The television, it is safe to say, has become firmly entrenched in modern day society. No other medium is as widely used – television ranks first, with computers and the radio coming second and third respectively – or appeals to such a wide range of age groups and interests. It is no surprise then that the broadcasters have worked hard to ensure television continues to provide a relevant level of service to its viewers.
One of the most notable developments in the history of the television is digitisation. No longer as limited by size, broadcasters have found that by switching to digital the channels take up less bandwidth, meaning it’s possible to provide more content within the same space. Not only that, but they can also offer the viewer additional multi-media services, which has led to a much greater level of viewer interactivity.
According to the latest statistics, seven countries, including America, Germany and Luxembourg have already changed from analog terrestrial broadcasting to digital transmission. Many others, like the UK and Australia are currently in the process of switching, and it is expected that most other countries will follow suit within the next decade.
This switch from analog to digital highlights the fundamental change television has undergone since its first appearance in the early 1900s and serves to show how the relationship between broadcaster and viewer has altered. Indeed, in contrast to merely being broadcast at, the viewer now has a much greater level of control. The result is that you can now individually tailor different entertainment packages to suit your needs.
The biggest advantage of this is that you don’t have to pay for the channels or programmes you are not interested in. Whereas before there was not much choice in the content available, or you had hundreds of channels that you weren’t interested in, you can now pick and choose from the offerings, in order to create your own packages.
Not only does this offer you more viewing freedom, but you can also enhance how you use your television. Take Sky TV, for example. Situated at the front of the digital telecommunications industry, it provides people with the tools to personalise their viewing options and offers them the chance to take advantage of the most recent technological developments, such as pausing and rewinding live television.
Offering up a variety of different entertainment packages, it is also possible to select the channels relevant to your interests. Therefore, if you enjoy watching nature documentaries, keeping abreast of world events and catching the latest sporting action, you can simply create a package around this. Conversely, if you have children and want to filter the content available to them, you can choose to place parental blocks on certain channels.
If you haven’t yet discovered how digital television such as Sky TV can work for you, don’t worry you won’t get left behind. As most countries – such as the United Kingdom – are making a nationwide move from analogue to digital, there will be plenty of information and support for those confused about the move.
Find a good library that has back issues of the Bell System Technical Journal ( BSTJ ). It's all in there.
If the store is too far away or too annoying, people shop online. I bought shoes online since I don't even know where a good shoe store is.
Once your analog phone voice signal reaches your local telephone exchange switching center, it is probably converted to digital for processing and forwarding to the destination exchange you are calling. There it is converted back to analog for delivery to the analog phone line you are calling.
But, for sure one day all telecom signals will be digital. (except for the RF transmittion methods)
McDonalds. Landscaping. Painting.
The simplest answer is 'noise'. Since digital information moves in predetermined patterns, like ones and zeros, it is much easier to determine if a bit of 'signal' is part of the information.
Analogue can have any value signals, and so it is much more difficult to determine if there is noise (read errors) in the information.
Further, since digitalized data is quantized, it can even be counted, with totals arriving with the other information. So, as a simplified example, I can send you the word "Three" and also include that the letter count is 5, and the value count is 48 (if you use the numeric value of each letter from 1 – 26.) Now if there is a mistake in transmission, I have a way to know, and perhaps even correct the error. analogue carries no such possibilities.
Radar is a fascinating subject to me as it covers practically every aspect of general engineering as well as radio communications and elecronics
I would say radio communications engineering plus electronics would be the primary subjects to start with. Digital computing methods such as Digital Signal Processing should be covered in the comms syllabus
You will need a knowledge of Microwave and millimetric techniques beyond the normal communications syllabus
You may also need a good knowledge of mechanical engineering, hydraulics engineering and low temperature physics as well if your interested in "heavy" high power ground based Radars, though aviation radar may well need these subjects as well.
A good Radar scientist/ engineer really needs to have a good working knowledge of almost every branch of engineering there is!
This is why (to me) it such an interesting field
The change for FM radio falls under the name HD Radio. Cellphones have been digital for quite sometime and have gone through several different standards. The latest deployed standards for cell phones are called CDMA2000 and UMTS. Aircraft communications would have been changed under a program called NEXCOM.
A good book on Digital Modulation is Digital Communications: Fundamentals and Applications (2nd Edition) by Sklar.
Much of the conversion from analog to digital is made possible by source coding. These methods greatly reduce the amount of data required to transmit data by techniques that might alter the actual data but appear the same. Examples in everyday life include MP3, JPEG, and MPEG.