VoIP drop amplifier

• US 20060015921A1
• Filed: 07/18/2005
• Published: 01/19/2006
• Est. Priority Date: 07/19/2004
• Status: Active Grant

• Current Assignee: PCT International Incorporated (Andes Industries Incorporated)
• Original Assignee: PCT International Incorporated (Andes Industries Incorporated)
• Inventors: Vaughan, Jay
• Granted Patent: US 7,530,091 B2
• Time in Patent Office: Days
• US Class Current: 725/127
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04N 7/102 Circuits therefor, e.g. noise reducers, equalisers, amplifiers H04N7/108 takes precedence

Abstract

The VOIP drop amplifier connects end user equipment to a broadband system, such as that provided by a cable provider. The amplifier includes a splitter for connecting the cable signal to multiple output connectors, and RF amplifiers compensating for losses in the splitter and other passive components in the amplifier. The drop amplifier includes an input connection for accepting a broadband cable signal from a cable system and returning broadband signals to the cable system. The drop amplifier includes an amplification path connecting the input connection to the plurality of output connections through RF amplifiers and a splitter, and a bypass path that bypass the splitter and forward and reverse amplifiers in the amplification path to connect the input connection directly to the output connection for the essential circuits. A sensing circuit monitors the amplifiers and the supply voltages, and selects the bypass path when a failure is detected.

Claims

1. A VoIP drop amplifier for connecting equipment to a broadband signal, the VoIP drop amplifier comprising:

an input connector adapted for accepting a broadband cable signal from a cable system and returning broadband signals to the cable system;

a plurality of output connectors, the output connectors having at least one non-essential output connector and at least one essential output connector, the at least one essential output connector including an output adapted for connection to VoIP telecommunication equipment;

an amplification path connecting the input connector to the plurality of output connectors, the amplification path having;

a diplex filter for separating the broadband signal into return and forward signals;

a forward amplifier for amplifying the forward signals;

a path for the return signals; and

a splitter for connecting signals traveling on the amplification path to each of the plurality of output connectors;

a bypass path connecting the input connector to the at least one essential output connector;

a switching circuit for switching between the amplification path and the bypass path; and

a dc current and voltage sensing circuit connected to the switching circuit for selecting the bypass path upon the dc current and voltage sensing circuit detecting an abnormal condition, and for selecting the amplification path when the dc current and voltage sensing circuit detects absence of an abnormal condition.

2. The VoIP drop amplifier according to claim 1, wherein said amplification path further comprises a reverse amplifier in the path for the return signals for amplifying the return signals.

3. The VoIP drop amplifier according to claim 1, wherein the dc current and voltage sensing circuit comprises:

a circuit for monitoring a dc voltage supplied to the reverse amplifier and the forward amplifier;

a voltage comparator circuit for comparing total dc voltage supplied to the amplifier circuitry to a low voltage limit and for generating an output based on the voltage comparison in order to detect the abnormal condition.

4. The VoIP drop amplifier according to claim 3, wherein the dc current and voltage sensing circuit further comprises:

a circuit for detecting a dc current powering the amplifier circuitry;

a first comparator circuit for comparing the dc current powering the amplifier circuitry to a high current limit and for generating a first output based on the comparison; and

a second comparator circuit for comparing dc current powering the amplifier circuitry to a low current limit and generating a second output based on the comparison, the low current limit being lower than the high current limit, in order to detect the abnormal condition.

5. The VoIP drop amplifier according to claim 4, wherein the circuit for detecting dc current powering the amplifier circuitry comprises a resistor carrying the current powering the dc current powering the amplifier circuitry.

6. The VoIP drop amplifier according to claim 4, wherein the amplification path further comprises a reverse amplifier in the path for the return signals for amplifying the return signals and wherein the circuit for detecting dc current powering the amplifier circuitry includes a first resistor carrying current powering the forward amplifier and a second resistor carrying current powering the reverse amplifier.

7. The VoIP drop amplifier according to claim 1, wherein the switching circuit comprises an input RF switch having:

a normally open contact connected to the amplification path;

a normally closed contact connected to the bypass path; and

a common contact connected to the input connector, the input RF switch being operable to select between connecting the normally open contact to the common contact and connecting the normally closed contact to the common contact.

8. The VoIP drop amplifier according to claim 7, wherein the input RF switch comprises a single-pole double-throw relay.

9. The VoIP drop amplifier according to claim 1, wherein the switching circuit comprises an output RF switch having:

a normally open contact connected to the amplification path;

a normally closed contact connected to the bypass path; and

a common contact connected to the at least one essential output connector, the output RF switch being operable to select between connecting the normally open contact to the common contact and connecting the normally closed contact to the common contact.

10. The VoIP drop amplifier according to claim 9, wherein the output RF switch comprises a single-pole double-throw relay.

11. A VoIP drop amplifier for connecting equipment to a broadband signal, the VoIP drop amplifier comprising:

an input connector for accepting a broadband cable signal from a cable system and returning broadband signals to the cable system;

a plurality of output connectors including at least one non-essential output connector and at least one essential input connectors, the at least one essential output connector including an output adapted for connection to VoIP telecommunication equipment;

an amplification path connecting the input connector to the plurality of output connectors, the amplification path having;

a diplex filter for separating the broadband signal into return and forward signals;

amplifier circuitry comprising a forward amplifier for amplifying the forward signals;

a return path for the return signals; and

a splitter for connecting signals traveling on the amplification path to each of the plurality of output connectors;

a bypass path connecting the input connector to the at least one essential output connector;

a switching circuit for switching between the amplification path and the bypass path; and

a dc current and voltage sensing circuit connected to the switching circuit for to selecting the bypass path upon dc current and voltage sensing circuit detecting an abnormal condition and for selecting the amplification path when the dc current and voltage sensing circuit does not detect an abnormal condition, the dc current and voltage sensing circuit comprising;

a circuit for detecting total dc current powering the amplifier circuitry;

a first comparator circuit for comparing the total dc current powering the amplifier circuitry to a high current limit and generating a first output based on the comparison;

a second comparator circuit for comparing the total dc current powering the amplifier to a low current limit and generating a second output based on the comparison, the low current limit being lower than the high current limit;

a circuit for monitoring dc voltage supplied to the reverse amplifier and the forward amplifier, and

a voltage comparator circuit for comparing dc voltage supplied to the amplifier circuitry to a low voltage limit and for generating an output based on the voltage comparison, the abnormal condition being detected when the first output exceeds the high current limit, the second output is less than the low current limit, or the output based on the voltage comparison detects dc voltage supplied to the amplifier circuitry less than the low voltage limit.

12. The VoIP drop amplifier according to claim 11, wherein said amplification path further comprises a reverse amplifier in the path for the return signals for amplifying the reverse signals.

13. The VoIP drop amplifier according to claim 11, wherein the switching circuit comprises an input RF switch having:

a first normally open contact connected to the amplification path;

a first normally closed contact connected to the bypass path; and

a first common contact connected to the input connection, the input RF switch being operable to switch between connecting the first normally open contact to the first common contact, and connecting the first normally closed contact to the first common contact.

14. The VoIP drop amplifier according to claim 13, wherein the switching circuit comprises an output RF switch having:

a second normally open contact connected to the amplification path;

a second normally closed contact connected to the bypass path; and

a second common contact connected to the at least one essential output connector, the output RF switch being operable to switch between connecting the second normally open contact to the second common contact, and connecting the second normally closed contact to the second common contact.

15. A VoIP drop amplifier for connecting equipment to a broadband signal, the VoIP drop amplifier comprising:

an input connector adapted for accepting a broadband cable signal from a cable system and returning broadband signals to the cable system;

a plurality of output connectors, the output connectors having at least one non-essential output connector and at least one essential output connector, the at least one essential output connector including an output adapted for connection to VoIP telecommunication equipment;

an amplification path connecting the input connector to the plurality of output connectors, the amplification path having;

a diplex filter for separating the broadband signal into return and forward signals;

a forward amplifier for amplifying the forward signals;

a reverse amplifier for amplifying the return signals; and

a splitter for connecting signals traveling on the amplification path to each of the plurality of output connectors;

a bypass path connecting the input connector to the at least one essential output connector;

a switching circuit for switching between the amplification path and the bypass path; and

a dc current and voltage sensing circuit connected to the switching circuit for selecting the bypass path upon the dc current and voltage sensing circuit detecting an abnormal condition, and for selecting the amplification path when the dc current and voltage sensing circuit detects the absence of an abnormal condition.

16. The VoIP drop amplifier according to claim 15, wherein said dc current and voltage sensing circuit further comprises

a first circuit for sensing a first dc current powering the forward amplifier;

a second circuit for sensing a second dc current powering the reverse amplifier;

a first comparator circuit for comparing the first dc current powering the forward amplifier to a first high current limit and generating a first output based on the comparison;

a second comparator circuit for comparing the first dc current powering the forward amplifier to a first low current limit and generating a second output based on the comparison, the first low current limit being lower than the second current high current limit;

a third comparator circuit for comparing the second dc current powering the reverse amplifier to a second high current limit and generating a third output based on the comparison;

a fourth comparator circuit for comparing the second dc current powering the reverse amplifier to a second low current limit and generating a fourth output based on the comparison, the second low current limit being lower than the second current high current limit;

output generating circuitry for generating an abnormal condition detection output for detecting an abnormal condition, the abnormal condition detection output depending on the first output, the second output, the third output, and the fourth output.