Television Aims to Educate and Inform Viewers

Television signals were originally transmitted exclusively via land-based transmitters. Television genres include a broad range of programming types that entertain, inform, and educate viewers. Television genres that aim to educate and inform viewers include educational shows, DIY programs on cooking, gardening, or home renovation, history shows, performing arts programs, and documentaries. Television service providers also offer video on demand, a set of programs which could be watched at any time.

Dtv

DTV is a new type of broadcasting technology that will transform television as we now know it. DTV technology will allow broadcasters to offer television with movie-quality picture and CD-quality sound, along with a variety of other enhancements. DTV technology can also be used to transmit large amounts of other data into the home, which may be accessible by using your computer or television set. DTV allows the same number of stations to broadcast using fewer total channels (less of the broadcast spectrum) which will free up scarce and valuable spectrum for public safety and new wireless services. DTV technology can also be used to provide interactive video and data services that are not possible with “analog” technology. DTV allows a number of new and better services. DTV is a more flexible and efficient technology than the current analog system. DTV can provide interactive video and data services that are not possible with “analog” technology. DTV provides viewers with sharper images, better sound, and more viewing options than have ever been available over the air.

Broadcast

A television system may be made up of multiple components, so a screen which lacks an internal tuner to receive the broadcast signals is called a monitor rather than a television. A television may be built to receive different broadcast or video formats, such as high-definition television (HDTV). The elements of a simple broadcast television system are:An image source. An antenna coupled to the output of the transmitter for broadcasting the encoded signals. An antenna to receive the broadcast signals. A receiver (also called a tuner), which decodes the picture and sound information from the broadcast signals, and whose input is coupled to the antenna. A typical NTSC broadcast signal’s visible portion has an equivalent resolution of about 640×480 pixels. It actually could be slightly higher than that, but the vertical blanking interval (VBI), allows other signals to be carried along with the broadcast. Higher frequencies behave more like light and do not penetrate buildings or travel around obstructions well enough to be used in a conventional broadcast TV system, so they are generally only used for MMDS and satellite television, which uses frequencies from 2 to 12 GHz.

Television and Young People (TVYP) is the UK’s leading forum for young people aspiring to work in television. Television shows are available in the US and UK only, and video availability varies by country. Television preservation is a relatively new field.

White Space – The Debate Over Free Wireless Spectrum

With the announcement of the website FreetheAirWaves.com by Google in order to support the white space campaign, the debate over the “white space” issue has reached a new level.

In terms of Google white space is the space of unused frequencies in the range traditionally defined for TV channels. Google and some other leading companies wants to transform this range from licensed, like TV where specific frequencies are granted exclusively to a specific channel, to unlicensed, like Wi-Fi where anyone can use it. They call it “Wi-Fi on steroids.” The spectrum would enable longer-range, higher data rate, and faster wireless connectivity for all types of gadgets.

Along with Google other technology companies like Intel, Dell, HP, Microsoft, and Phillips Electronics are united in a coalition called the Wireless Innovation Alliance. They have been lobbying the FCC (Federal Communications Commission) to open up this spectrum for unlicensed use after the digital TV transition early next year.

The National Association of Broadcasters (NAB) and phone companies are entirely against this initiative. The Television and phone companies want exclusive rights to various frequencies. These spectrum that sit idle between TV channels as buffers, in order to ensure that TV signals don’t interfere with each other, could be used to provide broadband wireless services. But according to the broadcasters, these channels will cause interference with their TV signals and eventually resulting in major problems for people watching TV.

The FCC has done a number of testing of the spectrum to see if wireless devices will interfere with each other. The results of the tests have been mixed. But Google has make out a solution for this problem. Now it is proposing new rules to designate specific frequencies for TVs, wireless microphones, and for other devices, and then another spectrum for wireless Internet access.

Next month the FCC is likely to release a report based on the test results. It will finally vote on whether to open the spectrum in the next few months. This issue has become as much of a political debate as it has a technical one. The National Association of Broadcasters is pointing that interference can’t be avoided, based on tests as evidence. While Google and other technology companies argue that these are simply proof of concept devices and are not even like the prototypes that could be used in commercial products.

NAB and other Wireless companies, such as Verizon are opposing the use of white spaces because they have their own business motivations for opposing the use of white spaces. The afraid of interference might be a concern for the NAB but the more prominent reason for opposing this concept is that its members are reluctant to give up control of airwaves, which they believes are theirs.

Along with other technology companies, Google has its own motivations and interests to consider. Google can make more from advertising if more wireless spectrum and broadband services are available. Other companies like Intel, Microsoft, and Motorola would also be benefited as they could sell more products and services to consumers who use this unlicensed spectrum.

The Digital Television Revolution

The 2012 London Olympics really brought home to me just what a massive technological jump in digital media has occurred during the last few years. There has been significant advances in digital compression and transmission.

This year, in addition to high definition broadcast, which made its appearance in the 2008 Beijing games, 3D television was also added to the line up, offering more channels and choices. With analogue television broadcast almost becoming extinct, digital televisions promise of delivering more for less has become a reality. Now, how did we arrive at this point and what does the future hold for digital multimedia?

Prior to the digital switchover, analogue television was resource hungry in terms of the amount of bandwidth required to carry a single channel. This is typically between 6 – 8 MHz depending on the type of video standard being used. This limited the number of channels which could be transmitted, since there is a finite amount of spectrum that must be shared with other services such as mobile, radio and two way communications.

What the digital standards of ATSC (North America) and DVB (Rest of the World) provided was the ability to reuse the existing analogue spectrum more efficiently. This meant a typical 8 MHz carrier used for analogue broadcast could be converted to DVB-T (Digital Video – Terrestrial) making it possible to carry 9 standard definition channels or 3 HD channels plus one SD channel for the same amount of bandwidth.

It would have required in excess of 70 MHz of frequency spectrum to achieve this with the old analogue standard. In addition to squeezing more channels into less space, digital television is much clearer and doesn’t suffer from ghosting or other artifacts which troubled analogue systems. Being digital also allows other features like improved digital sound, electronic program guide and subtitle support to be included.

Televisions are sold with the digital decoder integrated and older televisions can use a separate set top box. As technology advances, we will also see improvements in the compression techniques used, which means even more content for digital media, already this has enabled 3D broadcasts for some events such as the Olympics.

The Future

Eventually as fibre to the home is deployed worldwide, the all IP enabled set top box will replace the DVB standard, since the IP set top box has a distinct advantage over digital broadcast technologies, specifically multicast join requests. Unlike DVB-T or DVB-S, IP multicast allows the receiver to send a join message to the network for the desired channel then if the request is successful the broadcast is routed to the receiver, only the bandwidth for the requested channel is used. With the DVB standard, all available channels are being broadcast simultaneously, and the channel count is limited by the finite amount of channel bandwidth regardless of the compression techniques being used.

The IP set top box can support both selective multicast (one to many) and on demand unicast (one to one) broadcast, this allows for virtually unlimited amount of content. However, unlike DVB, IP set top boxes have to worry about latency and QOS, since there is traffic contention with both residential broadband and IP Telephony. A poorly implemented IPTV deployment can behave like analogue television in an over subscribed service provider network, unless the correct traffic management is in place.

High Definition

Today HD is regarded as premium content by most operators and is charged at a higher rate than SD (Standard Definition). However, over time this will change as people upgrade their televisions to HD models. Today there are two standards for digital HD broadcast, 720p and 1080i. The ‘p’ means progressive and the ‘i’ means interlaced. In 720p broadcast, the picture is made of 720 horizontal scan lines and a vertical resolution of 1280 pixels, which has the advantage that one frame represents a complete image.

In 1080i broadcast, the picture is made from two 540 horizontal scan images which when combined make 1080 lines. The vertical resolution becomes 1920 pixels. Most modern televisions support playback of 1080p, which is definitely more desirable than 1080i especially in fast moving sequences where motion blur can be experienced. However, on modern televisions the difference is barely discernible.

Initially the public uptake of HD was slow, the receivers were expensive and the available content was limited. HD television has really been an evolution rather than a revolutionary change for most of us and this is also true of digital television in general. As digital switchover continues worldwide and consumers replace their televisions, digital will become the new standard. However, it is unfortunate that technology won’t help to improve the content.