Wireless communication present the most attractive sign of development in this decades. It contributes to the appearance of Wireless Sensor Network (WSN) which is invented in order to increase the supervision capacity for such phenomenon. It gets more regard from both the customer and the research society. (WSNs) is composed from numerous wireless sensor nodes which suffer from a very serious energy constraint. For this raison we are interested to the standard of IEEE 802.15.4 with beacon enabled mode. We suggest a multi mode approach to the technology of IEEE 802.15.4 as a new technique to extend the lifetime of the network. Our paper interest to network largely extended with cluster tree topology. In such a way that the network become divided to many subgroups. In each subgroup, a PAN coordinator is placed as a coordinator to its children. Besides, every subgroup has his specific parameters of Beacon Order (BO) and Superframe Order (SO) which depend only from the remaining energy in the battery of the nodes. When a node suffer from lack of energy, its Pan coordinator parent intervene by changing its main parameters (BO, SO) in order to postpone its death.