A model to estimate the costs of a partial clearance of spectrum in the 900MHz band

The roll-out of UMTS/HSPA networks in 900MHz band offers the possibility to bring third generation and mobile broadband services to new areas with less base station sites and to improve the indoor coverage in the existing UMTS coverage areas. However, a necessary first step in order to take advantage of the mentioned benefits of UMTS/HSPA900 networks is a partial clearance of spectrum in the 900 MHz band currently used for GSM. This paper presents a methodology to estimate the costs associated with this partial clearance for three different approaches to deal with the traffic displaced as a consequence of the reduction of available spectrum and therefore, of the traffic carrying capacity of the GSM network. Finally, the model has been applied to the GSM networks of two mobile operators presented in the Spanish market. From the results obtained, the approach 3 based on expanding the use of GSM1800 transceivers on existing GSM sites seems to be the most cost-efficient in almost all the cases analyzed.