US 5,815,794 AGranted

Undesirable energy suppression system in the return path of a bidirectional cable network having dynamically allocated time slots

AssigneeCable Television Laboratories, Inc.

InventorThomas H. Williams

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Abstract

A bidirectional cable network having a signal distribution system that prevents undesirable energy in the bidirectional cable network's return path from adversely effecting the entire network. The signal distribution system a first signal transmitted in a forward path direction over the bidirectional communication path from a headend to a plurality of remote points. Signals transmitted in a return path direction are time division multiplexed on a series of cyclically reoccurring time slots where at least one of the cyclically reoccurring time slots is assigned to each of the plurality of remote points. At least one primary return gate is effective during each occurrence of the cyclically reoccurring time slots for isolating all of the plurality of remote points from accessing the network to transmit a signal in second direction except for the one of the plurality of remote points which is assigned the cyclically reoccurring time slot that is presently providing a path to transmit in the second direction from the remote point to the headend. In one embodiment each return gate services a plurality of remote points within the return gate's distribution branch. In a second embodiment each remote point has a dedicated return gate.

Claims25

Dependent claims

A bidirectional cable network system for enabling bidirectional signal exchanges in a network having a bidirectional communication path between a headend signal source and a plurality of remote points, said system comprising:

first means for enabling said plurality of remote points to receive a first signal transmitted in a first direction over said bidirectional communication path from said headend to said plurality of remote points;
means for defining a series of cyclically reoccurring time slots for use on said bidirectional communication path between said headend and said plurality of remote points;
at least one return gate located in a second direction of said bidirectional communication path to connect and disconnect said second direction of said bidirectional communication path in concert with any one of said series of cyclically reoccurring time slots on behalf of any of said plurality of remote points that are downstream from said at least one return gate;
means for requesting an assignment of at least one of said series of cyclically reoccurring time slots at will by any of said plurality of remote points;
means for dynamically assigning at least one of said series of cyclically reoccurring time slots in real time to said requesting one of said plurality of remote points;
second means for enabling said requesting one of said plurality of remote points to transmit in said second direction to said headend during an occurrence of each of said at least one of said series of cyclically reoccurring time slots to which said requesting one of said plurality of remote points is assigned;
and
means for engaging each of said at least one return gate independent of said headend to disconnect said second direction of said bidirectional communication path by way of each of said at least one return gate at all times except to connect said second direction of said bidirectional communication path by each of said at least one return gate that is in an upstream path from said requesting one of said plurality of remote points during an occurrence of each of said series of cyclically reoccurring time slots to which said requesting one of said plurality of remote points is assigned.

5 more elements

A method for use in a bidirectional cable network system for enabling bidirectional signal exchanges in a network having a bidirectional communication path between a headend signal source and a plurality of remote points, said method comprising the steps of:

first step of enabling said plurality of remote points to receive a first signal transmitted in a first direction over said bidirectional communication path from said headend to said plurality of remote points;
defining a series of cyclically reoccurring time slots for use on said bidirectional communication path between said headend and said plurality of remote points;
locating at least one return gate located in a second direction of said communication path to connect and disconnect said second direction of said bidirectional communication path in concert with any one of said series of cyclically reoccurring time slots on behalf of any of said plurality of remote points that are downstream from said at least one return gate;
requesting an assignment of at least one of said series of cyclically reoccurring time slots at will by any of said plurality of remote points;
dynamically assigning at least one of said series of cyclically reoccurring time slots in real time to said requesting one of said plurality of remote points;
second step of enabling said requesting one of said plurality of remote points to transmit in said second direction to said headend during an occurrence of each of said at least one of said series of cyclically reoccurring time slots to which said requesting one of said plurality of remote points is assigned;
and
engaging each of said at least one return gate independent of said headend to disconnect said second direction of said bidirectional communication path by way of each of said at least one return gate at all times except to connect said second direction of said bidirectional communication path by each of said at least one return gate that is in an upstream path from said requesting one of said plurality of remote points during an occurrence of each of said series of cyclically reoccurring time slots to which said requesting one of said plurality of remote points is assigned.

5 more elements

Dependencies are inferred from the claim text.