Hi there!
This time, I will share with you about The auxiliary detection board.
Auxiliary Detection Board
When setting the OTU and OSC boards as auxiliary detection boards, ensure that the OTU, OSC, and control implementation boards are in the same subrack.
In a Raman system, OSC signals are also amplified by the CRPC board. However, the OSC board can identify noise and service signals through the R_LOF alarm. Therefore, an OSC board can be set as an auxiliary detection board in a Raman system.
When an OTU board is set as an auxiliary detection board, it is recommended to configure as many auxiliary detection boards (a maximum of four) as possible.
When IPA pairs are configured station-by-station for regeneration stations, only the OSC board can be set as an auxiliary detection board.
When a CRPC board is set as an auxiliary detection board:
Measure the input optical power (P1) of the CRPC board when services in the single-wavelength system are normal. Then shut down the laser on the upstream OA board (also shut down the laser on the forward CRPC board if there is one) and start the laser on the local CRPC board. After that, measure the input optical power (P0) of the CRPC board. Use Pr to represent the value of the Raman Board Threshold (dBm). This parameter indicates the optical power threshold for the CRPC board to report a LOS alarm.
If the following conditions are met, the CRPC board can be set as an auxiliary detection board and you need to set Enable Raman Board Alarm to Enabled. If the following conditions are not met, set Enable Raman Board Alarm to Disabled.
The CRPC board supports optical power detection. Currently, only the TN11CRPC01 board for Huawei DWDM system supports optical power detection.
The difference between P1 and P0 is equal to or greater than 3 dB.
The system carries at least one of the wavelengths numbered 74, 76, 78, and 80.
When an OTU or OSC board is set as an auxiliary detection board:
Generally, the OSC board is set as an auxiliary detection board at a regeneration station while the OTU board is set as an auxiliary detection board at an OTM station.
The OTU board detects the R_LOS, R_LOF, and R_LOC alarms.
The OSC board detects the R_LOS, R_LOF, and OSC_RDI alarms.
Restart Mode
If Raman Board Threshold is set and the IPA function is configured, it is recommended to set Restart Mode to Automatic.
If Raman Board Threshold is not set, the default threshold is 0x7fffffff. In this case, it is recommended to set Restart Mode to Manual. After a broken fiber is repaired, restart the laser on the CRPC board first.
If no OSC board is configured at a regeneration station, the laser on the CRPC board cannot be manually started when the NE is unreachable to the NMS. To prevent such issue, set Enable Raman Board Alarm to Enabled and set Raman Board Threshold.
Enable Raman Board Alarm
A CRPC board can be set as an auxiliary detection board only after you set Enable Raman Board Alarm to Enabled and set Raman Board Threshold.
On Period (0.01s)/ Off Period (s)
The values of On Period (0.01s) set at two ends of an IPA pair must be the same. This rule also applies to the Off Period (s) and Testing Period (s) parameters.
For an IPA pair involving multiple spans (not a point to point IPA pair), the value of On Period (0.01s) depends on the number of intermediate OA boards. The following table lists the mapping relationship.
Number of Intermediate OA Boards | 0 | 5 | 10 | 15 | 20 | 25 | > 25 |
On Period (0.01s) | 300 | 1500 | 2000 | 2500 | 3500 | 4000 | 4500 |
The IPA function does not need to be configured at the regeneration station that passes through all services and does not add or drop any service. The ALS function is enabled by default on an OTU board at the regeneration station. In this case, the value of On Period (0.01s) is increased by 10s for each electrical regeneration board that optical signals traverse. If the ALS function on the OTU boards at the regeneration station is disabled, configure the IPA function at the regeneration station. It is recommended to disable the ALS function on the OTU boards at the regeneration station.
If an OADM station where services are added or dropped exists on the line, configure the OADM station and the upstream adjacent OTM or OADM station in an IPA protection group, and configure the OADM station and the downstream adjacent OTM or OADM station in another IPA protection group. Set On Period (0.01s) based on the preceding table.
The IPA function does not need to be configured for an OEQ station.
When two OTM stations in a system work in back-to-back mode, the two OTM stations must be configured in different IPA protection groups.
If the actual number of intermediate OA boards is not listed in the preceding table, set On Period (0.01s) to a value greater than the value calculated according to the proportion of the actual number of intermediate OA boards to the number listed in the table. For example, if there are two intermediate OA boards, the calculated value is 7.5s. In this case, you can select a greater value, for example, 10s, that is, set On Period (0.01s) to 1000.
Thank you!
