1. The left side of the EM (electromagnetic spectrum) is used for communication. They are:
Radio waves e.g. tv, radio
Microwaves e.g. telecommunications, radar,
Infrared e.g. remote control
There are many devices which rely on electromagnetic radiation to work, two devices which have
been used that require the use of electromagnetic radiation are:
Mobile phone: Mobile phones use microwave signals. The signals from the phones reflect off metal
surfaces and walls to communicate with the nearest transmitter. There is a network of transmitters
which convey the signals on to the nearest mast to the receiving phone. The wavelength frequency has
to be tuned specifically so it does not cause damage to the human health (Revisionworld). With
mobile phones you do not need a direct line of sight, you will be able to connect regardless of walls
etc.
Remote control: infrared light signals between a remote control and tv or box set that it controls
consists of pulses of infrared light. The light is invisible to the human eye, however, can be seen
through a digital camera or a phone camera. The infrared light corresponds to specific binary codes
which allows the information to be passed through for the device to do the operations you want
(Waonderopolis). The device does not work if it is being used from behind a wall or around a corner
there needs to be a direct line-of-sight, between the transmitter and receiver.
2.
Wireless
Advantage Disadvantage
Signals can pass through walls. Sometimes distance may affect signal
strength
Have long range frequency Interference from other wireless devices or
Easy to move around devices too many users.
Can broadcast to many receivers May be expensive to install sometimes
Easy to maintain Security vulnerabilities
Wired
Advantages Disadvantages
Weather less likely to disturb signal as it is Cannot move devices around
through wires
Lack of interference Cannot broadcast to multiple receivers
More security A lot of wires
Enhanced speed Can be a trip hazard
High installation and replacement costs
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