Optical distribution network system with large usable bandwidth for DBA

• US 20020027682A1
• Filed: 08/31/2001
• Published: 03/07/2002
• Est. Priority Date: 09/01/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Yoshida, Toshikazu, Asashiba, Yoshihiro, Ichibangase, Hiroshi, Iwasaki, Mitsuyoshi
• Granted Patent: US 7,020,162 B2
• Time in Patent Office: Days
• US Class Current: 398/9
• CPC Class Codes: H04L 2012/5605 Fibre
• CPC Class Codes: H04L 2012/5627 Fault tolerance and recovery
• CPC Class Codes: H04L 2012/5632 Bandwidth allocation
• CPC Class Codes: H04Q 11/0062 Network aspects
• 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 2011/0081 Fault tolerance; Redundancy; Recovery; Reconfigurability
• CPC Class Codes: H04Q 2011/0086 Network resource allocation, dimensioning or optimisation

Abstract

An optical distribution network system includes an OLT; a plurality of ONUs; a first optical network and a second optical network, one of which connects the OLT with the plurality of ONUs; and a bandwidth controller. The bandwidth controller apportions the plurality of ONUs between the first optical network and the second optical network, assigns a predetermined transmission bandwidth to each of the plurality of ONUs, and accepts a bandwidth change of the transmission bandwidth. It solves a problem of a conventional optical distribution network system in that the maximum bandwidth available by DBA (dynamic bandwidth assignment) is equal to the total transmission bandwidth of working side minus the sum total of the minimum cell rates of the ONUs, and hence it cannot secure a large usable bandwidth for DBA, when congestion of bandwidth increase takes place among the plurality of ONUs.

Claims

1. An optical distribution network system comprising:

an OLT (optical line termination);

a plurality of ONUs (optical network units);

a first optical network and a second optical network, one of which connects said OLT with said plurality of ONUs; and

bandwidth control means for apportioning said plurality of ONUs between said first optical network and said second optical network, for assigning a predetermined transmission bandwidth to each of said plurality of ONUs, and for accepting a bandwidth change of the transmission bandwidth.

2. The optical distribution network system according to claim 1, wherein when a failure occurs in one of said first optical network and said second optical network, said bandwidth control means assigns all transmission bandwidths of said ONUs to the other optical network.

3. The optical distribution network system according to claim 1, wherein when a failure occurs in a working side ONU of said plurality of ONUs, said bandwidth control means switches the working side ONU to a standby side, and switches a standby side ONU to the working side.

4. The optical distribution network system according to claim 3, wherein when apportionment balance is lost of said plurality of ONUs between said first optical network and said second optical network, said bandwidth control means carries out apportionment of said plurality of ONUs between said first optical network and said second optical network, again.

5. The optical distribution network system according to claim 1, wherein said bandwidth control means assigns a minimum cell rate to each of said plurality of ONUs.

6. The optical distribution network system according to claim 5, wherein said bandwidth control means apportions each of said plurality of ONUs to one of said first optical network and said second optical network such that a sum total of minimum cell rates of said ONUs in said first optical network becomes nearly equal to a sum total of minimum cell rates of said ONUs in said second optical network.

7. The optical distribution network system according to claim 5, wherein said bandwidth control means apportions each of said plurality of ONUs to one of said first optical network and said second optical network such that a sum total of peak cell rates of said ONUs in said first optical network becomes nearly equal to a sum total of peak cell rates of said ONUs in said second optical network.

8. The optical distribution network system according to claim 5, wherein said bandwidth control means apportions each of said plurality of ONUs to one of said first optical network and said second optical network such that a sum total of differences between peak cell rates and minimum cell rates of said ONUs in said first optical network becomes nearly equal to a sum total of differences between peak cell rates and minimum cell rates of said ONUs in said second optical network.

9. The optical distribution network system according to claim 5, wherein said bandwidth control means apportions each of said plurality of ONUs to one of said first optical network and said second optical network such that a sum total of established bandwidths of said ONUs in said first optical network becomes nearly equal to a sum total of established bandwidths of said ONUs in said second optical network.

10. An optical distribution network system comprising:

an OLT;

a plurality of ONUs;

a first optical network and a second optical network, one of which connects said OLT with said plurality of ONUs; and

bandwidth control means for apportioning a plurality of paths contained in said plurality of ONUs between said first optical network and said second optical network, for assigning a predetermined transmission bandwidth to each of said path, and for accepting a bandwidth change of the transmission bandwidth.

11. The optical distribution network system according to claim 10, wherein when a failure occurs in one of said first optical network and said second optical network, said bandwidth control means assigns all the paths contained in said plurality of ONUs to the other optical network.

12. The optical distribution network system according to claim 10, wherein when a failure occurs in a working side path of said plurality of paths, said bandwidth control means switches the working side path to a standby side, and switches a standby side path to the working side.

13. The optical distribution network system according to claim 12, wherein when apportionment balance is lost of said plurality of paths between said first optical network and said second optical network, said bandwidth control means carries out apportionment of said plurality of paths between said first optical network and said second optical network, again.

14. The optical distribution network system according to claim 10, wherein said bandwidth control means assigns a minimum cell rate to each of said plurality of paths.

15. The optical distribution network system according to claim 14, wherein said bandwidth control means apportions each of said plurality of paths to one of said first optical network and said second optical network such that a sum total of minimum cell rates of said paths in said first optical network becomes nearly equal to a sum total of minimum cell rates of said paths in said second optical network.

16. The optical distribution network system according to claim 14, wherein said bandwidth control means apportions each of said plurality of ONUs to one of said first optical network and said second optical network such that a sum total of peak cell rates of said paths in said first optical network becomes nearly equal to a sum total of peak cell rates of said paths in said second optical network.

17. The optical distribution network system according to claim 14, wherein said bandwidth control means apportions each of said plurality of paths to one of said first optical network and said second optical network such that a sum total of differences between peak cell rates and minimum cell rates of said paths in said first optical network becomes nearly equal to a sum total of differences between peak cell rates and minimum cell rates of said paths in said second optical network.

18. The optical distribution network system according to claim 14, wherein said bandwidth control means apportions each of said plurality of ONUs to one of said first optical network and said second optical network such that a sum total of established bandwidths of said paths in said first optical network becomes nearly equal to a sum total of established bandwidths of said paths in said second optical network.