"The Internet is set to
revolutionize TV within the next five years, due to an
explosion of online video content and the merging of PCs
and TV sets", Bill Gates at the World Economic Forum,
2007.
As noted by Microsoft founder Bill Gates,
the abundance of video contents online will drastically
change the TV watching population's viewing habits. Various
surveys noted that the global market for IP delivery of
video entertainment will blossom in exponential pace,
with revenue exceeding $7 billion and IPTV subscriber
base exceeding 60 million by 2010. All these forecasts
point to a booming entertainment sector delivered over
the IP network.
Unfortunately, video delivered over the
Internet still have shortcomings to overcome, such as
unpredictable quality for live and VoD streaming, and
excessively long duration for file downloading. This is
mainly due to the original design of the Internet, which
did not have time-sensitive, quality-centric media delivery
in mind.
In a typical client/server model of media
delivery, there are several bottle-necks that the content
providers must address in order to serve a massive number
of customers. As indicated in Figure 1, suppose an Internet
Content Provider (ICP) is serving a number of (N) customers
from the same subnet of an Internet Service Provider (ISP).
As such, N unicast video sessions originating from the
ICP's server must be established to deliver the video
to the N clients. It creates burdens at the server capacity,
the server side's upstream bandwidth, as well as the Internet
bandwidth at the clients' ISP.
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