A Data Allocation Method over Multiple Wireless Broadcast Channels

In this paper, we concentrate on data allocation methods for multiple wireless broadcast channels to reduce the average data access time. Existing works first sorted data by their access probabilities and allocate the partitions of the sorted data to the multiple wireless channels. They employ the Flat broadcast schedule for each channel to cyclically broadcast all the data items allocated to it. The different access probabilities of the data items within a channel are ignored. To cope with this problem, S2AP method was proposed. It allocates a popular data item more than once per cycle to the channel to which it is assigned. The number of times that each data item is allocated reflects its access probability. However, the performance improvement of S2AP method is somewhat limited because the skewness of data access probability distribution within each channel is not large. We propose ZGMD method which first allocates data over multiple wireless channels by trying to maximize the average skewness of data access probability distributions over multiple channels. ZGMD method then computes the broadcast repetition frequencies of all the data items in each channel by using the method proposed in S2AP scheme. Finally, ZGMD method generates the broadcast disk program for multiple wireless broadcast channels. Our performance analysis shows that ZGMD method gives the better average access time than the existing methods.