Switching of time division multiplex lines through telephone central offices

Claim 2

An arrangement for switching communications channels carried by time division multiplex lines through a space division switching network of a switching office having a common control unit, comprising, a trunk circuit for each of said communications channels carried by one of said time division multiplex lines, each of said trunk circuits having an appearance in said switching network, means for storing in each said trunk circuit the contents of a respective incoming one of said communications channels, means responsive to the appearance of a predetermined code in said storing means for signaling said common control unit to establish a cross-office connection in said switching network, means for transmitting the contents of said stored channel through said established cross-office connection at a bit transmission rate lower than the characteristic pulse repetition rate of any of said time division multiplex lines, means for receiving said communications channel information transmitted over said cross-office connection, and means for transferring said received channel information from said receiving means to an outgoing one of said time division multiplex channels at said characteristic pulse repetition rate.

Claim 3

An arrangement for switching communications channels carried by time division multiplex lines through a switching network of a common control switching office, said office having an incoming register normally operable to receive call signaling information from an incoming trunk, an incoming register link operable to connect a trunk in the calling condition to said incoming register, and a common control for establishing a cross-office connection through said network in response to information received in said register over said link, comprising, first means in each of said trunk circuits for storing the contents of one of said communications channels incoming from a distant office, second means in said trunk circuit for storing information destined for said distant office, means for detecting the storage of information in said first storing means representing a request for the establishment of a cross-office connection, means controlled by said detecting means for operating said incoming register link to connect said incoming register to said first storing means, means responsive to the connection of said incoming register to said first storing means for making an information entry into said second storing means for transmission to said distant office, and means operative subsequent to the establishment of said cross-office connection by said common control for transmitting the contents of said first storing means through said cross-office connection at a bit transmission rate lower than the characteristic pulse repetition rate of said time division multiplex lines.

Claim 4

An arrangement for switching communications channels carried by time division multiplex lines through a switching network of a common control switching office, said office having an incoming register normally operable to receive call signaling information from an incoming trunk, an incoming register link operable to connect a trunk in the calling condition to said incoming register, and a common control for establishing a cross-office connection through said network in response to information received in said register over said link, comprising, first means in each of said trunk circuits for storing the contents of one of said communications channels incoming from a distant office, second means in said trunk circuit for storing information destined for said distant office, means for detecting the storage of information in said first storing means representing a request for the establishment of a cross-office connection, means controlled by said detecting means for operating said incoming register link to connect said incoming register to said first storing means, means responsive to the connection of said incoming register to said first storing means for making an information entry into said second storing means for transmission to said distant office, and means operative subsequent to the establishment of said cross-office connection by said common control for transmitting the contents of said first storing means through said cross-office connection at a bit transmission rate lower than the characteristic pulse repetition rate of said time division multiplex lines.

Claim 5

An arrangement for switching time division multiplex signals through a telephone central office having a switching network, comprising an incoming time division multiplex line appearing at one side and an outgoing time division multiplex line appearing at the other side of said switching network, said incoming line defining a number of information carrying time slots, a first plurality of shift registers equal in number to the number of time slots defined by said incoming line, said registers being connected between said incoming line and said one side of said network, means for storinG the contents of said time slots defined by said incoming line in respective ones of said shift registers, a plurality of pulse sources equal in number to the number of said time slots, said pulse sources having a repetition rate low enough to prevent excessive crosstalk in said switching network, a second plurality of shift registers connected between said other side of said network and said outgoing time division line, and means for sequentially connecting said pulse sources to transfer the contents of successive ones of said first plurality of registers through said network to respective ones of said second plurality of registers during a plurality of said time slot intervals.

Claim 6

An arrangement for switching time division multiplex signals through a telephone central office having a switching network, comprising an incoming time division multiplex line appearing at one side and an outgoing time division multiplex line appearing at the other side of said switching network, said incoming line defining a number of information carrying time slots, a first plurality of shift registers equal in number to the number of time slots defined by said incoming line, said registers being connected between said incoming line and said one side of said network, means for storinG the contents of said time slots defined by said incoming line in respective ones of said shift registers, a plurality of pulse sources equal in number to the number of said time slots, said pulse sources having a repetition rate low enough to prevent excessive crosstalk in said switching network, a second plurality of shift registers connected between said other side of said network and said outgoing time division line, and means for sequentially connecting said pulse sources to transfer the contents of successive ones of said first plurality of registers through said network to respective ones of said second plurality of registers during a plurality of said time slot intervals.

Claim 7

An arrangement for switching communications channels carried by time division multiplex lines through a switching network of a common control switching office adapted normally to establish cross-office connections between incoming and outgoing trunks appearing in said switching network comprising, an incoming time division multiplex line and an outgoing time division multiplex line each adapted to carry information at a characteristic pulse repetition rate higher than that normally transmissible through said switching network without causing excessive crosstalk, first and second storing means associated respectively with each of said outgoing and each of said incoming time division multiplex lines, means for storing the contents of an incoming one of said channels in said first storing means associated with said incoming time division multiplex line, and means for transmitting the contents of said first storing means associated with said incoming time division multiplex line to said second storing means associated with said outgoing time division multiplex line at a rate lower than said characteristic repetition rate.

Claim 8

An arrangement for switching communications channels carried by time division multiplex lines through a switching network of a common control switching office adapted normally to establish cross-office connections between incoming and outgoing trunks appearing in said switching network comprising, an incoming time division multiplex line and an outgoing time division multiplex line each adapted to carry information at a characteristic pulse repetition rate higher than that normally transmissible through said switching network without causing excessive crosstalk, first and second storing means associated respectively with each of said outgoing and each of said incoming time division multiplex lines, means for storing the contents of an incoming one of said channels in said first storing means associated with said incoming time division multiplex line, and means for transmitting the contents of said first storing means associated with said incoming time division multiplex line to said second storing means associated with said outgoing time division multiplex line at a rate lower than said characteristic repetition rate.

Claim 11

A method in accordance with claim 5 wherein said outpulsing is effective under the control of a pulse source rendered operative immediately following the loading of said input buffer.

Claim 12

A method in accordance with claim 5 wherein said cross-office connection is established by identifying a signal signifying a request for a cross-office connection in said input buffer, establishing a connection to extract call signaling information subsequently appearing in said input buffer, and signaling said remote central office to commence sending said call signaling information.

Claim 13

A method in accordance with claim 6 wherein said frame of time division multiplex signals includes N time slots wherein said input buffer is loaded during one of said time slots and wherein said second buffer is loaded during an interval longer than one said time slot but shorter than the N-1 time slots next ensuing after said input buffer is loaded.

Claim 14

An arrangement for switching through a telephone central office time division multiplex signals arriving over a line from a remote central office comprising a plurality of input buffers equal to the number of time slots defined by a frame of said time division multiplex signals, means for entering in a respective one of said buffers the contents of a corresponding one of said time slots, a plurality of outgoing trunks identifiable in accordance with call signaling inFormation contained in said input buffers, means for establishing a cross-office connection from each of said input buffers to one of said outgoing trunks identified by the call signaling information contained in the respective input buffer, means including a plurality of sources for delivering during an interval of time longer than that of one of said time slots but less than that defined by a complete frame of time slots a sequence of pulses equal in number to the number of bits contained in said input buffer and means for applying each of said sources to a respective one of said input buffers after the respective buffer has been loaded with information from a corresponding one of said time slots in said frame to thereby outpulse the contents of said respective one of said buffers.

Claim 15

An arrangement for switching through a telephone central office time division multiplex signals arriving over a line from a remote central office comprising a plurality of input buffers equal to the number of time slots defined by a frame of said time division multiplex signals, means for entering in a respective one of said buffers the contents of a corresponding one of said time slots, a plurality of outgoing trunks identifiable in accordance with call signaling inFormation contained in said input buffers, means for establishing a cross-office connection from each of said input buffers to one of said outgoing trunks identified by the call signaling information contained in the respective input buffer, means including a plurality of sources for delivering during an interval of time longer than that of one of said time slots but less than that defined by a complete frame of time slots a sequence of pulses equal in number to the number of bits contained in said input buffer and means for applying each of said sources to a respective one of said input buffers after the respective buffer has been loaded with information from a corresponding one of said time slots in said frame to thereby outpulse the contents of said respective one of said buffers.