| 摘要 |
<p>PROBLEM TO BE SOLVED: To execute a degeneration mode in which uplink multiplex access control for a plurality of PON lines is performed by fewer access control units and a communication frame does not go to remaining access control units.SOLUTION: A degeneration control unit 20 is provided that can switch an upper switch 11 and a lower switch 14 of a station side device 2 to which a plurality of PON lines 4A, 4B are connected in such a way as the following (a) and (b): (a) output destinations of downlink frames which go to the first and second PON lines 4A, 4B and which are input to the upper switch 11 are concentrated to a first access control unit 12A, and output destinations of downlink frames input to the lower switch 14 from the first access control unit 12A are de-concentrated to first and second optical transmission and reception units 16A, 16B; and (b) output destinations of uplink frames input to the lower switch 14 from the first and second optical transmission and reception units 16A, 16B are concentrated to the first access control unit 12A by multiplexing in time division.</p> |
