SIST I-ETS 300 380 E1:2003

SIST I-ETS 300 380 E1:2003 is the Slovenian publication of ETSI I-ETS 300 380 Edition 1 for Universal Personal Telecommunication (UPT). It specifies the tone-generating and acoustical characteristics of a one-way Dual Tone Multi Frequency (DTMF) access device that is acoustically coupled to a handset telephone, and the test arrangement used to check conformance. In practice, it tells manufacturers and test labs what frequencies, output level, timing and unwanted components such a sender must meet for use with PSTN and ISDN terminals.

What does SIST I-ETS 300 380 E1:2003 specify?

SIST I-ETS 300 380 E1:2003 covers a UPT DTMF sender intended for acoustic coupling to the mouthpiece or microphone of a handset telephone. It focuses on transmission behavior and testability, not on the functional architecture of the device.

The scope links the device to transmission requirements aligned with ETS 300 001 so that the sender is generally suitable for use in the Public Switched Telephone Network (PSTN) and Integrated Services Digital Network (ISDN). It also notes that physical dimensions cannot be standardized because handset shapes vary widely.

The document is organized into the following main parts:

What are the key requirements of SIST I-ETS 300 380 E1:2003?

Clause 4 sets the transmission limits for the DTMF sender, and Clause 5 defines how those limits are checked. The main practical point is that the device must produce the right tones at a controlled level when pressed against a handset telephone.

Tone set and frequency accuracy

Clause 4 requires the sender to use either 12 or 16 DTMF frequency combinations. If only 12 are used, the A, B, C and D characters are not used. The frequencies in Table 1 must stay within 1.5 % of the specified values.

In practice, this means the device must generate the standard DTMF keypad tones accurately enough for receivers to recognize them reliably.

Output level

Clause 4 limits the total Sound Pressure Level (SPL) of each tone combination to not more than -12 dBPa. This is the level control that keeps the acoustically coupled sender within the range expected by telephone receivers.

For a buyer or tester, this means the device must be checked as a complete acoustic system with the handset, not just as an electrical sender.

Timing of manual sending

Clause 4.3.1 says that, when the device is manually controlled, the tone duration and the pause between tones must follow the pushbutton action directly. If two or more buttons are pressed together, only one tone combination or no tone combination should be sent.

In practice, the user interface must not create ambiguous or overlapping dialing signals.

Timing of automatic sending

Clause 4.3.2 requires automatic sending to keep each tone and each pause longer than 70 ms. The notes also point readers to ETS 300 001 for guidance on suitable timing values.

This matters when the sender is built into equipment that controls dialing automatically, because the timing must still be long enough for network recognition.

Unwanted frequency components

Clause 4.4 requires all unwanted frequency components between 300 Hz and 3 400 Hz to be at least 20 dB below the lower of the two DTMF components. This keeps speech-band noise and distortion low enough for reliable detection.

Test method

Clause 5 requires measurements with the device placed on an IEC 318 artificial ear fitted with a flat plate, then moved to the position that gives the highest output. Tests are performed with fresh batteries.

This means conformance is judged under a defined acoustic setup, so results are repeatable across laboratories.

What terms does SIST I-ETS 300 380 E1:2003 define?

• DTMF - Dual Tone Multi Frequency, the two-tone signalling method used to represent digits and special characters.
• UPT - Universal Personal Telecommunication, the service context for the access device.
• PSTN - Public Switched Telephone Network, the analogue telephone network context referenced in the scope.
• ISDN - Integrated Services Digital Network, the digital network context referenced in the scope.
• SLR - Sending Loudness Rating, a measure used in Annex B when discussing handset coupling behavior.
• SPL - Sound Pressure Level, the acoustic output measure used in the transmission requirement.

Who uses SIST I-ETS 300 380 E1:2003?

SIST I-ETS 300 380 E1:2003 is used by terminal equipment designers, acoustic test laboratories, quality managers and compliance engineers working on UPT access devices. It is also relevant to manufacturers and buyers who need a handset-coupled DTMF sender that can be verified against a defined acoustic test arrangement for PSTN and ISDN use.

What changed in SIST I-ETS 300 380 E1:2003 from the previous edition?

SIST I-ETS 300 380 E1:2003 is identical to I-ETS 300 380 Edition 1.

Which standards are used with SIST I-ETS 300 380 E1:2003?

• IEC 318 - provides the artificial ear used in the normative test arrangement of Annex A.
• ETS 300 001 - gives the transmission requirements the sender is designed to align with, and additional guidance on DTMF timing and measurement.
• prETS 300 391-1 - is cited for information on the functional requirements of UPT devices.
• CCITT Recommendation P.35 - is used in Annex B as a reference point for handset telephone behavior.

What does the SIST I-ETS 300 380 E1:2003 document contain?

The document contains one transmission-frequency table for the DTMF character set, plus test methods for frequencies, transmission level, duration and unwanted frequency components. Annex A gives the IEC 318 coupler/flat plate test arrangement in Figure A.1. Annex B explains why acoustic coupling can vary so much across handset telephones and discusses output level spread, unwanted signals and level balance. Annex C lists the bibliography used for background and related requirements.