Nortel Networks OPTera Metro 3500 - Manual (Page 151)

Operation, administration, and maintenance (OAM) features 2-113
Planning and Ordering Guide—Part 1 of 2 NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004
OPRN
OPRN is the deviation from the receivers midpoint operational range. This
value is expressed as a percentage and is derived from the following formula:
Where:
• OPRnominal is the midpoint operational range of the receiver
• OPRmax is the maximum received optical power
• OPRmin is the minimum received optical power
OPRN is 0% when the received power is equal to the nominal value (mid-
range value), 100% when the received power is at the maximum level of the
operational range, and -100% when the received power is at the minimum level
of the operational range.
Storage and retrieval of physical PMs
For the physical PMs, the following PM registers are stored and can be
retrieved:
• untimed (taken every second), OPR parameter only
• current 15-minute interval, OPRN parameter only
• current day, OPRN parameter only
• last 32 15-minute intervals, OPRN parameter only
• previous day, OPRN parameter only
Note: The OPRN current 15-minute and current day bins are updated once
at the start of each interval (15-minutes or 1-day).
Resetting registers and invalid data flag
Both OPR and OPRN registers can be reset. Resetting the OPRN register
causes that value to be recalculated.
The physical PM OPR and OPRN parameters will have an invalid data flag
(IDF) value when the measured value is beyond the minimum or maximum
values.
OPRN 2
OPR OPRnominal – ( )
OPRmax OPRmin –
( )
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