DTMF and MF Detector Performance Measurements

 

DTMF Detection for ITU-T Q.24 Specifications

 

Parameters

Values

NTT

NTT Test Result

 

AT&T

AT&T Test Result

Frequency tolerance

Operation

1.8%

Pass

DTMFFreqOffsetMinus18,

DTMFFreqOffsetPlus18

 

1.5%

Pass

DTMFFreqOffsetMinus15,

DTMFFreqOffsetPlus15

Non-operation

3.0%

PASS

DTMFFreqOffsetMinus30,

DTMFFreqOffsetPlus30

 

3.5%

PASS

DTMFFreqOffsetMinus35,

DTMFFreqOffsetPlus35

Power Levels per Frequency

Operation

-3 to -24 dBm

(Note 1)

PASS

DTMFLevelMinus3,

DTMFLevelMinus24

 

0 to -25 dBm

(Note 1)

PASS

DTMFLevelMinus0,

DTMFLevelMinus25

Non-operation

Max. -29 dBm

PASS

DTMFLevelMinus29

 

Max. -55 dBm

PASS

DTMFLevelMinus55

Power Level Difference between Frequencies

Max. 5 dB

PASS

DTMFLevelDifferenceMinus5,

DTMFLevelDifferencePlus5

 

+4 dB to -8 dB

PASS
DTMFLevelDifferenceMinus8,

DTMFLevelDifferencePlus4

Signal Duration

Operation

Min. 40 ms

PASS

DTMFSignalDuration40

 

Min. 40 ms

PASS

DTMFSignalDuration40

Non-operation

Max. 24 ms

PASS

DTMFSignalDuration24

 

Max. 23 ms

PASS
DTMFSignalDuration23

Pause Duration

Min. 30 ms

PASS

DTMFSignalPause30

 

Min. 40 ms

PASS
DTMFSignalPause40

Signal Interruption

Max. 10 ms

PASS

DTMFSignalInterruption10

 

Max. 10 ms

PASS

DTMFSignalInterruption10

Signalling Velocity

Min. 120 ms/digits

PASS

DTMFSignalVelocity120

 

Min. 93 ms/digit

PASS
DTMFSignalVelocity93

Signal Simulation by Speech

6 false/46 hours for speech

with a mean level of

-15 dBm

(Note 2)

PASS, 2 false detections

DTMFSignalSpeechMitel1B

PASS, 66 total false detections

DTMFSignalSpeechBell1S1, DTMFSignalSpeechBell1S2,

DTMFSignalSpeechBell2S1,

DTMFSignalSpeechBell2S2,

DTMFSignalSpeechBell3S1,

DTMFSignalSpeechBell3S2

 

For the codes 0-9,

1 false/3000 calls

For the codes 0-9, *, #,

1 false/2000 calls

For the codes 0-9,

*, # A-D,

1 false/1500 calls

(Note 2)

PASS, 2 false detections

DTMFSignalSpeechMitel1B

PASS, 66 total false detections

DTMFSignalSpeechBell1S1, DTMFSignalSpeechBell1S2,

DTMFSignalSpeechBell2S1,

DTMFSignalSpeechBell2S2,

DTMFSignalSpeechBell3S1,

DTMFSignalSpeechBell3S2

Interference by Echoes

 

 

 

Should tolerate echos

delayed up to 20 ms and

at least 10 dB down

PASS
DTMFSignalEcho20Minus10

 

 

NOTES:

  1. These tests were run using the VSIM32 simulation at the command line. All of the signal generated are saved to file in ascii text format with the name convention "testName.signal.txt". The VSIM32 results were also captured to file with the name convention "testName.results.txt".
  2. MESi Components transmit power level is scaled such that 16-bit Q15.1 fractional integer +/-1.0 equivilent (0x7fff,0x8000) is defined  as 0 dBm0. For G.711 compressed systems, the maximum level is about +3.0 dBm. Therefore, MESi signal levels must be scaled by a factor of 2 to match G.711. This means that MESi transmit levels should be shifted down by 1 (-6 dB) to match G.711 line levels.
  3. No standard source is known or available for these tests, so the standard Mitel CM-7291 Side B and Bellcore TR-TSY-00763 3-hour test tapes were used.

 

Test Name and VSIM32 Command Line:

Test: DTMFFreqOffsetMinus18, vsim32 -vDTMF -O-1.8% -Q2 -oDTMFFreqOffsetMinus18.Signal.txt,d

Test: DTMFFreqOffsetPlus18, vsim32 -vDTMF -O1.8% -Q2 -oDTMFFreqOffsetPlus18.Signal.txt,d

Test: DTMFFreqOffsetMinus30, vsim32 -vDTMF -O-3.0% -Q2 -oDTMFFreqOffsetMinus30.Signal.txt,d

Test: DTMFFreqOffsetPlus30, vsim32 -vDTMF -O3.0% -Q2 -oDTMFFreqOffsetPlus30.Signal.txt,d

Test: DTMFFreqOffsetMinus15, vsim32 -vDTMF -O-1.5% -Q2 -oDTMFFreqOffsetMinus15.Signal.txt,d

Test: DTMFFreqOffsetPlus15, vsim32 -vDTMF -O1.5% -Q2 -oDTMFFreqOffsetPlus15.Signal.txt,d

Test: DTMFFreqOffsetMinus35, vsim32 -vDTMF -O-3.5% -Q2 -oDTMFFreqOffsetMinus35.Signal.txt,d

Test: DTMFFreqOffsetPlus35, vsim32 -vDTMF -O3.5% -Q2 -oDTMFFreqOffsetPlus35.Signal.txt,d

Test: DTMFLevelMinus3, vsim32 -vDTMF -t-9 -Q2 -oDTMFLevelMinus3.Signal.txt,d

Test: DTMFLevelMinus24, vsim32 -vDTMF -t-29 -Q2 -oDTMFLevelMinus24.Signal.txt,d

Test: DTMFLevelMinus29, vsim32 -vDTMF -t-38 -Q2 -oDTMFLevelMinus29.Signal.txt,d

Test: DTMFLevelMinus0, vsim32 -vDTMF -t-6 -Q2 –oDTMFLevelMinus0.Signal.txt,d

Test: DTMFLevelMinus25, vsim32 -vDTMF -t-31 -Q2 -oDTMFLevelMinus25.Signal.txt,d

Test: DTMFLevelMinus55, vsim32 -vDTMF -t-55 -Q2 –oDTMFLevelMinus55.Signal.txt,d

Test: DTMFLevelDifferenceMinus5, vsim32 -vDTMF t-11 -twist-5 -Q2 -oDTMFLevelDifferenceMinus5.Signal.txt,d

Test: DTMFLevelDifferencePlus5, vsim32 -vDTMF -twist5 -Q2 -oDTMFLevelDifferencePlus5.Signal.txt,d

Test: DTMFLevelDifferenceMinus4, -vDTMF -t-16 -twist4 -Q2 -oDTMFLevelDifferenceMinus4.Signal.txt,d

Test: DTMFLevelDifferencePlus8, -vDTMF -t-8 -twist-8 -Q2 -oDTMFLevelDifferencePlus8.Signal.txt,d

Test: DTMFSignalDuration40, vsim32 -vDTMF,40e-3,120e-3 -Q2 -oDTMFSignalDuration40.Signal.txt,d

Test: DTMFSignalDuration24, vsim32 -vDTMF,24e-3,120e-3 -Q2 -oDTMFSignalDuration24.Signal.txt,d

Test: DTMFSignalDuration23, vsim32 -vDTMF,23e-3,120e-3 -Q2 -oDTMFSignalDuration23.Signal.txt,d

Test: DTMFSignalInterruption10, vsim32 -vDTMF,100e-3,120e-3 -GH,40e-3,0,10e-3,120e-3 -Q2 -oDTMFSignalInterruption10.Signal.txt,d

Test: DTMFSignalVelocity120, vsim32 -vDTMF,40e-3,120e-3 -Q2 -oDTMFSignalVelocity120.Signal.txt,d

Test: DTMFSignalVelocity93, vsim32 -vDTMF,40e-3,93e-3 -Q2 –oDTMFSignalVelocity93.Signal.txt,d

Test: DTMFSignalSpeechMitel1B, vsim32 -vDTMF -fc:\products\components\modems\performance\DTMF\MitelB.wav,b,1

Test: DTMFSignalSpeechBell1S1, vsim32 -vDTMF -fc:\products\components\modems\performance\DTMF\Bell1S1.wav,b,1 -t-10

Test: DTMFSignalSpeechBell1S2, vsim32 -vDTMF -fc:\products\components\modems\performance\DTMF\Bell1S2.wav,b,1 -t-10

Test: DTMFSignalSpeechBell2S1, vsim32 -vDTMF -fc:\products\components\modems\performance\DTMF\Bell2S1.wav,b,1 -t-10

Test: DTMFSignalSpeechBell2S2, vsim32 -vDTMF -fc:\products\components\modems\performance\DTMF\Bell2S2.wav,b,1 -t-10

Test: DTMFSignalSpeechBell3S1, vsim32 -vDTMF -fc:\products\components\modems\performance\DTMF\Bell3S1.wav,b,1 -t-10

Test: DTMFSignalSpeechBell3S2, vsim32 -vDTMF -fc:\products\components\modems\performance\DTMF\Bell3S2.wav,b,1 -t-10

Test: DTMFSignalEcho20Minus10, vsim32 -vDTMFA -Q2 -ERLfarA-10 -F80 -oDTMFSignalEcho20Minus10.Signal.txt,d

DTMF Detection for Bellcore and EIA\TIA Specifications

 

Test ID

Test Type

Bellcore

TR-TSY-000181

EIA/TIA-464A

Results

D-1

Frequency

Deviation

±1.5% must accept;

±3.5% must reject

±1.5% must accept;

±3.5% must reject

PASS:

All digits detected at ±1.5%

All Digits rejected at ±3.5%

 

D-2

Minimum Tone

Duration

 

40 ms must accept;

23 ms must reject

 

40 ms must accept

PASS:

All digits detected with 40 ms pulse.

All digits rejected with 23 ms pulse.

 

D-3

Minimum

Interdigital

Interval

40 ms

40 ms

PASS 40 ms:

Double digits detected for all digits.

 

PASS 10 ms: Single digits detected for all digits..

 

D-4

Minimum Cycle

Time

93 ms

93 ms

PASS:

All digits detected.

 

D-5

Accept Levels

0 to -36 dBm must

accept; -55 dBm

must reject

0 to -25 dBm must

accept

 

PASS (Bellcore, EIA/TIA-464A, and ITU-T Q.24):

Detect all digits in range of -10 to -48 dBm0 (38 dB range).

 

PASS (Bellcore and ITU-T Q.24):

Reject all digits £ -66 dBm0 (-55 dBm).

 

 

D-6

Twist (ratio of

high group

power to low)

-8 to +4 dB

-8 to +4 dB

PASS:

Detects all tones for twist of +4 and -8 dB.

 

D-7

Bellcore talk-off

Tape TR-TSY-00763

 

Fewer than 670

total talkoffs; fewer

than 330 talkoffs of

digits 0-9; fewer

than 170 talkoffs of

signals * and #.

-

PASS:

82 total false detections for Bellcore 3 hour test

digits 0-9: 60 talkoffs

signals # and *: 15 talkoffs

signals A-D: 7 talkoffs

 

D-8

Mitel talk-off tape CM-7291

-

-

PASS:

Mitel side B with 3 false detections.

 

D-9

SNR

23 dB

15 dB

PASS:

All tones detected for 15 and 23 dB SNR.

 

 

D-10

Impulse Noise

Fewer than 14

missed or split

digits in Bellcore

Impulse Noise Tape

No. 201

 

Fewer than 10 errors in 10,000 tones for EIA test #1; fewer than 500 errors in 10,000 tones for

test #2

PASS:

No detections in Bellcore Impulse Noise Tape.

 

D-11

Echo

16 dB

Signal-to-Echo ratio

10 dB

Signal-to-Echo ratio at 20ms

PASS:

Detected all digits with 10 dB Signal to Echo ratio.

 

 

Mitel CM-7291 Test Tape for DTMF Receivers

 

Test File

Description

Expected number of detects

MESi DTMF Detector Results

Summary

Mitel Tape Side A - Receiver parameter evaluation

MitelA1

Calibration Tone

0

0

Pass

MitelA2

Decode Check

160

160

Pass

MitelA3 Bandwidth and center frequency check

MitelA3a

Test 3a - digit  1,   697 Hz, varied  0.1% to  4%

15-34

18

Pass

MitelA3b

Test 3b - digit  1,   697 Hz, varied -0.1% to -4%

15-34

40

Pass

MitelA3c

Test 3c - digit  1,  1209 Hz, varied  0.1% to  4%

15-34

34

Pass

MitelA3d

Test 3d - digit  1,  1209 Hz, varied -0.1% to -4%

15-34

26

Pass

MitelA3e

Test 3e - digit  5,   770 Hz, varied  0.1% to  4%

15-34

28

Pass

MitelA3f

Test 3f - digit  5,   770 Hz, varied -0.1% to -4%

15-34

18

Pass

MitelA3g

Test 3g - digit  5,  1336 Hz, varied  0.1% to  4%

15-34

31

Pass

MitelA3h

Test 3h - digit  5,  1336 Hz, varied -0.1% to -4%

15-34

30

Pass

MitelA3i

Test 3i - digit  9,   852 Hz, varied  0.1% to  4%

15-34

35