Transparent photonic switch architectures for optical communication networks

• US 20020186434A1
• Filed: 05/08/2002
• Published: 12/12/2002
• Est. Priority Date: 06/08/2001
• Status: Abandoned Application

• Current Assignee: Intelligent Photonics Control Corp.
• Original Assignee: Intelligent Photonics Control Corp.
• Inventors: Forde, Ryan Erskine Robert, Friesen, Greg Peter, Solheim, Alan Glen, Roorda, Peter David
• Application Number:
  US10/140,116
• Publication Number:
  US 20020186434A1
• Time in Patent Office: Days
• US Class Current: 398/82
• 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 14/0206 Express channels arrangements
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0213 Groups of channels or wave bands arrangements
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0009 using wavelength filters
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• CPC Class Codes: H04Q 2011/0035 using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical

Abstract

A n×n transparent photonic switch TPS for an optical communication network uses wavelength selective elements connected in the switch fabric, to allow channels to pass, or to block channels from passing according to a network-wide routing connectivity data. The WSE may be a two-port blocker, in which case all input and output ports of the TPS are provided with 1:(n−1) splitters/combiners for providing internal routes between all pairs of input I(i) and output O(j) ports. The WSE may be assembled using wavelength selective switches WSS, or combinations of WSSs, splitters/combiners and circulators.

Claims

1. A method of routing a communication channel at a transparent photonic switch TPS, comprising:

broadcasting an input multi-channel optical signal along a plurality of internal routes, an internal route for connecting an input port of said TPS to an output port of said TPS;

on each said internal route, selecting a set of channels destined to a respective output port, while blocking all remaining channels destined to other output ports; and

dynamically allocating the channels in said set of channels according to current network-wide connectivity data.

2. In an optical communication network, a transparent photonic switch TPS with n input ports and n output ports, comprising:

an internal route for each I(i)-O(j) pair of ports, where i j,

a wavelength selective element WSE on each internal route for allowing a set of channels to pass from said input port I(i) to said output port O(j), and blocking all channels destined to other output ports O(k), where k j and

a controller for dynamically allocating the channels in said set of channels according to current network-wide connectivity data.

3. A TPS as claimed in claim 2, wherein an input port comprises means for broadcasting an input WDM signal along (n−

1) internal routes.

4. A TPS as claimed in claim 3, wherein an output port comprises means for combining an output WDM signal from (n−

1) internal routes.

5. A TPS as claimed in claim 2, wherein said WSE comprises a filter with a wavelength dependent transfer characteristic.

6. A TPS as claimed in claim 5, wherein said WSE further comprises an optical amplifier.

7. A TPS as claimed in claim 4, with n(n−

1) two-port WSEs and n(n−

1) internal routes, to provide a unidirectional TPS.

8. A TPS as claimed in claim 4, with n(n−

1)/2 two port WSEs, wherein each said WSE is provided with a circulator on each said port, for connection along two internal routes.

9. In an optical communication network, a transparent photonic switch TPS with n input ports and n output ports, comprising:

for each pair of ports I(i)-O(j), means for routing an eastbound WDM signal and a westbound WDM signal between said input port I(i), output port O(i) and a TPS port P(i);

an internal route for each P(i)-P(j) pair of ports;

a wavelength selective element WSE on each internal route for allowing a set of channels to pass from said port P(i) to said port P(j), and blocking all channels destined to other ports P(p), where p j, and

a controller for dynamically allocating the channels in said set of channels.

10. A transparent photonic switch TPS for an optical communication network comprising:

n bidirectional TPS ports P(i) for connecting said TPS with a respective associated input port I(i) and output port O(i);

on each said port P(i), a wavelength selective element WSE with an express port connected to said port P(i), and (n−

1) add/drop ports, for routing a set of channels between said express port and a respective add/drop port;

a plurality of internal routes for connecting each said add/drop port of each WSE(i) with an add/drop port of each other WSE(j), where i j, and

a controller for dynamically allocating the channels in each said set of channels according to current network-wide connectivity data.

11. A TPS as claimed in claim 10, wherein said bidirectional port P(i) comprises a circulator for connecting said associated input port, said associated output port and said express port, to separate/combine a westbound WDM signal from/with an eastbound WDM signal.

12. A TPS as claimed in claim 10, wherein said WSE comprises a 1×

(n−

1) wavelength selective switch WSS with an input/output port connected to said respective express port and (n−

1) WSS add/drop ports, each connected to a respective internal route.

13. A TPS as claimed in claim 10, wherein said WSE comprises two (n−

1)/2×

1 WSSs, each WSS being connected with an input/output port to said respective express port over a 1;

2 splitter/combiner, and with each said (n−

1) WSS add/drop ports to a respective internal route,

wherein each said WSS switches a channel from said input/output port to one of said WSS add/drop ports or none, and n is an odd integer.

14. A TPS as claimed in claim 10, wherein said WSE comprises two m×

1 WSSs, the input/output port of a first WSS being connected to an add/drop port of said second WSS, and the input/output port of said second WSS being connected to said respective express port of said TPS and with each said remaining WSS add/drop ports to a respective internal route.

15. A TPS as claimed in claim 10, wherein said WSE comprises:

a first 1;

2 splitter/combiner with a common port and a first and a second arm, for separating/combining a WDM signal on said common port from/into said arms;

a (n−

1)/2×

1 WSS with an input/output port connected with said respective express port over said first arm, and with (n−

1)/2 WSS add/drop ports;

a second 1;

(n−

1)/2 splitter combiner with a common port and k/2 arms, connected with said respective express port over said common port,

wherein each said WSS switches a channel from said input/output port to one of said WSS add/drop ports or none, and n is an odd integer.

16. A TPS as claimed in claim 10, wherein said WSE comprises:

a (n−

1)/2×

1 WSS with an input/output port connected with the respective express port and k/2 add/drop ports;

(n−

1)/2 splitters/combiners, each having a common port and (n−

1)/2 arms, connected with said common port to an add/drop port, and with said arms to a respective internal route, where n is an odd integer.

18. A TPS as claimed in claim 17, wherein said input WSE comprises:

a 1×

(n−

1)/2 WSS with an input port connected with a respective input port and (n−

1)/2 drop ports;

a 1;

(n−

1)/2 splitter with a common port connected to a respective drop port of said WSS and (n−

1)/2 arms, each connected to a respective internal route.

19. A TPS as claimed in claim 17, wherein said output device comprises

a 1×

(n−

1)/2 WSS with an output port connected with the respective output port and (n−

1)/2 add ports;

a (n−

1)/2;

1 combiner with a common port connected to a respective add port and (n−

1)/2 arms, each connected to a respective internal route.

20. A TPS as claimed in claim 17, wherein said input WSE comprises:

a 1;

2 splitter with a common port a first and a second arm, having said common port connected to a respective TPS input port,

a 1;

(n−

1) splitter with a common port and (n−

1)/2 drop arms, having said common port connected to said first arm of said 1;

2 splitter; and

a 1×

(n−

1)/2 WSS with a bidirectional input/output port and (n−

1)/2 WSS add/drop ports, said bidirectional input/output port being connected to said second arm of said 1;

2 splitter.

21. A TPS as claimed in claim 17, wherein said output device comprises:

a 2;

1 combiner with a common port, a first and a second arm, having said common port connected to the respective TPS output port;

a (n−

1);

1 combiner with an output port and (n−

1)/2 add arms, having said output port connected with said first arm of said 2;

1 combiner;

a (n−

1)/2×

1 WSS(i) with a bidirectional input/output port and (n−

1)/2 WSS add/drop ports, said bidirectional input/output port being connected to said second arm of said 2;

1 combiner.

17. A transparent photonic switch TPS for an optical communication network comprising:

n input ports I(i) and n output ports O(i);

on each input port I(i), an input wavelength selective element WSE with an express port connected to said input port I(i), and with (n−

1) drop ports, for routing said set of channels between said express port and a respective drop port;

on each output port O(i), an output device with an express port connected to said output port O(i), and with (n−

1) add ports, for routing said set of channels between a respective add port and said express port;

a plurality of internal routes for connecting each said drop port of each said input WSE(i) with an add port of each other output WSE(j), where i j; and

a controller for dynamically allocating the channels in each said set of channels C(k) according to current network-wide connectivity data.

22. In an optical communication network, an optical add/drop multiplexer OADM with a first and a second line port connected into a bidirectional line, comprising:

a first 1×

n wavelength selective switch WSS with a first input/output port, a first through port and a plurality (n−

1) of first add/drop ports, for routing a set of passthrough channels between said first line port and said first through port;

a second 1×

m WSS with a second input/output port, a second through port and a plurality (m−

1) of second add/drop ports for routing said set of passthrough channels between said second line port and said second through port;

a passthrough route for routing said passthrough channels between said first and second line ports; and

a controller for dynamically allocating the channels in said set of passthrough channels according to current network-wide connectivity data.

23. An OADM as claimed in claim 22, further comprising (n−

1) bidirectional west routes for connecting each said first add/drop port to a west access structure to route a plurality of west local channels between said first express port and said west access structure, wherein n 2

24. An OADM as claimed in claim 22, further comprising (m−

1) bidirectional east routes for connecting each second add/drop port to an east access structure, for routing a plurality of east local channels between said second input/output port and said east access structure, wherein m 2

25. An OADM as claimed in claim 22, wherein said first and second input/output ports, said first and second through ports, said (n−

1) first add/drop ports, and said (m−

1) second add/drop ports are provided with means for making each said respective port bidirectional.

26. An OADM as claimed in claim 22, wherein said first input/output port is connected directly to said first line port, said second input/output port is connected directly to said second line port, and said first through port is connected with said second through port.

27. An OADM as claimed in claim 22, further comprising:

a first splitter/combiner with a common port, a first arm and a second arm, wherein said common port is connected to said first line port, said first arm is connected to said second through port and said second arm is connected to said first input/output port; and

a second splitter/combiner with a common port, a first arm and a second arm, wherein said common port is connected to said second line port, said first arm is connected to said first through port and said second arm is connected to said second input/output port.

28. An OADM as claimed in claim 27, wherein said first and second through ports are unidirectional.

29. An OADM as claimed in claim 22, further comprising:

means for routing a plurality of drop channels from said first and second add/drop ports to a west and east access structure, and routing a plurality of add channels to said first and second add ports from both said west and east access structure

(n−

1) bidirectional west routes for connecting each first add/drop port to said means for routing; and

(m−

1) bidirectional east routes for connecting each second add/drop port to said means for routing.