Impact of an intelligent jammer on the emergency services' communication system

C2000 is a communication system based on the Terrestrial Trunked Radio (TETRA) protocol and is used in the Netherlands by emergency services. We investigated the resilience of the voice component of C2000 against intelligent intentional electromagnetic interference (IEMI). Low power signals interfering with the system’s higher protocols have the advantage of staying covert. The analysis shows that if the access assignment channel is corrupted, the mobile stations cannot start conversations with the base station. TETRA’s modulation scheme is also investigated. π/4 Differential Quaternary Phase Shift Keying (DQPSK) is interfered with a continuous wave and a Quaternary Phase Shift Keying (QPSK) signal. The results show that a continuous wave created the largest error vector magnitude (EVM), but creates a peak in the received spectrum. The power of the QPSK signal, however, is distributed over a bandwidth and is more difficult to detect than the continuous wave in the received spectrum. From this we conclude that the QPSK signal functions better as an intelligent interference signal compared to the continuous wave. In this thesis it is shown that it is possible to create a jammer that combines the vulnerability in the TETRA protocol with the QPSK signal to disrupt the communication system, while staying covert. This can cause dangerous situations during large calamities, but also during small felonies where adversaries can disrupt the communication locally.