Optical network terminal, optical network and switch for same

摘要

The device is connected to the optical network via an appropriate optical connection. The device contains a light receiving arrangement for light of a first wavelength modulated with a broadband signal (86,87). There is also and a device for receiving light of a second wavelength (3). which is modulated with an input signal. Light of a third wavelength (4) can be transmitted, or both received and transmitted. The device contains an arrangement for modulating this light with a return signal, by a sub-carrier modulation (SCM) process.