Distributed cable modem termination system (CMTS) architecture implementing a media access control chip

• US 20040045037A1
• Filed: 08/27/2002
• Published: 03/04/2004
• Est. Priority Date: 08/27/2002
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Burrell, Paul Eugene, Danzig, Joel I., Cummings, Scott Andrew
• Application Number:
  US10/228,192
• Publication Number:
  US 20040045037A1
• Time in Patent Office: Days
• US Class Current: 725/129
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 69/32 Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
• CPC Class Codes: H04L 69/323 in the physical layer [OSI layer 1]
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 69/325 in the network layer [OSI layer 3], e.g. X.25 H04L69/16 takes precedence
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A distributed cable modem termination system (CMTS) in a hybrid fiber/coaxial (HFC) plant. The distributed CMTS comprises a network layer, at least one media access control layer, and at least one physical layer. The media access control layer implements a media access control chip. The media access control chip interfaces with the physical layer to provide timing to maintain components within the physical layer. At least one physical layer is connected to a respective at least one media access control layer. The network layer, media access control layer, and physical layer each function as separate modules. The media access control chip does not require packet level media access control functions to be implemented in the same physical location. This enables the network layer to be in a separate component location of the HFC plant from the at least one media access control layer and the at least one physical layer, yet physically connected throughout the HFC plant.

Claims

1. A distributed cable modem termination system in a hybrid fiber/coaxial (HFC) plant, comprising:

a network layer;

at least one media access control layer, each of said one or more media access control layer implementing a media access control chip; and

at least one physical layer, said at least one physical layer interfacing to said media access control chip in said at least one media access control layer, wherein said at least one physical layer is connected to a respective at least one media access control layer;

wherein said network layer, said at least one media access control layer, and said at least one physical layer each function as separate modules, enabling said network layer to be in a separate component location of said HFC plant from said at least one media access control layer and said at least one physical layer, wherein said network layer is connected to said at least one media access control layer.

2. The distributed cable modem termination system of claim 1, wherein said media access control chip provides timing signals to maintain components in said at least one physical layer.

3. The distributed cable modem termination system of claim 2, wherein said components in said at least one physical layer include a downstream module and an upstream module.

4. The distributed cable modem termination system of claim 1, wherein said media access control chip is coupled to a first buffer for buffering upstream packets and to a central processing unit (CPU), said CPU coupled to a second buffer, wherein said CPU extracts and processes said buffered upstream packets for transmission to said network layer via a network interface subsystem coupled to said CPU and to said network layer.

5. The distributed cable modem termination system of claim 1, wherein said network layer is located in a fiber portion of said HFC plant and said at least one media access control layer and said at least one physical layer are co-located in a fiber portion of said HFC plant to increase bandwidth allocations to one or more cable modems located in a coaxial portion of said HFC plant.

6. The distributed cable modem termination system of claim 1, wherein said network layer is located in a fiber portion of said HFC plant and said at least one media access control layer and said at least one physical layer are co-located in a coaxial portion of said HFC plant to increase bandwidth allocations to one or more cable modems located in a coaxial portion of said HFC plant.

7. The distributed cable modem termination system of claim 1, wherein said network layer is placed in a hub of a fiber portion of said HFC plant and said at least one media access control layer and said at least one physical layer are co-located in one or more fiber nodes of said HFC plant to increase bandwidth allocations to one or more cable modems located in a coaxial portion of said HFC plant.

8. The distributed cable modem termination system of claim 1, wherein said network layer is placed in a hub of a fiber portion of said HFC plant and said at least one media access control layer and said at least one physical layer are co-located in one or more post fiber nodes of said HFC plant to increase bandwidth allocations to one or more cable modems located in a coaxial portion of said HFC plant.

9. The distributed cable modem termination system of claim 8, wherein said hub is a primary hub.

10. The distributed cable modem termination system of claim 8, wherein said hub is a secondary hub.

11. The distributed cable modem termination system of claim 1, wherein said network layer is placed in a headend of said HFC plant and said at least one media access control layer and said at least one physical layer are co-located in one or more post fiber nodes of said HFC plant to increase bandwidth allocations to one or more cable modems.

12. The distributed cable modem termination system of claim 1, wherein said network layer is placed in a headend of said HFC plant and said one or more media access control layers and said one or more physical layers are co-located in one or more fiber nodes or one or more post fiber nodes of said HFC plant to increase bandwidth allocations to one or more cable modems.

13. The distributed cable modem termination system of claim 1, wherein said network layer is placed in a hub of a fiber portion of said HFC plant and said at least one media access control layer and said at least one physical layer are co-located in one or more fiber nodes or one or more post fiber nodes of said HFC plant to increase bandwidth allocations to one or more cable modems.

14. The distributed cable modem termination system of claim 13, wherein said hub is a primary hub.

15. The distributed cable modem termination system of claim 13, wherein said hub is a secondary hub.

16. The distributed cable modem termination system of claim 1, wherein said HFC plant comprises a headend, a primary hub, a secondary hub, one or more fiber nodes, one or more post fiber nodes, one or more taps, and one or more cable modems, wherein said network layer is placed in one of said headend, said primary hub, and said secondary hub, and said at least one media access control layer and said at least one physical layer are co-located in said one or more fiber nodes to increase bandwidth allocations to one or more cable modems.

17. The distributed cable modem termination system of claim 1, wherein said HFC plant comprises a headend, a primary hub, a secondary hub, one or more fiber nodes, one or more post fiber nodes, one or more taps, and one or more cable modems, wherein said network layer is placed in one of said headend, said primary hub, and said secondary hub, and said at least one media access control layer and said at least one physical layer are co-located in said one or more post fiber nodes to increase bandwidth allocations to one or more cable modems.

18. The distributed cable modem termination system of claim 1, wherein said HFC plant comprises a headend, a primary hub, a secondary hub, one or more fiber nodes, one or more post fiber nodes, one or more taps, and one or more cable modems, wherein said network layer is placed in one of said headend, said primary hub, and said secondary hub, and said at least one media access control layer and said at least one physical layer are co-located in said one or more fiber nodes or said one or more post fiber nodes to increase bandwidth allocations to one or more cable modems.

19. A distributed cable modem termination system in a hybrid fiber/coaxial (HFC) plant, comprising:

a network layer;

at least one media access control layer, said at least one media access control layer including a media access control chip; and

at least one physical layer, said at least one physical layer coupled to said media access control chip in said at least one media access control layer for providing timing signals to maintain components in each of said one or more physical layer, wherein said at least one physical layer is connected to a respective at least one media access control layer;

wherein said network layer, said at least one media access control layer, and said at least one physical layer each function as separate modules, enabling said network layer to be in a separate component location from said at least one media access control layer and said at least one physical layer of said HFC plant, yet having said network layer connected to said at least one media access control layer, wherein said at least one media access control layer is co-located with said at least one physical layer.

20. The distributed cable modem termination system of claim 19, wherein said components in said at least one physical layer include a downstream module and an upstream module.

21. The distributed cable modem termination system of claim 19, wherein said media access control chip is coupled to a first buffer and a central processing unit (CPU), and said CPU is coupled to a second buffer and a network interface subsystem, wherein said media access control chip buffers upstream packets and said CPU extracts and processes said buffered packets for transmission to said network layer via said network interface subsystem.

22. The distributed cable modem termination system of claim 19, wherein said network layer is placed in a headend and said at least one media access control layer is co-located with said at least one physical layer in a hub of said HFC plant to increase bandwidth allocations to one or more cable modems.

23. The distributed cable modem termination system of claim 22, wherein said hub is a primary hub.

24. The distributed cable modem termination system of claim 22, wherein said hub is a secondary hub.

25. The distributed cable modem termination system of claim 19, wherein said network layer is placed in one of a headend and a hub and said at least one media access control layer is co-located with said at least one physical layer in one or more fiber nodes of said HFC plant to increase bandwidth allocations to one or more cable modems.

26. The distributed cable modem termination system of claim 19, wherein said network layer is placed in one of a headend and a hub and said at least one media access control layer and said at least one physical layer are located in one or more post fiber nodes of said HFC plant to increase bandwidth allocations to one or more cable modems.