Call progress tone system

• US 4,669,110 A
• Filed: 10/25/1985
• Issued: 05/26/1987
• Est. Priority Date: 10/25/1985
• Status: Expired due to Term

• Current Assignee: Alcatel NV (Nokia Corporation)
• Original Assignee: ITT Corporation (ITT, Inc.)
• Inventors: Turner, Joe L., Marsh, Charles H., Daie, Hedayat
• Primary Examiner(s): Dwyer, James L.
• Application Number:
  US06/791,263
• Time in Patent Office: 578 Days
• Field of Search: 179/84 VF, 179/84 T, 179/99 LC, 179/99 R, 179/99 A, 179/81 R, 179/18 AD, 379/165, 379/353, 379/361, 379/375
• US Class Current: 379/165
• CPC Class Codes: H04M 1/82 Line monitoring circuits for call progress or status discrimination for detecting caller identity H04M1/573
• CPC Class Codes: H04Q 1/45 using multi-frequency signalling H04Q1/46 takes precedence
• CPC Class Codes: H04Q 3/625 Arrangements in the private branch exchange

Abstract

A tone source is located at each telephone set of a private branch exchange (PBX) or a key telephone system. The tone source provides call progress tones and warble ring tone, as well as a feedback tone in response to the depression of telephone set keypad buttons by the user. The signaling to the central system unit is transmitted via a digital link.

Claims

1. A communication system, comprising:

means, located at a communication set of said system, for providing tones including call progress tones for said set;

means, coupled to said tone means, for coupling control signals for said tone means from a central unit of said system,

means, coupled to said tone means, for coupling said tones to an audio unit of said communication sets, wherein said tone means comprises;

means for generating a first single frequency;

means for generating a second single frequency;

means, coupled to said first and second single frequency generating means, for selectively switching between said first and second single frequency generating means to produce one of said tones comprised of a selectable combination over time of said first single frequency and said second single frequency; and

means, coupled to said switching means, for providing said switched frequency to said tone coupling means.

2. A communication system according to claim 1, wherein said tone means further comprises means for generating a confidence tone frequency, in response to depression of a keypad of said communication set.

3. A communication system according to claim 1, wherein said tones further include ring tones and keypad dialing feedback tones.

4. A communication system according to claim 1, wherein said control signal coupling means comprises a digital link.