| 摘要 |
A passive, coexisting 10 Gb/s passive optical network (XGPON) and Gb/s passive optical network (GPON) is created by using a pair of counter-propagating laser pump sources at a network-based optical line terminal, in combination with a feeder fiber, to create distributed Raman amplification for the upstream signals associated with both GPON and XGPON systems. A passive remote node is located at the opposite end of the feeder fiber, in the vicinity of a group of end-user locations, and includes a cyclic WDM and a pair of power splitters for the GPON and XGPON signals such that the GPON signals are thereafter directed through a first power splitter into optical network units (ONUs) specifically configured for GPON wavelengths and XGPON signals are directed through a second power splitter into ONUs configured for the XGPON wavelengths. The arrangement of the remote node allows for the reach and split ratios of the GPON and XGPON systems to be individually designed for optimum performance. |
| 主权项 |
1. A passive optical distribution network supporting bi-directional communication for a plurality of different bit rate communication systems, each different bit rate communication system associated with a different pair of upstream and downstream communication wavelengths, the network comprising
a transmission fiber for carrying a plurality of downstream signals, each downstream signal associated with a different bit rate system and using a different downstream wavelength, and a multiplicity of upstream signals, groups of upstream signals associated with different bit rate systems and each group using a different upstream wavelength; a plurality of optical pump sources coupled to a near-end termination of the transmission fiber for providing a plurality of counter-propagating pumps at different pump wavelengths, each pump wavelength associated with a different group of upstream signals and utilized to create Raman amplification of the multiplicity of upstream signals along at least an extended portion of the transmission fiber; and a passive remote node coupled to a far-end termination of the transmission fiber, the passive remote node comprising:
a cyclic wavelength division multiplexer (WDM) including a common port coupled to the transmission fiber and a plurality of signal ports with a separate signal port associated with each different bit rate system, the cyclic WDM comprising a plurality of wavelength-selective elements for separating the plurality of downstream signals entering at the common port such that downstream signals exit at the separate signal ports associated with the different bit rate systems, the cyclic WDM also receiving groups of upstream signals at the plurality of signal ports, each signal port receiving a group of upstream signals associated with a different bit rate system, and directing the upstream signals through the wavelength-selective elements to exit at the common port and be coupled into the transmission fiber; anda plurality of power splitters, each power splitter coupled to a separate signal port and associated with a different bit rate system, each power splitter for dividing its associated downstream signal into a plurality of sub-signals to be transmitted to a set of predefined optical network units associated with that bit rate system, and receiving upstream signals therefrom. |
