Once upon a time there was a sign of television that wanted to leave the living room of his home: he wanted walking the streets, running on the highways, getting to rural areas and be seen by all, without tunnels, high buildings or industrial zones interfere. But their Physical characteristics prevented him from doing so and in the outside world there were no conditions to transmit it or receive it well. The analog world was in full swing.
However, things they would change and a new era would come transforming it. all. The widespread decision to adopt a standard of digital television, in conjunction with the emergence of devices laptops such as cell phones, PDAs and players multimedia, would generate various initiatives to change the fate of this restless television signal, to which we will call mobile tv.
The idea of mobile TELEVISION arises from the technical potentialities of television digital, in the form of any of your current presentations (ATSC, DVB, ISDB or DMB), and the spectacular development of portable devices such as cell phones and PDAs. Several concerns arose around these facts: how get more out of the terrestrial television signal digital that reaches (or will reach) millions of households in TELEVISION?, how to take it to all those mobile devices of such high acceptance among consumers?, what to do to expand the market within the community than broadcasters how to offer audiovisual content to that audience who craves information and entertainment on your phone cellular or on your PDA?
The answer or, really, the Answers come from two distinct areas: on the one hand they are manufacturers, network operators, creators of software and regulatory bodies, brought together in consortia of east and other side of the Atlantic and Pacific, which have developed standards and technologies for the delivery of the digital television and data services. These standards some more than others cover various aspects of the digital television, which can go from the broadcast (broadcasting, satellite, cable and, now, IP and portable devices) up to content or access rights management conditional.
The other is the one offered by the cell phone companies, which propose to provide content on demand to its users. These contents could be as much data such as informative or entertainment video clips.
While in the first case the user would see in real time the programming of their local channel or national, in the second, the user could request the information you want (newsletters, report of weather conditions, music videos, etc.). The two cases they would enjoy the benefits of interactivity. Let's look at each one.
The proposal of the broadcasters
Although there are several standards of digital television
proposed (American ATSC, European DVB, Japanese
ISDB, south Korea's DMB and The Chinese of the same name), three
lead the adoption of digital television in America
Latin: the ATSC, DVB and ISDB. Some countries have already done their
Decision: Mexico opted for ATSC, while Brazil adopted the
ISDB with modifications. However, for the purposes of our
Theme - mobile television - we will stop to review the
developments carried out in this arena within the European standard
and the American, which have a higher probability of adoption
in our region.
ATSC
At NAB 2007, two pairs of companies presented their developments
from the ATSC standard for mobile TV or ATSC-M/H
(ATSC Mobile and Handheld Standard). These were Harris in
partnered with LG, and Samsung in conjunction with Rohde & Schwarz.
The Harris-LG duo
MPH mobile TV technology
of Mobile-Pedestrian-Handheld) developed by the company of
Harris communications and technology, and by the
ZENITH research and development, from LG, in the United States,
allows broadcasters to transmit programming from
high definition to fixed receivers, and definition programming
standard and datacasting to devices
mobiles and laptops.
MPH In-Band Mobile Technology TV stands on two key ATSC standards, the system Enhanced VSB (E-VSB) and the 8-VSB, proven modulation system which lies at the heart of the ATSC standard for television digital broadcast type. The initial objective of the work in common of the two companies was to design a robust solution, compatible with the ATSC standard, which allowed broadcasters maximize the use of 6 MHz and 19.39 megabit per second of your digital channel, to offer profitable and attractive services to your viewer audience.
To enable a mobile reception robust, the broadcaster will be able to allocate a portion of your transport flow for mobile TV service and other for fixed receivers. For example, if 4.4 Mpbs are destined for MPH stream, then about 15 Mbps are maintained for the main programming. Using MPEG-2, current compression, 15 Mbps can support one HDTV channel at 1080i and one or two channels SDTV, or one HDTV channel at 720p and two or three SDTV channels.
Harris has planned for a broadcaster could start an MPH service with a width destination of total band of no more than 3 Mbps, which would provide a mobile channel good quality and a slightly quality secondary channel inferior. MPH In-Band Mobile TV is designed to offer the broadcaster the flexibility to choose how much bandwidth you want to allocate to your mobile TV service and how many mobile channels program.
