  We consider indoor mobile access, a vital use case for current and future
mobile networks. For this key use case, we outline a vision that combines a
neutral-host based shared small-cell infrastructure with a common pool of
spectrum for dynamic sharing as a way forward to proliferate indoor small-cell
deployments and open up the mobile operator ecosystem. Towards this vision, we
focus on the challenges pertaining to managing access to shared spectrum (e.g.,
3.5GHz US CBRS spectrum). We propose Iris, a practical shared spectrum access
architecture for indoor neutral-host small-cells. At the core of Iris is a deep
reinforcement learning based dynamic pricing mechanism that efficiently
mediates access to shared spectrum for diverse operators in a way that provides
incentives for operators and the neutral-host alike. We then present the Iris
system architecture that embeds this dynamic pricing mechanism alongside
cloud-RAN and RAN slicing design principles in a practical neutral-host design
tailored for the indoor small-cell environment. Using a prototype
implementation of the Iris system, we present extensive experimental evaluation
results that not only offer insight into the Iris dynamic pricing process and
its superiority over alternative approaches but also demonstrate its deployment
feasibility.
