DATA TRANSMISSION SYSTEM FOR A LOCAL NETWORK

摘要

A local network, in which a plurality of data processors are coupled by modems to a communication medium, is disclosed. Each modem is arranged to shift a carrier frequency to a first and second frequency according to a digital signal from the associated data processor. In order to provide for reliable and quick detection of a collision of signals simultaneously transmitted from a plurality of modems to the communication medium, the difference between the first and second frequencies is set such that one cycle of a beat signal generated on the communication medium due to a collision of signals is not longer than one bit time length of the digital signal.