A Retrieval Algorithm for Time-constrained Heterogeneous Data Items in Wireless Networks

Homogeneous and heterogeneous data retrieval problem refers that these requested data items are retrieved on the basis of data items broadcast at some channels such that the access latency of all requested data items is minimized. The problem has an important study significance in MIMO (Multiple Input and Multiple Output) wireless communication. Almost researches are focused on proposing some schemes for solving signal antenna or multiple antennae data retrieval based on homogeneous data items, but these schemes are not suitable for heterogeneous data retrieval problem. So in this paper, we describe a SPR (Shortest Paths Retrieval) algorithm that is suitable for solving homogeneous and heterogeneous data retrieval problem at the same time. Moreover, for avoiding the retrieval time too long, when the each requested data item is set a constrained condition -deadline, we propose another DKPR (Deadline-based Key Path Retrieval) algorithm that finds the critical path with the largest number of requested data items in a broadcast cycle, so as to complete the retrieval operation of data items within the deadline of requesting data items as much as possible. Through experiments, the proposed scheme has good efficiency.