Application of Optical Line Protection

As shown in Figure 1, station A and station B form a point-to-point network in project T. Both A and B are OTM stations. The optical line protection is adopted between the two stations. Each station is configured with an OLP board.

Figure 1 Application of optical line protection (normal)

: Direction of the working signal flow

: Direction of the protection signal flow

See Figure 1.

When signals are transmitted from station A to station B, the OLP board in station A sends signals over the working line fiber and the protection line fiber at the same time. The OLP board in station B selects the signals transmitted over the working line fiber.

When signals are transmitted from station B to station A, the OLP board in station B sends signals over the working line fiber and the protection line fiber at the same time. The OLP board in station A selects the signals transmitted over the working line fiber.

Figure 2 Application of optical line protection (switching)

: Direction of the working signal flow

: Direction of the protection signal flow

See Figure 2.

In the direction from station A to station B:

When the working line fiber breaks, the OLP board in station B detects that there are no signals in the working receiving direction. The board performs the switching. It selects the signals transmitted over the protection line fiber.

In the direction from station B to station A:

There is no switching because the optical power is normal, and the route of signals remains the same.

NOTE:

The equipment monitors the protection line fiber in real time. When the protection line fiber breaks or degrades in performance, the equipment can detect it in time and the trouble can be shot immediately.