WAVELENGTH CONFIGURATION METHOD AND APPARATUS FOR MULTI-WAVELENGTH PASSIVE OPTICAL NETWORK, AND MULTI-WAVELENGTH PASSIVE OPTICAL NETWORK SYSTEM

• US 20150098704A1
• Filed: 12/13/2014
• Published: 04/09/2015
• Est. Priority Date: 06/13/2012
• Status: Active Grant

• Current Assignee: Apex Net LLC (IP Edge LLC)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: GAO, Bo, LIN, Huafeng, GAO, Jianhe, YE, Fei
• Granted Patent: US 9,647,791 B2
• Time in Patent Office: Days
• US Class Current: 398/68
• CPC Class Codes: H04B 10/27 Arrangements for networking
• CPC Class Codes: H04J 14/0232 for downstream transmission
• CPC Class Codes: H04J 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/0247 Sharing one wavelength for at least a group of ONUs
• CPC Class Codes: H04J 14/025 using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0252 Sharing one wavelength for at least a group of ONUs, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0257 Wavelength assignment algorithms
• CPC Class Codes: H04J 14/0258 Wavelength identification or labelling
• CPC Class Codes: H04J 14/0267 Optical signaling or routing
• CPC Class Codes: H04J 14/0269 using tables for routing
• CPC Class Codes: H04J 14/0275 using an optical service channel
• CPC Class Codes: H04J 14/0282 WDM tree architectures

Abstract

The present application provides a wavelength configuration method for a multi-wavelength passive optical network, which includes: scanning, by an ONU, a downstream receiving wavelength, and receiving, downstream wavelength information of each downstream wavelength channel that is broadcast by an OLT separately through each downstream wavelength channel of a multi-wavelength PON system; establishing, by the ONU, a downstream receiving wavelength mapping table, where an entry of the downstream receiving wavelength mapping table includes downstream receiving wavelength information, drive current information of a downstream optical receiver and receiving optical physical parameter information of the ONU; selecting, by the ONU, one downstream wavelength from the downstream wavelength information broadcast by the OLT, and setting, according to the drive current information of the downstream optical receiver recorded in a related entry of the downstream receiving wavelength mapping table, an operating wavelength of the downstream optical receiver to the selected downstream wavelength.

Claims

1. A wavelength configuration method for a multi-wavelength passive optical network PON, comprising:

scanning, by an optical network unit ONU, a downstream receiving wavelength, and receiving, during the process of scanning the downstream receiving wavelength, downstream wavelength information of each downstream wavelength channel that is broadcast by an optical line terminal OLT separately through each downstream wavelength channel of a multi-wavelength PON system;

establishing, by the ONU, a downstream receiving wavelength mapping table according to the downstream wavelength information, wherein an entry of the downstream receiving wavelength mapping table comprises downstream receiving wavelength information, drive current information of a downstream optical receiver, and a receiving optical physical parameter of the ONU; and

selecting, by the ONU, one downstream wavelength from the downstream wavelength information broadcast by the OLT, and setting, according to the drive current information of the downstream optical receiver recorded in a related entry of the downstream receiving wavelength mapping table, an operating wavelength of the downstream optical receiver to the selected downstream wavelength.

2. The wavelength configuration method according to claim 1, wherein the establishing, by the ONU, a downstream receiving wavelength mapping table according to the downstream wavelength information comprises:

detecting, by the ONU, a receiving optical current of the ONU, or receiving optical power of the ONU, or a received signal strength indication RSSI during the process of scanning the downstream receiving wavelength, and searching for a peak value of the receiving optical current of the ONU, or a peak value of the receiving optical power of the ONU, or an RSSI peak value; and

when the peak value of the receiving optical current of the ONU, or the peak value of the receiving optical power of the ONU, or the RSSI peak value is searched out, recording, by the ONU, a current drive current of the downstream optical receiver and downstream wavelength information of a downstream wavelength channel corresponding to the peak value of the receiving optical current of the ONU, or the peak value of the receiving optical power of the ONU, or the RSSI peak value, and establishing a downstream receiving wavelength mapping entry according to the foregoing three parameters.

3. The wavelength configuration method according to claim 2, further comprising:

scanning, by the ONU, an upstream sending wavelength, and sending a registration request to the OLT in a registration authorization timeslot allocated by the OLT; and

determining whether an ONU identifier allocation message sent by the OLT is received, and if the ONU identifier allocation message sent by the OLT is not received, sending, in a next registration authorization timeslot allocated by the OLT, the registration request to the OLT again until the ONU identifier allocation message is successfully received.

4. The wavelength configuration method according to claim 3, wherein the scanning, by the ONU, an upstream sending wavelength, and sending a registration request to the OLT in a registration authorization timeslot allocated by the OLT comprises:

selecting, by the ONU, one boundary value from a value range of drive currents supported by an upstream optical transmitter of the ONU as an initial current value, and adjusting a drive current of the upstream optical transmitter by using a preset variation so as to perform a progressive increase or decrease; and

sending, by the ONU and within the registration authorization timeslot provided by the OLT for the ONU, the ONU registration request to the OLT according to an upstream sending wavelength corresponding to a drive current value to which the drive current of the upstream optical transmitter is currently adjusted.

5. The wavelength configuration method according to claim 4, further comprising:

detecting, by the ONU according to the downstream receiving wavelength mapping table, whether a drift occurs on a downstream receiving wavelength of the downstream optical receiver of the ONU, and calibrating the downstream receiving wavelength when the drift occurs.

6. The wavelength configuration method according to claim 1, further comprising:

receiving, by the ONU, an upstream sending wavelength adjustment instruction sent by the OLT, and fine-tuning an upstream sending wavelength of an upstream optical transmitter according to the upstream sending wavelength adjustment instruction, so that the OLT detects a receiving optical physical parameter of the OLT and establishes an upstream receiving wavelength mapping table, wherein an entry of the upstream receiving wavelength mapping table comprises upstream receiving wavelength information, ONU sequence number information, and the receiving optical physical parameter of the OLT.

7. The wavelength configuration method according to claim 6, further comprising:

receiving, by the ONU, upstream receiving wavelength information delivered by the OLT after the upstream receiving wavelength mapping table is established, and establishing an upstream sending wavelength mapping table according to the upstream receiving wavelength information, wherein the upstream sending wavelength mapping table comprises upstream sending wavelength information and drive current information of the upstream optical transmitter.

8. The wavelength configuration method according to claim 7, wherein when receiving the downstream wavelength information broadcast by the OLT, the ONU further receives upstream wavelength information that is broadcast by the OLT separately through each downstream wavelength channel and is available for ONU registration.

9. The wavelength configuration method according to claim 8, further comprising:

querying, by the ONU according to the upstream wavelength information that is available for ONU registration, the drive current information of the upstream optical transmitter recorded in a related entry of the upstream sending wavelength mapping table, and setting the upstream sending wavelength of the upstream optical transmitter according to the drive current information.

10. The wavelength configuration method according to claim 6, further comprising:

monitoring, by the OLT according to the upstream receiving wavelength mapping table, whether a drift occurs on an upstream sending wavelength of the ONU, and instructing the ONU to calibrate the upstream sending wavelength when the drift occurs.

11. A wavelength configuration apparatus for a multi-wavelength passive optical network PON, comprising:

a receiving module, configured to scan a downstream receiving wavelength, and receive, during the process of scanning the downstream receiving wavelength, downstream wavelength information of each downstream wavelength channel that is broadcast by an optical line terminal OLT separately through each downstream wavelength channel of a multi-wavelength PON system;

a wavelength mapping table establishing module, configured to establish a downstream receiving wavelength mapping table according to the downstream wavelength information, wherein an entry of the downstream receiving wavelength mapping table comprises downstream receiving wavelength information, drive current information of a downstream optical receiver, and a receiving optical physical parameter of an ONU; and

a wavelength configuration module, configured to select one downstream wavelength from the downstream wavelength information broadcast by the OLT, and set, according to the drive current information of the downstream optical receiver recorded in a related entry of the downstream receiving wavelength mapping table, an operating wavelength of the downstream optical receiver to the selected downstream wavelength.

12. The wavelength configuration apparatus according to claim 11, wherein the wavelength mapping table establishing module comprises:

a peak value searching unit, configured to search for a peak value of a receiving optical current of the ONU, or a peak value of receiving optical power of the ONU, or an RSSI peak value from detected receiving optical current of the ONU, or receiving optical power of the ONU, or received signal strength indication during the process of scanning the downstream receiving wavelength; and

an entry establishing module, configured to;

when the peak value searching unit searches out the peak value of the receiving optical current of the ONU, or the peak value of the receiving optical power of the ONU, or the RSSI peak value, record a current drive current of the downstream optical receiver and downstream wavelength information of a downstream wavelength channel corresponding to the peak value of the receiving optical current of the ONU, or the peak value of the receiving optical power of the ONU, or the RSSI peak value, and establish a downstream receiving wavelength mapping entry according to the foregoing three parameters.

13. The wavelength configuration apparatus according to claim 12, further comprising:

a sending module, configured to scan an upstream sending wavelength, and send a registration request to the OLT in a registration authorization timeslot allocated by the OLT; and

a control module, configured to;

determine whether the receiving module receives an ONU identifier allocation message sent by the OLT; and

if the receiving module does not receive the ONU identifier allocation message sent by the OLT, control the sending module to send the registration request to the OLT again in a next registration authorization timeslot allocated by the OLT, until the receiving module successfully receives the ONU identifier allocation message.

14. The wavelength configuration apparatus according to claim 13, wherein the sending module comprises:

a drive current adjusting unit, configured to select one boundary value from a value range of drive currents supported by an upstream optical transmitter as an initial current value, and adjust a drive current of the upstream optical transmitter by using a preset variation so as to perform a progressive increase or decrease; and

a sending unit, configured to send, within the registration authorization timeslot provided by the OLT for the ONU, an ONU registration request to the OLT according to an upstream sending wavelength corresponding to a drive current value to which the drive current of the upstream optical transmitter is currently adjusted.

15. The wavelength configuration apparatus according to claim 14, further comprising:

a wavelength calibrating module, configured to detect, according to the downstream receiving wavelength mapping table, whether a drift occurs on a downstream receiving wavelength of the downstream optical receiver of the ONU, and calibrate the downstream receiving wavelength when the drift occurs.

16. The wavelength configuration apparatus according to claim 14, wherein,

the receiving module is further configured to receive an upstream sending wavelength adjustment instruction sent by the OLT;

and

the sending module is further configured to fine-tune the upstream sending wavelength of the upstream optical transmitter according to the upstream wavelength adjustment instruction, so that the OLT detects a receiving optical current of the OLT and establishes an upstream receiving wavelength mapping table.

17. The wavelength configuration apparatus according to claim 16, wherein,

the receiving module is further configured to receive upstream receiving wavelength information delivered by the OLT after the upstream receiving wavelength mapping table is established;

and

the wavelength mapping table establishing module is further configured to establish an upstream sending wavelength mapping table according to the upstream receiving wavelength information, wherein the upstream sending wavelength mapping table comprises upstream sending wavelength information and drive current information of the upstream optical transmitter.

18. The wavelength configuration apparatus according to claim 17, wherein,

the receiving module is further configured to:

when the downstream wavelength information broadcast by the OLT is received, receive upstream wavelength information that is broadcast by the OLT separately through each downstream wavelength channel and is available for ONU registration.

19. The wavelength configuration apparatus according to claim 18, wherein,

the wavelength configuration module is further configured to query, according to the upstream wavelength information that is available for ONU registration, the drive current information of the upstream optical transmitter recorded in a related entry of the upstream sending wavelength mapping table, and set the upstream sending wavelength of the upstream optical transmitter according to the drive current information.

20. A multi-wavelength passive optical network PON system, comprising at least one optical line terminal OLT and multiple optical network units ONUs, wherein the at least one OLT is connected to the multiple ONUs in a point-to-multipoint manner by using an optical distribution network, and the ONUs comprise the wavelength configuration apparatus for a multi-wavelength PON according to claim 11.