To construct optical transmission route redundancy while utilizing a non-redundant type optical node that is simply configured and cost-reduced relatively to a redundant type optical node, by effectively utilizing an existent optical node device by constructing the optical transmission route redundancy without exchanging the optical node device with a redundant type device in a case where the existent optical node device is a non-redundant type.
An optical signal switcher comprising an optical switch is disposed at a downstream optical transmission side, an optical transmission route between the optical signal switcher and an optical node is made redundant, an output from the optical signal switcher can be switched and transmitted to any redundant optical transmission route by the optical signal switcher, so that a downlink optical signal transmitted through the optical transmission route can be transmitted to the optical node. An optical passive constitutive device is disposed in front of the optical node, so that a downlink optical signal transmitted through the optical transmission route can be transmitted to the optical node via the optical passive constitutive device. A transmission area charged by the optical node is divided to extend optical nodes in charge of respective divided areas, and an output from the optical passive constitutive device is distributed into multiple outputs so as to be distributed to the respective optical nodes.
| JP2003338788A | 2003-11-28 | |||
| JPH0983990A | 1997-03-28 | |||
| JP2007184908A | 2007-07-19 | |||
| JPH09312614A | 1997-12-02 | |||
| JPH11122172A | 1999-04-30 |
Masahide Kobayashi
Teppei Kai
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