Comparative analysis of downlink signal levels emitted by GSM 900, GSM 1800, UMTS, and LTE base stations

Determination of exposure levels is considered as one of the parameters of planning and optimization of green cellular networks. While moving towards 5G technology and standardization, the results of comparative exposure levels induced by 2G, 3G and 4G networks are of interest. We present the results of in-situ determination of downlink signal levels emitted by GSM 900, GSM 1800, UMTS, and LTE networks in urban areas. The measurements are conducted with calibrated spectrum analyzer NARDA SRM 3006 at outdoor and indoor spots, including LOS and NLOS positions. The highest measured value is 2.82 V/m registered in outdoor LOS position for GSM 900. The results of comparative research highlight GSM 900 as the biggest contributor to the overall cellular systems downlink signal level, followed with UMTS, GSM 1800 and LTE. Obtained results are compared with the ICNIRP reference levels as well as with downlink signal levels emitted by cellular systems in other countries.