1. A method for optimizing access to a medium in a communication network which can be accessed by a plurality of nodes, each node of the plurality of nodes using a medium access mechanism of the Carrier Sense Multiple Access with Collision Avoidance type based on a computation of a backoff value, the method comprising: identifying a set of nodes of the plurality of nodes; associating, for each node of the set, a specific value known by the other nodes of the set; determining, by each node of the set, a backoff value for each node of the set, each backoff value being determined as a function of the specific value associated with that node; and decrementing, by each node of the set, the backoff values associated with all the nodes of the set if all the backoff values associated with all the nodes of the set are different from zero.