Method and system for power management control in passive optical networks

• US 20080056720A1
• Filed: 07/17/2007
• Published: 03/06/2008
• Est. Priority Date: 08/30/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadlight, Ltd. (Broadcom, Inc.)
• Inventors: Sitton, Gal, Harel, Jacob, Naaman, Ifat
• Granted Patent: US 7,925,164 B2
• Time in Patent Office: Days
• US Class Current: 398/98
• CPC Class Codes: H04B 10/27 Arrangements for networking
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0049 Crosstalk reduction; Noise; Power budget

Abstract

An optical line terminal (OLT) performs power management control in a passive optical network (PON) by acquiring a respective reception level for each optical network unit (ONU) in the PON and maintaining a reception table that stores the respective reception level for each ONU. Prior to receiving a burst signal from an ONU, it sets a reception threshold of an optical receiver at the OLT with the reception level of the ONU.

Claims

1. A method for power management control in a passive optical network (PON), the method comprising:

acquiring by an optical line terminal (OLT) a respective reception level for each optical network unit (ONU) in the PON;

maintaining in the OLT a reception table that stores the respective reception level for each ONU; and

prior to receiving a burst signal from an ONU, setting a reception threshold of an optical receiver at the OLT with the reception level of the ONU.

2. The method of claim 1, wherein the reception level is acquired during a ranging window in a set-up mode operation of the PON.

3. The method of claim 2, further comprising:

receiving at least an identification (ID) number of the ONU;

setting the reception threshold to a lowest possible energy level;

measuring the power of a received burst signal, if a burst signal is received during the ranging window; and

saving the power of the received signal together with the respective ID number of the ONU in the reception table.

4. The method of claim 3, wherein the lowest possible energy level allows fast detection of the burst signal.

5. The method of claim 4, wherein the measured power of the received signal is the reception level of the ONU.

6. The method of claim 1, wherein setting the reception level further comprises:

prior to receiving a burst signal from an ONU, retrieving the reception level from the reception table according the ID number of the ONU; and

setting the reception threshold to the reception level.

7. The method of claim 6, further comprising:

measuring the power of the received burst signal; and

updating the reception table with the measured optical power of the received burst signal.

8. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform a method for power management control in a passive optical network (PON), the method comprising:

acquiring by an optical line terminal (OLT) a respective reception level for each optical network unit (ONU) in the PON;

maintaining in the OLT a reception table that stores the respective reception level for each ONU; and

prior to receiving a burst signal from an ONU, setting a reception threshold of an optical receiver at the OLT with the reception level of the ONU.

9. The program storage device of claim 8, wherein the reception level is acquired during a ranging window in a set-up mode operation of the PON.

10. The program storage device of claim 9, wherein the method further comprises:

receiving at least an identification (ID) number of the ONU;

setting the reception threshold to a lowest possible energy level;

measuring the power of a received burst signal, if such signal is received during the ranging window; and

saving the power of the received signal together with the respective ID number of the ONU in the reception table.

11. The program storage device of claim 10, wherein the lowest possible energy level allows fast detection of the burst signal.

12. The program storage device of claim 11, wherein the measured power of the received signal is the reception level of the ONU.

13. The program storage device of claim 8, wherein setting the reception level further comprises:

prior to receiving a burst signal from an ONU, retrieving the reception level from the reception table according the ID number of the ONU; and

setting the reception threshold to the reception level.

14. The program storage device of claim 13, wherein the method further comprises:

measuring the power of the received burst signal; and

updating the reception table with the measured optical power of the received burst signal.

15. An optical line terminal (OLT) controller for power management control in a passive optical network (PON), said OLT comprising:

a power management controller for setting a reception threshold of an optical receiver with a reception level of an optical network unit (ONU), prior to receiving a burst signal from the ONU; and

a memory for storing a reception table that maintains the respective reception level for each of the ONUs.

16. The OLT controller of claim 15, wherein the power management controller is further adapted to acquire the reception level of each ONU.

17. The OLT controller of claim 16, wherein the power management controller is adapted to acquire the reception level during a ranging window in a set-up mode of operation of the PON.

18. The OLT controller of claim 17, wherein the power management controller is adapted to:

receive at least an identification (ID) number of the ONU;

set the reception threshold to a lowest possible energy level;

measure the power of a received burst signal, if such signal is received during the ranging window; and

save the power of the received signal together with the respective ID number of the ONU in the memory.

19. The OLT controller of claim 18, wherein the lowest possible energy level allows fast detection of the burst signal.

20. The OLT controller of claim 19, wherein the measured power of the received signal is the reception level of the ONU.

21. The OLT controller of claim 15, wherein power management controller is adapted to retrieve the reception level from the reception table according the ID number of the ONU prior to receiving a burst signal from an ONU and to set the reception threshold to the reception level.

22. The OLT controller of claim 21, wherein the power management controller is further adapted to measure the power of the received burst signal;

and update the memory with the measured optical power of the received burst signal.

23. The OLT controller of claim 15, wherein the PON is at least one of:

an Ethernet PON (EPON) a Gigabit PON (GPON).