# Spectrum Awareness for Cognitive Radios Supported by Radio Environment Maps: Zonal Approach +
## 6 Conclusions
Taking into account both the RMSE and the number of Correct Estimation Points, the interpolation technique based on Kriging should be recommended for the Electromagnetic Situational Awareness of Cognitive Radios supported by REM. As future work, it would be worthwhile to investigate the influence of the semivariogram selection on the quality of the signal level estimation with the application of Kriging. We would also like to pay attention to the problem of the REM construction for zones that are close to the transmitter. Thus, the development of the hybrid method of REM construction seems to be valuable. All the authors have contributed to collecting results, performing analysis and creating this article. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. Data Availability Statement: Data is contained within the article in Appendix A. The authors declare no conflict of interest. The measurement results collected for all the 39 points (sensors) are presented in the table below. The geographical coordinates and sensor IDs correspond to the deployment of the sensors shown in Figure 2. The average levels of measured signals are expressed in dBm. The variance was about 3 dB\({}^{2}\) for most of the sensors and reached 7.4 dB\({}^{2}\) in the worst case. [PERSON]; [PERSON]; [PERSON]; [PERSON] _Intelligent Vehicular Networks and Communications: Fundamentals, Architectures and Solutions_; Elsevier: Amsterdam, The Netherlands; Boston, MA, USA; Heidelberg, Germany, 2017; ISBN 9780128092668. * [6] IEEE Standard--Information Technology--Telecommunications and information exchange between systems--Wireless Regional Area Networks--Specific requirements--Part 22: Cognitive Wireless RAN MAC and PHY specifications: Policies and Procedures for Operation in the Bands that Allow Spectrum Sharing where the Communications Devices May Opportunusistically Operate in the Spectrum of Primary Service. In _IEEE Std 802.22-2019_; (Revision of IEEE Std 802.22-2011); IEEE: New York, NY, USA, 2020; pp. 1-1465. * [7] [PERSON] [PERSON]; [PERSON]; [PERSON] Image Transmission over Cognitive Radio Networks for Smart Grid Applications. _Appl. Sci._**2019**, \(9\), 5498. [CrossRef]
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