The backbone network of optical fiber quantum secure communication has the characteristics of long link distance, large bearing capacity, high reliability and robustness requirements. The backbone network built by the company’s products has the following technical characteristics:

◆It has good capacity expansion, long safe distance for quantum key distribution, and stable support for single link distance over 100km.

◆It can be matched the single-segment distance of classical optical communication, sharing the construction and maintenance facilities such as computer rooms and pipeline shaft.

◆It is Suitable for buried cable, suspended cable, and so on… The key generation rate (code rate) is high, and the configuration management is flexible.

◆When the main chain is interrupted, the encryption service still can operate by using the classical backup links, reserve time for removal of barrier.

◆Defend against single point of failure , the failure recovery time is short.  

The application scheme of backbone network is shown in the following figure, which has been applied to the backbone network of quantum secure communication such as "Beijing-shanghai trunk line" and "Wu-he trunk line".