Stromberg-carlson Corporation

Jayantkumar R Shah

Pedro A Lenk

Barrie Brightman

William H Stewart

George D Elliott

John W Woodward

Thomas E Ellis

Haresh C Jotwani

David L Hinshaw

James E Jones

Thomas H McKinney

Dennis L Edinger

Robert H Bradshaw

Rick L Mantz

Nickoline P Mealo

A telephone switching system for telephone trunk and subscriber lines that carry voice and associated supervisory information signals. The voice signals are received through one of a plurality of ports under the control of a port event processor, and are transferred through a switching arrangement under the control of a call processor for transmission through a second port. The supervisory information is received with the associated voice signals, and is sampled and stored in a port data store memory. The call processor can retrieve or modify the supervisory information stored in the port data memory store, and can store control information in the port data store. The port event processor enables the transfer of certain supervisory information from the port data store for transmission with the associated voice signals to the respective port. The port event processor also performs certain operations specified by the commands and supervisory information stored in the port data store memory. The port event processor and port data store memory both operate under control of timing signals from a timing signal generator. The timing generator generates timing signals of two frequencies. The port data store memory samples the sense supervisory information signals at a rate dependent upon the higher frequency timing signal, and the port event processor controls the operation of the respective ports in response to the lower frequency timing signal.

Sampled port data switching system employing interactive processors

A telephone switching system for telephone lines in a telephone network that carry voice and associated supervisory information signals. The voice signals are received through one of a plurality of ports under the control of a port event processor and are transferred through a switching arrangement, under the control of a call processor, and transmitted through a port again under the control of the port event processor. The received supervisory information is stored in a port data store memory, which also stores call state and command information. The port event processor retrieves the stored supervisory information and commands from the port data store memory, and processes the supervisory information in response to the commands in at least two functional units, and returns processed information for storage in the port data store memory.

Arrangement of interactive telephone switching processors providing

A common control for a community office (C.O.) switching system includes two interactive processors. A call control processor comprises the uppermost element in the control hierarchy and is a stored program processor that controls call progression, marks paths through a matrix switch network, and performs other functions. A port event processor constructed of 'combinatorial logic' is sequentially coupled to every port equipment position connected thereto over a four millisecond scan cycle. Interaction between the call control processor and the port event processor is effected through a port data store, which provides an individual port data file per port equipment position. The port event processor also includes timers that respond to call timing information that can be stored in a port data field for controlling the processing of certain signals from the corresponding port equipment position.

Arrangement of interactive telephone switching processors for performing

A ring trip circuit adapted for use in a community office switching system that includes a call control processor and a port event processor. The call control processor and port event processor interact through a port storage unit that contains information corresponding to each telephone line connected to the switching system. The switching system also includes a ringing generator for transmitting ringing signals onto a telephone line to a called party. Windings for a common bridge relay connect in circuit with each telephone line and diodes shunt the windings so the relay responds only to signals of one polarity. The contacts of the common bridge relay, therefore, reflect the duty cycle of the signal through the common bridge relay and this duty cycle varies when the called party goes off-hook during a ringing burst. The common bridge relay produces a supervisory signal that is sampled and transferred, for each telephone line, to a corresponding port storage area. A single ring trip analyzer sequentially monitors each port storage means during a ringing operating to determine whether the supervisory signal indicates that the called instrument has been taken off-hook. When this occurs, the analyzer updates control information in a corresponding port storage area to control the state of a ring delay. The ring delay then opens and removes the ringing signal from the corresponding telephone line. The analyzer also detects off-hook status during intervals between successive ringing bursts and during normal operations when a subscriber lifts a telephone off-hook in order to place a call.

Ring trip apparatus for a line circuit connected to DCO switch

A central office telephone switching system including two interactive processors, including a call control processor that controls calls by establishing sequences of call progression states, and a port event processor that controls the ports and transmits and receives supervisory information to and from the ports. The port event processor and call control processor communicate through a port data store. The port event processor transfers the received supervisory information to the port data store, for use by the call control processor. The port event processor includes a digital filter that periodically time-samples the received supervisory information and determines the proper state of the received supervisory signal based on the states of the majority of the received sample signals.

Filtering of port data in a switching system employing interactive

A community office switching system includes a three-level hierarchy of distributed processors operating in parallel with one another to control the operation of a central office matrix switch network interconnecting 1,920 ports. At the highest level, a stored-program call control processor controls call progression, establishing paths through the matrix switch network. At the second level, a series of special-purpose, stored-program, port control processors each service 960 ports, sensing and transmitting supervisory signals and communicating the occurrence of significant port events to the call control processor. Each port event control processor dedicates approximately 32 microseconds out of every 32 milliseconds to each of the 960 ports in time-multiplexed fashion, and hence no port can ever be locked out at the port-control-processor level. One from a series of stored programs is executed to service each port precisely one every 32 milliseconds. At the lowest level, a digital filtering processor, associated with each port control processor, samples some signals from each port once every millisecond, filters the sampled signals to give one filtered sample every four milliseconds, and stores the filtered samples for presentation to the associated port control processor once every 32 milliseconds.

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Longwood, FL, United States of America

Jayantkumar R Shah