Frequency agile transponder

Details Frequency agile transponder Frequency agile transponder

1999-05-18

2002-08-13

Negash, Kinfe-Michael (Department: 2633)

Optical: systems and elements

Deflection using a moving element

Using a periodically moving element

C359S199200, C359S199200, C725S129000

Reexamination Certificate

active

06433905

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a tester which tests equipment of a hybrid fiber-coaxial network and, more particularly, to a tester having frequency adjustable transmit and receive frequencies.
2. Description of the Prior Art
A typical hybrid fiber-coaxial (HFC) network
2
for communicating data, such as cable television program material, is shown in FIG.
1
. The HFC network
2
includes a receiving antenna
4
which receives RF signals which include program material from a satellite or microwave transmission station (not shown) and provides the RF signals to a fiber optic head end
6
via a coaxial cable
8
. The fiber optic head end
6
converts the received RF signals into optical program signals that are supplied to a fiber optic network
10
. A computer
12
is connected to the fiber optic head end
6
for monitoring and controlling the operation thereof.
Connected to an end of the fiber optic network
10
opposite the fiber optic head end
6
is a fiber optic node
14
1
. The fiber optic node
14
1
converts the optical program signals received from the fiber optic network
10
into RF program signals that are supplied via
75
ohm coaxial cables
16
1
-
16
3
to subscribers
18
1
-
18
3
at frequencies between 50 and 750 MHz. Connected to the fiber optic node
14
1
is a power supply
20
1
. The power supply
20
1
converts incoming AC power, supplied from power lines (not shown), into an AC power signal, preferably a 60 Hz square wave signal having an RMS voltage of 60 or 90 volts. The AC power signal is supplied by the power supply
20
1
to the fiber optic node
14
1
which includes a rectifier which converts the AC power signal into DC power usable by electronic circuitry of the fiber optic node
14
1
.
Another fiber optic node
14
2
can be connected to the fiber optic head end
6
via the fiber optic network
10
. Another power supply
20
2
, similar to power supply
20
1
, is connected between incoming AC power and the fiber optic node
14
2
. The-fiber optic node
14
2
converts the optical program signals received from the fiber optic network
10
into RF program signals at frequencies between 50 and 750 MHz. The fiber optic. node
14
2
supplies the RF program signals to a line amplifier
24
via a 75 ohm coaxial cable
22
. The line amplifier
24
amplifies the RF program signals and supplies the amplified RF program signals to a subscriber
28
via a 75 ohm coaxial cable
26
.
The power supply
202
superimposes its AC power signal on the coaxial cable
22
extending between the fiber optic node
14
2
and the line amplifier
24
. The line amplifier
24
includes a rectifier which converts the AC power signal on the coaxial cable
22
into DC power usable by electronic circuitry of the line amplifier
24
. Alternatively, the power supply
20
2
is connected to the line amplifier
24
and the fiber optic node
14
2
receives its AC power signal from the power supply
20
2
via the line amplifier
24
and coaxial cable
22
.
A telephony network
30
supplies data signals and/or telephony signals to the fiber optic head end
6
via telephony lines
32
. The fiber optic head end
6
converts the data signals and/or telephony signals received from the telephony network
30
into optical data/telephony signals that are supplied to the fiber optic network
10
. One or more of the fiber optic nodes
14
1
and
14
2
receives the optical data/telephony signals and converts the received optical data/telephony signals into RF data/telephony signals which are supplied to the subscribers
18
1
-
18
3
and
28
via the coaxial cables
16
1
-
16
3
and
26
at frequencies between 50 and 750 MHz.
The subscribers
18
1
-
18
3
and
28
can also generate RF data/telephony signals which are supplied to the fiber optic nodes
14
1
and
14
2
at frequencies between 5 and 40 MHz. The fiber optic nodes
14
1
and
14
2
convert the data signals and/or telephony signals received from the subscribers
18
1
-
18
3
and
28
into optical data/telephony signals that are supplied to the fiber optic head end
6
via the fiber optic network
10
. The fiber optic head end
6
converts the optical data/telephony signals received from the fiber optic nodes
14
1
and
14
2
into data signals and/or telephony signals that are supplied to the telephony network
30
.
As can be seen, the HFC network
2
can be utilized to supply data signals and/or telephony signals between the telephony network
30
and subscribers
18
1
-
18
3
and
28
and can be utilized to supply cable television program material from the antenna
4
to the subscribers
18
1
-
18
3
and
28
.
Proliferation of HFC networks has increased the need for cable service providers to quickly and accurately identify problems with equipment of such HFC networks. Specifically, if one or more pieces of equipment, such as the fiber optic nodes
14
1
or
14
2
, the power supplies
20
1
or
20
2
and/or the line amplifier
24
, are inoperative or are operating at a reduced performance level, the cable operator is often unaware of the problem until a subscriber reports the problem. Thereafter, a craftsperson must be dispatched to identify and repair the faulty component.
It is an object of the present invention to provide a tester which tests test points of equipment of the HFC network and which reports test results to a central data collection computer. It is an object of the present invention to provide a frequency agile tester which can be connected to test points of equipment of the HFC network and which has selectable transmit and receive frequencies which enable bidirectional communication between the tester and a central data collection computer. Still other objects of the invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description.
SUMMARY OF THE INVENTION
Accordingly, we have invented a frequency agile (F/A) transponder which is connectable to at least one test point of equipment of a hybrid fiber-coaxial network. The F/A transponder includes a receiver configured to be connected to a first cable of the HFC network. The receiver receives from the first cable signals modulated around a receive center frequency and obtains from the received signals receive data. A controller is connected to receive the receive data from the receiver. The controller is configured to detect an electrical condition at the at least one test point. The controller compares the detected electrical condition to a predetermined electrical condition and produces as a function of the comparison transmit data. A transmitter is connected to receive from the controller the transmit data. The transmitter is configured to produce from the transmit data signals modulated around a transmit center frequency. The transmitter supplies the signals modulated around the transmit center frequency to one of the first cable and a second cable of the HFC network. The receive center frequency and the transmit center frequency are different frequencies. In response to a frequency change signal received by the receiver on the first coaxial cable at the receive center frequency, the receiver changes to receive signals at another receive center frequency or the transmitter changes to transmit signals at another transmit center frequency.
We have also invented a hybrid fiber-coaxial (HFC) network for communicating data between a fiber optic head end and a subscriber. The HFC network includes a fiber optic node connected between a fiber optic network and a conductive cable. The fiber optic node is configured to receive optical signals via the fiber optic network and to convert the received optical signals into signals modulated around a receive center frequency. The fiber optic node supplies to the conductive cable the signals modulated around the receive center frequency. The fiber optic node also receives from the conductive cable signals modulated around a transmit center frequency and converts the received signals modulated around the transmit center fr

Affiliated with

Also associated with

Rating

Frequency agile transponder does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Frequency agile transponder, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Frequency agile transponder will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2942686