System for controlling communications on a cable television network
First Claim
1. A cable television system for transmitting via a cable network television signals from a head end to a plurality of subscriber premises, and other signals between the head end and the plurality of subscriber premises, comprising:
- polling signal means associated with the head end for applying polling signals to the cable network;
external control unit means located at a plurality of remote locations, each location being adjacent but external to a subset of the subscriber premises, for receiving the television signals and the polling signals from the cable network, each external control unit means having an address;
a plurality of drop cables connected to each external control unit means, each drop cable conducting a selected portion of the television signal from the external control unit means to a respective one of the subscriber premises associated with that external control unit means;
subscriber processing unit means connected to each drop cable at the subscriber premises for allowing the subscriber to apply to the drop cable a control signal indicative of information to be transmitted to said external control unit means, including information indicating the portion of the television signal which that subscriber wishes to select and information for transmission to the head end;
control signal processing means associated with the external control unit for receiving and storing the information indicated by the control signals applied to all of the drop cables associated with that external control unit means and for applying to each drop cable the portion of the television signal indicated by the television signal selection information received via the drop cable;
polling signal processing means associated with each external control unit means for processing the received polling signals and for responding thereto by applying to the cable network for transmission to the head end a response signal communicative solely of whether or not said external control unit means has information to transmit to the head end; and
means associated with said polling signal means for, responsive to receipt from said external control unit means of a response signal communicative of a desire by said external control unit means to transmit information to the head end, applying additional polling signals to the cable network for determining the address of said external control unit means desiring to communicate.
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Accused Products
Abstract
A system for controlling a cable television network includes a head end, a plurality of addressable external control units having subscriber converters located off the subscriber'"'"'s premises, and one or more subscriber devices located on the subscriber premises for communicating with associated external control units. The head end can selectively and rapidly poll the external control units for information on a general or on a priority basis. Information is transmitted to the head end from the external control units on any of a plurality of reverse communication channels under control of the head end. External control units use a two-part polling scheme to poll a plurality of associated drop cables, and individual subscriber devices attached to the drop cables. The polling rapidly identifies subscriber devices desiring to communicate with the external control unit.
97 Citations
7 Claims
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1. A cable television system for transmitting via a cable network television signals from a head end to a plurality of subscriber premises, and other signals between the head end and the plurality of subscriber premises, comprising:
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polling signal means associated with the head end for applying polling signals to the cable network; external control unit means located at a plurality of remote locations, each location being adjacent but external to a subset of the subscriber premises, for receiving the television signals and the polling signals from the cable network, each external control unit means having an address; a plurality of drop cables connected to each external control unit means, each drop cable conducting a selected portion of the television signal from the external control unit means to a respective one of the subscriber premises associated with that external control unit means; subscriber processing unit means connected to each drop cable at the subscriber premises for allowing the subscriber to apply to the drop cable a control signal indicative of information to be transmitted to said external control unit means, including information indicating the portion of the television signal which that subscriber wishes to select and information for transmission to the head end; control signal processing means associated with the external control unit for receiving and storing the information indicated by the control signals applied to all of the drop cables associated with that external control unit means and for applying to each drop cable the portion of the television signal indicated by the television signal selection information received via the drop cable; polling signal processing means associated with each external control unit means for processing the received polling signals and for responding thereto by applying to the cable network for transmission to the head end a response signal communicative solely of whether or not said external control unit means has information to transmit to the head end; and means associated with said polling signal means for, responsive to receipt from said external control unit means of a response signal communicative of a desire by said external control unit means to transmit information to the head end, applying additional polling signals to the cable network for determining the address of said external control unit means desiring to communicate. - View Dependent Claims (2, 3)
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4. A cable television system for transmitting television signals via a cable network from a head end to a plurality of remote locations, each remote location being adjacent but external to a selected set of subscriber premises, comprising:
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external control unit means at each of the remote locations for receiving the television signals from the cable network; a plurality of drop cables connected to at least one external control unit means, each drop cable conducting a selected portion of the television signal from the external control unit means to a respective one of the subscriber premises associated with that external control unit means; subscriber device means connected to the drop cable at the subscriber premises for applying to the drop cable a service request signal communicative solely of a request by the subscriber device means to communicate with the external control unit means; and drop polling means associated with the external control unit means for sensing in a predetermined order on each drop cable the presence of the service request signal to enable the associated external control unit means to rapidly locate a drop cable on which a subscriber device means is requesting to communicate with the external control unit means;
wherein;said service request signal has a duration at least as long as the time needed for said drop polling means to sense all of said plurality of drop cables in said predetermined order. - View Dependent Claims (5, 6, 7)
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Specification