Minimizing the Average Waiting Time of Unequal-Size Data Items in a Mobile Computing Environment

摘要

In a mobile computing environment, waiting time is an important indicator of customer satisfaction. In order to achieve better customer satisfaction and shorter waiting times, we need to overcome different constraints and make the best use of limited resources. In this study, we propose a minimization problem, allocating unequal-size data items to broadcast channels with various bandwidths. The main idea is to solve the problem in the continuous space R-n. First, we map the discrete optimization problem from Z(n) to R-n. Second, the mapped problem is solved in R-n optimally. Finally, we map the optimal solution from R-n back to Z(n). With the theoretical analyses, we can ensure the solution quality and execution speed. Computational experiments show that the proposed algorithm performs well. The worst mean relative error can be reduced to 0.353 for data items with a mean size of 100. Moreover, almost all the near-optimal solutions can be obtained within 1 millisecond, even for N = 500, where N is the number of data items, that is, the problem size.