Issue 1 Jan 2006
LKA-200
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4
6.0
ELECTRICAL CHARACTERISTICS
6.1
TRANSMISSION 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
2800
7
- 1
- 4
- 12
5
-
1000
7
- 1
- 4
- 12
10
-
500
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:
High-frequency component
:
-6.5 ~
-10.5 dBm.
Low-frequency component :
-8.5 ~
-12.5 dBm.
6.2.2 DTMF Difference (Twist)
The different DTMF level between low frequency component and the high
frequency component. Required result: 2
+
1dBm.
