Large scale spectrum survey in rural and urban environments within the 50 MHz–6 GHz bands

• Space variable introduced to existing metrics to form a modified duty cycle metric.
• Short and long term temporal variations of duty cycle for each band were studied.
• Measurement conducted in rural and urban locations in 50 MHz–6 GHz bands.
• An adaptive energy detection threshold technique was employed.
• Choice of detection threshold significantly affects duty cycle in GSM 900 and 1800.

In-depth spectrum measurement was conducted in rural and urban locations, covering 50 MHz–6 GHz bands, during the weekdays and weekends. A modified duty cycle metric is presented by introducing a space variable into the existing metrics available today. An adaptive energy detection threshold technique was employed, the results indicate the average spectral occupancy of 0.18%, and 5.08% in rural and urban locations respectively during weekdays and 1.45% on weekends for urban locations. Furthermore, short and long term temporal variations of the duty cycle for each of the bands were studied, and it was found that GSM 900 shows significant temporal variation when compared with GSM 1800. It was also found that the choice of the detection threshold would significantly affect the duty cycle as GSM 900 and 1800 give exponential decay with increase in detection threshold while TV band shows very sharp exponential decay which becomes invariant after −85 dBm.