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.

All About LCD Televisions

LCD televisions are generally known as Liquid Crystal Display televisions which generally use the LCD TFT technology, offering the users crystal clear display of the images. In general, the advantages of the LCD televisions are high when compared with other type of televisions. The users are assured to enjoy really good experience in watching their favourite programmes through LCD television. Other main features the users have to look in these types of televisions are its size and price and more importantly the technical features.

The other important factor that has to be taken care technically is the response time and colour. Also the latest model television sets are integrated with the best features making the users feel at ease in watching the programmes they like with better display. When compared with the normal CRT television models, the sizes of these televisions are the most highlighting factor, which attracts the users the most. Also many renowned features are available in this model, for the users to enjoy handling these television models.

RGB spectrum is used in these television sets which helps to display the images incorporated with all the colours. But still the research is on in adding more colours to this spectrum. The display range of this model television sets are better, when comparing the screen display and resolution of the plasma televisions. The LCD televisions are portable and highly flexible to use. It is a complete home entertainment television set, where the users can enjoy watching whatever they like in complete theatre effect both in the picture and sound quality.

Apart from the image and screen resolution, other features the users have to take care is the memory slots, USB, DVD, camcorder and video games connectors are the few to mention. There are thousands of brands are available in the market and the manufacturers are really facing a tough competition. So, in order to increase the sales, the LCD televisions integrated with the latest technology are offered at a comparatively lower rate in the market.

The History of Scented Candles

Not many people seem to know this… By the end of 2012 the UK will have been the only country in the world to have totally made the switchover to all digital television. The digital switchover starts in 2008 – less than 2 short years away.

A recent Which Report (Which is the major consumer champion in the UK) shows that in many areas the awareness of the digital switchover is less than 2 %. Even in the Borders Television region – the first to make the change – only about a third of the people surveyed knew what was going to happen.

It really does seem that the UK is sleepwalking in to the Digital Switchover.

Not surprisingly, the whole switchover programme is being watched with keen interest by other nations around the World. The benefits of digital television for broadcasters, manufacturers and programme makers are pretty clear. The new media is already changing programme making – Planet Earth, currently showing on the BBC – is a prime example of what can be achieved. And of course the manufacturers are positively drooling at the thought of all the new televisions, video recorders and set-top boxes they expect to sell.

Consumers are set to benefit too – better pictures and sound, high definition television, interactivity, movies on demand… The list goes on.
Governments have a keen commercial interest too. They own the air waves. And digital television takes up much less band width than conventional analogue signals. So the move to digital frees up precious broadcasting capacity that Governments are keen to sell to the highest bidders. The sale of the mobile telephone spectrum for 3G providers raised over £20 billion. Who would bet that the sale of the television spectrum won’t raise significantly more?

The move to digital television benefits us all. So why do so few people know what is happening?

Simply being able to receive digital television is only part of the issue. Just about every television bought more than 12 months ago, and a good percentage of those being sold now, are effectively obsolete. All of them will need a separate satellite receiver or set top decoder box to receive digital signals. Every video recorder will also need an additional decoder.

The UK Government puts the average cost per household to upgrade to digital television at £132 ($210). I feel the real figure is likely to be 4 or times this level. Most homes in the UK have upwards of 4 televisions – each and every one will need significant investment to receive digital television signals.

In the UK 68% of homes already receive digital television in some form- satellite (which means BSkyB – the only UK satellite television provider), cable or terrestrial freeview. In almost all cases digital television is only watched on the main television in the house. The other sets are still restricted to the main analogue, terrestrial stations. From 2008 this has all got to change.

It’s time to wake up. We are at the threshold of the biggest change in the television experience since it was first invented.

Start planning your own digital switchover now.