Noise control system for transmission network

Claim 2

In a two-way, broad-band, high frequency coaxial communications system, a central transmitting and receiving unit, a plurality of remote transmitting and receiving units, a primary coaxial trunk line connected to said central unit, a plurality of coaxial feeder lines each connected to one or more of said remote units, means connecting said feeder lines to said trunk line at spaced points therealong to establish signal transmission paths between said central unit and said remote units, a plurality of bi-directional amplifier means interposed at selected points in said transmission paths, each including a forward amplifier for amplifying signals transmitted downstream from said central unit to one or more selected remote units and a return amplifier for amplifying signals transmitted upstream from one or more remote units to said central unit, and a control means including: means for normally disabling selected ones of said return amplifiers sufficient to block the upstream signal paths from all of said remote units; means for sensing an upstream transmission from a remote unit having a disabled return amplifier in its upstream signal path; means for enabling each return amplifier in said upstream signal path of said transmitting remote unit in response to a predetermined signal characteristic of said upstream transmission; and means for disabling each said enabled return amplifier when said transmitting remote unit ceases transmission.

Claim 3

The combination set forth in claim 1 wherein each of said normally disabled return amplifiers blocks the upstream signal paths of all of the remote units connected to a selected feeder line.

Claim 4

The combination set forth in claim 2 wherein each of said normally disabled return amplifiers blocks the upstream signal paths of all of the remote units associated with at least one additional selected feeder line.

Claim 5

The combination set forth in claim 1 wherein said control means includes a control unit associated with each of said selected normally disabled return amplifiers for controlling said associated amplifier, said control unit comprising: a signal detector and amplifier means having an input connected to the input of a controlled amplifier and an output connected to said controlled amplifier for normally disabling said controlled amplifier and for sensing an upstream transmission to said controlled amplifier to deliver an output enabling signal to said amplifier in response to said predetermined signal characteristic of said sensed upstream transmission.

Claim 6

The combination set forth in claim 4 wherein said predetermined signal characteristic occurs in a predetermined frequency range and said control unit is tuned to respond to upstream transmissions within said predetermined frequency range.

Claim 7

The combination set forth in claim 1 wherein said means for connecting said feeder lines to said trunk line includes: at least one isolation network having a plurality of coaxial terminals, wherein signals delivered to one of said terminals is transmitted to the remainder of said terminals and signals delivered to said remainder of said terminals are transmitted only to said one terminal; and a like plurality of bi-directional amplifier means, each including a forward amplifier and a return amplifier, one of said bi-directional amplifiers connecting said one terminal of said isolation network to said trunk line and said remainder of said bi-directional amplifier means each connecting one of said remaining terminals to a feeder line.

Claim 8

The combination set forth in claim 6 wherein said selected return amplifiers comprise the return amplifier of each bi-directional amplifier means connecting each isolation network to said trunk line.

Claim 9

The combination set forth in claim 6 wherein said selected return amplifiers comprise the return amplifier of each bi-directional amplifier means connecting each isolation network to a feeder line.

Claim 10

In a two-way, broad-band, high frequency coaxial communications system, a central transmitting and receiving unit, a plurality of remote transmitting and receiving units, a primary coaxial trunk line connected to said central unit, a plurality of coaxial feeder lines, each connected to one or more of said remote units, at least one isolation network having a plurality of coaxial terminals wherein signals delivered to one of said terminals are transmitted to the remainder of said terminals and signals delivered to said remaining terminals are transmitted only to said one terminal, a plurality of bi-directional amplifier means, each including a forward amplifier for amplifying signals transmitted downstream from said central unit to one or more selected remote units and a return amplifier for amplifying signals transmitted upstream from one or more of said remote units to said central unit for connecting said one terminal of each isolation network to said trunk line and for connecting said remaining terminals of each isolation network to said feeder lines, and a control unit for controlling selected ones of said bi-directional amplifier means, said control unit comprising: a receiver for serially receiving downstream data signals applied to said controlled bi-directional amplifier means identifying a selected remote unit for subsequent upstream transmission therefrom; a buffer register coupled to said receiver for Accepting and storing signals and having a parallel coded output; decoder means coupled to the output of said buffer register for generating a first signal in response to a coded output from said buffer register identifying a remote unit in the signal path of said controlled bi-directional amplifier means and for generating a second signal in response to a coded output from said buffer register not identifying a remote unit in said signal path; clock means coupled to said receiver for generating timing pulses when said receiver receives a downstream transmission; means for applying said timing pulses to said buffer register to enable said buffer register to accept and store said downstream signals from said receiver and for applying said stored signals to said decoder means; and a flip-flop connected between said decoder means and the return amplifier of said controlled bi-directional amplifier means for enabling said return amplifier in response to said first generated decoder signal and for disabling said return amplifier in response to said second generated decoder signal.

Claim 11

In a two-way, broad-band, high frequency coaxial communications system, a central transmitting and receiving unit, a plurality of remote transmitting and receiving units, a primary coaxial trunk line connected to said central unit, a plurality of coaxial feeder lines, each connected to one or more of said remote units, at least one isolation network having a plurality of coaxial terminals wherein signals delivered to one of said terminals are transmitted to the remainder of said terminals and signals delivered to said remaining terminals are transmitted only to said one terminal, a plurality of bi-directional amplifier means, each including a forward amplifier for amplifying signals transmitted downstream from said central unit to one or more selected remote units and a return amplifier for amplifying signals transmitted upstream from one or more of said remote units to said central unit for connecting said one terminal of each isolation network to said trunk line and for connecting said remaining terminals of each isolation network to said feeder lines, and a control unit for controlling selected ones of said bi-directional amplifier means, said control unit comprising: a receiver for serially receiving downstream data signals applied to said controlled bi-directional amplifier means identifying a selected remote unit for subsequent upstream transmission therefrom; a buffer register coupled to said receiver for Accepting and storing signals and having a parallel coded output; decoder means coupled to the output of said buffer register for generating a first signal in response to a coded output from said buffer register identifying a remote unit in the signal path of said controlled bi-directional amplifier means and for generating a second signal in response to a coded output from said buffer register not identifying a remote unit in said signal path; clock means coupled to said receiver for generating timing pulses when said receiver receives a downstream transmission; means for applying said timing pulses to said buffer register to enable said buffer register to accept and store said downstream signals from said receiver and for applying said stored signals to said decoder means; and a flip-flop connected between said decoder means and the return amplifier of said controlled bi-directional amplifier means for enabling said return amplifier in response to said first generated decoder signal and for disabling said return amplifier in response to said second generated decoder signal.

Claim 12

The combination set forth in claim 9 wherein a downstream transmission immediately following an upstream transmission from said selected remote unit generates a non-identifying coded output from said buffer register.

Claim 13

A control means for minimizing noise in a two-way, broad-band, high frequency, communications system of the type including a central transmitting and receiving unit, a plurality of remote transmitting and receiving units, a primary coaxial trunk line connected to the central unit, coaxial feeder lines connected to one or more remote units, distributing means at selected points along the trunk line for selectively coupling two or more feeder lines to the trunk line at each selected point to establish signal transmission paths between said central and remote units, a plurality of bi-directional amplifier means interposed in said paths each including a forward amplifier for amplifying signals transmitted downstream from the central unit to one or more selected remote units and a return amplifier for amplifying signals transmitted upstream from one or more selected remote units to the central unit, said control means comprising: means for normally disabling a selected one of the return amplifiers; means for sensing an upstream transmission from a remote unit in the signal path of said disabled return amplifier; means for enabling said return amplifier in response to a predetermined signal characteristic of the upstream transmission; and means for disabling said return amplifier when the remote unit associated therewith ceases transmission.

Claim 14

A control means for minimizing noise in a two-way, broad-band, high frequency, communications system of the type including a central transmitting and receiving unit, a plurality of remote transmitting and receiving units, a primary coaxial trunk line connected to the central unit, coaxial feeder lines connected to one or more remote units, distributing means at selected points along the trunk line for selectively coupling two or more feeder lines to the trunk line at each selected point to establish signal transmission paths between said central and remote units, a plurality of bi-directional amplifier means interposed in said paths each including a forward amplifier for amplifying signals transmitted downstream from the central unit to one or more selected remote units and a return amplifier for amplifying signals transmitted upstream from one or more selected remote units to the central unit, said control means comprising: means for normally disabling a selected one of the return amplifiers; means for sensing an upstream transmission from a remote unit in the signal path of said disabled return amplifier; means for enabling said return amplifier in response to a predetermined signal characteristic of the upstream transmission; and means for disabling said return amplifier when the remote unit associated therewith ceases transmission.

Claim 15

A control means according to claim 11 wherein said control means includes a signal detector and amplifier means having an input connected to the input of a controlled return amplifier and an output connected to said controlled return amplifier for delivering an enabling signal thereto in response to said predetermined signal characteristic of said sensed upstream transmission.

Claim 16

A control means according to claim 12 wherein said predetermined signal characteristic occurs in a predetermined frequency range and said detector and amplifier means is tuned to respond to only those upstream transmission signals within said predetermined frequency range.

Claim 17

A control means according to claim 13 wherein the controlled return amplifier forms part of a distributing means.

Claim 18

A control means according to claim 13 wherein a controlled return amplifier is connected in a feeder line.

Claim 19

A control means according to claim 15 wherein the controlled return amplifier is the feeder line return amplifier nearest the distribution means coupling the feeder line to the trunk line.

Claim 22

The method set forth in claim 17 wherein a disabled return amplifier is selectively enabled in response to a downstream transmission.

Claim 23

The method set forth in claim 17 wherein a disabled return amplifier is selectively enabled in response to an upstream transmission.