise a bidirectional counter and wherein said common equipment further includes directional control means connected to said bidirectional counting means, operated in response to receipt of a particular count from said counting means, to condition said counting means to reverse the direction of count from said first direction.

3. Apparatus as claimed in claim 1 wherein:

said common equipment further includes polarity control means including circuit connections to said directional control means and to said gating means, operated in response to said directional control means to reverse the polarity of signals transmitted from said memories.