Time-division switching system

In combination:

• timing means for generating a plurality of equally spaced timing signals defining time slots of fixed duration;
• an input time-division multiplex line carrying a plurality of channels of digital data words wherein the time duration of each channel is substantially equal to one of said time slots of fixed duration and wherein each digital data word is in a first format and occupies substantially an entire time multiplexed channel;
• a switching network having input and output terminals and comprising a plurality of switching elements;
• means for establishing communication paths through said switching network at a rate such that any given switching element may be used in any given communication path for a period of time less than or equal to one of said time slots of fixed duration;
• first formatting means for converting said digital data words from said first format to a second format wherein each data word includes a start code;
• means, responsive to said timing signals, for serially transmitting the data words in said second format to an input terminal of said switching network in a period of time less than one of said time slots of fixed duration;
• receive means, connected to the output terminals of said switching network, responsive to said start code for receiving the data words in said second format;
• second formatting means for converting the data words in said second word format received by said receive means to said first format;
• and
• retransmission means for transmitting said data words in said first format from said second formatting means on output time-division multiplex lines wherein the time duration of each channel of said output time-division multiplex lines is substantially equal to one of said time slots of fixed duration and wherein each digital data word occupies substantially an entire time multiplex channel.

In combination:

• timing means for generating a series of equally spaced timing signals defining time slots of fixed duration;
• a source of digital words;
• a storage means for storing said digital words;
• means for serially transmitting said digital words from said source to said storage means at a first bit rate;
• a switching network comprising input and output terminals for selectively completing time-division communication paths between said input and said output terminals wherein said communication paths exhibit transmission delays of significant duration with respect to one of said word time slots and which time delays vary in accordance with the communication path selected;
• means for controlling said switching network to establish communication paths such that the holding time for any point along said communication path is less than or equal to one of said time slots;
• reformatting means for reading digital words from said storage means and for concatenating a start code to the beginning thereof;
• means responsive to said timing signals for serially transmitting each of said digital words and its associated start code obtained from said reformatting means to the inputs of said switching network at a second bit rate and within a period of time less than or equal to one of said time slots, said second bit rate being faster than said first bit rate;
• and
• receive means connected to the output terminals of said switching network responsive to said start code for receiving said digital words.

In combination:

• a first digital transmitter for transmitting serial data words in time separated channels in a first code format wherein each data word in said first code format occupies substantially an entire one of said channels;
• a first digital data receiver, operating in synchronism with said first digital data transmitter, for receiving data words in said first code format and for converting said data words to a second code format wherein each data word includes a start code;
• a switching network having a plurality of input and output terminals;
• a second digital data transmitter connected to said first digital data receiver for serially transmitting date words in said second format to an input terminal of said switching network in a period of time less than one of said time separated channels;
• and
• a second digital data receiver connected to an output terminal of said switching network responsive to said start code for receiving data words in said second code format asynchronously with respect to said second digital data transmitter.

In combination:

• a first digital transmitter for transmitting serial data words in time separated channels in a first code format wherein each data word digit in said first code format comprises two digit portions and each data word occupies substantially an entire one of said time separated channels;
• a first digital data receiver, operating in synchronism with said first digital data transmitter, for receiving data words in said first code format and for converting said data words to a second code format wherein each data word digit comprises one digit portion and each data word includes a start code;
• a high-capacity switching network having a plurality of input and output terminals with a plurality of serially connected networdk stages therebetween;
• control means for establishing communication paths between said input and output terminals of said switching network by establishing paths through said serially connected network stages in sequence and overlapped in time;
• a second digital data transmitter connected to said first digital data receiver for serially transmitting data words in said second format to an input terminal of said switching network in a period of time approximately 5/8 of the time duration of one of said time separated channels;
• and
• a second digital data receiver connected to an output terminal of said switching network responsive to said start code for receiving data words in said second code format asynchronously with respect to said second digital data transmitter.