Method for accessing a medium in a synchronous communications network by a transmit node, computer program product, storage means and transmit node

摘要

The invention concerns a method for accessing a medium by a transmit node (111) in a synchronous communications network (101) comprising a plurality of nodes (110, 111) capable of accessing said medium during access time slots of predetermined duration to transmit data frames via said network. The plurality of nodes comprises a master node (110) that implements a clocking that defines a network cycle (313) for accessing said medium and comprises at least two slave nodes being slaves of said clocking including said transmit node. Each network cycle comprises a plurality of frames transmitted during said access time slots according to a predetermined transmission sequence. According to the invention, the transmit mode performs the following steps:- receiving (6021) at least one frame coming from at least one of the other nodes of the network;- from each frame received, obtaining (6023) synchronization information (317) pertaining to a level of synchronization of the node having sent said frame, said level of synchronization being relative to the master node;- selecting (603) a reference node from the node(s) from which at least one frame has been received, as a function of said pieces of synchronization information;- determining (606) a start of access time slot from the positions in said transmission sequence of the frames associated with the reference node and with said slave node; and- accessing said medium at said determined start of access time slot.