Interesting because the idea originally was to use satellite for the regular theaters but the studios were too paranoid for that so shipped films on HDDs. My local theater here in the burbs was about the first all digital theater in the SF Bay Area but it seems they were running a consulting service for theater owners wishing to convert to digital (this was over 10 years ago).You learn a lot when you talk with the main manager of your local location. IMAX is so paranoid that they still send HDDs to the locations containing the movies. All of the regular movies are sent via Ku satellite to the location's servers.
They keep a union projectionist on staff who mainly fills the popcorn and drinks. Any real problems the projector company sends in a tech.