distribution networks for digital cinema

A geographically inclusive transition of movie theaters to digital cinema will require geographically comprehensive high-bandwidth connectivity.  Movie theaters offer cheap, popular entertainment.  The physical distribution of film prints places little economic and technological constraint on movie theater location.  Hence movie theaters are geographically ubiquitous.  Digital cinema, however, may make movie theater location practically relevant to movie distribution.

The bandwidth required for distributing digital cinema depends on formats and compression technology.  The leading specification for current digital cinema, the Digital Cinema Initiatives specification, prescribes a maximum image bit rate of 250 Mbit/s (megabits per second) and a maximum audio bit rate about 5 Mbit/s.  A plausible compression ratio of 10 thus implies bandwidth about 25 Mbit/s for real-time transmission of a single digital-cinema movie.  If a movie theater shows a different movie every day, it might have roughly 12 hours to acquire a movie from a digital network.  Thus connectivity of several megabits per second would be sufficient for non-real-time showing of current digital cinema formats.  Being able to show live events, however, is an important advantage of digital cinema.  Moveover, newer higher definition and 3-D digital formats will require greater bandwidth.  For example, the  Super Hi-Vision format specifies a 25 Gbit/s native image rate, and researchers envision a 80 Mbit/s compressed signal.

Both satellite systems and incumbent telephone companies have networks that could provide geographically ubiquitous distribution of digital movies to movie theaters.  Satellites are a good technology for geographically comprehensive broadcasting of high-bandwidth signals.[*]  A satellite distribution network, however, confronts location-specific issues such as satellite line-of-sight, signal fade in rain and snow, and aesthetic and zoning concerns about satellite dish placement. Despite their business being focused on over-the-air broadcasting, traditional television networks and other analog video service providers in 2008 spent an estimated $100 million purchasing legacy wireline video transmission capacity from telephone companies.  That figure suggests that satellite distribution systems for digital cinema are likely to require significant complementary wireline network services.  Telephone company video transmission revenue seems to be concentrated in telephone company service areas covering New York City, Washington, D.C., and Los Angeles.  These cities are associated with key video sources and video production facilities that probably require wireline transmission to satellite uplink facilities.  Wireline complements to satellite-based digital cinema distribution systems may be concentrated in those cities. Short inter-premises wireline links might be used elsewhere to place a (downlink) satellite dish off the site of a movie theater. The extent of such siting issues isn’t clear, but might matter for a geographically comprehensive transition to digital cinema.

Digital cinema offers exciting new possibilities for movie theaters.  Independent theater operators are concerned about being left behind in this transition.  Without good national broadband network development, a weak distribution network for digital cinema might be a problem.


[*] Cinedigm Digital Cinema Corp. (formerly Access Integrated Technologies, also called AccessIT) is a leader in digital cinema distribution.  Through its acquisition of FiberSat Global Services, it acquired a data storage and uplink facility at the Los Angeles International Media Center and capacity to distribute digital cinema via Ku-band and C-band satellites. In Oct. 2007, AccessIT (now Cinedigm) announced Cinelive, a new proprietary product to bring live 2-D and 3-D content to digital movie theaters.

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