Mobile telephony and mobile communication are both crucial and critical infrastructures for today's society and contribute to its security and safety. In contrast to landline telephony with its physically protectable medium, mobile telephony utilizes air and electromagnetic waves as communication medium, which cannot be easily protected. Due to the specific design and the openly shared medium, mobile communication infrastructure is particularly vulnerable to threats linked to a wide range of security issues and failures caused by overload and blocking. Especially in critical situations like human stampede or natural disasters, the network could break down while remaining physically intact. That is contrary to the desired behavior in catastrophe scenarios, as the infrastructure is meant to provide emergency call functionality and communication for the rescue teams. While traditional usage scenarios even for major events are well researched, there is a lack of knowledge on how to make mobile telephony networks more resilient to unpredictable load in disaster events. We propose a test environment to analyze such scenarios using the example of GSM mobile telephony networks. Furthermore, we identify relevant network parameters and discuss their impact on network resilience. The resulting test bed is based on real hardware and open-source software in order to create a realistic and defined environment which includes all aspects of the air interface in mobile telephony networks and is capable of simulating an overload situation in a defined and fully controlled environment.
