Method for broadcasting one or more signalling messages in a communication network comprising at least two clusters (10 1, 10 2), each of the clusters comprising at least one cluster head (24 1, 24 2) which is capable of administering communications and a plurality of nodes (11 1k, 11 2k) which are provided with transmitting/receiving means (12, 13), each of the clusters operating on a dedicated radio channel (CH 1, CH 2), and all the clusters accessing a common channel CS, in which each cluster has a time slot of the common channel CS which is dedicated to the set of nodes which belong to the cluster, the method comprising at least the following steps: • at least the cluster head (24 1) of the first cluster (10 1) transmits the signalling message M towards a set of nodes (11 1k) which are located in the cluster (10 1) thereof using the dedicated radio channel CH 1 thereof, • the nodes (11 1k) of the first cluster (10 1), which have received and decoded the signalling message M, relay this signalling message M towards one or more relay nodes (11 jk) which belong to other clusters of the network which are in radio range using a cooperative coherent transmission mechanism which is distributed over the time slot of the common channel CS which is dedicated to the first cluster in the following manner: the cluster head (24 1) selects one or more nodes (11 1k) in order to reach the adjacent clusters, • if two nodes (11 1k) selected do not share external proximity, they transmit on the same time slot, without interfering with each other, • if two nodes (11 1k) selected have in common a portion of the external proximities thereof, they use the same time slot in a cooperative manner in order to improve the quality of the transmission thereof, • the relay node(s) (11 jk) of the other clusters (10 j), which have received and decoded the signalling message M, transmit it to the cluster head (24 j) thereof using a distributed cooperative transmission method on the dedicated channel (CH j) thereof. • at least the cluster head (24 1) of the first cluster (10 1) transmits the signalling message M towards a set of nodes (11 1k) which are located in the cluster (10 1) thereof using the dedicated radio channel CH 1 thereof, • the nodes (11 1k) of the first cluster (10 1), which have received and decoded the signalling message M, relay this signalling message M towards one or more relay nodes (11 jk) which belong to other clusters of the network which are in radio range using a cooperative coherent transmission mechanism which is distributed over the time slot of the common channel CS which is dedicated to the first cluster in the following manner: the cluster head (24 1) selects one or more nodes (11 1k) in order to reach the adjacent clusters, • if two nodes (11 1k) selected do not share external proximity, they transmit on the same time slot, without interfering with each other, • if two nodes (11 1k) selected have in common a portion of the external proximities thereof, they use the same time slot in a cooperative manner in order to improve the quality of the transmission thereof, • if two nodes (11 1k) selected do not share external proximity, they transmit on the same time slot, without interfering with each other, • if two nodes (11 1k) selected have in common a portion of the external proximities thereof, they use the same time slot in a cooperative manner in order to improve the quality of the transmission thereof, • the relay node(s) (11 jk) of the other clusters (10 j), which have received and decoded the signalling message M, transmit it to the cluster head (24 j) thereof using a distributed cooperative transmission method on the dedicated channel (CH j) thereof.