Radio Environment Map Updating Procedure Considering Change of Surrounding Environment

In this paper, we propose a method to update a radio environment map (REM) considering change of surrounding environment. The REM provides statistical radio information of primary users (PUs) to secondary users (SUs). SUs can utilize the information to design communication parameters for improving communication efficiency. However, if surrounding environment changes, the newly observed datasets are significantly different from the initially observed datasets. The database server requires to detect change of surrounding environment and to update the REM based on the detected results. In this paper, we propose a method to update the REM based on hypothesis testing. In the proposed method, sensor nodes observe a received signal strength indicator (RSSI) in each location and report that to the database server. Then, the database server updates the REM using tested results. The simulation results show that the proposed method can detect change of surrounding environment and accurately predict the average RSSI in each location while significantly reducing the number of the REM updates.