Signal splitter matrix for a cable modem termination system

• US 6,769,132 B1
• Filed: 09/12/2000
• Issued: 07/27/2004
• Est. Priority Date: 09/12/2000
• Status: Expired due to Term

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: Arris International, Inc. (CommScope Holding Company, Inc.)
• Inventors: Cloonan, Thomas J., Cepeda, Ubaldo, Ryan, Gerald P., Hickey, Daniel W.
• Primary Examiner(s): Srivastava, Vivek
• Application Number:
  US09/660,120
• Time in Patent Office: 1,414 Days
• Field of Search: H04/N.7173, 725/111, 725/110, 725/109, 725/114, 725/116, 725/117, 370/281, 370/419, 370/420, 370/421, 370/422, 370/423
• US Class Current: 725/111
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• 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: H04N 7/104 Switchers or splitters
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications

Abstract

In a cable data system, several frequency division multiplexed upstream data signals on an individual cable can be selectively routed to frequency-selective band pass filters using a relay matrix between the filters and the cable. By appropriately controlling the relays, the upstream information can be split out to as many different filters that might be required to recover the frequency division multiplexed information. Cabling installation to a cable modem termination system is simplified and maintenance costs are reduced by carrying multiple signals on one cable.

Claims

1. Apparatus for routing a plurality of frequency division multiplexed cable data system signals within a CMTS, each signal having a carrier frequency, comprising:

a relay matrix comprised of a plurality of relays, said relay matrix further having at least a first input connection and a plurality of output connections connected to a midplane within the CMTS, such that the cable data input signals on said at least first input connection can be selectively routed to a number of said plurality of output connections according to the state of relays of said plurality of relays, wherein said state of relays is determined based on the carrier frequency or frequencies of the cable data system signals being input to the at least first input connection.

2. The apparatus of claim 1 wherein said relay matrix is comprised of at least one input and up to eight output connections.

3. The apparatus of claim 1 wherein said relay matrix is further comprised of a plurality of control signal inputs for said relays.

4. The apparatus of claim 1 further including at least one coaxial cable connector coupled to said at least a first input.

9. The apparatus of claim 1 wherein each midplane connection is coupled to a bandpass filter for selectively passing a signal having a desired carrier frequency to other components within the CMTS.

5. A cable modem termination system comprised of:

a. a cable interface, said cable interface having at least one band pass filter to selectively recover at least one signal from a plurality of frequency-division multiplexed signals on a cable;

b. a relay matrix comprised of a plurality of relays, said relay matrix further having at least a first input and at least one output coupled to said at least one band pass filter by which cable data input signals on said first input can be selectively routed to a number of said plurality of outputs according to the state of relays of said plurality of relays.

6. The apparatus of claim 5 wherein said cable interface is comprised of a plurality of band pass filters and a said relay matrix is comprised of a plurality of outputs.

7. The apparatus of claim 5 wherein said relay matrix is further comprised of a plurality of control signal inputs for said relays.

8. The apparatus of claim 5 further including at least one coaxial cable connector coupled to said at least a first input.

10. A method for routing one or more multiplexed upstream signals within a CMTS, each of the one or more multiplexed upstream signals containing at least one signal having a carrier frequency, and if one of the one or more upstream multiplexed signals contains more than one signal, each of the contained signals having a carrier frequency different from the others contained therein, comprising:

receiving the multiplexed signals at one or more upstream inputs of a CMTS; and

configuring a plurality of relays, the relays being connected between the one or more upstream inputs and a plurality of midplane connections, each midplane connection coupled to a bandpass filter and each relay having at least two switchable inputs for selectively receiving the multiplexed upstream signal from one of at least two of the upstream inputs of the CMTS, such that the upstream multiplexed signal received at any one of the upstream inputs of the CMTS is routed to at least one of the midplane connections coupled to a bandpass filter having a center frequency corresponding to one of the carrier frequencies of one of the signals contained therein.

11. The method of claim 10 wherein the input of each relay for receiving a multiplexed upstream signal is selected with a control signal.

12. The method of claim 11 wherein a first control signal selects the inputs of a first, second, third and forth relay, a second control signal selects the inputs of a fifth and sixth relay, and a third control signal selects the input of seventh relay.