Time-constrained service on air

Data broadcasting is an efficient and highly scalable technique for delivering data to mobile clients in wireless environments. In this paper, we study the problem of scheduling broadcast data that are with an expected time within which the client is expecting to receive the data item. We analyze the problem and derive the minimum number of broadcast channels required for such a task. Also, we discuss the problems when the number of available channels is not enough. We propose novel solutions for both of the cases and the performance study indicates that our method is much better than the previous ones and performs very close to optimal.