Abstract: To overcome the smooth scan algorithm' s weakness of not adapting to the varied network environment, a self-adaptive and prediction-based smooth handoff(APBSH) algorithm was proposed. The key idea of the algorithm is using the varying recent network environment to predict the next time's (it uses two parameters; the urgent of scan and the urgent of data-transmission to represent different network environment quantitatively)，and then self-adaptively choosing the suitable handoff strategy according to the prediction results to accomplish the handoff before losing the connection of the current AP and improve the duality of data service. The experiment shows that API3SH algorithm could accommodate with network environment, assure the Optimization of the handoff's performance and better than standard 802. 11 handoff algorithm and smooth handoff algorithm.

Key words: 802. 11 network, Handoff, Smooth, Sclf-adaptive, Prediction