NomadicBTS-2: A Network-in-a-Box with Software-Defined Radio and Web-Based App for Multiband Cellular Communication

Abstract

The proliferation of mobile communications technologies has greatly contributed to the development of emerging economies. However, a significant digital divide remains in many remote and hard-to-reach regions due to the high Capital Expenditure (CapEx) and Operating Expenditure (OPEX) of mobile network operators. This study addresses the issue by developing and prototyping a cost-effective, software-defined base station, called NomadicBTS-2, utilizing open-source technologies and the Software-Defined Radio (SDR) paradigm. NomadicBTS-2 incorporates the Universal Software Radio Peripheral (USRP) B200 as the Radio Frequency (RF) hardware front-end. The software backend is built on open-source solutions, including the USRP Hardware Driver (UHD) and services such as OpenBTS, Asterisk, SIPAuthserve, and SMQueue. Additionally, a custom web-based software, NomadicBTS WebApp, was developed to configure and monitor the UHD and software services via a Graphical User Interface (GUI). The system was tested using two mobile stations (MSs) for simplex and duplex communication, while network link quality parameters were evaluated to assess users’ Quality of Experience (QoE). Experimental results demonstrated that, within a pico-cell environment, the link quality is sufficient for call routing and Short Messaging Services (SMS) between user-to-user and network-to-user communications. NomadicBTS-2 presents a robust solution for a Network-in-a-Box, ideal for short-range communication in rural and hard-to-reach areas, emergency response scenarios, and IoT sensor networks. It can also be deployed to alleviate network congestion in existing mobile networks. Furthermore, this prototype offers a viable testbed for teaching and research laboratories to explore advancements in SDR, cognitive radio, and other wireless communication technologies, thus opening new frontiers in wireless communications researc