Abstract
Periodic broadcasting is known as an efficient technique to deliver popular videos by reducing bandwidth requirement for transmitting streaming videos to simultaneous viewers. Most of the existing periodic broadcasting protocols can be recognized as Pyramid-based, which possesses regular behavior as function (mathematical formula) thus favored by high practicability. Others are designed by somewhat ad hoc or optimization procedures, such as Pagoda-based or Harmonic protocols. In this dissertation, the channel transition problem, which is a noticed issue to be concerned about the variability of popularity of video in periodic broadcasting, is addressed. The channel transition schemes modify the channel allocation of a video by its hotness, thus optimize the bandwidth utilization. A hot video possesses more broadcast channels and shorter startup latency; otherwise, a video with fewer channels have longer startup latency. This kind of transition scheme should be “seamless,” i.e. the receptions of clients should not be interrupted or interfered. Present channel transition schemes such as Seamless Fast Broadcasting (SFB), Seamless Staircase Broadcasting (SSB) and Flexible Periodic Broadcasting (FPB) are dedicated to specific broadcasting protocols. The SFB and SSB even modify the original protocols. These schemes are rather complicated and difficult to apply to other protocols. Further more, they possibly decrease the performance of the original protocols. After the observation of several Pyramid-based broadcasting protocols, we found the common characteristic of the client buffer utilization. Based on the characteristic, we proposed a generic seamless channel transition scheme for pyramid-based broadcasting protocols, named as the Stairway Channel Transition (SWCT) scheme. The SWCT is applicable to any Pyramid-based protocol which conforms to our coordinated condition. Compared to the existing channel transition schemes, our design possesses more flexibility, while does not reduce the performance of the original protocols.