Cybersecurity recommendations for spectral impact in distributed antenna systems for nuclear energy

Wireless access to data is a challenge for environments with poor radio frequency (RF) coverage, such as nuclear power plants. An 802.11 Wi-Fi data network often is not a cost-effective solution due to the extensive antenna outlay requirement for large nuclear facilities and poor signal penetration due to thick concrete walls. Combining commercial Long-Term Evolution (LTE) with an existing distributed antenna system (DAS) resources and infrastructure is an attractive solution due to the lower implementation costs, while achieving the needed RF coverage. A 2017 technical report by the Electric Power Research Institute (EPRI) demonstrated that multiple systems such as Land Mobile Radio and LTE can be operated sharing the same DAS, leaky coaxial cabling and indoor antenna systems. Since the RF bands used by the two wireless systems are specified to be non-overlapping, it is believed that the systems are isolated from each other. This paper investigates the assumption of isolation between the two wireless systems and provides empirical testing to evaluate the channelization robustness of a DAS, identify specific vulnerabilities, and potential mitigations. The critical transceiver components were manipulated for the purpose of generating interference to adjacent incumbent protected communications users. This interference presents a direct vector to corrupt all signals being transmitted on the fiber link for the purpose of enabling a cyber-attack.