Method and apparatus for transmitting data in adjustable-sized packets

A method of transmitting data in packets in a data telecommunications system, said system including an initiating unit of data terminal equipment and a receiving unit of data terminal equipment, a first modem connected between the initiating unit and the communication lines and a second modem connected between said receiving unit and said telephone lines, said method comprising the steps of:

• (a) transmitting a stream of data characters from said initiating unit to said first modem for transmission over communication lines to said second modem;
• (b) forming a data packet of the next N characters in said data stream received by said first modem, said data packet including additional identifying data;
• (c) transmitting said data packet or a group of said data packets from said first modem to said second modem;
• (d) incrementing a counter indicating the number of data packets or groups of data packets transmitted;
• (e) checking said data in said transmitted data packet for errors;
• (f) if an error is found in a transmitted data package, incrementing a counter indicating the number of data packets or groups of data packets retransmitted and repeating steps (c) through (e);
• (g) determining an optimum packet size N based on a ratio of retransmissions to transmissions;
• (h) repeating steps (b) through (g) until said data stream is transmitted.

A data telecommunication system for transmitting data in packets over communication lines including an initiating unit of data terminal equipment and a receiving unit of data terminal equipment, a first modem connected between the intiating unit and communication lines and a second modem connected between the receiving unit and communication lines, the first and second modems including means to transmit data between said modems, the system comprising:

• means for dividing data transmitted from said initiating modem to said first modem into distinct data packets each of said packets including identifying data, and said means for transmitting data between said first and second modems including means to transmit said data packets;
• means for detecting errors in said data packets transmitted between said first and second modems;
• means for retransmitting data packets in which errors have been detected;
• means for counting the number of data packets or groups of data packets transmitted and means for counting the number of data packets or groups of data packets retransmitted
• means for determining an optimum size of said data packets based on a ratio of said count of transmissions to a count of retransmissions.

A modem for use in a data telecommunications system for transmitting data in packets over communication lines, said modem connected between the unit of data terminal equipment and communication lines, said modem including means to transmit data between said modem and a second modem, the modem comprising:

• means for dividing data transmitted from said modem to said second modem into distinct data packets each of said packets including identifying information, and said means for transmitting data between said modem and second modem including means to transmit said data packets;
• means for detecting errors in said data packets transmitted between said modem and second modem;
• means for retransmitting data packets in which errors have been detected;
• means for counting the number of data packets or groups of data packets transmitted and means for counting the number of data packets or groups of data packets retransmitted;
• means for determining an optimum size of said data packets based on a ratio of said count of transmissions to said count of retransmissions.