Protocol for multiple access to a telecommunications channel from auxiliary terminals by digitized information messages and corresponding system

An auxiliary terminal for intercommunication by digital information messages in a network of auxiliary communication terminals managed by a central terminal, according to a multiple access protocol, one of said network auxiliary communication terminals being a current auxiliary communication terminal sending a reservation message of a given transmission order and said central terminal sending to each auxiliary communication terminal an allocation message of a subsequent transmission order successively, said digital information messages being generated through concatenation from a plurality of successive elementary information messages, each made up of data packets, to be sent to another one of said auxiliary communication terminals, said current and said another auxiliary communication terminals comprising at least one first path comprising, in cascade, an information message generator, a circuit for segmenting an information message into data packets, a buffer memory for storing said data packets and a transmitter for transmitting generated information messages, and a second path comprising a reservation message transmitter driven by the data packet segmenting circuit and by a transmission delay circuit receiving an acknowledge receipt message generated by said central terminal, said current auxiliary communication terminal further comprising:

• a circuit, connected to said data packet segmenting circuit, for calculating a transmission capacity load variable from the number of said data packets stored within said buffer memory of said current auxiliary terminal, said circuit receiving a signal, delivered by the packet segmenting circuit, representing the number of data packets to be transmitted and a signal representing the number of time intervals allocated by said allocation message of said given order transmitted by said central terminal.

A central terminal for intercommunication by digital information messages in a network of auxiliary communication terminals managed by a central terminal according to a multiple access protocol, each auxiliary communication terminal sending a reservation message of a given transmission order to said central terminal and said central terminal sending to each auxiliary terminal an allocation message of a subsequent transmission order, successively, said digital information messages being generated by a current auxiliary communication terminal through concatenation from a plurality of successive elementary information messages, each made up of data packets to be sent to another auxiliary communication terminal, said central terminal comprising:

• a circuit for receiving said reservation messages generated in turn by each current auxiliary communication terminal;
• a circuit, connected to said receiving circuit, for generating an acknowledge receipt message output to said current auxiliary communication terminal when said receiving circuit indicates said reservation messages have been received;
• a circuit, connected to said receiving circuit, for managing said reservation messages of said current auxiliary communication terminal and outputting allocation messages;
• a circuit, connected to said receiving circuit, for updating, for each current auxiliary communication terminal, load variables of transmission, of the number of data packets, of transmission capacity allocation and of allocation request status, outputting said load variables as updated variables;
• and
• a circuit for storing these updated variables, said managing circuit, receiving said updated variables output from said updating circuit, including means for carrying out management of said reservation messages according to a FIFO procedure updated by the values of said updated variables.

In a system for intercommunication by digital information messages including a network of terminals arranged in a distributed configuration, each of said terminals comprising:

• a first path comprising, connected in cascade, a generator for generating information messages, a circuit for segmenting said messages into data packets, a buffer memory for storing said data packets and a transmitter for transmitting the information messages;
• a second path comprising a reservation message transmitter driven by the packet segmenting circuit and a delay control circuit for controlling said reservation message transmitter;
• a calculating circuit for calculating a transmission capacity local load variable of the number of packets stored within said buffer memory of the current terminal, said calculating circuit receiving a signal, delivered by said data packet segmenting circuit, representing the number of data packets to be transmitted, and a signal, from said transmitter for transmitting information messages, representing the number of data packets authorized for transmission;
• a circuit for receiving said reservation messages generated by other terminals in said network;
• a circuit, connected to said receiving circuit, for managing said reservation messages of the terminals and outputting said allocation messages;
• a circuit, connected to said receiving circuit, for updating the load variables of transmission, of the number of packets, of transmission capacity allocation, and of allocation request status, outputting updated load variables;
• and
• a circuit for storing said updated load variables, said managing circuit, receiving said updated load variables form said updating circuit, including means for carrying out the management of said reservation messages according to a FIFO procedure updated by values of said updated load variables.