Patent ID: 6122286
Filing Date: 2000-09-19
Classification: H04L

Abstract:
A method of controlling access to a transmission channel jointly used by a plurality of data sources, which comprises:transmitting, with each of a plurality of data sources, data frames with address information, useful data, and a check sequence;forming a logic AND combination of all output signals of the plurality of data sources through the transmission channel;evaluating, with the data sources, a data collision signal having a value corresponding to the logic AND combination;transmitting with each of the plurality of data sources, between two data frames, an idle bit sequence, which isa) a sequence of logic one values if the output signal of the data source and the data collision signal are not identical; andb) a FLAG signal after a complete transmission of a data frame or after a transmission of a data frame has been aborted, or if the data collision signal contained in direct succession a greater number of logic one values than a transmission abort signal; anddefining two priority levels for the transmission of data through the transmission channel, the priority levels being:0. corresponding to a high priority in which transmission is enabled when the data collision signal corresponds to a sequence of n FLAG signals; and1, corresponding to a low priority in which transmission is enabled when the data collision signal corresponds to a sequence of n+1 FLAG signals;wheren=1 in event of a common OPEN/CLOSE FLAG; andn=2 in event of separate OPEN and CLOSE FLAGS.