Establishing a return path in a forward path cable television testing environment

• US 20050276226A1
• Filed: 06/10/2004
• Published: 12/15/2005
• Est. Priority Date: 06/10/2004
• Status: Active Grant

• Current Assignee: Time Warner Cable Enterprises LLC (Charter Communications Incorporated)
• Original Assignee: Time Warner Cable Inc. (Charter Communications Incorporated)
• Inventors: Musser, Dennis, Moreno, Marin
• Granted Patent: US 7,707,615 B2
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: H04L 1/243 at the transmitter, using a loop-back
• CPC Class Codes: H04N 17/00 Diagnosis, testing or measuring for television systems or their details
• CPC Class Codes: H04N 17/004 for digital television systems
• CPC Class Codes: H04N 21/6168 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/17309 Transmission or handling of upstream communications

Abstract

A system and method for establishing a return path in a cable television test environment. A cable television test environment comprising a plurality of head-ends connected to a plurality of set top boxes through a one-way forward matrix switch having “M” inputs and “N” outputs is adapted to provide a reverse path for each of the available “N” outputs. A low band reverse signal is received from each of a plurality of set top boxes. The low band reverse signal from each of the plurality of set top boxes is combined to produce a composite signal. The composite signal is split into a plurality of composite signal sources. Each of the composite signal sources is sent to each of the plurality of head-ends (M) via the transmission means connecting that head-end to the matrix switch. The low band composite QPSK signal from the source diplexer travels in the reverse direction to the head-end. Each head-end is assigned a unique set of frequencies for return communications from the STBs serviced by that head-end. A QPSK demodulator in a head-end demodulates its assigned return frequencies as they appear in the low band composite QPSK signal.

Claims

1. A cable television testing environment with a return path comprising:

an RF matrix switch comprising;

an input terminal, wherein the input terminal receives a high-band forward input signal from a head-end via a transmission path; and

an output terminal, wherein the output terminal is connected to a set top box via an output module,

and wherein the RF matrix switch is adapted to map the high-band forward input signal received by the input terminal to the output terminal; and

the output module adapted to;

pass the high band forward input signal to the set top box;

pass a low band reverse signal from the set top box to a combining/splitting module; and

the combining/splitting module adapted to;

combine the low band reverse signal from set top box with one or more other low band reverse signals to produce a composite signal; and

split the composite signal into a plurality of composite signal sources, wherein one of the plurality of composite signal sources is connected to the head-end via the transmission path connected to that head-end thereby providing the return path.

2. The system of claim 1 wherein the output module is further adapted to isolate the low band reverse signal from the set top box from the output terminal to which the set top box is connected.

3. A method for establishing a return path in a cable television testing environment comprising:

receiving a low band reverse signal from a set top box;

combining the low band reverse signal from the set top box with one or more other low band reverse signals from other set top boxes to produce a composite signal;

splitting the composite signal into a plurality of composite signal sources; and

connecting one of the plurality of composite signal sources to a head end via a transmission path connected to that head-end thereby providing the return path.

4. The method for establishing a return path in a cable television testing environment as in claim 3, the method further comprising:

mapping a high-band forward input signal from the head-end applied to an input terminal of an RF matrix switch to an output terminal of the RF matrix switch connected to the set top box.

5. A cable television testing environment with a return path comprising:

an RF matrix switch comprising;

an input terminal, wherein the input terminal receives a high-band forward input signal from a head-end via a transmission path; and

an output terminal, wherein the output terminal is connected to a set top box via an output module,

and wherein the RF matrix switch is adapted to map the high-band forward input signal received by the input terminal to the output terminal; and

the output module adapted to;

pass the high band forward input signal to the set top box;

pass a low band reverse signal from the set top box to a combining module; and

the combining module adapted to;

combine the low band reverse signal from set top box with one or more other low band reverse signals to produce a composite signal that is transmitted to the head-end via the transmission path connected to that head-end thereby providing the return path.

6. The system of claim 5 wherein the output module is further adapted to isolate the low band reverse signal from the set top box from the output terminal to which the set top box is connected.

7. A method for establishing a return path in a cable television testing environment comprising:

receiving a low band reverse signal from a set top box;

combining the low band reverse signal from the set top box with one or more other low band reverse signals from other set top boxes to produce a composite signal; and

transmitting the composite signal to a head end via a transmission path connected to that head-end thereby providing the return path.

8. The method for establishing a return path in a cable television testing environment as in claim 7, the method further comprising:

mapping a high-band forward input signal from the head-end applied to an input terminal of an RF matrix switch to an output terminal of the RF matrix switch connected to the set top box.