Method of transmitting an optical signal in an optical transmission system and optical transmission system for implementing such a method

• US 20060257087A1
• Filed: 04/28/2006
• Published: 11/16/2006
• Est. Priority Date: 05/11/2005
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Bellotti, Giovanni, Iachelini, Alessandro
• Granted Patent: US 7,881,610 B2
• Time in Patent Office: Days
• US Class Current: 385/123
• CPC Class Codes: H04B 10/2513 due to chromatic dispersion
• 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 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/0279 WDM point-to-point architectures

Abstract

Described is a method of transmitting an optical signal in an optical transmission system. The method comprises: providing a length of an optical fiber having a zero chromatic dispersion wavelength, wherein the optical fiber belongs to an optical fiber group and wherein the optical fiber group comprises optical fibers having a zero chromatic dispersion wavelength comprised within a wavelength range; estimating a tolerated chromatic dispersion range; and transmitting the optical signal over the length of optical fiber at a first transmission wavelength. The method is characterized by estimating, within the wavelength range, at least one wavelength sub-range, the at least one wavelength sub-range being such that an optical signal is affected by a chromatic dispersion which is comprised within a tolerated chromatic dispersion range when the optical signal is transmitted a) at any wavelength of the at least one sub-range, and b) over any optical fiber of at least one optical fiber sub-group of the optical fiber group, wherein the first transmission wavelength is comprised within the at least one wavelength sub-range.

Claims

1. A method of transmitting an optical signal in an optical transmission system, said method comprising:

providing a length of an optical fiber having a zero chromatic dispersion wavelength, wherein said optical fiber belongs to an optical fiber group and wherein said optical fiber group comprises optical fibers having a zero chromatic dispersion wavelength comprised within a wavelength range;

estimating a tolerated chromatic dispersion range;

transmitting said optical signal over said length of optical fiber at a first transmission wavelength,

wherein it further comprises estimating, within said wavelength range, at least one wavelength sub-range, said at least one wavelength sub-range being such that an optical signal is affected by a chromatic dispersion which is comprised within said tolerated chromatic dispersion range when said optical signal is transmitted

at any wavelength of said at least one sub-range, and

over any optical fiber of at least one optical fiber sub-group of said optical fiber group,

wherein said first transmission wavelength is comprised within said at least one wavelength sub-range.

3. The method according to claim 1, wherein the step of transmitting said optical signal further comprises the step of transmitting at least a further optical signal at a second transmission wavelength other than said first transmission wavelength, said second transmission wavelength being comprised within said wavelength sub-range.

4. The method according to claim 1, wherein said at least one optical fiber sub-group substantially corresponds to said optical fiber group.

5. The method according to claim 1, wherein the step of estimating at least one wavelength sub-range comprises estimating two or more wavelength sub-ranges.

6. The method according to claim 1, wherein the step of estimating said tolerated chromatic dispersion range comprises estimating said tolerated chromatic dispersion range according to said length of optical fiber and according to a bit-rate of said wavelength division multiplexing transmission system.

7. The method according to claim 1, wherein said group of fibers comprises fibers according to one or more of ITU-T G.652, G.653 and G.655.

8. The method according to claim 1, wherein said optical transmission system is a single-channel transmission system.

9. The method according to claim 1, wherein said optical transmission system is a multi-channel transmission system.

30. Computer program comprising computer program code means adapted to perform all the steps of claim 1 when said program is run on a computer.

31. A computer readable medium having a program recorded thereon, said computer readable medium comprising computer program code means adapted to perform all the steps of claim 1 when said program is run on a computer.

2. The method according to claim I, wherein the step of transmitting said optical signal over said length of optical fiber at a first transmission wavelength comprises transmitting said optical signal at a first transmission wavelength which is affected by a transmission wavelength tolerance which is comprised within said wavelength sub-range.

10. The method according to claim L, wherein said optical transmission system is a single-span transmission system.

11. An optical transmission system comprising:

a length of an optical fiber having a zero chromatic dispersion wavelength, wherein said optical fiber belongs to an optical fiber group and wherein said optical fiber group comprises optical fibers having a zero chromatic dispersion wavelength comprised within a wavelength range;

a transmitter being adapted to transmit said optical signal over said length of optical fiber at a first transmission wavelength;

wherein said first transmission wavelength is comprised within a wavelength sub-range, said wavelength sub-range being comprised within said wavelength range and being such that an optical signal is affected by a chromatic dispersion which is comprised within a tolerated chromatic dispersion range when said optical signal is transmitted

at any wavelength of the wavelength sub-range, and

over any optical fiber of an optical fiber sub-group of said optical fiber group.

12. The system according to claim 11, wherein said transmitter is adapted to transmit at a first transmission wavelength which is affected by a transmission wavelength tolerance which is comprised within said wavelength sub-range.

13. The system according to claim 11, wherein said transmitter is further adapted to transmit at a second transmission wavelength other than said transmission wavelength, said second transmission wavelength being comprised within said wavelength sub-range.

14. The system according to claim 11, wherein said transmitter comprises a fixed-wavelength laser source.

15. The system according to claim 11, wherein said transmitter comprises a continuously tunable laser source.

16. The system according to claim 11, wherein said transmitter comprises a discretely tunable laser source.

17. The system according to claim 11, wherein said group of fibers comprises fibers according to one or more of ITU-T G.652, G.653 and G.655.

18. The system according to claim 11, wherein said system is a single-channel optical transmission system.

19. The system according to claim 11, wherein said system is a multi-channel optical transmission system.

20. The system according to claim 11, wherein said system is a single-span optical transmission system.

21. A method of selecting a transmission wavelength for transmitting a first optical signal in a wavelength division multiplexing transmission system, said method comprising:

selecting a group of optical fibers, the optical fibers of said group having a zero chromatic dispersion wavelength comprised within a wavelength range;

estimating a chromatic dispersion range;

estimating, within said wavelength range, one wavelength sub-range, said wavelength sub-range being such that the chromatic dispersion of any optical fiber of a sub-group of said group of optical fibers is comprised within said chromatic dispersion range for any wavelength of said wavelength sub-range; and

selecting said transmission wavelength such that it is comprised within said wavelength sub-range.

22. The method according to claim 21, wherein the step of selecting said transmission wavelength comprises selecting a first transmission wavelength which is affected by a transmission wavelength tolerance which is comprised within said wavelength sub-range.

23. The method according to claim 21, wherein the step of selecting said transmission wavelength further comprises the step of selecting at least a second transmission wavelength other than said first transmission wavelength, said second transmission wavelength being comprised within said wavelength sub-range.

24. The method according to claim 21, wherein said at least one optical fiber sub-group substantially corresponds to said optical fiber group.

25. The method according to claim 21, wherein the step of estimating at least one wavelength sub-range comprises estimating two or more wavelength sub-ranges.

26. The method according to claim 21, wherein the step of estimating said tolerated chromatic dispersion range comprises estimating said tolerated chromatic dispersion range according to said length of optical fiber and according to a bit-rate of said wavelength division multiplexing transmission system.

27. The method according to claim 21, wherein said group of fibers comprises fibers according to one or more of ITU-T G.652, G.653 and G.655.

28. Computer program comprising computer program code means adapted to perform all the steps of claim 21 when said program is run on a computer.

29. A computer readable medium having a program recorded thereon, said computer readable medium comprising computer program code means adapted to perform all the steps of claim 21 when said program is run on a computer.