Image Processing Reference
In-Depth Information
The DVB-H devices have very different characteristics from normal TV receivers in
terms of power consumption, screen size, and mobility. Even portable TV receivers are
more like the static sets that you have in your living room. The DVB-H standard also
describes data services.
Manufacturers such as Nokia and Pace are already showing prototype products
based on this standard.
Draft documents and initial versions of the standard are published on the DVB web
site. Other DVB-H material is available at IPDC, BMCO-Berlin, DigiTAG, and RTT.
Digital Multimedia Broadcasting
The digital multimedia broadcasting (DMB) service is a satellite-based system that is
designed to deliver TV and radio to mobile devices such as phones and laptops. It is very
new and still being developed but is currently being rolled out in Asia. Because it is satel-
lite based, there are gaps in the service, such as when the user is underground. These are
being dealt with by installing gap fillers to ensure that service is uninterrupted.
The design takes account of users who may be in transit, and so it is still usable at
speeds up to 150 km per hour (or about 90 miles per hour).
Initially delivering as many as 12 visual and 26 radio channels, the service is
expected to reach 8 million subscribers by 2010. The services are based on MPEG-4
standards and use H.264 coding for the video. The audio and video presentations are
combined in a BIFS container, which describes the scenes.
Integrated Services Digital Broadcasting—Terrestrial
ISDB-T has evolved from the digital terrestrial TV (DTT) services. It is another example of
how these technologies are adopted very early on in the Far East. ISDB-T is designed to
scale from audio only up to HDTV applications in mobile situations.
This service is similar enough to DVB-H that the two might converge in the future,
but for the time being they are moving forward independently of each other.
WiMAX (IEEE 802.16)
This is the next step onwards from the Wi-Fi IEEE 802.11 standards, which have become
popular for wireless networking over short ranges.
The WiMAX standard addresses similar needs to the DMB services in the Far East. It
is also designed to cope with the receiver's being on the move at rapid transit speeds. The
goal is to deliver broadband connectivity speeds to mobile devices over a range of 25 to 30
miles. This is far greater than the 300-foot radius of an 802.11 hotspot.
This is also known as Mobile-Fi as opposed to Wi-Fi; Mobile Broadband Wireless
Access (MBWA) is yet another name for it. It's the usual 1 concept to 300 different names
ratio just to confuse the innocent.
Samsung DMB chips:
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