Network GPRS Prototype based on SDR and OpenBTS, as an IoT-lab Testbed

INICTEL-UNI research institute participates in various projects related to the design and implementation of Internet-of-Things applications in Peru. Regarding the different radio-access technologies that exist so the end-devices can reach the IoT cloud, the conclusion we share is that, even though several radio-access options are being rolled-out worldwide, GPRS continues to be the most available radio-access at remote zones, if not the only option in some cases. GPRS has a massive deployment due to 2G networks, and its data rate and latency meet the requirements for IoT applications like in smart agriculture or water pollution monitoring, for instance.Given the necessity for counting with a GPRS network testbed to test our GPRS-based sensor node prototypes, at the lab, we managed to build a small-scale GPRS network based on the OpenBTS software platform and Software-Defined Radio hardware to employ it as a testbed for IoT application testing. In this paper, we briefly explain the concept of software defined radio and provide a succinct description of the OpenBTS functionalities. Then, we share details related to the prototype implementation, configuration, and start-up as well as an end-device setup for testing. Finally, we share conclusions obtained from two experiments conducted over the network prototype. The first is to verify the GPRS signaling generated in data exchange between an end-device and an IoT server, and the second is to experiment with the accessibility rate of the network prototype when various end-devices share the communication channel.