Data return for a television transmission system

Claim 1

A method for transmitting information over a communication network between a population of remote terminals and a central location having a capacity of simultaneously communicating with a predetermined number of remote terminals in said population, the method comprising the steps of: (A) fixing a sequence of at least two call-in windows each having an initial maximum length, a first call-in window defining a time period during which each remote terminal in said population of remote terminals will initiate a single attempt to communicate with said central location over said communication network and a second call-in window defining a time period during which remote terminals which were unsuccessful in their attempt to communicate with said central location during the first call-in window will initiate another single attempt to communicate with said central location over said communication network; (B) prompting said remote terminals to establish respective times within the first call-in window at which each of said remote terminals in said population of remote terminals will initiate its attempt to communicate with said central location; (C) monitoring a number of said remote terminals which simultaneously communicate with said central location to transmit information therebetween during the first call-in window; (D) varying the length of the first call-in window if the number of remote terminals which simultaneously communicate with said central location is less than the capacity of said central location, wherein the length of the first call-in period is varied so as to be decreased, but not increased; (E) prompting remote terminals which have not yet initiated their attempt to communicate with said central location to establish new respective times within the varied first call-in window for initiating their attempt to communicate with said central location; (F) repeating steps (C)-(E) to establish a final minimum length of the first call-in window at which the number of said remote terminals which simultaneously communicate with said central location is approximately equal to the capacity of said central location; (G) maintaining the final length of the first call-in window set in step (F) until each remote terminal in said population of remote terminals has initiated its attempt to communicate with said central location; (H) prompting remote terminals which were unsuccessful in their attempt to communicate with said central location during the first call-in window to establish respective times within the second call-in window for initiating their attempt to communicate with said central location; and (I) repeating steps (C)-(G) for the second call-in window.

Claim 2

A method for transmitting information over a communication network between a population of remote terminals and a central location having a capacity of simultaneously communicating with a predetermined number of remote terminals in said population, the method comprising the steps of: (A) fixing a sequence of at least two call-in windows each having an initial maximum length, a first call-in window defining a time period during which each remote terminal in said population of remote terminals will initiate a single attempt to communicate with said central location over said communication network and a second call-in window defining a time period during which remote terminals which were unsuccessful in their attempt to communicate with said central location during the first call-in window will initiate another single attempt to communicate with said central location over said communication network; (B) prompting said remote terminals to establish respective times within the first call-in window at which each of said remote terminals in said population of remote terminals will initiate its attempt to communicate with said central location; (C) monitoring a number of said remote terminals which simultaneously communicate with said central location to transmit information therebetween during the first call-in window; (D) varying the length of the first call-in window if the number of remote terminals which simultaneously communicate with said central location is less than the capacity of said central location, wherein the length of the first call-in period is varied so as to be decreased, but not increased; (E) prompting remote terminals which have not yet initiated their attempt to communicate with said central location to establish new respective times within the varied first call-in window for initiating their attempt to communicate with said central location; (F) repeating steps (C)-(E) to establish a final minimum length of the first call-in window at which the number of said remote terminals which simultaneously communicate with said central location is approximately equal to the capacity of said central location; (G) maintaining the final length of the first call-in window set in step (F) until each remote terminal in said population of remote terminals has initiated its attempt to communicate with said central location; (H) prompting remote terminals which were unsuccessful in their attempt to communicate with said central location during the first call-in window to establish respective times within the second call-in window for initiating their attempt to communicate with said central location; and (I) repeating steps (C)-(G) for the second call-in window.

Claim 13

A method for transmitting information over a communication network between a population of remote terminals and a central location having a capacity of simultaneously communicating with a predetermined number of remote terminals in said population, the method comprising the steps of: (A) fixing a sequence of at least tow call-in windows each having an initial maximum length, a first call-in window defining a time period during which each remote terminal in said population of remote terminals will initiate a single attempt to communicate with said central location over said communication network and a second call-in window defining a time period during which remote terminals which were unsuccessful in their attempt to communicate with said central location during the first call-in window will initiate another single attempt to communicate with said central location over said communication network; (B) prompting said remote terminals to establish respective times within the first call-in window at which each of said remote terminals in said population of remote terminals will initiate its attempt to communicate with said central location; (C) monitoring a number of said remote terminals which simultaneously communicate with said central location to transmit information therebetween during the first call-in window; (D) varying the length of the first call-in window if the number of remote terminals which simultaneously communicate with said central location is less than the capacity of said central location, wherein the length of the first call-in period is varied so as to be decreased, but not increased; (E) prompting remote terminals which have not yet initiated their attempt to communicate with said central location to establish new respective times within the varied first call-in window for initiating their attempt to communicate with said central location; (F) repeating steps (C)-(E) to establish a final minimum length of the first call-in window at which the number of said remote terminals which simultaneously communicate with said central location is approximately equal to the capacity of said central location; (G) maintaining the final length of the first call-in window set in step (F) until each remote terminal in said population of remote terminals has initiated its attempt to communicate with said central location; (H) setting a retry flag in remote terminals which initiate unsuccessful attempts to transfer information to said central location; and (I) repeating steps (A)-(G) during the second call-in window for those remote terminals whose retry flag is set.

Claim 14

A method for transmitting information over a communication network between a population of remote terminals and a central location having a capacity of simultaneously communicating with a predetermined number of remote terminals in said population, the method comprising the steps of: (A) fixing a sequence of at least tow call-in windows each having an initial maximum length, a first call-in window defining a time period during which each remote terminal in said population of remote terminals will initiate a single attempt to communicate with said central location over said communication network and a second call-in window defining a time period during which remote terminals which were unsuccessful in their attempt to communicate with said central location during the first call-in window will initiate another single attempt to communicate with said central location over said communication network; (B) prompting said remote terminals to establish respective times within the first call-in window at which each of said remote terminals in said population of remote terminals will initiate its attempt to communicate with said central location; (C) monitoring a number of said remote terminals which simultaneously communicate with said central location to transmit information therebetween during the first call-in window; (D) varying the length of the first call-in window if the number of remote terminals which simultaneously communicate with said central location is less than the capacity of said central location, wherein the length of the first call-in period is varied so as to be decreased, but not increased; (E) prompting remote terminals which have not yet initiated their attempt to communicate with said central location to establish new respective times within the varied first call-in window for initiating their attempt to communicate with said central location; (F) repeating steps (C)-(E) to establish a final minimum length of the first call-in window at which the number of said remote terminals which simultaneously communicate with said central location is approximately equal to the capacity of said central location; (G) maintaining the final length of the first call-in window set in step (F) until each remote terminal in said population of remote terminals has initiated its attempt to communicate with said central location; (H) setting a retry flag in remote terminals which initiate unsuccessful attempts to transfer information to said central location; and (I) repeating steps (A)-(G) during the second call-in window for those remote terminals whose retry flag is set.

Claim 19

A method of transferring information over a communication network from a remote apparatus to a central location, the method comprising the steps of: receiving instructions from said central location including instructions for initiating attempts to transfer information to said central location in accordance with a sequence comprising at least two call-in windows; establishing a time within a first call-in window at which said apparatus will initiate an attempt to communicate with said central location in accordance with instructions from said central location; attempting to communicate with said central location at the time within the first call-in window; transmitting the information over said communication network if said apparatus successfully communicates with said central location; setting a retry flag if said apparatus is unsuccessful in the attempt to communicate with said central location; establishing a new time within the first call-in window at which said apparatus will initiate an attempt to communicate with said central location in response to instructions from said central location if said apparatus has not attempted to initiate communication with said central location and an end time of the first call-in window is changed; and establishing a time within a second call-in window at which said apparatus will initiate an attempt to communicate with said central location in accordance with instructions from said central location if said retry flag is set.

Claim 20

A method of transferring information over a communication network from a remote apparatus to a central location, the method comprising the steps of: receiving instructions from said central location including instructions for initiating attempts to transfer information to said central location in accordance with a sequence comprising at least two call-in windows; establishing a time within a first call-in window at which said apparatus will initiate an attempt to communicate with said central location in accordance with instructions from said central location; attempting to communicate with said central location at the time within the first call-in window; transmitting the information over said communication network if said apparatus successfully communicates with said central location; setting a retry flag if said apparatus is unsuccessful in the attempt to communicate with said central location; establishing a new time within the first call-in window at which said apparatus will initiate an attempt to communicate with said central location in response to instructions from said central location if said apparatus has not attempted to initiate communication with said central location and an end time of the first call-in window is changed; and establishing a time within a second call-in window at which said apparatus will initiate an attempt to communicate with said central location in accordance with instructions from said central location if said retry flag is set.