Adjusting Cost for Mobile Suscribers Density in Mobile Tunisian Market

 In this paper  we develop a cost model  using real suscriber  density per sqKm of coverage, that  regulator can use to adjust the mobile termination  rate.  Theoritical model suggest that the values of  adjusting cost series  are 21% higher than the values estimated by debbichi,S ., and al .(2013) . Econometric model  looking to explore the effect of suscriber density per sqKm and the sum of inbound and outbound  voice traffic on adjusting cost during the period (2003-2023). Results show that suscriber density per sqKm affect negatively the adjusted Cost, but a positive effect of voice traffic.