Medium access technique for LAN systems

In a communication system comprising several nodes and a scheduler interconnected by a serial transmission medium, data are transmitted in time slots. The scheduler marks time slots either as reserved if nodes have previously made a request and received a confirmation, or it marks time slots as gratis for free use by any node. Slots are also marked gratis if the have reached their destination or removal node. To achieve fairness between nodes in the reservation process, they count gratis slots they used. When making a request for reserving a number NR of slots, a node must also transmit the number NG of gratis slots used. The scheduler then determines, according to a given rule, the number NC of slots to be granted to each node. A special signalling technique is also disclosed for effective transmission of the numbers in the reservation and confirmation process.