Efficient data broadcast scheme on wireless link errors

As portable wireless computers become popular, mechanisms to transmit data to such users are of significant interest. Data broadcast is effective in dissemination-based applications to transfer the data to a large number of users in the asymmetric environment where the downstream communication capacity is relatively much greater than the upstream communication capacity. Index based organization of data transmitted over wireless channels is very important to reduce power consumption. We consider an efficient (1:m) indexing scheme for data broadcast on unreliable wireless networks. We model the data broadcast mechanism on the error prone wireless networks, using the Markov model. We analyze the average access time to obtain the desired data item and find that the optimal index redundancy (m) is SQRT[Data/{Index*(1-p)/sup /spl and//K}], where p is the failure rate of the wireless link, Data is the size of the data in a broadcast cycle, Index is the size of index, and K is the index level. We also measure the performance of data broadcast schemes by parametric analysis.