| dc.description.abstract | With the advances in video compression and broadband access technologies, the Internet Protocol Television (IPTV) becomes a popular technology for the delivery of multimedia services directly to the end users. Periodic broadcasting is an efficient approach to deliver IPTV services. The approach divides a popular video into segments, which are then simultaneously broadcast on different data channels. Previous studies mainly focus on decreasing client waiting time, such as the fixed-delay Pagoda broadcasting (FDPB) and the harmonic broadcasting (HB) schemes. However, these schemes must buffer a large part of the video data in advance such that cannot support limited-capability client devices, such as set-top boxes (STBs). To address this issue, some literatures, including the staircase broadcasting (SB), the reverse fast broadcasting (RFB), and the hybrid broadcasting (HyB) schemes, were proposed. This Dissertation also concentrates on reducing buffering space. Motivated by HyB, this work proposes a new scheme, which combines FDPB and RFB to yield small buffer requirements, as well as short waiting time. In addition, another new scheme integrating HB and SB is also proposed to save client buffering space and waiting time. In comparison with SB, RFB, and HyB, the proposed schemes can yield the smallest waiting time under the same buffer requirements.
For above schemes, client receiving bandwidth equals server broadcasting bandwidth. This limitation causes these schemes to be infeasible in mobile networks because increasing receiving bandwidth at all client sites is expensive, as well as difficult. To alleviate this problem, the greedy disk-conserving broadcasting (GDB) scheme supports a client with a small bandwidth. In comparison with other similar scheme, such as the client-centric approach (CCA) scheme, the GDB clients have smaller waiting time. Extending GDB, this Dissertation 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.
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