A method and system for data transmission by computational devices in a wireless network (100) are disclosed. A computational device (102) organizes the wireless network in a hierarchical topology having at least one root node and updates a list of interferers and a list of descendents. Then, the computational device allocates a Contention Free Period (CFP) slot to each computational device in the wireless network based on at least one of the list of interferers and the list of descendents and transmits data during the allocated CFP slot.