aturesOSN 7500 
Technical Manual - System Description  8 Protection 
 
Huawei Technologies Proprietary 
8-2 
8.1.1  TPS Protection for Tributary Boards 
The OptiX OSN 7500 provides 1:N TPS protection for E1, DS1, E3, DS3, E4 and 
STM-1 (Electrical) services through electrical interface protection. That is, it provides 
TPS protection for PQ1, PQM, PL3, PD3, SPQ4 and SEP1. To be specific, it can 
support: 
 
One 1:N (N
≤
4) TPS protection group for E1/T1 service 
 
Two 1:N (N
≤
3) TPS protection groups for E3/DS3/E4/STM-1 service 
 
Coexistence of the above two different TPS protection groups 
8.1.2  TPS Protection for Ethernet Boards 
The OptiX OSN 7500 supports 1:1 TPS protection for 100M Ethernet FE (electrical) 
service, namely, 1:1 TPS protection for the EFS0. 
The protection EFS0 is inserted in slot 18, and the protected EFS0 is inserted in slot 
17. They work with the ETS8 and TSB8 to implement TPS protection for Ethernet FE 
services. 
8.1.3  1+1 Backup for ATM/IMA Interface Boards 
The OptiX OSN 7500 supports 1+1 backup for ATM data boards 
(ADL4/ADQ1/IDL4/IDQ1). Two ATM data boards backup each other. If either fails, the 
other takes over. 
8.1.4  1+1 backup for the Cross-Connect and Timing Unit 
The cross-connection and timing functions are provided by the GXCS board. The 
GXCS board use 1+1 backup for protecting the cross-connect unit and the timing unit 
at the same time. When the active cross-connect and timing units are working 
normally, the standby ones are in standby working mode, not performingthe service 
cross-connection function nor providing timing to the system. They have the same 
cross-connect matrix setting and clock configuration as the active units. When the 
standby units receive the information indicating abnormal performance of the active 
units or a switching command sent by the NM system, they will immediately take over 
the job of the active units, setting themselves to the active working mode and sending 
out a switchover alarm. 
8.1.5  1+1 Backup for the SCC Unit 
The SCC unit of the OptiX OSN 7500 is provided with 1+1 backup protection. The 
standby SCC unit is in standby working mode when the active one is working 
normally. 
8.1.6  1+1 Backup for the Power Input Unit