Efficient data retrieval algorithm for multi-item request in wireless broadcast environments

Data retrieval problem is an efficient way to assist disseminating public information in wireless data broadcast. It refers that a set of data items is orderly broadcast at multiple parallel channels and the client that requires multiple data items retrieves these parallel channels (find an optimal data retrieval sequence) to download their required information at a minimized access latency. Currently, although many schemes have been proposed to study on data retrieval problem with single request which includes multiple data items, the most efficient scheme with lower time complexity is not found. In this paper, we define data retrieval problem with multiple requests denoted as DRMR problem. Our algorithm adopts a novelty scheme to convert a wireless data broadcast system into a DAG, and applies topological sorting to address the DRMR problem. We have validated the performance of our proposed algorithm, and show that the proposed algorithm can obtain the best performance among all existing algorithms as far as we know.