Metropolitan Area Network (MAN) is responsible for the connection between different regions and different industry organizations in the city, which uplink backbone network and downlink LAN(local area network)/user area, it has the characteristics of medium link length, large service capacity, high scalability requirement and complex network topology.The metropolitan area network built by the company’s products has the following technical characteristics:

◆The single link meets 50 km radius length of Megacity, key supply can guarantee intra-city and inter-city communication.

◆The network topology adapts to the actual physical location distribution of many user units, supporting star,ring and hybrid network topology, which have good scalability.

◆The number of quantum communication links can be expanded and changed flexibly, autonomous management of routing partition satisfies the needs of key exchange of complex topology, flexible sharding management of key.

◆By using the technological means of wavelength planning, narrow-band filtering, intensity control…and so on, allowing quantum channels and classical communications to share optical fibers, savingoptical fiber resources and simplifying deployment.

The application scheme of metropolitan area network is shown in the following figure, which has been applied to multiple MANs in Hefei, Jinan, Wuhan, Beijing, Shanghai, Guiyang, and so on…