GAO Call Progress
Tone Detection
by GAO Research & Consulting Ltd.

Software Overview

Call progress is a tonal-signaling standard that is used to acquire connections between subscribers 
in telephone network systems and to indicate the status of the incoming and outgoing phone calls. 
GAO Call Progress Detector provides full call-progress-detection functionality and it operates on 
linear PCM samples.

Features and Benefits

•	Implemented in the assembly
•	Easily configured to different cadences and tones
•	Low data and program memory requirements
GAO Call Progress Detector is able to support the following signals:

Signals supported:
Dial Tone   Ring Back
Busy Tone   Off Hook
Congestion Signal

Processor and System Requirements

•	Devices supported: TMS320C3x, TMS320C5x, TMS320C54x
•	Algorithm category: Telecommunications
•	Required:
Function
Average MIPS
Data Memory
Program Memory
Detector
8.0
80
300

Algorithm Verification

•	Field tested.

Availability

•	The software is available now and demonstration is available at GAO's offices in Toronto, Canada.

Company Background and Contact Information

GAO Research & Consulting Ltd. is an established international supplier of DSP algorithms, 
software, and systems for the telecommunications market. It provides a complete line of telephony, 
fax, and modem solutions. Its products have been widely reported by over 30 leading publications in 
the industry.
GAO currently employs about 20 DSP engineers. It was founded in 1991 and has been managed by Dr. 
Frank X.Y. Gao.
Contact:	Dr. Frank X.Y. GAO, CEO
		GAO Research & Consulting Ltd.
		55 Nugget Avenue, Unit 204
		Scarborough,  Toronto
			Ontario, Canada M1S 3L1
		(416) 292-0038
		Fax: (416) 292-2364
		e-mail: gao@io.org
		www: http://www.io.org/~gao