An efficient scheme for broadcasting popular videos at low buffer demand

Data broadcasting is independent of arrivals of requests, and thus it is suitable to transmit popular videos that may interest many viewers at a particular period of time. One broadcasting method (called periodic broadcasting) is to divide a popular video into segments, which are then simultaneously broadcast on different data channels. Once clients want to watch the video, they download the segments from these channels. Specially, the greedy disk-conserving broadcasting (GDB) scheme supports a client with a small bandwidth. In comparison with other similar schemes such as the skyscraper broadcasting (SkB) and the client-centric approach (CCA) schemes, the GDB clients have smaller waiting time. Extending GDB, this work designs a reverse GDB (RGDB) scheme to achieve small buffering spaces as well as low bandwidths at the client. We further mathematically prove that RGDB still guarantees on-time video delivery at small client bandwidths. A formula is derived for the maximum number of segments buffered by an RGDB client. Finally, an analysis shows that RGDB has 33–50% smaller client buffer requirements than GDB in most situations.