In a wireless multihop network having node devices within communication range neighboring node devices in a corresponding local neighborhood, the node devices initiate repeated message broadcasts of a first message as a connection-less broadcast into the local neighborhood. Initiation of message broadcasts is governed such that the message broadcasts are permitted only at specified transmission times within a plurality of transmission time windows. Each of the node devices determines whether any of the connection-less-broadcasted messages are duplicates of the first message, and generate a count of those duplicates received during each of the transmission windows. Based on counts of the duplicates, initiation of a message broadcast of the first message in a current transmission window is suppressed in response to a corresponding count of duplicates of the first message received during the first transmission window exceeding a suppression limit.