Analogue and Digital Broadcasting
Analogue broadcasting is made up of continuously varying waves to make up an image. This is the old way of receiving and giving out signals and now many companies and methods of transmitting signals are not using analogue anymore. The quality given out from analogue can be lost very easily when it is transmitted and it has a very large bandwidth meaning it is hard to compress. The newest method is digital broadcasting. Digital broadcasting works on the concept of ‘multiplex’, which allows you to broadcast more than one channel together only using one bandwidth and computers encode TV signals to digital information, which are then sent by pulses. By doing this it had many advantages, such as is attracts more people to join it and view their programmes because they have more to offer and also it can be compressed to take up less bandwidth, meaning more channels can we multiplexed together at a better quality. For example before there were many channels, the BBC normally had half the viewers watching their programmes, however now that there are a greater range to choose from the BBC have to fight to get people to watch their TV channel. This then increases the competition between the channels and they get competitive to win over the viewers. However it also comes with some disadvantages, for example there are more channels for us to choose from, so that means that each channel is going to get fewer viewers overall. Extra bandwidth is also available so that the TV Companies can transmit interactive information. However to receive digital broadcasting you need a digital TV, set-top box or decoder. Soon the digital switchover is going to take place, which is where analogue is going to be turned off so you can’t transmit using it and everyone will have to use digital.
Terrestrial Broadcasting
Terrestrial broadcasting is the process where you send out pictures and sounds to a wide range of people from an aerial on the ground. The opposite of this is narrowcasting, which is where you transmit from the ground, however this may only be received by a small and specific group of people. Free view is terrestrial TV and run by transmitting digital signals and also the BBC traditionally uses this method to broadcast their TV. This type of broadcasting doesn’t involve either satellites or cables but instead radio waves which can only give out signal at a certain frequency. The band-width limits the frequency of the signal so that only certain frequencies are able to be used in the electromagnetic spectrum and which are only able to be a certain size for it to be able to transmit. Also because of analogue terrestrial broadcasting, it means that the bandwidth limits the number of channels you are able to see. However there are many drawbacks from this type of broadcasting, such as the weather can affect the signal a lot, for example when there is a thunderstorm there is poorer signal, which means that there are poorer quality images. Also the antennas that are used to broadcast cannot transmit far so this can affect where some people live and the signal they receive, for example if you live at the bottom of a hill and the mast is behind a hill then the signal is going to be a lot worse because the hill is blocking the signal reaching the house. As well as analogue terrestrial broadcasting there is also terrestrial digital broadcasting, also known as DVB-T, which stands for digital video broadcasting-terrestrial. Terrestrial broadcasting used to transmit by using analogue but now it also uses digital and soon, because of the digital switchover it will only run on digital signals.
Broadcasting – Satellite TV
Satellite broadcasting is the opposite of terrestrial broadcasting because instead of signals being transmitted from the ground, they are being transmitted from space. This comes with many advantages, for example it eliminates the drawback of the terrain on which you live on because the satellite is able to transmit from above. Also it can cover a larger area of ground so more people are able to receive the signals. Many interactive TV’s use this signal so that the viewer is able to choose from a wider selection of choices so they can pick the package deal they want with their TV satellite company, such as Sky or Virgin. It also provides a much higher definition and more channels; however it can still be affected in extreme weather conditions. Satellite broadcasting is transmitted using microwaves in the electromagnetic spectrum. By using this frequency it means that they are able to easily pass through the atmosphere giving you a better signal overall. Also satellite TV used to transmit using analogue signal but now only use digital. Companies such as Sky, BBC and Freesat use the Astra satellite group to transmit their signals in the UK and Astra is one of the most popular companies that are used. Also the cost for TV packages within the companies can vary a lot all depending on many things, for example what variety of channels you pick and how many channels you want to be able to receive. Th cost can go from £15 - £60 a month.
Broadcasting – Cable TV
Broadcasting through cable TV is transmitted differently from a satellite in the sky, instead it transmits TV via the signals through fixed optical fibres or coaxial cables laid to your property, however this is limited and can only be received in a certain places or streets. This then includes different packages for the viewer to be able to chose from, for example both phone and broadband. There are both advantages to the broadcasters who are transmitting the signals, but also drawbacks to the audience. Some of the advantages for the TV Companies are that the viewer has to subscribe to get the signal to be able to use cable TV so the Company, such as Virgin media are receiving more viewers and therefore getting more money for their company and transmitting more signals. This also means that no other company is able to touch the cables because each cable is owned by a different company. This means that the people living in that area has to pick that certain company and eliminates any competition for them. However some disadvantages are that only certain places receive it, so if you live outside that area you won’t be able to receive cable TV. Also there is often maintenance work, which affects when you are able to watch your TV and can lower the quality of the TV satellite that you are receiving. Cable TV is a subscription TV service so limits how many people are able to sign up for it. In the UK Virgin Media is the main cable provider taking about 95% of the market, with Sky being the main competitor. However Sky is still the main overall company with the most viewers using its service.
Internet Protocol Television (IPTV)
Internet TV is the newest way of being able to watch TV and was only introduced in 2005 onwards. It has become a lot more popular throughout the 21st century, for example iplayer and has rapidly increased the popularity for companies, such as broadband because it includes Live TV, catch-up and on-demand. Broadband is a high frequency signal on a telephone line, satellite or cable connection and allows you to get a high-speed connection to the Internet. The online TV can then be streamed, buffered or downloaded. The difference between these are that streaming is when you watch something online at any time and can be live, buffering is when the computer is capturing the footage before watching it and storing and signals in the computer and downloading is when you take something and keep it forever. This rise has happened mainly because of the invention of Broadband and online TV was only available since Broadband came along but also because more people want to watch online TV and is increasingly becoming more used by viewers. Also the rise has taken place because it appeals to the audience that you are able to watch any program they want and watch it when it suits them. This is often targeted more towards the younger generation because they are the ones who are using the computers more and know how to use the technology and a big factor that appeals to most people is that is for free. The advantages are that it allows you to watch what you want and whenever you want to watch it. However the rules for some channels are different, for instance some programs only stay on for a period of time and others stay on forever. This also comes with a disadvantage because that means not all the money is going straight to the channel providing the programmes, however this isn’t the same for all channels because the money from iplayer revenue goes to the BBC, but at the same time it is still advertising and promoting their channel and the things that they are able to offer.
