METHOD AND APPARATUS FOR LINK SHARING AMONG MULTIPLE EPONS

• US 20100254706A1
• Filed: 03/29/2010
• Published: 10/07/2010
• Est. Priority Date: 04/01/2009
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Teknovus Inc. (Broadcom, Inc.)
• Inventors: Hirth, Ryan E., Boyd, Edward W.
• Granted Patent: US 8,600,234 B2
• Time in Patent Office: Days
• US Class Current: 398/48
• CPC Class Codes: H04J 14/0239 in WDM-PON sharing multiple downstream wavelengths for groups of optical network units [ONU], e.g. multicasting wavelengths
• 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 14/026 using WDM channels of different transmission rates
• CPC Class Codes: H04J 14/0282 WDM tree architectures
• 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 2011/0064 Arbitration, scheduling or medium access control aspects

Abstract

One embodiment of the present invention provides an optical line terminal (OLT) in an Ethernet passive optical network (EPON). The OLT includes a number of bi-direction optical transceivers. At least one bi-direction optical transceiver is coupled to an optical network unit (ONU) group that includes a number of ONUs. The OLT further includes a first downstream media access control (MAC) interface configured to provide a first downstream control signal and a splitter configured to split the first downstream control signal to a number of sub-signals. At least one sub-signal is configured to control downstream transmission of a corresponding bi-direction optical transceiver to a corresponding ONU-group.

Claims

1. An optical line terminal (OLT) in an Ethernet passive optical network (EPON), comprising:

a number of bi-direction optical transceivers, wherein at least one bi-direction optical transceiver is coupled to an optical network unit- (ONU-) group comprising a number of ONUs;

a first downstream media access control (MAC) interface configured to provide a first downstream control signal; and

a splitter configured to split the first downstream control signal to a number of sub-signals, wherein at least one sub-signal is configured to control downstream transmission of a corresponding bi-direction optical transceiver to a corresponding ONU-group.

2. The OLT of claim 1, further comprising a number of individual upstream MAC interfaces, wherein at least one individual upstream MAC interface is configured to communicate with a corresponding ONU-group.

3. The OLT of claim 2, wherein the at least one individual upstream MAC interface is configured to arbitrate upstream transmissions from ONUs belonging to a corresponding ONU-group.

4. The OLT of claim 2, wherein different individual upstream MAC interfaces separately arbitrate upstream transmissions from different ONU-groups, thereby facilitating concurrent upstream transmission to the OLT from ONUs belonging to the different ONU-groups.

5. The OLT of claim 2, wherein the individual upstream MAC interfaces are configured to allocate discovery slots to respective ONU-groups, and wherein the discovery slots for the ONU-groups are aligned in time.

6. The OLT of claim 3, wherein the downstream transmission and the upstream transmission are carried on two different wavelengths.

7. The OLT of claim 2, wherein the first downstream MAC interface and at least one individual upstream MAC interface are configured to operate at two different data rates.

8. The OLT of claim 2, wherein the first downstream MAC interface and at least one individual upstream MAC interface are configured to operate at a same data rate.

9. The OLT of claim 2, further comprising a shared upstream MAC interface configured to interface with more than one of the ONU-groups.

10. The OLT of claim 9, further comprising a merger configured to:

merge upstream transmissions from the more than one ONU-groups; and

send the merged transmissions to the shared upstream MAC interface.

11. The OLT of claim 9, wherein upstream transmissions to a respective individual upstream MAC interface and upstream transmissions to the shared upstream MAC interface are carried on two different wavelengths over a single strand of fiber.

12. The OLT of claim 1, further comprising an optical transmitter and a second downstream MAC interface dedicated to an ONU-group, wherein the second downstream MAC is configured to control downstream transmission of the optical transmitter to the ONU-group.

13. The OLT of claim 12, wherein downstream transmissions from the bi-direction optical transceiver and the optical transmitter are coupled to a single strand of fiber via a wavelength division multiplexing (WDM) coupler.

14. An Ethernet passive optical network (EPON) system, comprising;

a number of optical network unit- (ONU-) groups, wherein at least one ONU-group includes a number of ONUs; and

an optical line terminal (OLT), wherein the OLT comprises;

a number of bi-direction optical transceivers, wherein at least one bi-direction optical transceiver is coupled to an ONU-group;

a first downstream media access control (MAC) interface configured to provide a first downstream control signal; and

a splitter configured to split the first downstream control signal to a number of sub-signals, wherein at least one sub-signal is configured to control downstream transmission of a corresponding bi-direction optical transceiver to a corresponding ONU-group.

15. The EPON system of claim 14, wherein the OLT further comprises a number of individual upstream MAC interfaces, and wherein at least one individual upstream MAC interface is configured to communicate with a corresponding ONU-group.

16. The EPON system of claim 15, wherein the individual upstream MAC interface is configured to arbitrate upstream transmissions from the ONUs belonging to a corresponding ONU-group.

17. The EPON system of claim 15, wherein different individual upstream MAC interfaces separately arbitrate upstream transmissions from different ONU-groups, thereby facilitating concurrent upstream transmission to the OLT from ONUs belonging to the different ONU-groups.

18. The EPON system of claim 15, wherein the individual upstream MAC interfaces are configured to allocate discovery slots to respective ONU-groups, and wherein the discovery slots for the ONU-groups are aligned in time.

19. The EPON system of claim 16, wherein the downstream transmission and the upstream transmissions are carried on two different wavelengths.

20. The EPON system of claim 15, wherein the first downstream MAC interface and at least one individual upstream MAC interface are configured to operate at two different data rates.

21. The EPON system of claim 15, wherein the first downstream MAC interface and at least one individual upstream MAC interface are configured to operate at a same data rate.

22. The EPON system of claim 15, wherein the OLT further comprises a shared upstream MAC interface configured to interface with more than one of the ONU-groups.

23. The EPON system of claim 22, wherein the OLT further comprises a merger configured to:

merge upstream transmissions from the more than one ONU-groups; and

send the merged transmissions to the common upstream MAC interface.

24. The EPON system of claim 22, further comprising a wavelength division multiplexing (WDM) coupler configured to decouple upstream transmissions to a respective individual upstream MAC interface and upstream transmissions to the shared upstream MAC interface to two separate strands of fibers, thereby facilitating receiving the upstream transmissions at different optical transceivers.

25. The EPON system of claim 14, wherein the OLT further comprises an optical transmitter and a second downstream MAC interface dedicated to an ONU-group, wherein the second downstream MAC is configured to control downstream transmission of the optical transmitter to the ONU-group.

26. The EPON system of claim 25, further comprising a wavelength division multiplexing (WDM) coupler configured to couple downstream transmissions from the bi-direction optical transceiver and the optical transmitter to a single strand of fiber.