Wave-length loop system

Application Number: 00107393
Application Date: 2000.05.12
Publication Number: 1274209
Publication Date: 2000.11.22
Priority Information: 1999/5/12 JP 131982/99
International: H04B10/12;H04B10/24
Applicant(s) Name: NEC Corp.
Inventor(s) Name: Miyao Yasuhiro
Patent Agency Code: 11021
Patent Agent: liu xiaofeng
Abstract To set wavelength assignment in a wavelength ring system in such a way that a utilizing efficiency of a fiber is increased and a required length of the fiber is decreased. In the wavelength ring system 1601 where a plurality of wavelength channels are set to one fiber and a prepared standby wavelength channel is selected when a current wavelength channel receives effect of a fault such as a broken fiber, a wavelength to be used by the set wavelength section is independently assigned to each wavelength section and a wavelength is assigned only to a spare wavelength section required to recover the active wavelength channel. The wavelength is assigned so that the active wavelength section and the spare wavelength section in the same wavelength ring system are contained in the same fiber and wavelength sections in different wavelength ring systems are contained in the same fiber.