  The process of contact tracing to reduce the spread of highly infectious and
life-threatening diseases has traditionally been a primarily manual process
managed by public health entities. This process becomes challenged when faced
with a pandemic of the proportions of SARS-CoV2. Digital contact tracing has
been proposed as way to augment manual contact tracing and lends itself to
widely proliferated devices such as cell phones and wearables. This paper
describes a method and analysis of determining whether two cell phones, carried
by humans, were in persistent contact of no more than 6 feet over 15 minutes
using Bluetooth Low Energy signals. The paper describes the approach to
detecting these signals, as well as a data-driven performance analysis showing
that larger numbers of samples coupled with privacy preserving auxiliary
information improves detection performance.
