RECONFIGURABLE ADD/DROP MULTIPLEXING IN OPTICAL NETWORKS

• US 20170279555A1
• Filed: 08/18/2015
• Published: 09/28/2017
• Est. Priority Date: 08/25/2014
• Status: Active Grant

• Current Assignee: Xieon Networks S.A.R.L. (Infinera Corp.)
• Original Assignee: Xieon Networks S.A.R.L. (Infinera Corp.)
• Inventors: SCHIMPE, Robert
• Granted Patent: US 10,498,479 B2
• Time in Patent Office: Days
• CPC Class Codes: H04J 14/0204 Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
• CPC Class Codes: H04J 14/0205 Select and combine arrangements, e.g. with an optical combiner at the output after adding or dropping
• CPC Class Codes: H04J 14/021 Reconfigurable arrangements, e.g. reconfigurable optical add/drop multiplexers [ROADM] or tunable optical add/drop multiplexers [TOADM]
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• CPC Class Codes: H04J 14/0294 Dedicated protection at the optical channel (1+1)

Abstract

The present invention relates to adding and dropping signals in a node of an optical network, wherein the node includes a reconfigurable optical add/drop multiplexer (ROADM). The reconfigurable optical add/drop multiplexer (ROADM) comprises output ports and at least one add port connectable to at least one line interface of the network and adapted to receive a modulated optical signal from the line interface. Selection units are connected to one of said add ports and adapted to forward the respective signals to a selected output terminal. A plurality of broadcast units is adapted to broadcast signals forwarded by the selection. Then a multiplexing and selecting device or apparatus selects and multiplexes the optical signals broadcast via broadcast unit output terminals into a plurality of wavelength-division multiplexing (WDM) optical signals and forwards the same to output ports of the reconfigurable optical add-drop multiplexer (ROADM).

Claims

1. A reconfigurable optical add-drop multiplexer (ROADM) for managing optical signals in a wavelength-division multiplexing (WDM) network, comprising:

a plurality of output ports, each connectable to an optical fiber of the network and adapted to transmit a WDM optical signal via the corresponding optical fiber,

a plurality of input ports, each connectable to an optical fiber of the network and adapted to receive a WDM optical signal carried on the corresponding optical fiber,

at least one add port connectable to at least one line interface of the network and each add port of the at least one add port adapted to receive a modulated optical signal from a respective line interface of the at least one line interface,

at least one drop port, each connectable to at least one line interface and adapted to transmit a modulated optical signal to the at least one line interface,

a plurality of selection units each comprising a plurality of selection unit output terminals, wherein each selection unit is connected to at least one of said at least one add port and adapted to select and use a selection unit output terminal to output the optical signal received from the add port to which the selection unit is connected,

a plurality of broadcast units connected to selection unit output terminals of said plurality of selection units, wherein each of the broadcast units comprises a plurality of broadcast unit output terminals, the broadcast units being adapted to receive at least one of said optical signals outputted by said selection units, and to broadcast the received at least one optical signal via a plurality of said broadcast unit output terminals,

a multiplexing and selecting device or apparatus connected to broadcast unit output terminals of said plurality of broadcast units and adapted to select and multiplex optical signals broadcast via said broadcast unit output terminals into a plurality of WDM optical signals and to forward the WDM optical signals to output ports of the ROADM, and

a broadcasting and switching device or apparatus connected to input ports of the ROADM, adapted to broadcast the WDM optical signals received from said input port into a plurality of modulated optical signals, and to select and convey said modulated optical signals to the drop ports.

2. The ROADM of claim 1, wherein at least one of the broadcast units is an optical star coupler comprising a plurality of input terminals and adapted to distribute each optical signal received via the input terminals to at least a subset of and preferably all broadcast unit output terminals of the broadcast unit.

3. The ROADM of claim 1, wherein at least one of the broadcast units comprises a combiner connected to said selection units and a splitter or star coupler connected to the broadcast output terminals of the broadcast unit, and wherein the combiner is connected to the splitter or star coupler.

4. The ROADM of claim 3, wherein the at least one of the broadcast units further comprises an optical amplifier adapted to receive an optical signal from the combiner, and wherein the splitter and combiner are connected via the optical amplifier.

5. The ROADM of claim 1, wherein at least one of said broadcast units is integrated in a single optical component, in particular wherein at least one of said broadcast units and at least one of said selection units is integrated into a single optical component.

6. The ROADM of claim 1, comprising at least N_O·

(N_O−

1)/2 broadcast units, wherein N_O is the number of output ports of the ROADM connected to broadcast unit output terminals of said broadcast units, wherein each of said broadcast units comprises at least two broadcast unit output terminals and wherein the broadcast unit output terminals of said broadcast units are connected to at least two output ports of the ROADM.

7. The ROADM of claim 1, comprising at least N_O broadcast units, wherein N_O is the number of output ports of the ROADM connected to broadcast unit output terminals of said broadcast units, wherein each of said broadcast units comprises at least N_O−

1 broadcast unit output terminals and wherein the broadcast unit output terminals of said broadcast units are connected to N_O−

1 output ports of the ROADM.

8. The ROADM of claim 1, wherein the multiplexing and selecting device or apparatus comprises at least one wavelength-selective switch (WSS).

9. The ROADM of claim 1, wherein the multiplexing and selecting device or apparatus is adapted to forward the optical signals broadcasted by one of the broadcast units to a plurality of output ports of the ROADM.

10. The ROADM of claim 9, wherein the multiplexing and selecting device or apparatus is adapted to forward the optical signals broadcasted by one of the broadcast units to a plurality of output ports of the ROADM such as to provide optical channel protection or bridge and role functionality.

11. The ROADM of claim 1, wherein the demultiplexing and switching device and apparatus further comprises at least one wavelength-selective switch (WSS) or optical splitter connected to an input port of said ROADM.

12. The ROADM of claim 1, said ROADM adapted to provide colorless, directionless and/or contentionless add/drop capabilities.

13. A method of managing signals in a reconfigurable optical add-drop multiplexer (ROADM) of a wavelength-division multiplexing (WDM) network, comprising the steps of:

receiving WDM optical signals carried on at least one optical fiber connected to the ROADM,

receiving at each of at least one add port of the reconfigurable optical add-drop multiplexer (ROADM) a modulated optical signal, wherein at least one add port is connected to a line interface,

selecting a broadcast unit of the ROADM for each of the received modulated optical signals,

conveying each of the received modulated optical signals to the corresponding selected broadcast unit,

broadcasting the optical signals received by each of the broadcast units via a plurality of output terminals of each of the broadcast units,

selecting and combining optical signals which are broadcast via said output terminals of the plurality of broadcast units into a plurality of WDM optical signals, and

routing each of said combined WDM optical signals to a plurality of optical fibers connected to the ROADM.

14. The method of claim 13, wherein the combined WDM optical signal is routed to a plurality of output ports of the ROADM.