WLC09-1: An Empirical Study on Statistical Properties of GSM Telephone Call Arrivals

We investigate the statistical properties of both originated and terminated call arrivals in sets of real GSM telephone traffic data (TIM, Italy), emphasizing results obtained by the modified Allan variance (MAVAR), a widely used time-domain quantity with excellent capability of discriminating power-law noise. The call arrival rate exhibits a diurnal trend, with peak hours in the morning and late afternoon. Besides this diurnal change, the number of call arrivals in a second is found perfectly uncorrelated to the number of arrivals in other seconds and Poisson distributed, with good consistency by chi²-test evaluation. Uniform and accurate whiteness of call arrivals per second is verified in all hours, regardless the time of the day. In all series analyzed, the empirical statistics of both originated and terminated call arrivals proved excellent consistency with the ideal Poisson model with variable rate lambda(t)- This study may be valuable to researchers concerned about realistic modelling of traffic in planning and performance evaluation of cellular networks.