Simplified set-top converter for broadband switched network

• US 5,483,277 A
• Filed: 12/15/1992
• Issued: 01/09/1996
• Est. Priority Date: 12/15/1992
• Status: Expired due to Fees

• Current Assignee: Alcatel Network Systems India Limited (Nokia Corporation)
• Original Assignee: Alcatel Network Systems India Limited (Nokia Corporation)
• Inventors: Granger, Alain
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): GRANT, CHRISTOPHER C
• Application Number:
  US07/990,456
• Time in Patent Office: 1,120 Days
• Field of Search: 358/86, 455/4.2, 455/6.1, 455/6.2, 455/180.1, 455/187.1, 455/191.1, 455/131, 455/3.1
• US Class Current: 725/120
• CPC Class Codes: H04N 7/16 Analogue secrecy systems; Analogue subscription systems

Abstract

For fiber-to-the-curb program switching, which is done at the central office, the same fixed frequency slot is always used for distributing the TV program selected for a video recording device at the subscriber'"'"'s premises; for its related display, another selected slot is always used for distributing another selected TV program; the set-top converter is provided with two narrow band filters, one for each dedicated slot, instead of expensive tuners; the same set-top converter can be used in other rooms of the subscriber premises, except using a plug-in tuner for placing additional selected TV programs received from remaining, nondedicated slots into the same filter band used for the TV associated with the video recording device.

Claims

1. A method, comprising the steps of:

providing, in response to subscriber program selection signals from a plurality of subscribers, corresponding program signals in a same plurality of fixed-frequency frequency division multiplexed (FDM) channels to each of the plurality of subscribers; and

dedicating a same one of the same plurality of fixed-frequency frequency division multiplexed (FDM) channels as a dedicated subscriber video recorder channel for each of the plurality of subscribers to provide respective subscriber video recorder output signals for recording on an associated subscriber video recording device by each of the plurality of subscribers.

2. The method of claim 1, further comprising the step of subscriber selecting the one dedicated channel by bandpass filtering the plurality of channels.

3. The method of claim 1, further comprising the step of dedicating a first another one of the plurality of channels for bandpass filtering for use by a subscriber display associated with the subscriber video recording device.

4. The method of claim 3, further comprising the step of frequency converting a second another one of the plurality of channels to a frequency corresponding to the first another dedicated channel for use by another subscriber display.

5. Apparatus, comprising:

means, responsive to subscriber program selection signals from a plurality of subscribers, for providing corresponding program signals in a same plurality of fixed-frequency frequency division multiplexed (FDM) channels to each of the plurality of subscribers, a same corresponding one of the same plurality of fixed-frequency frequency division multiplexed (FDM) channels being a dedicated subscriber video recorder channel for each of the subscribers with respective subscriber video recorder output signal for recording on an associated subscriber video recording device; and

means, responsive to the corresponding program signals in the same plurality of fixed-frequency frequency division multiplexed (FDM) channels, for providing for each subscriber the respective subscriber video recorder output signal for recording on the associated subscriber video recording device.

6. The apparatus of claim 5, wherein the means for providing the dedicated one of the channels includes means for selecting the one dedicated channel by bandpass filtering the plurality of channels.

7. The apparatus of claim 5, wherein a first another one of the plurality of channels is dedicated for use by a subscriber display associated with the subscriber video recording device and wherein the means for providing the dedicated one of the channels includes means for selecting the another one of the plurality of channels by bandpass filtering the plurality of channels.

8. The apparatus of claim 7, further comprising means for frequency converting a second another one of the plurality of channels to a frequency corresponding to the first another dedicated channel for use by another subscriber display.

9. A set-top converter for selecting programmed video in a switched video system for providing a plurality of frequency division multiplexed (FDM) fixed frequency channels on a signal to a subscriber'"'"'s premises, comprising:

an input interface, responsive to the plurality of FDM fixed frequency channels on the signal in a broadband thereof and to a data downlink signal on the signal in a downlink band thereof and a data uplink signal on the signal in an uplink band thereof, for providing the plurality of FDM fixed frequency channels on an interfaced signal and for providing for the downlink and uplink signals on a bidirectional control signal;

first and second tuners, responsive to the plurality of FDM fixed frequency channels on the interface signal, for providing selected first and second fixed frequency channels, respectively;

first and second FM demodulators, responsive to the selected first and second fixed frequency channels, respectively, for providing first and second intermediate frequency or baseband video signals, respectively;

first and second AM modulators, responsive to the first and second intermediate frequency or baseband video signals, for providing first and second AM video signals, respectively;

a modem, responsive to the downlink signal on the bidirectional control signal, for providing a demodulated downlink control signal, and responsive to an unmodulated uplink control signal, for providing the uplink signal on the bidirectional control signal;

a central processing unit, responsive to the demodulated downlink control signal, for providing control signals and responsive to user control signals for providing the unmodulated uplink signal and the control signal; and

user interface devices, responsive to user inputs, for providing the user control signals.

10. The set-top converter of claim 9, wherein the first and second tuners comprise first and second filters.

11. The set-top converter of claim 10, further comprising a plug-in switching module, comprising:

a splitter, responsive to the signal provided at an input of the module, for splitting the signal into first and second branch signals;

a tuner, responsive to the first branch signal and to a tuner control signal, for providing an additional selected TV program from one of the plurality of fixed frequency channels other than the selected first and second fixed frequency channels, wherein the set-top converter further comprises;

a switch, responsive to the interfaced signal, to the additional selected TV program and to a switch control signal from the CPU, for providing a switched signal to the first filter.

12. The set-top converter of claim 11, wherein the second filter is responsive to the second branch signal through the input interface.