Optical access network

An optical access network comprising:

• an upper loop optical fiber cable which includes a plurality of fixed station lines and at least one common line and is laid on a loop-like path passing through a communication carrier base facility;
• and
• a lower loop optical fiber cable of a plurality of lower loop optical fiber cables which includes at least one user line and at least one redundant line and is laid on a loop-like path passing through a connection point with the upper loop optical fiber cable and a user base facility,
• wherein
• a fixed connection line for connecting the user line and the fixed station lines in a 1:1 ratio, and an optical fiber switching function unit for exclusively connecting the redundant line and the common line are provided at the connection point,
• the number of the common lines is smaller than the total number of the redundant lines included in each of the plurality of lower loop optical fiber cables, and
• the optical fiber switching function unit switches connection between the redundant line and the common line according to demand fluctuation of the lower loop optical fiber cable.