Issue 1 Jan 2006
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6.0ELECTRICAL CHARACTERISTICS
6.1TRANSMISSION CHARACTERISTICS
6.1.1 Loudness Rating
Transmit, receive and sidetone objective loudness ratings shall be determined in accordance with the requirements of TBR21 standard. Data measure in term of separate numerical ratings for transmit (TOLR), receive (ROLR), and sidetone (SOLR) for each of the following line conditions.
TBR 21
Items |
| TOLR | ROLR | SOLR | |||
| Lower | Upper | Lower | Upper | Lower | Upper | |
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2800 | Ω | 7 | - 1 | - 4 | - 12 | 5 | - |
1000 | Ω | 7 | - 1 | - 4 | - 12 | 10 | - |
500 | Ω | 10 | - 1 | - 1 | - 12 | 7 | - |
6.1.2 Telephone noise
Required result: Less than - 60 dB for all conditions.
6.1.3 Receiver noise
Required result: Less than - 85 dB for all conditions.
6.2 NETWORKING SIGNAL CHARACTERISTICS 6.2.1 DTMF Level
DTMF Level generated for each of the two fundamental frequencies under 900 ohm termination at loop current of 20 mA.
Required results: |
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: | ||
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6.2.2 DTMF Difference (Twist)
The different DTMF level between low frequency component and the high frequency component. Required result: 2 + 1dBm.
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