Abstract:

The prefetch algorithm of proxy servers is the key element to determine the efficiency of VOD system in campus networks.This paper presents a data prefetching model,BP neural network is used to build the classifier,and the classifier is applied to classify the programs in VOD system,and the classification results were used to commit data prefetch based on group structure and demand rate consideration.Genetic algorithm was introduced to improve the BP neural network,so the problem of incidental trap in local minima with BP neural network was overcome.The simulation results show that model can achieve a good hit ratio and effectively improve the utilization of the VOD proxy servers.

Key words: genetic algorithm, BP neural network, data prefetching,proxy