C.3 Sensitivity/frequency characteristics

03.503GPPTransmission planning aspects of the speech service in the GSM Public Land Mobile Network (PLMN) systemTS

C.3.1 Sending – Handset MS

When measured at the DAI:

– the handset is mounted in the LRGP (see annex A of ITU‑T Recommendation P.76). The earpiece is sealed to the knife‑edge at the ERP;

– a pure tone signal with a sound level of –4,7 dBPa (in accordance with ITU‑T Recommendation P.64 shall be applied at the MRP as described in ITU‑T Recommendation P.64, using an artificial mouth conforming to ITU‑T Recommendation P.51;

– a digital measuring instrument, or high quality digital decoder followed by an analogue level measuring set, shall be connected at the interface;

– measurements shall be made at one twelfth‑octave intervals as given by the R.40 series of preferred numbers in ISO 3 for frequencies from 100 Hz to 4 kHz inclusive.

At each frequency, the output level for a sound pressure of –4,7 dBPa shall be measured.

Measured at the output of the reference speech decoder of the SS:

– the handset is mounted in the LRGP and the earpiece is sealed to the knife-edge of an artificial ear;

– a speech call is set up between the MS and the SS;

– artificial speech conforming to ITU‑T Recommendation P.50, shall be applied to the MRP, at a wideband sound pressure level of –4,7 dBPa. This implementation could be a real time algorithm producing the artificial speech or a pre‑recorded tape of the artificial speech;

– the artificial speech shall comprise of a concatenation of three 10 s intervals of "male" and "female" voice. The first 10 s interval is not used for measurement purposes but allows any noise/echo cancelling devices in the MS to adapt. The second and third 10 s intervals consist of separately "male" and "female" artificial voice;

– the 1/3 octave filtered long‑term average spectrum of the signal is measured at the digital output of the reference speech decoder of the SS and an average for the "male" and "female" voices obtained;

– the difference between the 1/3 octave input power and the 1/3 octave output power shall conform to the mask specified in clause 3.8.1.1.

C.3.2 Sending – Handsfree MS

– The handsfree MS is mounted as specified by the manufacturer and tested according to annex B clauses B.4.2.1 or B.4.2.2.

– A speech call is set up between the MS and the SS.

– Artificial speech conforming to ITU‑T Recommendation P.50, bandlimited to 200 Hz and 4 kHz shall be applied to the MRP of the test fixture, at a wideband sound pressure level of –4,7 dBPa. This implementation could be a real time algorithm producing the artificial speech or a pre‑recorded tape of the artificial speech.

– The artificial speech shall comprise of a concatenation of three 10 s intervals of "male" and "female" voice. The first 10 s interval is not used for measurement purposes but allows any noise/echo cancelling devices in the MS to adapt. The second and third 10 s intervals consist of separately "male" and "female" artificial voice.

– The 1/3 octave filtered long‑term average spectrum of the signal is measured at the digital output of the reference speech decoder of the SS and an average for the "male" and "female" voices obtained.

– The difference between the 1/3 octave input power and the 1/3 octave output power shall conform to the mask specified in clause 3.8.2.1.

C.3.3 Receiving – Handset

When measured from the DAI:

– the handset is mounted in the LRGP and the earpiece is sealed to the knife‑edge of the artificial ear;

– a digital signal generator shall be connected at the digital interface delivering a signal equivalent to a pure tone level of –16 dBm0, see ITU‑T Recommendation P.64;

– measurements shall be made at one twelfth‑octave intervals as given by the R.40 series of preferred numbers in ISO 3 for frequencies from 100 Hz to 4 kHz inclusive.

At each frequency, the sound pressure at the ERP shall be measured by connecting a suitable measuring set to the artificial ear.

Measured from the input of the reference speech encoder of the SS:

– the handset is mounted in the LRGP and the earpiece is sealed to the knife-edge of the artificial ear;

– a speech call is set up between the MS and the SS;

– artificial speech conforming to ITU‑T Recommendation P.50, shall be applied to the analogue or digital input of the reference speech encoder of the SS, at a wideband level of –16 dBm0. This implementation could be a real time algorithm producing the artificial speech or a pre‑recorded tape of the artificial speech;

– the artificial speech shall comprise of a concatenation of three 10 s intervals of "male" and "female" voice. The first 10 s interval is not used for measurement purposes but allows any echo cancellation devices in the MS to adapt. The second and third 10 s intervals consist of separately "male" and "female" artificial voice;

– the 1/3 octave filtered long‑term average spectrum of the signal is measured and an average for the "male" and "female" voices obtained;

– the difference between the 1/3 octave input power and the 1/3 octave output power shall conform to the mask specified in clause 3.8.1.2.

C.3.4 Receiving – Handsfree

– The handsfree MS is mounted as specified by the manufacturer and tested according to clauses B.4.2.1 or B.4.2.2, annex B.

– A speech call is set up between the MS and the SS.

– Artificial speech conforming to ITU‑T Recommendation P.50, bandlimited to 200 Hz and 4 kHz shall be applied to the analogue or digital input of the reference speech encoder of the SS, at a wideband level of ‑16 dBm0. This implementation could be a real time algorithm producing the artificial speech or a pre‑recorded tape of the artificial speech.

– The artificial speech shall comprise of a concatenation of three 10 s intervals of "male" and "female" voice. The first 10 s interval is not used for measurement purposes but allows any echo cancellation devices in the MS to adapt. The second and third 10 s intervals consist of separately "male" and "female" artificial voice.

– The 1/3 octave filtered long‑term average spectrum of the signal is measured at the ERP and an average for the "male" and "female" voices obtained.

– The difference between the 1/3 octave input power and the 1/3 octave output power shall conform to the mask specified in clause 3.8.2.2.