Ultra-low latency multi-protocol optical routers for the next generation internet

• US 6,925,257 B2
• Filed: 09/30/2002
• Issued: 08/02/2005
• Est. Priority Date: 02/29/2000
• Status: Expired due to Fees

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Yoo, Sung-Joo
• Primary Examiner(s): SEDIGHIAN, REZA
• Application Number:
  US10/261,816
• Publication Number:
  US 20030030866A1
• Time in Patent Office: 1,037 Days
• Field of Search: 398/45, 398/49, 398/50, 398/54, 370224-260
• US Class Current: 398/47
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]
• CPC Class Codes: H04L 45/52 Multiprotocol routers
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0066 Provisions for optical burst or packet networks
• CPC Class Codes: H04Q 2011/0011 using wavelength conversion
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• CPC Class Codes: H04Q 2011/0032 using static wavelength routers (e.g. arrayed waveguide grating router [AWGR] )
• CPC Class Codes: H04Q 2011/0073 Provisions for forwarding or routing, e.g. lookup tables
• CPC Class Codes: H04Q 2011/0088 Signalling aspects

Abstract

An ultra-low latency optical router with a peta-bit-per-second total aggregate switching bandwidth, that will scale to a total connectivity of 1000 by 1000, and beyond by modular upgrades, that utilizes advanced optical technologies to achieve such high capacity with two to three orders of magnitude less volume and power requirements than the electrical router counter part, that serves as a universal engine to other optical routers being developed by vendors and researchers today, that can function in the context of circuit-switching, flow-switching, burst-switching, and packet-switching, that uses advanced wavelength conversion technology to effectively achieve three methods of contention resolution in the router: deflection in wavelength, deflection in space, and buffering in time, and that interfaces a local network to the Supernet.

Claims

1. An optical router comprising:

(a) an optical wavelength router having an input and output;

(b) an input optical wavelength converter stage having an input and an output, said converter stage being tunable;

(c) an output optical wavelength converter stage having an input and an output;

(d) wherein said output of said input wavelength converter stage is connected to said input of said wavelength router,

(e) wherein said input of said output wavelength converter stage is connected to said output of said wavelength router;

(f) wherein said optical router is configured for contention resolution by time, space or wavelength domain switching, or a combination thereof, by tuning of said input optical wavelength converter stage; and

(g) wherein optical signals remain in optical form throughout switching, forwarding and transport by said optical router;

(h) a programmable data processor; and

(i) programming executable on said data processor for resolving switching conflicts by carrying out the operations of;

(i) receiving a data packet having an optical wavelength and a destination;

(ii) determining the preferred path to the destination from a routing table;

(iii) testing the packet to determine if the wavelength is available on the preferred path;

(iv) routing the packet on the preferred path if the wavelength is available on the preferred path;

(v) if the wavelength was not available on the preferred path, determining if the wavelength can be converted to a wavelength available on the preferred path; and

(vi) if the wavelength can be converted to a wavelength available on the preferred path, converting the wavelength and routing the packet on the preferred path.

2. An optical router as recited in claim 1, wherein said programming further carries out the operations of:

(vii) if the wavelength of the packet cannot be converted to a wavelength available on the preferred path at step (vi), determining if any wavelength is free on a loop back port;

(viii) determining if wavelength conversion is needed;

(ix) if wavelength conversion is needed, converting the wavelength, sending the packet on the loop back port, and repeating steps (iii) through (vi); and

(x) if wavelength conversion is not needed, repeating steps (iii) through (vi).

3. An optical router as recited in claim 2, wherein said programming further carries out the operations of:

(xi) if no wavelength was available at step (vii), determining a second preferred path from the routing table;

(xii) determining if a wavelength is available on the second preferred path;

(xiii) routing the packet on the second preferred path if the wavelength is available on the second preferred path;

(xiv) if the wavelength was not available on the second preferred path, determining if the wavelength can be converted to a wavelength available on the second preferred path; and

(xv) if the wavelength can be converted to a wavelength available on the second preferred path, converting the wavelength and routing the packet on the second preferred path.

4. An optical router comprising:

(a) an input port;

(b) a first plurality of tunable optical wavelength converters having inputs connected to said input port;

(c) an output port;

(d) a second plurality of optical wavelength converters having outputs connected to said output port; and

(e) an optical wavelength router connected between said first plurality of wavelength converters and said second plurality of wavelength converters;

(f) wherein said optical router is configured for contention resolution by time, space or wavelength domain switching, or a combination thereof, by tuning of a converter in said first plurality of tunable optical wavelength converters; and

(g) wherein optical signals remain in optical form throughout switching, forwarding and transport by said optical router;

(h) a programmable data processor; and

(i) programming executable on said date processor for resolving switching conflicts by carrying out the operations of;

(i) receiving a data packet having an optical wavelength and a destination;

(ii) determining a preferred path to the destination from a routing table;

(iii) testing the packet to determine if the wavelength is available on the preferred path;

(iv) routing the packet on the preferred path if the wavelength is available on the preferred path;

(v) if the wavelength was not available on the preferred path, determining if the wavelength can be converted to a wavelength available on the preferred path; and

(vi) if the wavelength can be converted to a wavelength available on the preferred path, converting the wavelength and routing the packet on the preferred path.

5. An optical router as recited in claim 4, wherein said programming further carries out the operations of:

(vii) if the wavelength of the packet cannot be converted to a wavelength available on the preferred path at step (vi), determining if any wavelength is free on a loop back port;

(viii) if a wavelength is free on the loop back port, determining if wavelength conversion is needed;

(ix) if wavelength conversion is needed, converting the wavelength, sending the packet on the loop back port, and repeating steps (iii) through (vi); and

(x) if wavelength conversion is not needed, sending the packet on the loop back port, and repeating steps (iii) through (vi).

6. An optical router as recited in claim 5, wherein said programming further carries out the operations of:

(xi) if no wavelength was available on the loop back port at step (vii), determining a second preferred path from the routing table;

(xii) determining if a wavelength is available on the second preferred path;

(xiii) routing the packet on the second preferred path if the wavelength is available on the second preferred path;

(xiv) if the wavelength was not available on the second preferred path, determining if the wavelength can be converted to a wavelength available on the second preferred path; and

(xv) if the wavelength can be converted to a wavelength available on the second preferred path, converting the wavelength and routing the packet on the second preferred path.

7. A method for resolving switching conflicts in an all-optical router, comprising:

(a) receiving a data packet having an optical wavelength and a destination;

(b) determining a preferred path to the destination from a routing table;

(c) testing the packet to determine if the wavelength is available on the preferred path;

(d) routing the packet on the preferred path if the wavelength is available on the preferred path;

(e) if the wavelength was not available on the preferred path, determining if the wavelength can be converted to a wavelength available on the preferred path; and

(f) if the wavelength can be converted to a wavelength available on the preferred path, converting the wavelength and routing the packet on the preferred path;

(g) wherein said optical router comprises

(i) an optical wavelength router having an input and output;

(ii) an input optical wavelength converter stage having an input and an output, said converter stage being tunable; and

(iii) an output optical wavelength converter stage having an input and an output;

(iv) wherein said output of said input wavelength converter stage is connected to said input of said wavelength router;

(v) wherein said input of said output wavelength converter stage is connected to said output of said wavelength router;

(vi) wherein said optical router is configured for contention resolution by time, space or wavelength domain switching, or a combination thereof, by tuning of said input optical wavelength converter stage; and

(vii) wherein optical input data remains in optical form throughout switching, forwarding and transport by said optical router.

8. A method as recited in claim 7, further comprising:

(g) if the wavelength of the packet cannot be converted to a wavelength available on the preferred path at step (f), determining if any wavelength is free on a loop back port;

(h) if a wavelength is free on the loop back port, determining if wavelength conversion is needed;

(i) if wavelength conversion is needed, converting the wavelength, sending the packet on the loop back port, and repeating steps (c) through (f); and

(j) if wavelength conversion is not needed, sending the packet on the loop back port, and repeating steps (c) through (f).

9. A method as recited in claim 8, further comprising:

(k) if no wavelength was available on a loop back port at step (g), determining a second preferred path from the routing table;

(l) determining if the wavelength is available on the second preferred path;

(m) routing the packet on the second preferred path if the wavelength is available on the second preferred path;

(n) if the wavelength was not available on the second preferred path, determining if the wavelength can be converted to a wavelength available on the second preferred path; and

(o) if the wavelength can be converted to a wavelength available on the second preferred path, converting the wavelength and routing the packet on the second preferred path.

10. A method for resolving switching conflicts in an optical router, comprising:

(a) receiving a data packet having an optical wavelength and a destination;

(b) determining a preferred path to the destination from a routing table;

(c) testing the packet to determine if the wavelength is available on the preferred path;

(d) routing the packet on the preferred path if the wavelength is available on the preferred path;

(e) if the wavelength was not available on the preferred path, determining if the wavelength can be converted to a wavelength available on the preferred path;

(f) if the wavelength can be converted to a wavelength available on the preferred path, converting the wavelength and routing the packet on the preferred path,

(g) if the wavelength of the packet cannot be converted to a wavelength available on the preferred path at step (f), determining if any wavelength is free on a loop back port;

(h) if a wavelength is free on the loop back port, determining if wavelength conversion is needed;

(i) if wavelength conversion is needed, converting the wavelength, sending the packet on the loop back port, and repeating steps (c) through (f); and

(j) if wavelength conversion is not needed, sending the packet on the loop back port, and repeating steps (c) through (f).

11. A method as recited in claim 10, further comprising:

(k) if no wavelength was available on a loop back port at step (g), determining a second preferred path from the routing table;

(l) determining if the wavelength is available on the second preferred path;

(m) routing the packet on the second preferred path if the wavelength is available on the second preferred path;

(n) if the wavelength was not available on the second preferred path, determining if the wavelength can be converted to a wavelength available on the second preferred path; and

(o) if the wavelength can be converted to a wavelength available on the second preferred path, converting the wavelength and routing the packet on the second preferred path.

12. An optical router, comprising:

(a) an optical wavelength router having an input and output;

(b) an input optical wavelength converter stage having an input and an output, said converter stage being tunable; and

(c) an output optical wavelength converter stage having an input and an output;

(d) wherein said output of said input wavelength converter stage is connected to said input of said wavelength router;

(e) wherein said input of said output wavelength converter stage is connected to said output of said wavelength router;

(f) wherein tuning said input wavelength converter stage can achieve time, space or wavelength domain switching;

(g) a programmable data processor; and

(h) programming executable on said data processor for resolving switching conflicts by carrying out the operations of;

(i) receiving a data packet having an optical wavelength and a destination;

(ii) determining the preferred path to the destination from a routing table;

(iii) testing the packet to determine if the wavelength is available on the preferred path;

(iv) routing the packet on the preferred path if the wavelength is available on the preferred path;

(v) if the wavelength was not available on the preferred path, determining if the wavelength can be converted to a wavelength available on the preferred path;

(vi) if the wavelength can be converted to a wavelength available on the preferred path, converting the wavelength and routing the packet on the preferred path;

(vii) if the wavelength of the packet cannot be converted to a wavelength available on the preferred path at step (vi), determining if any wavelength is free on a loop back port;

(viii) determining if wavelength conversion is needed;

(ix) if wavelength conversion is needed, converting the wavelength, sending the packet on the loop back port, and repeating steps (iii) through (vi); and

(x) if wavelength conversion is not needed, repeating steps (iii) through (vi).

13. An optical router as recited in claim 12, wherein said programming further carries out the operations of:

(x) if no wavelength was available at step (vii), determining a second preferred path from the routing table;

(xi) determining if a wavelength is available on the second preferred path;

(xii) routing the packet on the second preferred path if the wavelength is available on the second preferred path;

(xiii) if the wavelength was not available on the second preferred path, determining if the wavelength can be converted to a wavelength available on the second preferred path; and

(xiv) if the wavelength can be converted to a wavelength available on the second preferred path, converting the wavelength and routing the packet on the second preferred path.

14. An optical router, comprising:

(a) an input port;

(b) a first plurality of tunable optical wavelength converters having inputs connected to said input port;

(c) an output port;

(d) a second plurality of fixed optical wavelength converters having outputs connected to said output port;

(e) an optical wavelength router connected between said first plurality of wavelength converters and said second plurality of wavelength converters;

(f) wherein tuning a converter in said first plurality of tunable optical wavelength converters can achieve time, space or wavelength domain switching;

(g) a programmable data processor; and

(h) programming executable on said data processor for resolving switching conflicts by carrying out the operations of;

(i) receiving a data packet having an optical wavelength and a destination;

(ii) determining a preferred path to the destination from a routing table;

(iii) testing the packet to determine if the wavelength is available on the preferred path;

(iv) routing the packet on the preferred path if the wavelength is available on the preferred path;

(v) if the wavelength was not available on the preferred path, determining if the wavelength can be converted to a wavelength available on the preferred path; and

(vi) if the wavelength can be converted to a wavelength available on the preferred path, converting the wavelength and routing the packet on the preferred path;

(vii) if the wavelength of the packet cannot be converted to a wavelength available on the preferred path at step (vi), determining if any wavelength is free on a loop back port;

(viii) if a wavelength is free on the loop back port, determining if wavelength conversion is needed;

(ix) if wavelength conversion is needed, converting the wavelength, sending the packet on the loop back port, and repeating steps (iii) through (vi); and

(x) if wavelength conversion is not needed, sending the packet on the loop back port, and repeating steps (iii) through (vi).

15. An optical router as recited in claim 14, wherein said programming further carries out the operations of:

(xi) if no wavelength was available on the loop back port at step (vii), determining a second preferred path from the routing table;

(xii) determining if a wavelength is available on the second preferred path;

(xiii) routing the packet on the second preferred path if the wavelength is available on the second preferred path;

(xiv) if the wavelength was not available on the second preferred path, determining if the wavelength can be converted to a wavelength available on the second preferred path; and

(xv) if the wavelength can be converted to a wavelength available on the second preferred path, converting the wavelength and routing the packet on the second preferred path.

16. A method for resolving switching conflicts in an optical router, comprising:

(a) receiving a data packet having an optical wavelength and a destination;

(b) determining a preferred path to the destination from a routing table;

(c) testing the packet to determine if the wavelength is available on the preferred path;

(d) routing the packet on the preferred path if the wavelength is available on the preferred path;

(e) if the wavelength was not available on the preferred path, determining if the wavelength can be converted to a wavelength available on the preferred path; and

(f) if the wavelength can be converted to a wavelength available on the preferred path, converting the wavelength and routing the packet on the preferred path;

(g) if the wavelength of the packet cannot be converted to a wavelength available on the preferred path at step (f), determining if any wavelength is free on a loop back port;

(h) if a wavelength is free on the loop back port, determining if wavelength conversion is needed;

(i) if wavelength conversion is needed, converting the wavelength, sending the packet on the loop back port, and repeating steps (c) through (f); and

(j) if wavelength conversion is not needed, sending the packet on the loop back port, and repeating steps (c) through (f);

wherein said optical router comprises

(i) an optical wavelength router having an input and output;

(ii) an input optical wavelength converter stage having an input and an output, said converter stage being tunable; and

(iii) an output optical wavelength converter stage having an input and an output;

(iv) wherein said output of said input wavelength converter stage is connected to said input of said wavelength router;

(v) wherein said input of said output wavelength converter stage is connected to said output of said wavelength router; and

(vi) wherein tuning said input wavelength converter stage can achieve time, space or wavelength domain switching.

17. A method as recited in claim 16, further comprising:

(k) if no wavelength was available on a loop back port at step (g), determining a second preferred path from the routing table;

(l) determining if the wavelength is available on the second preferred path;

(m) routing the packet on the second preferred path if the wavelength is available on the second preferred path;

(n) if the wavelength was not available on the second preferred path, determining if the wavelength can be converted to a wavelength available on the second preferred path; and

(o) if the wavelength can be converted to a wavelength available on the second preferred path, converting the wavelength and routing the packet on the second preferred path.