Universal Tone Detection
by D2 Technologies, Inc.

Software Overview

D2's Universal Tone Detection algorithm module detects the presence FAX/CNG tones, modem ANS tones, 
special information tones, and other single tones under a broad range of network conditions and 
under international telecommunications specifications.
Designed to the VP Open interface, the Universal Tone Detection module easily integrates with other 
VP Open modules, runs in real-time concurrently with other VP Open modules, and handles any number 
of voice ports assigned to the DSP. Like all of D2's algorithm modules, Universal Tone Detection 
consists of robust software that is rigorously tested.

Features and Benefits

•	Programmable to detect any single tones in specified frequency range between 300 and 3300 Hz
•	Detects the modem ANS tone
•	Detects and translates all US Special Information Tones (SIT)
•	Accepts telephone-band codec or linear data
•	Detects the FAX-calling tone (CNG)

Processor and System Specifications

•	Devices supported: TMS320C2xx, TMS320C3x, TMS320C5x
•	Processor resources required:
•	Algorithm category: Telecommunications
TMS320C2xx (Est.)
TMS320C3x (Est.)
TMS320C5x
Program memory
2.6 kwords
2.2 kwords
2.4 kwords
Data memory/port
164 words
159 words
164 words
Processor loading
worst case
1.8 MIPS
1.4 MIPS
1.75 MIPS

Usage Limitations or Performance Considerations

•	The host, voice data input and output, memory allocation, and module to module communication 
interfaces must conform to VP Open as described in the VP Open Software Interface Specification.

Algorithm Verification

D2's Universal Tone Detection algorithm module is validated through the following suite of tests:
•	D2 universal tone detection tests, which test detection of tones with varying frequency, 
strength, SNR, and duration
•	D2 Special Information Tone (SIT), Modem ANS, and FAX/CNG tone detection tests, which test tone 
duration and frequency deviation requirements
•	D2 tone detection test with prerecorded samples of SIT, Modem ANS, ING tones from different local 
and long-distance calls
•	D2 tone detection talk-off test with 16 hours of Bellcore voice data
•	VP Open interface validation – the Universal Tone Detection module is integrated with other VP 
Open modules and tested concurrently in real-time on the D2 VDS50 system for multiple voice ports

Availability

Currently available for the TMS320C5x. A demonstration package is currently available for the TI 
EVM50 DSP board. Implementation for the TMS320C2xx and the TMS320C3x will be available 2Q 1996.

Company Background and Contact Information

D2 Technologies, Inc. was founded by David Y. Wong and David M. Lindsay to help companies innovate 
telecommunications and information products with voice processing technology, which include 
telephony and voice algorithms, real-time system software, and development services.

Contact:	D2 Technologies, Inc.
		Attn: Product Sales
		104 West Anapamu Street, Suite J
		Santa Barbara,  CA 93101
		(805) 564-3424
		Fax:  (805) 966-2144
		e-mail:  sales@d2tech.com