This article presents the results obtained by measuring the quality parameters of a telecommunications network on GSM (Global System Mobile) in the DCS-1800 (Digital Cellular Service - 1800MHz) band; which is used in order to articulate a system of disaster relief in emergency situations, using a USRP (Universal Software Radio Peripheral) in conjunction with IP telephony system based on Asterisk. The USRP is responsible for emulating the operation of a BTS (Base Transceiver Station) performing the functions of a PBX (Private Branch Exchange). The measurements of network performance were made from three probabilistic parameters: GoS (Grade of Service), DCR (Dropped Call Rate) and MOS (Mean Opinion Score). Traffic was generated using an 8 terminals and choosing a GoS of 2% to 3.6 Erlang, this measurement was performed using probabilistic models of Erlang B. The network coverage was obtained using the Okumura-Hata model for both indoors and outdoors, without the use of amplifiers. The consumption of power in the system was also measured.