Radio Waves and their uses in Media Technology Cat Riley P11258060
Radio WavesThis presentation will explore alternative uses for radio waves outside of traditional radio broadcasting.Radio waves are the lowest frequencies in the electromagnetic spectrum, and are used mainly for communications. They are created and sent round via transmitters. Stars, other gases in space, and lightening also emit radio waves. This is why interference is sometimes heard when listening to the radio during a storm.
Just Radio?Radio waves are used to transmit information from one destination to another through the air or some cases space. This does not mean just for the purpose of radio stations broadcasting to listeners; there are other important uses within the media field. To transmit television signals To allow people to communicate via telephone without being plugged into a landline To access the internet wirelessly and on the move To send and receive data through wireless pairing via bluetooth Etc…
BluetoothThis widely used communication system was named after Harald Bluetooth, a famous Danish king who introduced Christianity and united Denmark and part of Norway into a single kingdom. This reference was chosen for the name as a nod towards the Nordic region and how important its companies have been in the development of the communications industry.Bluetooth transmits data via very low frequency (between 2.402 and 2.480 gigahertz) radio waves. This band is know as the ISM (industrial, scienctific, medical). Baby monitors, mechanical garage doors and cordless phones also use this waveband. Bluetooth devices send extremely weak signals (about 1 milliwat) so as not to interfere with other devices. For example a poweful mobile phone which can transmit at around 3 milliwats.Click here for a useful video on the basics of Bluetooth
Bluetooth Example: The notification when sending a file from my mobile phone to my laptop.When devices that are both Bluetooth capable (such as a mobile phone and a headset as shown above) are in range, an automatic conversation occurs to decided whether they have data that needs sharing. Both devices then hop between frequencies within the ISM band so they can stay together and avoid any other piconnets, otherwise known as PANs or Personal Area Networks, that may be operating in the immediate area.With bluetooth, many different kind of data can be sent and receieved, depending on the type of devices that are connecting.
Wi-FiWireless networks are everywhere. Free wi-fi is commonly provided in public places such as cafes, airports libraries and on trains. These networks allow people to access the world wide web on their portable devices whenever they want, without the use of cables or wires.A wireless internet connection is comparable to a two-way radio communication. Data is translated into a radio signal and is transmitted using an antennae by the computer’s wireless router. This signal is then decoded by the wireless router, which sends the information to the internet using an Ethernet connection (a physical wire).Click here for a quick video explanation of Wi-fi
Wi-FiWi-fitransmits at a frequency of either 2.4 or 5 gigahertz, significantly higher than Bluetooth, mobile phones or televisons. A higher frequency enables the signal to carry more data.Wi-fi connections use 802.11 networking standards, which come in a few different varieties, transmitting at different speeds and able to handle different amounts of data: 802.11a – 5 GHz, 54 megabits per second 802.11b – 2.4 GHz, 11 megabits per second 802.11g – 2.4 GHz, 54 megabits per second 802.11n – 5 GHz, 24 megabits per second (but reportedly can achieve 140)
Bibliography• NASA’s Imagine the Universe! http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html• Electromagnetic Spectrum image http://lot.astro.utoronto.ca/images/spectrum.png• Infoplease http://www.infoplease.com/ce6/sci/A0860617.html• How Stuff Works http://electronics.howstuffworks.com/bluetooth1.htm http://computer.howstuffworks.com/wireless-network1.htm• Bluetooth Logo Image http://www.ketrin.co.uk/wp- content/blog/uploads/2011/05/BlueTooth.png
Bibliography continued…• Womanwith headset image http://2.bp.blogspot.com/_Qv8wb7pq08Q/TTwB7zsu2ZI/AAAAAAAAAlY/h OahyuY7lLg/s1600/Best_Bluetooth_Headsets.jpg• Wi-Fi logo image http://www.annectocomputers.co.uk/wp-content/uploads/2011/07/Wi- FI-Converted-copy.gif• How Wi-Fi works image http://static.ddmcdn.com/gif/wireless-network-1a.jpg• Youtube http://www.youtube.com/watch?v=e1p4c7Gf8d8&feature=related• E How http://www.ehow.com/video_4754178_wifi-work.html