Passive optical network system

• US 8,718,472 B2
• Filed: 05/26/2011
• Issued: 05/06/2014
• Est. Priority Date: 06/15/2007
• Status: Active Grant

• Current Assignee: Northpeak Enterprises Incorporated
• Original Assignee: Northpeak Enterprises Incorporated
• Inventors: Gadkari, Ketan, Warner, Tom
• Primary Examiner(s): CURS, NATHAN M
• Application Number:
  US13/116,320
• Publication Number:
  US 20110268444A1
• Time in Patent Office: 1,076 Days
• Field of Search: 398/67, 398/72
• US Class Current: 398/72
• CPC Class Codes: H04B 10/272 Star-type networks or tree-type networks
• CPC Class Codes: H04J 14/0226 Fixed carrier allocation, e.g. according to service
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0232 for downstream transmission
• CPC Class Codes: H04J 14/0239 in WDM-PON sharing multiple downstream wavelengths for groups of optical network units [ONU], e.g. multicasting wavelengths
• CPC Class Codes: H04J 14/0247 Sharing one wavelength for at least a group of ONUs
• CPC Class Codes: H04J 14/0252 Sharing one wavelength for at least a group of ONUs, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• CPC Class Codes: H04J 14/0298 with sub-carrier multiplexing [SCM]
• CPC Class Codes: H04N 7/22 Adaptations for optical transmission
• CPC Class Codes: H04Q 11/0067 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

Abstract

A system for providing bi-directional RF services over a point-to-multipoint Passive Optical Network (PON). A system that can transport upstream RF signals generated by devices such as a set top box or a cable modem, through a passive Optical Network while simultaneously supporting downstream RF video and bi-directional base-band services on the PON.

Claims

1. A node, consisting of:

an upstream port for coupling to an optical fiber carrying optical signals in a bidirectional passive optical network;

an RF optical transmitter for receiving an upstream RF signal from a diplexer and transmitting an upstream RF optical signal over the bidirectional passive optical network; and

a Wavelength-Division-Multiplexer (WDM), coupled to the RF optical transmitter and the upstream port, operative to multiplex the upstream RF optical signal with other upstream optical signals onto the bidirectional passive optical network,

wherein the node is configured for operation within an Optical Network Unit (ONU) that is operable to handle at least three wavelengths.

2. The node of claim 1, wherein the upstream RF optical signal comprises video content.

3. The node of claim 1, wherein the upstream RF optical signal is generated by a set top box.

4. The node of claim 1, wherein the upstream optical signal is generated by a cable modem.

5. The node of claim 1, wherein the upstream RF optical signal and a downstream optical signal each comprise video content.

6. The node of claim 5, wherein the upstream RF optical signal is generated by a set top box.

7. The node of claim 5, wherein the upstream optical signal is generated by a cable modem.

8. The node of claim 1, wherein the upstream RF optical signal is generated by a set top box.

9. The node of claim 1, wherein the upstream optical signal is generated by a cable modem.

10. A method of transporting RF optical signals through a passive optical network (PON) while supporting baseband optical signals on the PON comprising the steps of:

generating downstream baseband optical signals at an optical transmitter operating at a first wavelength λ

₁;

generating downstream RF optical signals at a first RF optical transmitter operating at a third wavelength λ

₃;

multiplexing the downstream baseband optical signals and the downstream RF optical signals together at a first Wavelength-Division Multiplexer (WDM) to generate multiplexed downstream optical signals;

transmitting the multiplexed downstream optical signals on the PON;

receiving the multiplexed downstream optical signals at a second Wavelength Division-Multiplexer in a node;

sending the multiplexed downstream optical signals from the second Wavelength Division-Multiplexer (WDM) for delivery to a multi-wavelength capable Optical Network Unit (ONU);

generating upstream RF optical signals at a second RF optical transmitter in the node operating at a fourth wavelength λ

₄;

generating upstream baseband optical signals at the multi-wavelength capable ONU operating at a second wavelength λ

₂;

sending the upstream baseband optical signals from the multi-wavelength capable ONU to the second WDM;

multiplexing the upstream baseband optical signals and the upstream RF optical signals together at the second WDM to generate multiplexed upstream optical signals;

transmitting the multiplexed upstream optical signals via the PON;

demultiplexing the multiplexed upstream optical signals at the first WDM;

receiving the upstream baseband optical signals at an optical receiver; and

receiving the upstream RF optical signals at an RF optical receiver.

11. A method of transporting bidirectional RF optical signals and bidirectional baseband optical signals through a node comprising the steps of:

receiving at the node downstream baseband optical signals on a first wavelength λ

₁ and downstream RF optical signals on a third wavelength λ

₃;

sending the downstream baseband optical signals and the downstream RF optical signals through a Wavelength-Division-Multiplexer (WDM) in the node to a multi-wavelength capable Optical Network Unit (ONU);

generating upstream RF optical signals output by an RF optical transmitter in the node operating at a fourth wavelength λ

₄;

generating upstream baseband optical signals at the multi-wavelength capable ONU at a second wavelength λ

₂;

sending the upstream baseband optical signals from the multi-wavelength capable ONU to the WDM;

multiplexing the upstream RF optical signals and the upstream baseband optical signals in the WDM to generate multiplexed upstream optical signals; and

transmitting the multiplexed upstream optical signals from the node.

12. A method of transporting RF optical signals through a passive optical network (PON) while supporting baseband optical signals on the PON comprising the steps of:

generating downstream baseband optical signals at a first optical transmitter operating at a first wavelength λ

₁;

generating downstream RF optical signals at a first RF optical transmitter operating at a third wavelength λ

₃;

multiplexing the downstream baseband optical signals and the downstream RF optical signals together at a first Wavelength-Division Multiplexer (WDM) to generate multiplexed downstream optical signals;

transmitting the multiplexed downstream optical signals on the PON;

receiving the multiplexed downstream optical signals at a second Wavelength Division-Multiplexer (WDM) in a node;

demultiplexing the multiplexed downstream optical signals at the second WDM in the node to obtain the downstream baseband optical signals and the downstream RF optical signals;

transmitting the downstream baseband optical signals from the second WDM to a Two-Wavelength Optical Network Unit (ONU); and

transmitting the downstream RF optical signals through a third WDM in the node to an RF optical receiver in the node.

13. The method of claim 12, further comprising the steps of:

generating upstream RF optical signals at a second RF optical transmitter in the node operating at a fourth wavelength λ

₄;

transmitting the upstream RF optical signals from the second RF optical transmitter through the third WDM to the second WDM;

generating upstream baseband optical signals at the Two-Wavelength ONU operating at a second wavelength λ

₂;

transmitting the upstream baseband optical signals from the Two-Wavelength ONU to the second WDM;

multiplexing the upstream baseband optical signals and upstream RF optical signals at the second WDM to generate multiplexed upstream optical signals;

transmitting the multiplexed upstream optical signals via the PON;

demultiplexing the multiplexed upstream optical signals at the first WDM to obtain the upstream baseband optical signals and the upstream RF optical signals;

receiving the upstream baseband optical signals at an optical receiver; and

receiving the upstream RF optical signals at the RF optical receiver.

14. A method of transporting bidirectional RF optical signals and bidirectional baseband optical signals through a node comprising the steps of:

receiving at the node downstream baseband optical signals on a first wavelength Al and downstream RF optical signals on a third wavelength λ

₃;

demultiplexing the downstream baseband optical signals and the downstream RF optical signals at a first Wavelength-Division-Multiplexer (WDM) in the node;

transmitting the downstream baseband optical signals through the first WDM to a Two-Wavelength Optical Network Unit (ONU);

transmitting the downstream RF optical signals through a second WDM in the node to an RF optical receiver in the node;

generating upstream RF optical signals at an RF optical transmitter in the node operating at a fourth wavelength λ

₄;

transmitting the upstream RF optical signals from the RF optical transmitter through the second WDM to the first WDM;

generating upstream baseband optical signals at the Two-Wavelength ONU at a second wavelength λ

₂;

sending the upstream baseband optical signals from the Two-Wavelength ONU to the first WDM;

multiplexing the upstream RF optical signals and the upstream baseband optical signals together at the first WDM to generate multiplexed upstream optical signals; and

transmitting the multiplexed upstream optical signals from the node.

15. A method of transporting bidirectional RF optical signals through a passive optical network (PON) while supporting bidirectional baseband optical signals on the PON comprising the steps of:

generating downstream baseband optical signals at a first optical transmitter operating at a first wavelength λ

₁;

generating downstream RF optical signals at a first RF optical transmitter operating at a third wavelength λ

₃;

multiplexing the downstream baseband optical signals and the downstream RF optical signals together at a first Wavelength-Division Multiplexer (WDM) to generate multiplexed downstream optical signals;

transmitting the multiplexed downstream optical signals on the PON;

receiving the multiplexed downstream optical signals at one of a node, a two wavelength Optical Network Unit (ONU), or a bi-directional RF node;

in response to the multiplexed downstream optical signals being received at a node, the further steps of;

demultiplexing the multiplexed downstream optical signals at a second WDM in the node to obtain the downstream baseband optical signals and the downstream RF optical signals;

transmitting the downstream baseband optical signals from the second WDM to the Two-Wavelength ONU;

transmitting the downstream RF optical signals through a third WDM in the node to a first RF optical receiver in the node;

generating upstream RF optical signals at a second RF optical transmitter in the node operating at a fourth wavelength λ

₄;

transmitting the upstream RF optical signals from the second RF optical transmitter through the third WDM to the second WDM;

generating upstream baseband optical signals at the Two-Wavelength ONU operating at a second wavelength λ

₂;

transmitting the upstream baseband optical signals from the Two Wavelength ONU to the second WDM;

multiplexing the upstream baseband optical signals and upstream RF optical signals together at the second WDM to generate multiplexed upstream optical signals;

transmitting the multiplexed upstream optical signals via the PON;

demultiplexing the multiplexed upstream optical signals at the first WDM to obtain the upstream baseband optical signals and the upstream RF optical signals;

receiving the upstream baseband optical signals at a second optical receiver; and

receiving the upstream RF optical signals at a second RF optical receiver;

in response to the multiplexed downstream optical signals being received at the Two-Wavelength ONU, the further steps of;

receiving the downstream baseband optical signals at the TwoWavelength ONU;

generating upstream baseband optical signals at the second wavelength λ

₂ at the Two-Wavelength ONU;

transmitting the upstream baseband optical signals from the Two Wavelength ONU via the PON;

passing the upstream baseband optical signals through the first WDM; and

receiving the upstream baseband optical signals at the second optical receiver;

in response to the multiplexed downstream optical signals being received at the bidirectional RF node, the further steps of;

receiving the downstream RF optical signals at the bi-directional RF node;

generating upstream RF optical signals at the fourth wavelength λ

₄ at the bidirectional RF node;

transmitting the upstream RF optical signals from the bi-directional RF node via the PON;

passing the upstream RF optical signals through the first WDM; and

receiving the upstream RF optical signals at the second RF optical receiver.

16. A point-to-multipoint passive optical network (PON) system comprising:

a. a first RF optical transmitter;

b. a first RF optical receiver;

c. a first Wave-Division-Multiplexer (WDM) comprising a first upstream port, a second upstream port, and at least one downstream port;

d. an optical fiber connecting the first RF optical transmitter to the first upstream port of the first WDM;

e. an optical fiber connecting the first RF optical receiver to the second upstream port of the first WDM;

f. an optical splitter with at least one upstream port and a plurality of downstream ports;

g. an optical fiber connecting the downstream port of the first WDM to at least one upstream port of the optical splitter;

h. one or more nodes, each node comprising;

i. a first upstream port;

ii. a downstream port;

iii. a second RF optical transmitter comprising an upstream port and a downstream port;

iv. a second RF optical receiver comprising an upstream port and a downstream port;

v. a second Wave-Division-Multiplexer (WDM) comprising an upstream port, a first downstream port, and a second downstream port;

vi. an optical fiber connecting the upstream port of the node to the upstream port of the second WDM;

vii. an optical fiber connecting the first downstream port of the second WDM to the upstream port of the second RF optical transmitter;

viii. an optical fiber connecting the second downstream port of the second WDM to the upstream port of the second RF optical receiver; and

ix. a diplexer, the diplexer connected to the second RF optical transmitter, the second RF optical receiver, and the downstream port of the node;

i. an optical fiber connecting a downstream port of the optical splitter to the first upstream port of the node;

j. one or more bidirectional RF nodes, each bidirectional RF node comprising;

i. a first upstream port;

ii. a second upstream port;

iii. a third RF optical transmitter comprising an upstream port and a downstream port;

iv. a third RF optical receiver comprising an upstream port and a downstream port;

v. a third Wave-Division-Multiplexer (WDM) comprising a first upstream port, a second upstream port, and a downstream port;

vi. an optical fiber connecting the first upstream port of the third WDM and the upstream port of the node;

vii. an optical fiber connecting the second upstream port of the third WDM and the second upstream port of the node;

viii. an optical fiber connecting the downstream port of the third WDM to the upstream port of the third RF optical transmitter;

ix. an optical fiber connecting the downstream port of the third WDM to the upstream port of the third RF optical receiver; and

x. an RF connection between the downstream port of the second RF optical transmitter and the downstream port of the node;

k. an optical fiber connecting a downstream port of the optical splitter to the first upstream port of the bidirectional RF node;

l. at least one two-wavelength capable Optical Network Unit (ONU), comprising;

i. an upstream port; and

ii. a downstream port; and

m. an optical fiber connecting the second upstream port of the node to the upstream port of the ONU.