Simulation study of the spectral capacity requirements of Switched Digital Broadcast

Switched Digital Broadcast (SDB) is a new method of distributing video programming. Compared with traditional broadcast methods, it reduces spectrum requirements by taking advantage of the fact that not all program channels are being viewed by subscribers at the same time. The actual spectrum savings depends on human TV watching behavior, the popularity of delivered TV programs, streaming bit-rate composition and subscriber group size. We have developed a simulation model of an SDB system that allows us to explore the impact of these factors, in particular subscriber’s channel flipping behavior, on the capacity requirement. Our subscriber viewing model ranges from intense, correlated channel flipping behavior to minimal flipping behavior representing DVR usage. Our results suggest that frequent channel flipping has little effect on the spectrum requirements under normal viewing assumptions.