MiniMAC implementation of a distributed cable modem termination system (CMTS) architecture

• US 20040045032A1
• Filed: 08/27/2002
• Published: 03/04/2004
• Est. Priority Date: 08/27/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Burrell, Pual E., Cummings, Scott A., Danzig, Joel I.
• Granted Patent: US 7,551,610 B2
• Time in Patent Office: Days
• US Class Current: 725/111
• CPC Class Codes: H04L 12/2801 Broadband local area networks

Abstract

A miniMAC implementation of a distributed CMTS in a hybrid fiber/coaxial (HFC) plant. The distributed CMTS comprises at least one network layer, at least one media access layer, and one or more physical layers. The at least one media access layer includes one or more miniMAC layers. The one or more miniMAC layers are remotely located from a remaining part of the at least one media access layer. The at least one network layer, the remaining part of the at least one media access layer, the one or more miniMAC layers, and the one or more physical layers each function as separate modules, enabling each layer to be in separate component locations of the HFC plant, yet having the at least one network layer connected to the remaining part of the at least one media access layer, the at least one media access layer connected to each of the one or more miniMAC layers, and each of the one or more physical layers connected to each of the one or more miniMAC layers. The one or more miniMAC layers are located in close proximity to the one or more physical layers in the HFC plant. The one or more miniMAC layers convert digital bit streams into packets and maintain timing constraints between the one or more miniMAC layers and the one or more physical layers.

Claims

1. A miniMAC layer in a distributed cable modem termination system (CMTS), comprising:

an upstream interface for buffering bit streams received from a physical layer of said CMTS;

a network interface for converting the buffered bit streams from said upstream interface into a packet interface; and

a digital network interface for converting said packet interface into a packet format acceptable by an exterior network coupled to said distributed CMTS.

2. The miniMAC layer of claim 1, wherein said digital network interface converts packets received by said exterior network coupled to said distributed CMTS into said packet interface and said network interface separates the packets,

wherein said miniMAC layer further comprises:

a map processor for receiving packets categorized as maps from said network interface, wherein said maps are used to allocate bandwidth to cable modems in a cable modem system for upstream transmissions; and

a downstream interface for receiving said packets categorized as maps from said map processor and for receiving all remaining packets from said network interface, wherein said downstream interface converts each packet into bit streams for transmission to said physical layer.

3. The miniMAC layer of claim 2, wherein said map processor sends said maps to said upstream interface to enable said upstream interface to identify which of said cable modems in said cable modem system sent said stream of bits.

4. The miniMAC layer of claim 1, wherein said miniMAC layer includes interfacing circuitry to maintain timing constraints between said miniMAC layer and said physical layer in said distributed CMTS.

5. The miniMAC layer of claim 1, wherein said miniMAC layer is in close proximity to said physical layer in said distributed CMTS.

6. The miniMAC layer of claim 1, wherein said miniMAC layer enables said physical layer to be positioned deep into a hybrid fiber/coax plant, closer to a plurality of cable modems to increase bandwidth allocations to said plurality of cable modems.

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

at least one network layer;

at least one media access layer, wherein said media access layer includes one or more miniMAC layers, wherein said one or more miniMAC layers are remotely located from a remaining part of said at least one media access layer; and

one or more physical layers,

wherein said at least one network layer, said remaining part of said at least one media access layer, said one or more miniMAC layers, and said one or more physical layers each function as separate modules, enabling each layer to be in separate component locations of said HFC plant, yet having said at least one network layer connected to said remaining part of said at least one media access layer, said at least one media access layer connected to each of said one or more miniMAC layers, and each of said one or more physical layers connected to each of said one or more miniMAC layers,

wherein said one or more miniMAC layers are located in close proximity to said one or more physical layers in said HFC plant, said one or more miniMAC layers for converting digital bit streams into packets and maintaining timing constraints between said one or more miniMAC layers and said one or more physical layers.

8. The distributed cable modem termination system of claim 7, wherein said at least one network layer and said remaining part of said at least one media access layer are located in a fiber portion of said HFC plant and said one or more miniMAC layers and said one or more physical layers are located in a coaxial portion of said HFC plant to increase bandwidth allocations to one or more cable modems.

9. The distributed cable modem termination system of claim 7, wherein said at least one network layer and said remaining part of said at least one media access layer are located in a headend of said HFC plant and said one or more miniMAC layers and said one or more physical layers are located in a coaxial portion of said HFC plant to increase bandwidth allocations to one or more cable modems.

10. The distributed cable modem termination system of claim 7, wherein each of said one or more miniMAC layers and each of said one or more physical layers are co-located in said HFC plant.

11. The distributed cable modem termination system of claim 7, wherein said at least one network layer and said remaining part of said at least one media access layer are placed in hubs of said fiber portion of said HFC plant and said one or more miniMAC layers and said one or more physical layers are placed in one or more 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 7, wherein said at least one network layer and said remaining part of said at least one media access layer are placed in hubs of said fiber portion of said HFC plant, said one or more miniMAC layers are placed in said fiber nodes of said HFC plant, and said one or more physical layers are placed in 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 7, wherein said at least one network layer is placed in a headend and said remaining part of said at least one media access layer is placed in a hub of said fiber portion of said HFC plant, and said one or more miniMAC layers and said one or more physical layers are co-located in one or more fiber nodes or in 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 7, wherein said at least one network layer and said remaining part of said at least one media access layer are co-located in a headend or a hub of said fiber portion of said HFC plant and said one or more miniMAC layers and said one or more physical layers are co-located in one or more fiber nodes or in one or more post fiber nodes of said HFC plant to increase bandwidth allocations to one or more cable modems.

15. The distributed cable modem termination system of claim 7, wherein said at least one network layer is placed in one of said headend and said hub in a fiber portion of said HFC plant.

16. The distributed cable modem termination system of claim 7, wherein one of said one or more miniMAC layers are co-located with one of said plurality of physical layers in each fiber node of said HFC plant.

17. The distributed cable modem termination system of claim 7, wherein one of said one or more miniMAC layers are co-located with one of said plurality of physical layers in each post fiber node of said HFC plant.

18. The distributed cable modem termination system of claim 7, wherein one of said one or more miniMAC layers are placed in each fiber node of said HFC plant and each of said physical layers is placed in each post fiber node of said HFC plant.

19. The distributed cable modem termination system of claim 7, wherein said remaining part of said media access layer is placed in one of said headend and said hub in a fiber portion of said HFC plant.