Upgrading PON systems using a multi-cycle field AWG

Patent metadata

Field	Value
Publication number	US-10158930-B2
Application number	US-201715637939-A
Country	US
Kind code	B2
Filing date	Jun 29, 2017
Priority date	Nov 25, 2015
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

The communication system has first and second optical systems and an optical feed fiber in communication with the first optical system and arranged to convey a feeder optical signal to the second optical system. The first optical system includes a multiplexer configured to multiplex/demultiplex between a first optical line terminal signal, a second optical line terminal signal, and the feeder optical signal. The feeder optical signal includes the first optical line terminal signal and the second optical line terminal signal. The first optical line terminal signal includes a first upstream free spectral range and a first downstream free spectral range. The second optical line terminal signal includes a second upstream free spectral range and a second downstream free spectral range. The second optical system is in communication with the optical feed fiber and is configured to multiplex and demultiplex between the feeder optical signal and optical network unit signals.

First claim

What is claimed is:

1. A communication system comprising:
a first optical system comprising a multiplexer configured to multiplex and demultiplex between a first optical line terminal (OLT) signal, a second OLT signal, and a feeder optical signal,
wherein for a first period of time, the feeder optical signal comprises:
the first OLT signal comprising a wavelength in a first upstream free spectral range (FSR) and a wavelength in a first downstream FSR; and
an unused portion of spectrum,

wherein for a second period of time subsequent to the first period of time, the feeder optical signal comprises:
the first OLT signal; and
the second OLT signal comprising a wavelength in a second upstream FSR and a wavelength in a second downstream FSR, the second upstream FSR and the second downstream FSR using the unused portion of spectrum;

an optical feed fiber optically connected with the first optical system and arranged to convey the feeder optical signal; and
a second optical system optically connected with the optical feed fiber and configured to multiplex and demultiplex between the feeder optical signal and optical network unit (ONU) signals,
wherein for the first period of time, each ONU signal comprising a first upstream wavelength in the first upstream FSR and a first downstream wavelength in the first downstream FSR,
wherein for the second period of time, each ONU signal comprising the first upstream wavelength in the first upstream FSR, the first downstream wavelength in the first downstream FSR, a second upstream wavelength in the second upstream FSR, and a second downstream wavelength in the second downstream FSR.

2. The system of claim 1 , wherein the second optical system comprises a cyclical arrayed waveguide grating.

3. The system of claim 1 , wherein the second optical system comprises an arrayed waveguide grating having outputs optically connected with optical couplers, each coupler combining at least two outputs.

4. The system of claim 1 , further comprising:
a first OLT in communication with the first optical system, the first OLT transmitting/receiving the first OLT signal; and
a second OLT terminal in communication with the first optical system, the second OLT transmitting/receiving the second OLT signal.

5. The system of claim 1 , further comprising:
a first ONU optically connected with the second optical system and configured to receive an ONU signal having the first upstream wavelength in the first upstream FSR and the first downstream wavelength in the first downstream FSR; and
a second ONU optically connected with the second optical system and configured to receive the ONU signal, the ONU signal having the second upstream wavelength in the second upstream FSR and the second downstream wavelength in the second downstream FSR.

6. The system of claim 5 , further comprising an optical power splitter in communication with the second optical system and the first and second ONUs, the optical power splitter configured to:
split the ONU signal received from the second optical system for delivery to the first and second ONUs; and
combine a first upstream signal from the first ONU and second upstream signal from the second ONU for delivery of the optical network signal from the first and second ONUs to the second optical system.

7. The system of claim 5 , wherein the first ONU and the second ONU operate using different protocols.

8. The system of claim 5 , wherein the first ONU and the second ONU each comprises a fixed bandpass filter.

9. The system of claim 1 , wherein the first upstream FSR and the first downstream FSR are associated with a first protocol, and the second upstream FSR and the second downstream FSR are associated with a second protocol different from the first protocol.

10. A method comprising:
receiving, at a first optical system, and multiplexing/demultiplexing between a first optical line terminal (OLT) signal, a second OLT signal, and a feeder optical signal,
wherein for a first period of time, the feeder optical signal comprises:
the first OLT signal comprising a wavelength in a first upstream free spectral range (FSR) and a wavelength in a first downstream FSR; and
an unused portion of spectrum,

wherein for a second period of time subsequent to the first period of time, the feeder optical signal comprises:
the first OLT signal; and
the second OLT signal comprising a wavelength in a second upstream FSR and a wavelength in a second downstream FSR, the second upstream FSR and the second downstream FSR using the unused portion of spectrum;

transmitting the feeder optical signal between the first optical system and a second optical system; and
receiving, at the second optical system, and multiplexing/demultiplexing between the feeder optical signal and optical network unit (ONU) signals,
wherein for the first period of time, each ONU signal comprising a first upstream wavelength in the first upstream FSR and a first downstream wavelength in the first downstream FSR,
wherein for the second period of time, each ONU signal comprising the first upstream wavelength in the first upstream FSR, the first downstream wavelength in the first downstream FSR, a second upstream wavelength in the second upstream FSR, and a second downstream wavelength in the second downstream FSR.

11. The method of claim 10 , further comprising transmitting at least one of the ONU signals from the second optical system to:
a first ONU optically connected with the second optical system and configured to receive an ONU signal having the first upstream wavelength in the first upstream FSR and the first downstream wavelength in the first downstream FSR; and
a second ONU optically connected with the second optical system and configured to receive an ONU signal having the second upstream wavelength in the second upstream FSR and the second downstream wavelength in the second downstream FSR.

12. The method of claim 11 , wherein the first ONU and the second ONU operate using different protocols.

13. The method of claim 12 , wherein the first ONU and the second ONU each comprises a fixed bandpass filter.

14. The method of claim 10 , wherein the first upstream FSR and the first downstream FSR are associated with a first protocol, and the second upstream FSR and the second downstream FSR are associated with a second protocol different from the first protocol.

15. The method of claim 10 , wherein the first optical system comprises a multiplexer and the second optical system comprises a cyclical arrayed waveguide grating.

16. The method of claim 10 , wherein the second optical system comprises an arrayed waveguide grating having outputs, wherein at least two outputs are optically connected with a coupler.

17. A communication system comprising an optical system receiving a feeder optical signal from an optical feeder optically connected with the optical system, the optical system configured to multiplex and demultiplex between the feeder optical signal and optical network unit (ONU) signals,
wherein for a first period of time, the feeder optical signal comprises:
a first optical line terminal (OLT) signal comprising a wavelength in a first upstream free spectral range (FSR) and a wavelength in a first downstream FSR; and
an unused portion of spectrum,

wherein for the first period of time each ONU signal comprises:
a first upstream wavelength in a first upstream FSR: and
a first downstream wavelength in the first downstream FSR,

wherein for a second period of time subsequent to the first period of time, the feeder optical signal comprises:
the fir

Assignees

• Google Inc
• Google Llc

Inventors

• Du Liang
• Zhao Xiangjun
• Lam Cedric Fung
• Wang Daoyi
• Jiang Changhong Joy

Classifications

• H04L69/18

  Multiprotocol handlers, e.g. single devices capable of handling multiple protocols · CPC title

• H04J14/0241 Primary

  Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths · CPC title

• H04Q11/0062 Primary

  Network aspects · 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

• H04Q2011/0079

  Operation or maintenance aspects · CPC title