Cyber Security Concerns for Sharing Distributed Antenna Systems
Wireless access to data is a challenge for environments with poor radio frequency coverage such as nuclear power plants. An 802.11 Wi-Fi data network is often not a cost-effective solution not a cost-effective solution due to the requirement for extensive antenna outlays in large nuclear facilities and poor signal penetration due to thick concrete walls. Combining commercial Long-Term Evolution (LTE) with an existing distributed antenna system’s (DAS) resources and infrastructure is an attractive solution due to and lower cost of implementation and likely coverage increases. A 2017 technical report by EPRI has demonstrated that multiple systems such as Land Mobile Radio (LMR) and LTE can be operated using the same DAS and by sharing the leaky coaxial cabling and indoor antenna systems (Reference 1). Since the radio frequency (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. No extensive analysis has been conducted to determine whether RF signals from one system sharing antennas and coaxial cable can influence another. This paper investigates the assumption of isolation between the two wireless systems and provides recommendations for future needed work to identify specific vulnerabilities and potential mitigations.