Dear Praveen,
For Singapore, if DTMF signal detection is provided, the following requirements are to apply: (a) DTMF signals that are within the following limits shall be recognised: (i) Frequency tolerances of
±1.5% from the nominal frequency as specified in iDA PSTN1 Standard. (ii) The sending level for low group frequencies shall be -8±2 dBm. (iii) The sending level for high group frequencies shall be -6±2 dBm. (iv) The total power of unwanted frequency components during signalling shall be at least 20dB below level of signal frequecy. (v) The sending length of the signal shall be at least 65 ms. (vi) A break between tone signals of 65 ms and greater, as an interdigital pause. PSB Singapore is able to provide testing to PSTN1 requirements. Please contact me if you need further assistance. Regards. Benjamin Foo Senior Engineer Telecoms & IT PSB No.1 Science Park Drive Singapore 118221 DID: +65-772 9769 Fax: +65-774 1459 email: [email protected] ---------------------- Forwarded by Benjamin FOO/SP/Psb on 01/03/2001 08:11 AM --------------------------- Praveen Rao <[email protected]> on 28/02/2001 02:27:32 PM Please respond to Praveen Rao <[email protected]> To: [email protected] cc: Subject: DTMF tone detection
Hello members, I'm trying to find the requirements of DTMF tone detection for various countries. I have the requirements for Australia ( shown below ). Can someone help me with the other countries please. I believe there are no mandatory requirements for DTMF detection for Europe and USA, please correct me if I'm wrong. Australian Requirements : AS/ACIF S003 : 1999 If DTMF signal detection is provided, the following requirements are to apply: (a) DTMF signals that are within the following limits shall be recognised: (i) Frequency tolerances of
± (1.5% + 2 Hz) from the nominal frequency as specified in ACA Technical Standard 002 [2]. (ii) A total RMS power level between 0 dBm and -20 dBm with a maximum difference between the high frequency tone and the low frequency tone power of +4 dB to -4 dB relative to that of the low frequency tone. (iii) A break between tone signals of 70 ms and greater, as an interdigital pause. (iv) A valid tone signal of 40 ms duration and greater. Now, what are these limits for : USA, Europe (especially UK), South Africa, Korea and Singapore Thanks very much in advance. Praveen Rao
