Time division multiplexing over broadband modulation method and apparatus

• US 7,194,001 B2
• Filed: 04/30/2004
• Issued: 03/20/2007
• Est. Priority Date: 03/12/2001
• Status: Expired due to Term

• Current Assignee: Inceptia LLC
• Original Assignee: Advent Networks, Inc.
• Inventors: Leatherbury, Ryan M., Johnson, Robert Edward Lee
• Primary Examiner(s): Hsu, Alpus H.
• Application Number:
  US10/835,976
• Publication Number:
  US 20040218606A1
• Time in Patent Office: 1,054 Days
• Field of Search: 370/395.64, 370/466, 370/474, 398/58, 398/74, 725/109, 725/119
• US Class Current: 370/395.64
• CPC Class Codes: H04L 2012/5605 Fibre
• CPC Class Codes: H04L 2012/5606 Metallic
• CPC Class Codes: H04L 2012/561 Star, e.g. cross-connect, concentrator, subscriber group equipment, remote electronics
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6168 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

A packet switch router that processes downstream digital information to provide dedicated bandwidth to each subscriber destination on a hybrid fiber coax (HFC) network. The router includes a network module that terminates a network connection, a switch that forwards data from the network module, and a channel module. The channel module includes a switch interface, a cell processing engine, one or more modulators, and a radio frequency (RF) transmitter network. The switch interface forwards packetized data from the switch to the cell processing engine. The cell processing engine organizes the packetized data into multiple data streams, encapsulates data in each stream into data cells, and multiplexes the data cells into a multiplexed cell stream. Each modulator is configured to modulate a multiplexed cell stream into an analog signal. The RF transmitter network up converts and combines a plurality of analog signals into a combined electrical signal for transmission.

Claims

1. A method of providing dedicated bandwidth to a plurality of destinations, comprising:

forwarding data packets into a plurality of data streams, each data stream corresponding to one of the plurality of destinations;

framing one or more of the data packets in each data stream into a data cell, wherein one or more data cells in the same data stream form a corresponding one of a plurality of cell streams;

channelizing the plurality of cell streams into cell groups, each cell group having an equal number of time slots;

inserting data cells from one or more of the plurality of cell streams into one or more of the time slots of each cell group, thereby forming a multiplexed cell stream; and

modulating the multiplexed cell stream into a modulated signal within a frequency channel.

2. The method of claim 1, wherein an original packet format for each data packet is one of IPv4, IPv6, Ethernet 802.3, Ethernet II, Ethernet 802.2, Ethernet SNAP, 802.1Q Ethernet VLAN, ATM, Frame Relay, MPLS, PPP or HDLC.

3. The method of claim 1, wherein the step of inserting data cells comprises:

inserting data cells into the time slots of each cell group in a round-robin manner.

4. The method of claim 1, further comprising:

assigning at least one transport channel to each data stream, each transport channel comprising a series of corresponding time slots; and

said inserting comprising inserting data cells from each of the plurality of cell streams into corresponding time slots of assigned transport channels.

5. The method of claim 1, wherein said framing includes appending a cell header to each data cell, the cell header including a synchronization value.

6. The method of claim 5, wherein said synchronization value is in accordance with MPLG-2 format.

7. A method of providing dedicated bandwidth to each of a plurality of destinations, comprising:

forwarding digital information into a plurality of data streams, each data stream corresponding to one of the plurality of destinations;

framing the digital information in each data stream into data cells;

multiplexing the data cells of each of the plurality of data streams into a multiplexed cell stream, wherein multiplexing the data cells of each of the plurality of data streams into a multiplexed cell stream comprises;

(a) channelizing the plurality of data streams into cell groups, each cell group having an equal number of time slots in the multiplexed cell stream;

(b) inserting data cells from each of the plurality of data streams into one or more time slots of a corresponding cell group; and

modulating the multiplexed cell stream into an analog signal.

8. The method of claim 7, wherein an original packet format for each data packet is one of IPv4, IPv6, Ethernet 802.3, Ethernet II, Ethernet 802.2, Ethernet SNAP, 802.1Q Ethernet VLAN, ATM, Frame Relay, MPLS, PPP or HDLC.

9. The method of claim 7, further comprising:

converting the analog signal to an optical signal; and

transmitting the optical signal to the plurality of subscriber destinations over an HFC network.

10. The method of claim 7, further comprising:

assigning at least one transport channel to each data stream, each transport channel comprising a series of corresponding time slots; and

said inserting comprising inserting data cells from each of the plurality of cell streams into corresponding time slots of assigned transport channels.

11. The method of claim 7, wherein said framing includes appending a cell header to each data cell, the cell header including a synchronization value.

12. The method of claim 11, wherein said synchronization value is in accordance with MPLG-2 format.

13. The method of claim 7, wherein the step of inserting data cells comprises:

inserting data cells into the time slots of each cell group in a round-robin manner.

14. A system for processing digital information at a point of distribution to provide dedicated bandwidth for each of a plurality of destinations, comprising:

an interface that receives packetized data;

a cell processing engine, coupled to the interface, comprising;

a switch that forwards the packetized data into a plurality of data streams comprised of data cells;

a channelizer that multiplexes the data cells of the plurality of data streams into a multiplexed stream of data cells, wherein the channelizer organizes the multiplexed stream of data cells into cell groups, each cell group having a plurality of assigned time slots, and inserts data cells from each of the plurality of data streams according to assigned time slots; and

a modulator, coupled to the cell processing engine, that modulates the multiplexed stream of data cells into an analog signal; and

a radio frequency (RF) transmitter network that transmits the analog signal into a frequency channel.

15. The system of claim 14, wherein an original packet format for the packetized data is one of IPv4, IPv6, Ethernet 802.3, Ethernet II, Ethernet 802.2, Ethernet SNAP, 802.1Q Ethernet VLAN, ATM, Frame Relay, MPLS, PPP or HDLC.

16. The system of claim 14, further comprising:

an optical converter that converts the analog signal to an optical signal and transmits the optical signal to the plurality of subscriber destinations over an HFC network.

17. The system of claim 14, wherein at least one transport channel is assigned to each data stream, each transport channel comprising a series of corresponding time slots, and said channelizer inserts data cells from each of the plurality of cell streams into corresponding time slots of assigned transport channels.

18. The system of claim 14, wherein the channelizer inserts data cells into the assigned time slots of each cell group in a round-robin manner.