A non-federal remote tower seeking FAA acceptance must satisfy several requirement sets: a Concept of Operations (ConOps) describing how the facility will operate; an Operational Safety Assessment (OSA) identifying and mitigating hazards; technical requirements for the camera, sensor, display, and communications systems; and operational visual requirements defining what the controller must be able to see and resolve.
These flow through the FAA's Remote Tower Systems pathway and, historically, a System Design Approval process. Public PDFs for several of these are indexed in the Documents library.