B.2 Test signal levels

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

B.2.1 Sending

B.2.1.1 Handset and headset MSs

For the tests of Handset and headset MS, unless specified otherwise, the test signal level shall be –4,7 dBPa at the MRP.

B.2.1.2 Office type Handsfree MS

For the office type handsfree the test signal level shall be –28,7 dBPa at the HFRP. The characteristics of the artificial mouth shall be in conformance with ITU‑T Recommendation P.51.

Calibration of the artificial mouth

Figure 8

To perform the calibration of the artificial mouth, the following procedure shall be used:

– the input signal from the artificial mouth is first calibrated under free field conditions at the MRP (the total level in the frequency range corresponding to the third octave bands from 200 Hz to 4000 Hz is set to –4,7 dBPa);

– then the level is adjusted to –28,7 dBPa at the HFRP. The spectrum is not altered. The actual level at the MRP (measured in third octaves) is used as reference for calculating SLR.

NOTE: The HFRP corresponds to the measurement point 11 of ITU‑T Recommendation P.51 [13]. The transfer function between HFRP and MRP amounts to 24,0 dB + 3/‑4 dB.

B.2.1.3 Car type Handsfree MS

For the car type handsfree MS the test signal level shall be –28,7 dBPa at the HFRP. The characteristics of the artificial mouth of the HATS shall be in conformance with ITU‑T Recommendation P.58.

Calibration of the artificial mouth of the HATS

To perform the calibration of the artificial mouth of the HATS, the following procedure shall be used:

– the input signal from the artificial mouth is first calibrated under free field conditions at the MRP (the total level in the frequency range corresponding to the third octave bands from 200 Hz to 4 000 Hz is set to –4,7 dBPa). The spectrum at MRP is recorded;

– then the level is adjusted to –28,7 dBPa at the HATSHFRP The actual level at the MRP (measured in third octaves) is used as the reference for sending characteristics;

– The test set up shall be in conformance with the figure 8, but the HFRP replaced by the appropriate HATSHFRP defined as follows:

– the HATSHFRP corresponds to a reference point "n" from ITU‑T Recommendation P.58: "n" shall be one of the points numbered from 11 to 17 and defined in table 6a/P.58 (co‑ordinates of far field front point). The HATSHFRP depends on the location(s) of the microphones in the car: the appropriate axis lip‑ring/HATSHFRP shall be as close as possible to the axis lip‑ring/HFT microphone.

NOTE: As an example, if the manufacturer indicates that the handsfree microphone should be located in front of the HATS, but with an elevation angle of 40° from the horizontal plane, the HATSHFRP shall be chosen as point 13 (table 6a/P58). In such a case the transfer function between HATSHFRP and MRP amounts to 25,0 dB + 3/‑4 dB in the third octave bands centred on 200 Hz; 24 dB + 3 dB in the octave bands centred on 250 Hz, 315 Hz, 400 Hz, 500 Hz and 2 kHz;
24 dB + 3/‑4 dB in the octave bands centred on 1 250 Hz and 1 600 Hz; 25,5 dB + 3/‑4 dB in the octave bands centred on 630 Hz and 1 kHz; and 27 dB +3/‑4 in the octave band centred on 800 Hz.

B.2.2 Receiving

Unless specified otherwise, the applied test signal level at the digital input shall be –16 dBm0, and the user‑controlled receiving volume control set to the position at which RLR is met.