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Abstract |
In communication systems, the
digital technologies also progressively advance channel capacity both in wire
and wireless systems. For ubiquitous multimedia services, the development of
wireless communication systems has moved toward the so-called the 3G epoch,
which could provide live video service via wireless channel, respectively.
However, the wireless multimedia service with dedicated bandwidth through 3G
system is till too expensive for two-hour movies. Recently, the traditional
analog broadcasting audio and video services, such as AM and FM audio and
television systems, have gradually migrated to the digital formats by taking the
advances of effective digital communication systems and multimedia compression
standards. With the coded orthogonal frequency division multiplexing modulation
(COFDM) technique, the digital multimedia broadcasting system with larger
coverage and sharing bandwidth will provide cheaper and higher quality
multimedia services.
After several evolutions of MPEG-related digital multimedia standards, the
services for video, image, audio, speech become more efficient, more effective
and more secure for the modern and high quality entertainments. Along with
development of VLSI and hardware designs, the users could pay a low cost devise
terminal and reasonable expenses in acquired bandwidth and demanded services to
enjoy fully utilizing 4C technologies, which involve computer, communication,
consumer electronics, and contents. Currently, MPEG-4 T/F audio coding and H.264
advanced video coding standards exhibit further improvement of coding efficiency
such that we could further reduce the bandwidth cost. In addition to compression
standards, MPEG-7 by providing multimedia content description interface helps
content retrieval for pull and push multimedia services. Furthermore, MPEG-21
for multimedia framework provides access to information and services from almost
anywhere at anytime with ubiquitous terminals and heterogeneous networks.
Nowadays, the digital multimedia contents still have encountered some questions:
how to efficiently compress and decompress the multimedia; how to manage the
intellectual right property protection for digital multimedia; and how to
effectively store and retrieve multimedia data, especially from bulky video and
audio files.
The digital broadcasting system is a one-way communication, which might only
provide push multimedia services intuitively. First, we should not be able to
interact with television station. The digital multimedia broadcasting through a
designed multimedia home platform (MHP) could enable an enhanced broadcasting
system. You still can interactively select the electronic guide, sport and
weather information, which are pre-loaded data along with live video
broadcasting signals. You can play video games and facilitate the video on
demand service on your MHP once the game programs and the video sequences were
also pre-loaded in the hard disk of the MHP. All the pre-loaded processes could
be conducted in off-peak period through broadcasting. All the payments and
records of interaction and selections will be discharged from and stored into
the pre-paid smart card, respectively. With an intelligent agent, the multimedia
service providers could also offer context-aware and personalized ubiquitous
media by exploiting data mining techniques while the users bring their smart
cards to recharge their payments. |
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