Efcient Broadcasting Protocols for Video on Demand

Broadcasting protocols can improve the efciency of video on demand services by reducing the bandwidth re-quired to transmit videos that are simultaneously watched by many viewers. We present here two broadcasting pro-tocols that achieve nearly the same low bandwidth as the best extant broadcasting protocol while guaranteeing a lower maximum access time. Our rst protocol, cautious harmonic broadcasting, requires somewhat more band-width than our second protocol, quasi-harmonic broad-casting, but is also much simpler to implement