With the development of optical fiber communication and MEMS technology, large-capacity communication optical cable networks have entered thousands of households, and the realization of non-blocking communication systems and products has matured. Against this background, optical path protection systems came into being.

The so-called intelligent optical path protection is a device or system that uses fiber optic communication technology and optical switch technology to intelligently protect or switch fiber optic communication lines, bypasses, and ring networks so as to achieve non-blocking communication. Its main uses are as follows:

1）Line redundancy protection

2）Automatic switching protection

3）Bypass shunt protection

4）Self-healing loop protection

According to different applications, optical path protection systems are mainly divided into the following types:

1. Optical Bypass Protection(OBP )

The optical bypass protection, OBP, is an intelligent optical path switching system used in the field of optical fiber communications and can automatically bypass faulty network nodes. It can automatically identify the power supply status and optical signal output status of network nodes. When the local optical equipment fails (including power interruption) , hardware or software failure, etc.), it can instantly switch to the bypass optical path, and the communication line will bypass the local device (i.e., the faulty node), thus avoiding total obstruction due to the faulty node and ensuring normal system connectivity.

2. Optical Line Protection(OLP )

The optical line protection, OLP, is a functional device used in the field of optical fiber communication to automatically switch between master and backup optical paths. It can monitor the optical signal status of the main and backup links in real time. When the main link optical cable fails, the system automatically switches to the backup link for transmission, protecting the normal operation of the system and improving system stability. OLP can easily and economically form protection solutions for various channels and trunk lines, and can also protect various networks that require optical path switching, thus establishing an optical communication network that is non-blocking, highly reliable, safe, flexible, and disaster-resistant. GLSUN OLP system is widely used in various important optical network transmissions, such as operator backbone networks and 5G base station fronthaul, government and enterprise backbone networks, bank financial dedicated lines and other fields. The common protection methods of OLP are 1:1 and 1+1.

1+1 Protection Methods

With the features of independent and transparent transmission signal, safety and reliability, and fast fault recovery, 1+1 optical protection card can help users build an optical communication network that is non-blocking, highly reliable, safe, flexible, and highly resistant to disasters.

1:1 Protection Methods

OLP protects the line by 1:1 (selective send, selective receive) protection method. The 1:1 protection method has much lower losses than 1+1, so this protection method is also widely used in transmission links.