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Technical Review | January-March 2012
Discovery channels. Relationship building has forged cooperation with producers from different regions. However most HD production in Asia tends to be undertaken by producers from the West. It is time for a change and to encourage Asian producers to make the content which is more authentic.
The Korean viewpoint is that broadcasters have to take viewers who do not have HD receivers into consideration. Cropping takes place when down converting from HD to SD and subtitles are too small to read in SD. It is therefore best to make two different versions where it is important that content is enjoyed by all viewers. As for 3DTV, technology has not evolved fast enough and still requires the viewers to wear glasses. There is currently a dearth of 3D content, restricting the number of available 3D transmission hours.
Delivery of Content including 3DTV and UHDTV
carry the proper combination of FFT size, guard interval and pilot pattern to mitigate mobile propagation condition without disrupting any T2 fixed receivers. This new mode of DVB-T2 is termed DVB-T2 Lite because certain parameters that are not relevant for mobile reception are discarded.
Hybrid TV uses both broadcast and broadband to send content to the viewers. As an example, Media Broadcast’s Smart TV portal provides information on the screen mostly using text and pictures. The broadcast channel transmits only the relevant programme ID, URL and still pictures. There is no broadcasting of video or audio data and therefore requires only a narrow bandwidth. Once the user selects the programme, the content stream is delivered through the broadband/internet network and displayed on the screen.
Multichannel surround sound is an integral part of the HDTV experience and the 5.1 channel surround sound can be implemented with Dolby E-AC3 without the need to pay royalties for producing and transmitting. Minimal charges are imposed on receivers but this does not have a
The session looked at the different approaches that had been developed for terrestrial and satellite delivery of UHDTV, 3DTV as well as mobile multimedia services. Super Hi- Vision provides higher resolution and wider angle of view with its large frame size of 7680 x 4320 pixels, and uses a progressive scan frame rate of 120Hz with an aspect ratio of 16:9 and 22.2 multi-channel sound system, providing an immersive experience. Transmission experiments have been done using Ku and Ka band satellites as well as optical fibre and terrestrial means. To meet capacity needs, the 21GHz frequency band will be used for delivery but this band has higher rain attenuation, a problem which is currently under going further studies by experts.
Although DVB-T2 can cater for fixed, portable and mobile reception, some of its specifications are targeted specifically at mobile reception. Mobile propagation conditions induce frequency shifted echoes which require smaller FFT size. The Future Extension Frame (FEF) can be optimised to
significant impact on prices, even for the low cost segment of the HD receiver market.
Regional and local content is a key driver and differentiator for DTT networks compared to DTH systems. It can also be used to generate new revenue streams through local or regional advertising. A well configured DVB-T2 network can be used to distribute the same DTH content from satellite at the same time allowing insertion of local content. The DVB-T2 parameters allow easy insertion of content within the network.
Digital Radio: Looking to the Future
This session addressed current developments in digital radio and how it will march into the new future.
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