Off-hook initiated demand assignment communications
First Claim
1. A method of establishing a communication link between a calling switch and a called switch through originating and terminating relay stations via selected channels from a pool of demand assigned channels between said originating and terminating relay stations, comprising the steps of:
- (a) generating, on a selected one of a plurality of originating trunks between said calling switch and an originating earth station, first supervisory signals indicative of the on-hook or off-hook state of said trunk, each of said trunks being dedicated to communications destined for a particular called switch via a particular terminating relay station;
(b) monitoring said selected trunk to detect a first supervisory signal indicative of the off-hook state of said selected trunk;
(c) determining at said originating relay station the particular called switch and particular terminating relay station to which said selected trunk is dedicated;
(d) selecting an available channel from said pool of channels to connect said originating and terminating relay stations;
(e) determining at said terminating relay station the particular called switch to which the selected channel is to be connected; and
(f) connecting said selected channel to said calling and called switches.
1 Assignment
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Accused Products
Abstract
Off-hook initiated demand assignment (OHIDA) has particular application in communications satellite systems and provides basic demand assignment trunk service by utilizing an off-hook and on-hook signal processing system to monitor and control terrestrial access circuits. The signal processing system operates under the control of a central processing unit to interrogate each trunk of line. The detection by a signal scanner of an off-hook condition initiates the call processing sequence. Once the trunks between the originating and terminating terrestrial circuit switches are connected via the satellite circuits, the connected trunks are under the control of the circuit switches throughout the address signalling, the message and the call terminating stages. Call complete detection is performed by a signal scanner to detect an on-hook condition so that the satellite circuit may be disconnected.
36 Citations
11 Claims
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1. A method of establishing a communication link between a calling switch and a called switch through originating and terminating relay stations via selected channels from a pool of demand assigned channels between said originating and terminating relay stations, comprising the steps of:
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(a) generating, on a selected one of a plurality of originating trunks between said calling switch and an originating earth station, first supervisory signals indicative of the on-hook or off-hook state of said trunk, each of said trunks being dedicated to communications destined for a particular called switch via a particular terminating relay station; (b) monitoring said selected trunk to detect a first supervisory signal indicative of the off-hook state of said selected trunk; (c) determining at said originating relay station the particular called switch and particular terminating relay station to which said selected trunk is dedicated; (d) selecting an available channel from said pool of channels to connect said originating and terminating relay stations; (e) determining at said terminating relay station the particular called switch to which the selected channel is to be connected; and (f) connecting said selected channel to said calling and called switches. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification