System and method for transmitting data between terminals based upon progress vectors

Abstract

By employing easy determination logic, the amount of communication required for broadcasting and relaying is effectively reduced, and the message transmission efficiency is improved. A mobile terminal Tincludes determination logic. According to this logic, when a message is issued, via an arbitrary terminal, by a transmission source terminal Tto a relay terminal Tand the message is relayed by the relay terminal Tto the terminal Tthe terminal Tcalculates an information progress vector I, which indicates the direction in which information progresses, and a terminal progress vector M, which indicates the direction in which the terminal Tprogresses. Then, the terminal Tobtains an inner product cos θ for which the information progress vector I and the terminal progress vector M are standardized, and forwards the received message when the condition cos θ≧0 is established.