Global System for Mobile Communications (GSM)

Introduction️ With the deployment of a virtual base station virtual and a mobile device with OsmocomBB software, it is now possible to analyze traffic generated when making a phone call or sending text messages using Wireshark.️ Starting the Wireshark tool.️ We start a new session of Wireshark, monitoring by -f UDP packets with the filter -Y gsmtap on the interface -i lo.️ wireshark -k -f udp -Y gsmtap -i lo Start of the virtual base station.️ We are starting the virtual base station.️ ...

Introducción Amplifying the previous article, with the creation of a virtual GSM base station, it is possible to develop another proof of concept using the software OsmocomBB. With a phone with Calypso processor, such as the Motorola C115, C123, C140, C155 or V171, it is possible to create a physical GSM base station, with a limited functionality, only circuit-based operations such as sending and receiving text messages. This network can be connected to other physical devices by configuring the corresponding SIM card.️ ...

Introduction️ Osmocom (Open Source Mobile Communications) is an open source project dedicated to developing software and tools for mobile communication networks. Its main objective is to implement a range of mobile network technologies, such as GSM (2G), in an open and accessible way, with its different modules in the form of libraries.️ The project related to the creation of mobile networks is the CNI (Cellular Network Infrastructure), which are implementations of the protocol stack and network elements of GSM. The projects used for creating the network are OsmoMSC, OsmoBSC, OsmoSTP, OsmoHLR, OsmoMGW. On the other hand, we need the element that creates the base station, OsmoBTS, which supports different hardware and software devices. And finally, the transceiver that will support OsmoBTS, the component OsmocomBB.️ ...

Introduction️ GSM (Global System for Mobile Communications) (2G) is a communication standard developed for the transmission of voice and data in mobile networks. Originally created in Europe in the 80s by the European Telecommunications Standards Institute (ETSI), it became the most popular mobile phone system worldwide, used by most mobile network operators around the world. The GSM technology allows users from different operators to communicate with each other and use services like SMS (text messages) or calls. With the arrival of 4G and 5G, the use of GSM networks has decreased and some operators are gradually removing support for these networks.️ ...