This paper presents an academic implementation of a GSM system that guarantees communication across GSM air interface and interconnection with other networks using a joint operation of USRP as hardware platform and GNU Radio, OpenBTS and Asterisk as software platforms and applications. That solution will be useful in academic environments where telecommunication infrastructure is limited for operation. In addition, some tools like Wireshark and AirProbe are used to complement the whole solution and to develop a low cost laboratory platform.