| 摘要 |
<p>The present invention provides an Optical Line Terminal (OLT) for an optical ring network. The OLT comprises a plurality of transmitters each configured to transmit a downstream signal at a respective wavelength. The OLT further comprises a multiplexer configured to wavelength division multiplex the downstream signals into a wavelength division multiplexed signal, an optical power splitter, and an optical switch having a first state and a second state. When the optical switch is in the first state, the wavelength division multiplexed signal is transmitted in a first direction around the optical ring. When the optical switch is in the second state, the wavelength division multiplexed signal is split by the optical power splitter into two wavelength division multiplexed signals and a first of the wavelength division multiplexed signals is transmitted in the first direction around the ring and the second of the wavelength division multiplexed signals is transmitted in a second, different direction around the ring. The OLT further comprises a controller configured to cause the optical switch to switch from the first state to the second state when a break in the ring is detected. There is also provided an optical ring network comprising the OLT, and a radio access network comprising the optical ring network.</p> |
