| 摘要 |
PURPOSE:To reduce the number of wavelength of an optical signal used between a subscriber side device using a light frequency division multiplexing system and an exchange and to improve the working efficiency of the wavelength. CONSTITUTION:Call control between the subscriber side device 100 and the exchange 200 is performed by further allocating one kind of wavelength lambda1 in addition to wavelength lambda2, lambda3 used in communication. When a call is set, the exchange 200 allocates one wavelength out of null wavelength lambda2, lambda3 for the communication between the subscriber side device 100 and the exchange 200. The exchange 200 transmits the wavelength lambda2 or lambda3 to be used by the subscriber side device on the wavelength lambda1 for call control. The communication is performed on such set wavelength lambda2 or lambda3. |
