Risk Analysis of GPS-Dependent Communications Critical Infrastructure Utilized by the US Electric Power Grid

The nation's Critical Infrastructure (CI) forms a complex System of Systems (S-o-S) comprised of 16 sectors defined by the United States Department of Homeland Security (DHS). This S-o-S is characterized by myriad interconnections and interdependent subsystems. Of these 16 sectors, the communications sector and electricity subsector provide basic functionality to one another, as well as to the remaining 14 sectors of CI. As the nation moves forward with Department of Energy's (DOE) Smart Grid initiative, the dependence of these sectors upon GPS timing is rapidly increasing. Under this initiative, the electricity subsector becomes dependent upon GPS timing through the proposed use of Phasor Measurement Units (PMUs) for determining control actions on the grid, as well as by the already existing dependence on GPS timing through communications CI utilized by the electricity subsector for the transmission of PMU and Supervisory Control and Data Acquisition (SCADA) data. While there is extensive literature addressing GPS timing dependency of PMUs in the electricity subsector, this thesis
provides a systematic risk analysis of the threats to the electricity subsector through the use of GPS timing dependent communications CI. This thesis provides a methodological approach for first assessing the risks to the US electric power grid through the use of GPS-dependent communications CI to carry both PMU and SCADA data, and then determining risk management options for mitigating the risk to electricity subsector through the use of GPS-dependent communications CI. The thesis builds upon fault and event tree analysis, and addresses scenario development for events with unknown likelihoods.