Abstract: To meet the requirements of wireless sensor networks ( WSNs)，a QoS guarrantee mechanism based on serviccoricnted middleware was presented. Focusing on the problem of QoS evaluation, a QoS evaluation algorithm based on multi-dimension cloud was proposed. It evaluated quantitatively the tasks, which could make the network be scheduled properly by middlcware according to the results of the evaluation. Moreover, to conquer the weakness of cloud parameters that were set by expert's experiences, the algorithm also used benefit driven function to adj ust the parameters,which could improve the accuracy of evaluation. Experimental results show the algorithm can improve execution efficicncy of tasks and can extend the network lifetime.

Key words: Wireless sensor networks, Service-oriented middleware, Cloud model, QoS