Impact of the number of sensors on the network cost and accuracy of the radio environment map

Spectrum management using a radio environment map (REM) to dynamically allocate frequencies may facilitate the efficient exploitation of the spectrum in a heterogeneous environment. The overhead costs of networking radios to create the map must be balanced against the impact of a poor REM due to low quality or quantity of sensor data. To study this cost-benefit balance, simulations were performed to evaluate a REM using a variable number of randomly-located sensors. It was seen that too few sensors provides insufficient coverage of the area of interest and may not provide connectivity to the data collection centre, whereas in a more dense sensor environment, sensor location was the most important factor. The results show that information about the REM´s accuracy is required to mitigate false confidence and that exact replication of the ground truth is not required for dynamic spectrum management; rather, it is sufficient to identify the regions where spectrum could be reused.