DTMF and MF Detector Performance Measurements

Various standards bodies have established performance tests and criteria for DTMF and MF digit detectors. The

DTMF Detection for ITU-T Q.24 Specifications

Parameters		Values
Parameters		NTT	NTT Test Result	AT&T	AT&T Test Result
Frequency tolerance	Operation	1.8%	Pass DTMFFreqOffsetMinus18, DTMFFreqOffsetPlus18	1.5%	Pass DTMFFreqOffsetMinus15, DTMFFreqOffsetPlus15
Frequency tolerance	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
Power Levels per Frequency	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
Signal Duration	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:

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".
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.
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
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	Pass
MitelA3j	Test 3j - digit 9, 852 Hz, varied -0.1% to -4%	15-34	26	Pass
MitelA3k	Test 3k - digit 9, 1477 Hz, varied 0.1% to 4%	15-34	28	Pass
MitelA3l	Test 3l - digit 9, 1477 Hz, varied -0.1% to -4%	15-34	27	Pass
MitelA3m	Test 3m - digit 16, 941 Hz, varied 0.1% to 4%	15-34	34	Pass
MitelA3n	Test 3c - digit 16, 941 Hz, varied -0.1% to -4%	15-34	31	Pass
MitelA3o	Test 3c - digit 16, 1633 Hz, varied 0.1% to 4%	15-34	25	Pass
MitelA3p	Test 3c - digit 16, 1633 Hz, varied -0.1% to -4%	15-34	25	Pass
Mitel4 Acceptable Amplitude Ratio
Mitel4a	Digit 1, L1/H1, 0 to –20dB	>=40	65	Pass
Mitel4b	Digit 1, L1/H1, 0 to +20dB	>=80	82	Pass
Mitel4c	Digit 5, L2/H2, 0 to –20dB	>=40	65	Pass
Mitel4d	Digit 5, L2/H2, 0 to +20dB	>=80	83	Pass
Mitel4e	Digit 9, L3/H3, 0 to –20dB	>=40	64	Pass
Mitel4f	Digit 9, L3/H3, 0 to +20dB	>=80	80	Pass
Mitel4g	Digit D, L4/H4, 0 to –20dB	>=40	61	Pass
Mitel4h	Digit D, L4/H4, 0 to +20dB	>=80	80	Pass
Mitel5	Dynamic Range, 35 pulses: Digit 1, -1 to –35 dBV	>=25	30	Pass
Mitel6	Guard Time (400 pulses): Digit 1, 49 to 10 ms	100-270	160	Pass
Mitel7 Acceptable signal to noise ratio
Mitel7a	Digit 1, S/N –24 dBV	1000	1000	Pass
Mitel7b	Digit 1, S/N –18 dBV	1000	1000	Pass
Mitel7c	Digit 1, S/N –12 dBV	1000	1000	Pass

*Mitel* *Tape Side B - Talkoff Immunity Test*
MitelB		<30	1	Pass

Bellcore Tape – Talkoff Immunity Test
Bellcore		<666	6	Pass

NOTES:

1) Method: The DTMF detection tests were run using the VSIM simulator and digitized Bellcore and Mitel test tape sample files.

2) Nominal power level was -16 dBm0 unless noted otherwise.

3) Where possible, test were run using the command line arguments to VSIM to create the desired test signals. These signals were saved using the -o[filename] option. File names are identified below. See the VSIM Product User Manual for details of the command line arguments.

4) These test may be repeated using either the command line arguments as shown below, or by using the -f[filename] option. (For example, test D-1 may be run either by using "vsim -vDTMF -O1.5%" or "vsim -vR1 -fDFO_p15.txt".

TEST DETAILS:

D-1: VSIM Command Line: vsim -vDTMF -O1.5% File: DFO_p15.txt (+1.5% freq deviation)

VSIM Command Line: vsim -vDTMF -O-1.5% File: DFO_m15.txt (-1.5% freq deviation)

VSIM Command Line: vsim -vDTMF -O3.5% File: DFO_p35.txt (+3.5% freq deviation)

VSIM Command Line: vsim -vDTMF -O-3.5% File: DFO_m35.txt (-3.5% freq deviation)

D-2: VSIM Command Line: vsim -vDTMF -L0.040 File: DTL_40.txt (40 msec tone duration)

VSIM Command Line: vsim -vDTMF -L0.023 File: DTL_23.txt (23 msec tone duration)

D-3: VSIM Command Line: vsim -vDTMF -fDII_40.txt File: DII_40.txt (40 msec between repeated digits)

VSIM Command Line: vsim -vDTMF -fDII_10.txt File: DII_10.txt (10 msec between repeated digits)

D-4: VSIM Command Line: vsim -vDTMF -fDCT_93.txt File: DCT_93.txt (40 ms tones at 93 ms spacing)

D-5: VSIM Command Line: vsim -vDTMF -t-11 File: DL_m11.txt (-11 dBm0 power level)

VSIM Command Line: vsim -vDTMF -t-38 File: DL_m38.txt (-38 dBm0 power level)

VSIM Command Line: vsim -vDTMF -t-66 File: DL_m66.txt (-66 dBm0 power level)

D-6: VSIM Command Line: vsim -vDTMF -twist4 File: DTW_p4.txt (+4 dB twist)

VSIM Command Line: vsim -vDTMF -twist-8 File: DTW_m8.txt (-8 dB twist)

D-7:

D-8:

D-9: VSIM Command Line: vsim -vDTMF -n15 File: DSNR_15.txt (15 dB SNR)

VSIM Command Line: vsim -vDTMF -n23 File: DSNR_23.txt (23 dB SNR)

D-10:

D-11: VSIM Command Line: vsim -vDTMF -fDE_5_10.TXT File: DE_5_10.TXT (Echo)

VSIM Command Line: vsim -vDTMF -fDE_10_10.TXT File: DE_10_10.TXT (Echo)

VSIM Command Line: vsim -vDTMF -fDE_20_10.TXT File: DE_20_10.TXT (Echo)

Note: 40 msec burst, 93 msec cycle time. Tested at 10 dB signal to echo ratio with 5, 10, and 20 msec echo delay.

R1 Detection Specification

Test ID	Test Type	Bellcore	CCITT/ITU	Results
R1-1	Frequency Deviation	±(1.5% + 5 Hz) must accept	±1.5% must accept	PASS: Detected all digits at +1.5% Detected all digits at -1.5% Detected all digits at +2.2% Detected all digits at -2.2% (Note: 2.2% corresponds to worst case of R1 freq = 700 Hz)
R1-2	Tone Duration	KP signal: ³54 ms must accept; £30 ms must reject All others: ³30 ms must accept; £10 ms must reject	³30 ms must accept £10 ms must reject	PASS: Detected all digits ³ 30 ms. Rejected all digits £10 ms.
R1-3	Minimum Interdigital Interval	Must accept interdigital intervals ³25 ms. Must bridge interdigital intervals £10 ms	Must accept interdigital intervals ³20 ms	PASS: Detects two consecutive digits for interdigit intervals >= 20 msec. Bridges all gaps <=10 msec.
R1-4	Minimum Cycle Time	Up to 10 pulses per second (100 ms cycle time)	-	PASS: All digits detected with 80 msec cycle time.
R1-5	Accept Levels	0 to -25 dBm must accept £-35 dBm must reject	-	PASS: All digits detected within a 32 dB range. All digits rejected when 35 dB or more below the top of that range.
R1-6	Twist	£6 dB twist must accept	£6 dB twist must accept	PASS: All digits detected with twist of 0, 3, and 6 dB.
R1-7	SNR (white noise)	20 dB	-	PASS: Detects all digits with 20 dB SNR.
R1-8	Impulse Noise	Fewer than 14 missed or split digits in Bellcore Impulse Noise Tape No. 201	-	NOT TESTED.
R1-9	Disturbing Frequencies	Detection in the presence of 2A-B and 2B-A modulation products 28 dB below each frequency component level of the signals.	-	PASS: Detects all digits in presence of 2A-B and 2B-A interferers 28 dB below the desired tones.

NOTES:

1) Method: The R1 detection tests were run using the VSIM.

2) Nominal power level was -16 dBm0 unless noted otherwise.

4) These test may be repeated using either the command line arguments as shown below, or by using the -f[filename] option. (For example, test R1-1 may be run either by using "vsim -vR1 -O1.5%" or "vsim -vR1 -fFO_p15.txt".

TEST DETAILS:

R1-1: VSIM Command Line: vsim -vR1 -O1.5% File: RFO_p15.txt (+1.5% freq deviation)

VSIM Command Line: vsim -vR1 -O-1.5% File: RFO_m15.txt (-1.5% freq deviation)

VSIM Command Line: vsim -vR1 -O2.2% File: RFO_p22.txt (+2.2% freq deviation)

VSIM Command Line: vsim -vR1 -O-2.2% File: RFO_m22.txt (-2.2% freq deviation)

NOTE: 2.2% corresponds 1.5% + 5 Hz with worst case R1 freq = 700 Hz

R1-2: VSIM Command Line: vsim -vR1 -L0.030 File: RTL_030.txt (30 msec tone duration)

VSIM Command Line: vsim -vR1 -L0.010 File: RTL_010.txt (10 msec tone duration)

R1-3: VSIM Command Line: vsim -vR1 -fII_25.txt File: RII_25.txt (25 msec between repeated digits)

VSIM Command Line: vsim -vR1 -fII_20.txt File: RII_20.txt (20 msec between repeated digits)

VSIM Command Line: vsim -vR1 -fII_10.txt File: RII_10.txt (10 msec between repeated digits)

R1-4: VSIM Command Line: vsim -vR1 - fCT_80.txt File: RCT_80.txt (40 ms tones at 80 ms spacing)

R1-5: VSIM Command Line: vsim -vR1 -t-6 File: RL_m6.txt (-6 dBm0 power level)

VSIM Command Line: vsim -vR1 -t-11 File: RL_m11.txt (-11 dBm0 power level)

VSIM Command Line: vsim -vR1 -t-38 File: RL_m38.txt (-38 dBm0 power level)

VSIM Command Line: vsim -vR1 -t-46 File: RL_m46.txt (-46 dBm0 power level)

Note: This indicates 32 dB of dynamic range with all digits detected.

R1-6: VSIM Command Line: vsim -vR1 -twist0 File: RTW_0.txt (0 dB twist)

VSIM Command Line: vsim -vR1 -twist3 File: RTW_3.txt (3 dB twist)

VSIM Command Line: vsim -vR1 -twist6 File: RTW_6.txt (6 dB twist)

R1-7: VSIM Command Line: vsim -vR1 -n20 File: RSNR_20.txt (20 dB SNR)

R1-8: Not tested

R1-9: VSIM Command Line: vsim -vR1 -h100 -H28 File: RHI_100.txt (100 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h300 -H28 File: RHI_300.txt (300 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h500 -H28 File: RHI_500.txt (500 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h700 -H28 File: RHI_700.txt (700 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h900 -H28 File: RHI_900.txt (900 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h1100 -H28 File: RHI_1100.txt (1100 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h1300 -H28 File: RHI_1300.txt (1300 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h1500 -H28 File: RHI_1500.txt (1500 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h1700 -H28 File: RHI_1700.txt (1700 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h1900 -H28 File: RHI_1900.txt (1900 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h2100 -H28 File: RHI_2100.txt (2100 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h2300 -H28 File: RHI_2300.txt (2300 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h2500 -H28 File: RHI_2500.txt (2500 Hz interferer at -28 dB)

VSIM Command Line: vsim -vR1 -h2700 -H28 File: RHI_2700.txt (2700 Hz interferer at -28 dB)

R2 Detection Specification

Test ID	Test Type	CCITT/ITU Requirement	Results
R2-1	Frequency Deviation	±10 Hz must accept	PASS: Detected all digits at +10 Hz (minimum) offset. Detected all digits at -10 Hz (minimum) offset.
R2-2	Tone Duration	Must reject signals £7 ms	PASS: Rejected all digits £7 ms
R2-3	Minimum response time for R2 compelled signaling	detect delay + generate delay £70ms detect delay + decision delay +generate delay £80 ms	NOT TESTED
R2-4	Accept Levels	-5 dBm0 to -31.5 dBm0 must detect; -38.5 dBm0 must reject	PASS: All digits detected within a 27 dB range. All digits rejected when 33 dB or more below the top of that range.
R2-5	Twist (ratio of high group power to low)	£5 dB twist must accept for adjacent frequencies; £7 dB twist must accept for non-adjacent frequencies; 20 dB twist must reject	PASS: All digits detected with 5 dB twist. All digits detected with 7 dB twist. No digits detected with 20 dB twist.
R2-6a	Disturbing Frequencies	Must not falsely detect due to any one or more valid R2 frequencies at -55 dBm per frequency.	PASS: No digits detected for any 1 or combination of 2 valid tones, or for all (6) valid tones, with power level of -55 dBm0.
R2-6b		In the presence of a valid R2 tone, no missed detections and no false detections due to any of the remaining frequencies at 20 dB below the highest of the MF tone pair.	PASS: Expected digits detected, no false detections occurred.
R2-6c		Must not falsely detect due to any 1 or 2 pure sine waves, each at -38.5 dBm0, 300-3400 Hz.	PASS: See tests R2-4, R2-6e, and R2-6f.
R2-6d		Must not falsely detect due to any 1 or 2 pure sine waves, each at -42 dBm, 300-3400 Hz.	PASS: See tests R2-4, R2-6e, and R2-6f.
R2-6e		Forward Detector: Must not falsely detect due to any 2 pure sine waves, each at -5 dBm, 330-1150 Hz or 2130-3400 Hz.	PASS: No digits detected in 100 random pairs.
R2-6f		Backward detector: Must not falsely detect due to any 2 pure sine waves, each at -5 dBm, 1300-3400 Hz.	PASS: No digits detected in 100 random pairs.
R2-7	Transmitted signal interference	Must not falsely detect due to generation of outgoing MF digits	NOT TESTED

NOTES:

1) Method: The R2 detection tests were run using the VSIM simulator.

2) Nominal power level was -20 dBm0 unless noted otherwise.

4) These test may be repeated using either the command line arguments as shown below, or by using the -f[filename] option. (For example, test R2-1 may be run either by using "vsim -vR2F -O1%" or "vsim -vR2 -fR2FFO_p1.txt".

TEST DETAILS:

R2-1: VSIM Command Line: vsim -vR2F -t-20 -O1% File: R2FFO_p1.txt (+1% freq deviation)

VSIM Command Line: vsim -vR2F -t-20 -O-1% File: R2FFO_m1.txt (-1% freq deviation)

VSIM Command Line: vsim -vR2B -t-20 -O2% File: R2BFO_p2.txt (+2% freq deviation)

VSIM Command Line: vsim -vR2B -t-20 -O-2% File: R2BFO_m2.txt (-2% freq deviation)

Note: Used 1% for R2_F (min freq is 1380 Hz) and 2% for R2_B(min freq is 540 Hz) to get at least 10 Hz offset for all tones

R2-2: VSIM Command Line: vsim -vR2F -t-20 -L0.007 File: R2FTL_7.txt (7 msec tone duration)

VSIM Command Line: vsim -vR2B -t-20 -L0.007 File: R2BTL_7.txt (7 msec tone duration)

R2-3: Not tested

R2-4: VSIM Command Line: vsim -vR2F -t-11 File: R2FL_m11.txt (-11 dBm0 power level)

VSIM Command Line: vsim -vR2F -t-38 File: R2FL_m38.txt (-38 dBm0 power level)

VSIM Command Line: vsim -vR2F -t-44 File: R2FL_m44.txt (-44 dBm0 power level)

VSIM Command Line: vsim -vR2B -t-11 File: R2BL_m11.txt (-11 dBm0 power level)

VSIM Command Line: vsim -vR2B -t-38 File: R2BL_m38.txt (-38 dBm0 power level)

VSIM Command Line: vsim -vR2B -t-44 File: R2BL_m44.txt (-44 dBm0 power level)

R2-5: VSIM Command Line: vsim -vR2F -t-20 -twist5 File: R2FTW_5.txt (5 dB twist)

VSIM Command Line: vsim -vR2F -t-20 -twist7 File: R2FTW_7.txt (7 dB twist)

VSIM Command Line: vsim -vR2F -t-30 -twist20 File: R2FTW_20.txt (20 dB twist)

VSIM Command Line: vsim -vR2F -t-20 -twist5 File: R2FTW_5.txt (5 dB twist)

VSIM Command Line: vsim -vR2F -t-20 -twist7 File: R2FTW_7.txt (7 dB twist)

VSIM Command Line: vsim -vR2F -t-30 -twist20 File: R2FTW_20.txt (20 dB twist)

Note: Tests with 20 dB of twist were performed at a nominal power level of -30 dBm0.

R2-6a: VSIM Command Line: vsim -vR2F -fR2Freqs.txt File: R2Freqs.txt (1, 2, and all R2 freqs, -55 dBm0)

VSIM Command Line: vsim -vR2B -fR2Freqs.txt File: R2Freqs.txt (1, 2, and all R2 freqs, -55 dBm0)

Note: This test file contains all single digits from R2B and R2F, all combinations of two digits from R2F and R2B, and all R2F and R2B digits simultaneously. All tones are at -55 dBm0.

R2-6b: VSIM Command Line: vsim -vR2F -t-20 -h540 -H20 File: R2F_540.txt (540 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h660 -H20 File: R2F_660.txt (660 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h780 -H20 File: R2F_780.txt (780 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h900 -H20 File: R2F_900.txt (900 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h1020 -H20 File: R2F_1020.txt (1020 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h1140 -H20 File: R2F_1140.txt (1140 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h1380 -H20 File: R2F_1380.txt (1380 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h1500 -H20 File: R2F_1500.txt (1500 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h1620 -H20 File: R2F_1620.txt (1620 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h1740 -H20 File: R2F_1740.txt (1740 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h1860 -H20 File: R2F_1860.txt (1860 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2F -t-20 -h1980 -H20 File: R2F_1980.txt (1980 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h540 -H20 File: R2B_540.txt (540 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h660 -H20 File: R2B_660.txt (660 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h780 -H20 File: R2B_780.txt (780 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h900 -H20 File: R2B_900.txt (900 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h1020 -H20 File: R2B_1020.txt (1020 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h1140 -H20 File: R2B_1140.txt (1140 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h1380 -H20 File: R2B_1380.txt (1380 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h1500 -H20 File: R2B_1500.txt (1500 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h1620 -H20 File: R2B_1620.txt (1620 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h1740 -H20 File: R2B_1740.txt (1740 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h1860 -H20 File: R2B_1860.txt (1860 Hz interferer at -20 dB)

VSIM Command Line: vsim -vR2B -t-20 -h1980 -H20 File: R2B_1980.txt (1980 Hz interferer at -20 dB)

R2-6c: Not explicitly tested. Passed by reference to tests R2-4, R2-6e, and R2-6f.

R2-6d: Not explicitly tested. The -42 dBm level corresponds to the vsim level of -53 dBm0. Passed by reference to tests R2-4, R2-6e, and R2-6f.

R2-6e: VSIM Command Line: vsim -vR2F -fR2FRandf.txt File: R2FRandf.txt (Random pairs at -16 dBm0)

Note: This test file contains 100 random pairs of tones within the specified frequency range. Each tone in the pair has an amplitude of -16 dBm0 (5 dB below the detector maximum).

R2-6f: VSIM Command Line: vsim -vR2B -fR2BRandf.txt File: R2BRandf.txt (Random pairs at -16 dBm0)

Note: This test file contains 100 random pairs of tones within the specified frequency range. Each tone in the pair has an amplitude of -16 dBm0 (5 dB below the detector maximum).

DTMF Detection for ITU-T Q.24 Specifications

DTMF Detection for Bellcore and EIA\TIA Specifications

Mitel CM-7291 Test Tape for DTMF Receivers

Mitel Tape Side A - Receiver parameter evaluation

MitelA3 Bandwidth and center frequency check

Mitel4 Acceptable Amplitude Ratio

Mitel7 Acceptable signal to noise ratio

Mitel Tape Side B - Talkoff Immunity Test

Bellcore Tape – Talkoff Immunity Test

R1 Detection Specification

R2 Detection Specification