  Mission-critical wireless networks are being up-graded to 4G long-term
evolution (LTE). As opposed to capacity, these networks require very high
reliability and security as well as easy deployment and operation in the field.
Wireless communication systems have been vulnerable to jamming, spoofing and
other radio frequency attacks since the early days of analog systems. Although
wireless systems have evolved, important security and reliability concerns
still exist. This paper presents our methodology and results for testing 4G LTE
operating in harsh signaling environments. We use software-defined radio
technology and open-source software to develop a fully configurable
protocol-aware interference waveform. We define several test cases that target
the entire LTE signal or part of it to evaluate the performance of a
mission-critical production LTE system. Our experimental results show that
synchronization signal interference in LTE causes significant throughput
degradation at low interference power. By dynamically evaluating the
performance measurement counters, the k- nearest neighbor classification method
can detect the specific RF signaling attack to aid in effective mitigation.
