Auto-setting and optimization of EAM with optical line systems

• US 20040208514A1
• Filed: 10/22/2002
• Published: 10/21/2004
• Est. Priority Date: 12/07/2001
• Status: Active Grant

• Current Assignee: Oplink Communications, LLC (KOCH Industries Incorporated)
• Original Assignee: Ar Card
• Inventors: Shi, Feng, Fu, Xiaoli, Zhang, Genzao, Wang, Tongqing, Li, Jinghui
• Granted Patent: US 6,970,652 B2
• Time in Patent Office: Days
• US Class Current: 398/25
• CPC Class Codes: H04B 10/0795 Performance monitoring; Measurement of transmission parameters
• CPC Class Codes: H04B 10/07953 Monitoring or measuring OSNR, BER or Q
• CPC Class Codes: H04B 10/0799 Monitoring line transmitter or line receiver equipment

Abstract

According to the invention there is provided a method of controlling an optical communication system comprising an optical transmitter, an optical receiver and an optical fiber interconnecting the optical transmitter and the optical receiver, the method comprising determining the performance of the optical communication system and controlling at least one setting parameter of the optical transmitter according to the measured performance.

Claims

1. A method of controlling an optical communication system comprising an optical transmitter having at least one setting parameter, an optical receiver that measures at least one Raw System Performance Information (RSPI), and an optical fibre interconnecting the optical transmitter and the optical receiver, the method comprising the steps of:

i. measuring the RSPI;

ii. calculating at least one Performance Indicating Parameter (PIP) from the RSPI;

iii. controlling the at least one setting parameter of the optical transmitter according to the at least one PIP.

2. A method according to claim 1 applied to a single-span optical communication system.

3. A method according to claim 1 applied to a multiple-span optical communications system comprising the optical transmitter, the optical receiver, and at least two fibres and at least one optical amplifier, the at least two fibres interconnecting in sequence the optical transmitter, the at least one optical amplifier and the optical receiver.

4. A method according to claim 1, wherein the optical transmitter includes an EAM fed by a DA and an LD and the at least one setting parameter is one of the TEC of the EAM, the RF Signal Cross Point, the Swing Range and Bias Voltage of the DA.

5. A method according to claim 1, wherein the step of determining the performance comprises measuring raw system performance information (RSPI).

6. A method according to claim 1, wherein the controlling step is performed by a controller having an idle mode, an auto-setting mode and a dynamic control mode.

7. A method according to claim 6, wherein the auto-setting mode comprises a speed search stage, a fine tune stage, and a setting decision stage.

8. A method according to claim 7, wherein the speed search stage, comprises deciding upon a search range of the at least one setting parameter, calculating a plurality of search points, setting at least one setting parameter, determining the performance of the system and calculating the fine tune range.

9. A method according to claim 7 wherein the fine tune stage comprises increasing the search resolution based on the fine tune range, followed setting the at least one setting parameter, determining the performance of the system, generating a decision range from the performance and calculating final decision range.

10. A method according to claim 6, wherein the dynamic control mode of the controller comprises the following steps:

i. incrementally changing the at least one setting parameter of the optical transmitter according to a prediction algorithm;

ii. measuring a revised RSPI based on the incrementally changed setting parameter;

iii. calculating at least one revised PIP based on the revised RSPI;

iv. building at least one PIP matrix from multiple cycles of steps i., ii., and iii

v. adjusting the at least one setting parameter based on the at least one PIP matrix;

vi. repeating steps (i), (ii), (iii), (iv) and (v) until an indication is received by the controller for the dynamic control mode to stop.

16. An optical communications system according to claim 9 configured as a multiple-span optical communications system comprising the optical transmitter, the optical receiver, and at least two fibres and at least one optical amplifier, the at least two fibres interconnecting in sequence the optical transmitter, the at least one optical amplifier and the optical receiver.

11. A controller for an optical communication system comprising an optical transmitter, an optical receiver and an optical fibre interconnecting the optical transmitter and the optical receiver, the controller having means for receiving raw system performance information (RSPI) and means for processing the RSPI from which at least one performance indication parameter (PIP) is derived and controlling at least one setting parameter of the optical transmitter according to the processing of the RSPI.

12. A controller according to claim 11 adapted to control a single-span optical communication system.

13. A controller according to claim 11 adapted to control a multiple-span optical communications system comprising the optical transmitter, the optical receiver, and at least two fibres and at least one optical amplifier, the at least two fibres interconnecting in sequence the optical transmitter, the at least one optical amplifier and the optical receiver.

14. A controller according to claim 11 further adapted to carry out method steps as claimed in any one of claim 3.

15. An optical communication system comprising an optical transmitter, an optical receiver, an optical fibre interconnecting the optical transmitter and the optical receiver, and a feedback loop between the optical receiver and the optical transmitter, the feedback loop permitting control of at least one setting parameter of the optical transistor in accordance with information at the optical receiver indicating system performance.

17. An optical communications system according to claim 15 further adapted to carry out the method steps as claimed in claim 3.

18. A method of controlling an optical communication system comprising an optical transmitter, an optical receiver and an optical fibre interconnecting the optical transmitter and the optical receiver, the method comprising of determining the performance of the optical communication system and controlling at least one setting parameter of the optical transmitter according to the measured performance.

19. A method according to claim 18 applied to control a single span optical communication system.

20. A method according to claim 18 applied to a multiple-span optical communications system comprising the optical transmitter, the optical receiver, and at least two fibres and at least one optical amplifier, the at least two fibres interconnecting in sequence the optical transmitter, the at least one optical amplifier and the optical receiver.

21. A method according to claim 18 further comprising the steps of claim 3.