Local area network with star topology and ring protocol

A star network coupler for switching data between optical transmission lines in a network, each of the optical transmission lines connecting said star network coupler to a communication node, said star network coupler comprising:

• a plurality of interface means, corresponding to the optical transmission lines, for interfacing with the optical transmission lines, and each of said interface means has at least one corresponding optical transmission line;
• switching means for switching transmission data from each of said interface means to any one of said interface means, said switching being dependent upon a ring protocol, said interface means being ordered according to the ring protocol to define a sequence of said interface means, the data bypassing any of said interface means corresponding to an inactive optical transmission line;
• said at least one corresponding optical transmission line includes opto/electrical conversion means for converting input optical signals from the at least one corresponding optical transmission line into electrical signals output as the transmission data from said interface means;
• electro/optical conversion means for converting the transmission data, switched thereto by said switching means, into output optical signals for output to the at least one corresponding optical transmission line;
• and
• status means for supplying a line status signal indicating communication activity on the at least one corresponding optical transmission line;
• wherein said switching means includes selective multiplexing means for receiving the line status signal from said status means in each of said interface means and the transmission data from said interface means and for switching the transmission data to said interface means in dependence upon the ring protocol and the line status signal from said status means in each of said interface means;
• said selective multiplexing means including a plurality of multiplexers, each having an output operatively connected to said electro/optical conversion means in a corresponding interface means and inputs operatively connected to said opto/electrical conversion means in said interface means to receive the transmission data;
• and
• a like plurality of priority encoders, each having inputs operatively connected to said status means in said interface means and an output operatively connected to a corresponding multiplexer to supply a selection signal controlling selection of the transmission data from said opto/electrical conversion means in said interface means most closely preceding the corresponding interface means and having an active communication status indicated by the line status signal.

A star network coupler for switching data between optical transmission lines in a network, each of the optical transmission lines connecting said star network coupler to a communication node, said star network coupler comprising:

• a plurality of interface means, corresponding to the optical transmission lines, for interfacing with the optical transmission lines, and each of said interface means has at least one corresponding optical transmission line;
• switching means for switching transmission data from each of said interface means to any one of said interface means, said switching being dependent upon a ring protocol, said interface means being ordered according to the ring protocol to define a sequence of said interface means, the data bypassing any of said interface means corresponding to an inactive optical transmission line;
• said at least one corresponding optical transmission line includes opto/electrical conversion means for converting input optical signals from the at least one corresponding optical transmission line into electrical signals output as the transmission data from said interface means;
• electro/optical conversion means for converting the transmission data, switched thereto by said switching means, into output optical signals for output to the at least one corresponding optical transmission line;
• and
• status means for supplying a line status signal indicating communication activity on the at least one corresponding optical transmission line;
• wherein said switching means includes selective multiplexing means for receiving the line status signal from said status means in each of said interface means and the transmission data from said interface means and for switching the transmission data to said interface means in dependence upon the ring protocol and the line status signal from said status means in each of said interface means;
• said selective multiplexing means comprises groups of logic gates, each group connected to a corresponding electro/optical conversion means to supply the transmission data and comprising:
• first logic gates, each producing a selection signal and operatively connected to receive the line status signal from said status means in a corresponding interface means and to receive an inverted selection signal from an immediately preceding first logic gate according to the sequence of said interface means, except for an initial first logic gate operatively connected to receive a cascade input;
• second logic gates, each having an output and having inputs operatively connected to receive the selection signal from a corresponding first logic gate, the transmission data from said opto/electrical conversion means in the corresponding interface means and one of the inverted selection signal and the cascade input received by the corresponding first logic gate;
• and
• an output logic gate having inputs operatively connected to the output of each of said second logic gates and an output operatively connected to the corresponding electro/optical conversion means.

A switching system for a star coupled communication network having transmission lines connecting said switching system to communication nodes, comprising:

• communication status means for outputting line status signals, each indicating communication activity on a corresponding one of the transmission lines transmitting data to said switching system;
• selective multiplexing means for receiving the line status signals from said communication status means and data signals from the transmission line sand for switching the data signals received from each of the transmission lines transmitting data to a following transmission line according to a sequence defined by a ring protocol and corresponding to one of the line status signals indicating active communication;
• said selective multiplexing means includes a plurality of multiplexers, each having an output operatively connected to the corresponding transmission line and inputs operatively connected to all of the transmission lines capable of sending data to the switching system;
• and
• a plurality of priority encoders, each having inputs operatively connected to said communication status means and an output operatively connected to a corresponding multiplexer to supply a selection signal controlling selection of the transmission data from the transmission line having a corresponding line status signal indicating active communication and most closely preceding the corresponding transmission line according to the sequence defined by the ring protocol.

A switch system for a star coupled communication network having transmission lines connecting said switching system to communication nodes, comprising:

• communication status means for outputting line status signals, each indicating communication activity on a corresponding one of the transmission lines transmitting data to said switching system;
• selective multiplexing means for receiving the line status signals from said communication status means and data signals from the transmission line sand for switching the data signals received from each of the transmission lines transmitting data to a following transmission line according to a sequence defined by a ring protocol and corresponding to one of the line status signals indicating active communication;
• said selective multiplexing means includes groups of logic gates, each group connected to a corresponding transmission line to supply the transmission data thereto and including:
• first logic gates, each producing a selection signal and operatively connected to receive one of the line status signals from said communication status means and to receive an inverted selection signal from an immediately preceding first logic gate according to the sequence of transmission lines defined by the ring protocol, except for an initial first logic gate, the initial first logic gate receiving a cascade input;
• second logic gates, each having an output and input operatively connected to receive the selection signal from a corresponding first logic gate, the transmission data from one of the transmission lines and one of the inverted selection signal and the cascade input received by the corresponding first logic gate;
• and
• an output logic gate having inputs operatively connected to the output of said second logic gates and an output operatively connected to the corresponding transmission line.

A data communication network transmitting data between communication nodes, comprising:

• transmission lines for transmitting data, each transmission line having first and second ends, the first end operatively connected to one of the communication nodes;
• and
• star network couplers operatively connected to the second ends of said transmission lines, each of said star network couplers including:
• communication status means including a plurality of multiplexers each for outputting line status signals, each indicating communication activity on a corresponding transmission line;
• and
• selective multiplexing means for receiving the line status signal from said communication status means and data signals from the transmission lines, respectively, through one of a like plurality of priority encoders and for switching the transmission data received from each of the transmission lines transmitting data to a following transmission line according to a sequence defined by the ring protocol and corresponding to one of the line status signals indicating active communication, each of said star network couplers also operatively connected to at least one other star network coupler and transmitting data internally according to a ring protocol from one active transmission line to only one other active transmission line.

A method of centralizing the switching of data between transmission lines connected to communication nodes which form a ring topology, said method comprising:

• (a) automatically detecting communication activity in each of a plurality of transmission lines;
• (b) connecting the transmission lines by logical cognitive selection of said activity such that said communication nodes form a specific ring topology, said topology excluding a selected number of failed communication nodes and transmission lines;
• and
• (c) transmitting data received from the selected transmission lines to a single transmission line selected for each of the transmission lines as having an active communication activity level detected in step (a) and following most closely thereafter according to the sequence defined in step (b).