1.4 - Connectivity
Exam Board:
OCR
Specification:
2016 - Unit 1
For computers to communicate with other devices and share data a form of connection is required.
Wired Connections
Copper Cables
Copper cables are a cheaper type of wired internet connection that may be poorly insulated and therefore susceptible to electromagnetic interference.
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Copper cables are more likely to suffer from attenuation (network distortion).
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However, they are malleable (easier to bend) and less likely to break than other cables such as fibre optic.
They have a lower bandwidth - cannot transmit as much data at once - than fibre optic cables.
Fibre Optic Cables
Fibre optic cables are a very fast but expensive type of wired internet connection.
Signals are transmitted as waves of light through a glass tube. Because of this fibre optic cables are not affected by electromagnetic interference and suffer less from attenuation.
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Fibre optic cables have a higher bandwidth - can transfer more data at one time - than copper cables but they are more fragile.
Wireless Connections
Bluetooth
Bluetooth is a temporary short-range communication between devices within a limit of about 10 metres.
For example, Bluetooth can be used to transfer audio files from one smartphone to another.
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The close proximity is a disadvantage but no other hardware is required for a connection.
Infrared
Infrared networks have been replaced by Bluetooth or WiFi connections because infrared requires devices to be in direct line of sight.
Infrared is still used by some devices such as remote controls to transmit signals to a TV but it only works across a short distance.
Microwave
Microwave connections use radio waves to send signals across a large area via microwave towers.
It can transmit a large amount of data but antennas must be in the line of sight of each other with no obstructions.
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Microwave connections are affected by bad weather, leading to higher chances of attenuation (network distortion).
Laser
Satellite
GSM / 5G
Although not common, laser connections can send data between devices that are in the line of sight of each other as long as there are no barriers.
Laser connections can transmit data up to 2km but bad weather severely affects the transmission rate.
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Laser connections can be used in space as there are fewer barriers between the satellites.
Satellite networks use point-to-multipoint communication by using satellites above the Earth's atmosphere that receive a transmission and rebroadcast them back to Earth.
Because of the distance between the communication device and the satellite (roughly 45,000 miles), there is a delay between data transmission and it being received. See 3.4 for more information on satellite networks.
GSM (Global System for Mobile communications) is a technology for allowing mobile phones to connect to a network for calls and text messages.
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Advances in mobile technology are classified by generations such as 4G and 5G (the current generation). Each generation is generally faster, more secure and allows for new opportunities. See 3.4 for more information on cellular networks.
Questo's Questions
1.4 - Connection Methods:
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1. Compare the differences between copper and fibre optic cables (possibly in a table) by the following features:
a. Price
b. Bandwidth
c. Inteference
d. Attenuation
e. Malleability / Fragility [2 each]
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2. Describe each of the different types of wireless connection. Try to list 1 advantage and 1 disadvantage of using each type.
a. Bluetooth
b. Infrared
c. Microwave
d. Laser
e. Satellite
f. GSM / 5G [5 each]