Passive optical network arrangement and method

Patent metadata

Field	Value
Publication number	US-9853761-B2
Application number	US-201113995655-A
Country	US
Kind code	B2
Filing date	Apr 18, 2011
Priority date	Dec 20, 2010
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

This disclosure relates to wavelength division multiplexed (WDM) passive optical networks (PON), and the transmission of point-to-point and broadcast or multicast channels from an optical line transmitter (OLT) to an optical network unit (ONU). There is provided a WDM PON ( 100 ) comprising: an OLT ( 105 ) coupled to a plurality of ONU ( 110 a, 110 b ) using an optical fiber network ( 160 ); the OLT ( 105 ) having one or more WDM transceivers ( 115 a, 115 b ) each arranged to receive multi-cast and point-to-point channels and wherein the or each WDM transceiver ( 115 a, 115 b ) is arranged to transmit a said channel to a respective said ONU ( 110 a, 110 b ) using a respective dedicated wavelength (λa, λb); an input channel switch ( 130 a, 130 b ) associated with the or each WDM transceiver ( 115 a, 115 b ) and arranged to selectively couple the input of the WDM transceiver to the multi-cast channels and the point-to-point channels ( 140,135 ); wherein the selected multi-cast or point-to-point channels are directly converted to the respective dedicated wavelength.

First claim

The invention claimed is:

1. A wavelength division multiplexed (WDM) passive optical network (PON), comprising:
an optical line transmitter (OLT) comprising a WDM transceiver apparatus communicatively connected to a first optical network unit (ONU) via an optical fibre network and communicatively connected to a second ONU via the optical fibre network, wherein the WDM transceiver apparatus is operable to receive multi-cast data or point-to-point data, and wherein the WDM transceiver apparatus is arranged to transmit the multi-cast data or the point-to-point data to the first ONU using a first optical signal having a first wavelength and is further arranged to transmit the multi-cast data or the point-to-point data to said second ONU using a second optical signal having a second wavelength; and
an input channel switch apparatus connected to the WDM transceiver apparatus and arranged to i) selectively couple the first ONU to only one of a source of multi-cast data and a source of point-to-point data and ii) selectively couple the second ONU to only one of the source of multi-cast data and the source of point-to-point data,
wherein the input channel switch apparatus comprises i) a first input channel switch for selectively coupling the first ONU to the source of multi-cast data or to the source of point-to-point data and ii) a second input channel switch for selectively coupling the second ONU to the source of multi-cast data or to the source of point-to-point data, and
wherein both the first and second input channel switches are layer 1 switches.

2. The WDM PON as claimed in claim 1 , wherein
the first input channel switch is configured to selectively couple the first ONU to the source of multi-cast data or to the source of point-to-point data in response to a first control signal from the first ONU and ii) the second input channel switch is configured to selectively couple the second ONU to the source of multi-cast data or to the source of point-to-point data in response to a second control signal from the second ONU.

3. The WDM PON as claimed in claim 2 , wherein
the WDM transceiver apparatus comprises a first WDM transceiver and a second WDM transceiver,
the first WDM transceiver is configured to receive a first signal from the first input channel switch, convert the received first signal from the first input channel switch to the first optical signal having the first wavelength, and transmit the first optical signal having the first wavelength to the first ONU, and
the second WDM transceiver is configured to receive a second signal from the second input channel switch, convert the received second signal from the second input channel switch to the second optical signal having the second wavelength, and transmit the second optical signal having the second wavelength to the second ONU.

4. The WDM PON as claimed in claim 3 , wherein the first and second input channel switches are electrical switches arranged to receive the multi-cast and the point-to-point data.

5. The WDM PON as claimed in claim 3 , wherein the first and second input channel switches are optical switches arranged to receive the multi-cast and the point-to-point data.

6. The WDM PON as claimed in claim 1 , wherein the source of point-to-point data is a router and the source of multi-cast data is a multi-cast distribution server.

7. The WDM PON as claimed in claim 1 , wherein the WDM transceiver apparatus and the first and the second ONUs are associated with a control signal interface for receiving and sending respective control signals.

8. The WDM PON as claimed in claim 7 , wherein the respective control signals are an Ethernet frame or a dedicated slot in an upstream wavelength from the respective ONUs.

9. The WDM PON as claimed in claim 1 , wherein the WDM PON is configured so that a dedicated upstream wavelength is maintained between the first ONU and the OLT.

10. The WDM PON of claim 1 , wherein the input channel switch is configured to selectively couple the first ONU in response to a first control signal and to selectively couple the second ONU in response to a second control signal.

11. The WDM PON as claimed in claim 1 , wherein
the WDM transceiver apparatus comprises a first WDM transceiver and a second WDM transceiver,
the first WDM transceiver is configured to receive a first signal from the first input channel switch, convert the received first signal from the first input channel switch to the first optical signal having the first wavelength, and transmit the first optical signal having the first wavelength to the first ONU, and
the second WDM transceiver is configured to receive a second signal from the second input channel switch, convert the received second signal from the second input channel switch to the second optical signal having the second wavelength, and transmit the optical signal having the second wavelength to the second ONU.

12. A method of operating a wavelength division multiplexed (WDM) passive optical network (PON) comprising an optical line transmitter (OLT) coupled to a first optical network unit (ONU) and a second optical network unit (ONU) using an optical fiber network, the OLT comprising a first WDM transceiver arranged to transmit a received input channel to the first ONU using a first wavelength and a second WDM transceiver arranged to transmit a received input channel to the first ONU using a second wavelength, the method comprising:
receiving a multi-cast channel and a point-to-point channel;
using a first layer 1 (L1) switch to switchably couple the first WDM transceiver to only one of the multi-cast channel and the point-to-point channel;
using a second L1 switch to switchably couple the second WDM transceiver to only one of the multi-cast channel and the point-to-point channel;
receiving, with the first WDM transceiver, a first signal from the first L1 switch;
converting the first received signal from the first L1 switch to a first optical signal having the first wavelength;
transmitting the first optical signal having the first wavelength to the first ONU;
receiving, with the second WDM transceiver, a second signal from the second L1 switch;
converting the second received signal from the second L1 switch to a second optical signal having the second wavelength; and
transmitting the second optical signal having the second wavelength to the second ONU.

13. The method as claimed in claim 12 , wherein the coupling of the multi-cast or the point-to-point channels to respective WDM transceivers is dependent on control signals received from the respective ONU corresponding to the respective WDM transceiver.

14. An optical line transmitter (OLT) for a wavelength division multiplexed (WDM) passive optical network (PON), the OLT comprising:
a first WDM transceiver arranged to receive one of a multi-cast channel and a point-to-point channel and to transmit the multicast or point-to-point channel to a first optical network unit (ONU) using a first wavelength;
a second WDM transceiver arranged to receive one of the multi-cast channel and the point-to-point channel and to transmit the multicast or point-to-point channel to a second ONU using a second wavelength;
a first input channel layer 1 (L1) switch having a first port connected to an input of the first WDM transceiver and having a second port connected to a source of multi-cast data and a third port connected to a source of point-to-point data, wherein the first L1 switch is operable to switchably connect either its second or third port to its first port; and
a second input channel L1 switch having a first port connected to an input of the second WDM transceiver and h

Assignees

• Cavaliere Fabio
• Giorgi Luca
• ERICSSON TELEFON AB L M (publ)

Inventors

• Cavaliere Fabio
• Giorgi Luca

Classifications

• H04J14/0256

  at the optical channel layer · CPC title

• H04J14/0267

  Optical signaling or routing · CPC title

• H04J14/0238

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

• H04J14/0282 Primary

  WDM tree architectures · CPC title

• H04J14/0227 Primary

  Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation · CPC title