Rainbow Electronics DS26519 - Manual (Page 100)

DS26519 16-Port T1/E1/J1 Transceiver
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Table 9-42. T1.231, G.775, and ETS 300 233 Loss Criteria Specifications
STANDARD
CRITERIA
T1.231 ITU-T G.775 ETS 300 233
Loss
Detection
No pulses are detected for 175
±75 bits. No pulses are detected for
duration of 10 to 255 bit
periods. No pulses are detected for a
duration of 2048 bit periods or
1ms.
Loss Reset
Loss is terminated if a duration
of 12.5% ones are detected
over duration of 175 ±75 bits.
Loss is not terminated if 8
consecutive zeros are found if
B8ZS encoding is used. If
B8ZS is not used, loss is not
terminated if 100 consecutive
pulses are zero. The incoming signal has
transitions for duration of 10 to
255 bit periods. Loss reset criteria is not
defined.
9.12.3.6 ANSI T1.231 for T1 and J1 Modes
For short-haul mode, loss is declared if the received signal level is 3dB lower from the programmed value (based
on
Table 10-23 ) for a duration of 192-bit periods. Hence, if the sensitivity is programmed to be 12dB, loss is
declared at 15dB.
LOS is reset if all the following crieria are met:
1) 24 or more ones are detected in a 192-bit period with a programmed sensitivity level measured at RTIPn
and RRINGn.
2) During the 192 bits, fewer than 100 consecutive zeros are detected.
For long-haul mode, loss is detected if the received signal level is 3dB lower from the programmed value (based on
Table 10-23 ) for a duration of 192-bit periods. Hence, if the sensitivity is programmed to be 30dB, the loss
declaration level is 33dB.
LOS is reset if all the following crieria are met:
1) 24 or more ones are detected in a 192-bit period with a programmed sensitivity level measured at RTIPn
and RRINGn.
2) During the 192 bits, fewer than 100 consecutive zeros are detected.
9.12.3.7 ITU-T G.775 for E1 Modes
For short-haul mode, loss is declared if the received signal level is 3dB lower from the programmed value (based
on
Table 10-23 ) for a duration of 192-bit periods. Hence, if the sensitivity is programmed to be 12dB, loss is
declared at 15dB. LOS is reset if the receive signal level is greater than or equal to the programmed sensitivity
level for a duration of 192-bit periods.
For long-haul mode, loss is detected if the received signal level is 3dB lower from the programmed value (based on
Table 10-23 ) for a duration of 192-bit periods. Hence, if the sensitivity is programmed to be 30dB, the loss
declaration level is 15dB. LOS is reset if the receive signal level is greater than or equal to the programmed
sensitivity level for a duration of 192-bit periods.
9.12.3.8 ETS 200 233 for E1 Modes
For short-haul mode, loss is declared if the received signal level is 3dB lower from the programmed value (based
on
Table 10-23 ) continusou duration of 2048-bit periods (1ms). LOS is reset if the receive signal level is greater
than or equal to the programmed sensitivity level for a duration of 192-bit periods.
For long-haul mode, loss is declared if the received signal level is 3dB lower from the programmed value (based on
Table 10-23 ) continuous duration of 2048-bit periods (1ms). LOS is reset if the receive signal level is greater than
or equal to the programmed sensitivity level for a duration of 192-bit periods.