Arrangement for deploying co-existing GPON and XGPON optical communication systems

Patent metadata

Field	Value
Publication number	US-9497523-B2
Application number	US-201214342642-A
Country	US
Kind code	B2
Filing date	Sep 10, 2012
Priority date	Sep 8, 2011
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

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.

First claim

What is claimed is:

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; and
a 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.

2. The passive optical distribution network of claim 1 further comprising at least one discrete optical amplifier associated with a source of downstream signals to provide optical amplification thereto prior to entering the transmission fiber.

3. The passive optical distribution network of claim 2 wherein the at least one discrete optical amplifier comprises a plurality of discrete optical amplifiers, associated with a plurality of sources of downstream signals, each operating in a different bit rate system, in a one-to-one relationship.

4. The passive optical distribution network of claim 2 wherein the at least one discrete optical amplifier is selected from the group consisting of: semiconductor optical amplifiers, discrete Raman amplifiers and doped fiber amplifiers.

5. The passive optical distribution network of claim 1 wherein each power splitter is configured to have a split ratio selected specifically for use with the associated bit rate system.

6. The passive optical distribution network of claim 1 where the downstream signals operate in continuous mode transmission and the upstream signals operate in burst mode transmission.

7. The passive optical distribution network of claim 1 wherein the plurality of different bit rate systems comprises a pair of different bit rate systems and the remote node includes a pair of power splitters comprising a first power splitter associated with a first bit rate system of the pair of different bit rate systems and a second power splitter associated with a second bit rate system of the pair of different bit rate systems.

8. A passive optical distribution network as defined in claim 7 wherein the first bit rate system is a GPON bit rate system and the second bit rate system is an XGPON bit rate system.

9. A passive optical distribution network as defined in claim 8 wherein the GPON bit rate system utilizes an upstream GPON signal wavelength within the range of approximately 1290-1330 nm and a pump wavelength within the range of approximately 1225-1260 nm to provide Raman gain to the upstream GPON signal along an extended portion of the transmission fiber, the GPON bit rate system also utilizing a downstream GPON wavelength within the range of approximately 1480-1490 nm.

10. A passive optical distribution network as defined in claim 9 configured in accordance with a narrowband wavelength option defining an upstream GPON wavelength range of approximately 1300-1320 nm.

11. A passive optical distribution network as defined in claim 8 wherein the XGPON bit rate system utilizes an upstream XGPON signal wavelength within the range of approximately 1260-1280 nm and a pump wavelength within the range of approximately 1201-1211 nm to provide Raman gain to the upstream XGPON signals along an extended portion of the transmission fiber, and also a downstream XGPON wavelength within the range of 1575-1580 nm.

12. A passive optical distribution network as defined in claim 8 wherein the GPON system utilizes an upstream GPON wavelength within the range of approximately 1290-1330 nm and a first pump wavelength within the range of approximately 1225-1260 nm to provide Raman gain to the upstream GPON signals, and the XGPON bit rate system utilizes an upstream XGPON signal wavelength within the range of approximately 1260-1280 nm and a second pump wavelength within the range of approximately 1201-1211 nm to provide Raman gain to the upstream XGPON signals, wherein a second pump power for the XGPON upstream signals is determined to provide sufficient gain to the upstream XGPON signals, while also compensating for power transfer from the second pump to the first pump.

13. A passive optical distribution network as defined in claim 12 wherein a tail region of the power of the first pump source is maintained to be less than power of the XGPON upstream signal where the XGPON signal wavelengths are in close proximity to the tail region.

14. A passive optical distribution network as defined in claim 12 wherein the first pump wavelength is selected to minimize interaction with the XGPON upstream signal wavelength.

15. A passive optical distribution network as defined in claim 7 wherein the transmission fiber comprises a length in the range of about 20-60 km, with the first power splitter having a ratio in the range of 1:16 to 1:128 and the second power splitter having a ratio in the range of 1:16 to 1:64.

16. A network architecture for overlaying a first bi-directional optical communication system operating at a first set of data rates on a plurality of n second bi-directional optical communication systems operating at a second set of data rates, the network architecture including
a bi-directional optical amplifier coupled to an optical line terminal of the first system operating at the first set of data rates, the bi-directional optical amplifier including a Raman pump source for providing counter-propagating Raman amplification to upstream optical communication signals associated with the first system and operating at the first set of data rates, the bi-directional optical amplifier further including a discrete optical amplifier for providing amplification to the downstream communication signal at the first set of data rates; and
a 1:n power splitter d

Assignees

• Zhu Benyuan
• Ofs Fitel Llc

Inventors

• Zhu Benyuan

Classifications

• H04J14/025

  using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU · CPC title

• H04Q2011/0086

  Network resource allocation, dimensioning or optimisation · CPC title

• H04Q11/0067 Primary

  Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring · CPC title

• H04B10/2503

  Electricity · mapped topic

• H04J14/0252

  Sharing one wavelength for at least a group of ONUs, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU · CPC title