1.4 - Internet Connections
Exam Board:
OCR
Specification:
2016 - Unit 2
The internet is a global network of interconnected networks.
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There are multiple methods of connecting to the internet.
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.
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).
Satellite
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.
GSM / 5G
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.
Connection Characteristics
When connecting to the internet there are several characteristics that a user must consider:​
Strength
Range
Latency
Bandwidth
Storage Capacity
Contention
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Latency is the delay when sending data across a network.
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Bandwidth is the maximum amount of data that can be sent across a network at once.
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Contention refers to whether a network is dedicated (uncontended) or shared between users (contended).
Questo's Questions
1.4 - The Internet:
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1. Compare the differences between copper and fibre optic cables (possibly in a table) by the following features:
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a. Price
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b. Bandwidth
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c. Interference
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d. Attenuation
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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.
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a. Bluetooth
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b. Microwave
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c. Satellite
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d. GSM / 5G [5 each]
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3a. State the 6 characteristics of a network. [6]
3b. Describe what is meant by the following characteristics:
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i. Latency
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ii. Bandwidth
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iii. Contention [1 each]