Abstract: There are many algorithms to increase the QoS of mobile networks thanks to an underlying mobility prediction.This paper aims how the accuracy of the prediction method can influence the network QoS. It shows that the mobiles behavior must be adapted according to the prediction scheme accuracy in order to achieve good performance and good QoS in network. The quick development of wireless networks brings new challenges to the network community. In particular, it is commonly admitted that those networks next generations should provide new kinds of services requiring a high QoS.