Wired & Wireless Networks (Edexcel GCSE Computer Science)

Wired & Wireless Networks

What is a wired network?

• A wired network is a network where physical cables are used to join devices together and transmit data

• Computers can be connected to networks using many different types of wires to transmit data

• Transmission media is the type of cable used in wired connections

• The most common types of transmission media are:

  • Fibre optic

  • Copper

What is fibre optic?

"Image Coming Soon"

• Fibre optic is a type of cable that uses light to transmit data on a wide area network (WAN)

• Fibre transmits data at a much higher speed and has a much higher bandwidth compared to copper cables

• Fibre optic cable does not suffer from interference which makes them the most secure option to send sensitive data

• Fibre optic cables can cover a long distance without any degradation, they can span cities and countries

What is copper cable?

"Image Coming Soon"

• Copper is a type of cable originally used in telecommunication to transmit voice signals, forming the traditional landline phone network

• The ability to use copper to deliver network traffic on a wide area network (WAN) made the internet possible

• Copper cables degrade over time which limits their range compared to fibre optic

• Copper cable suffers from interference which can disrupt data quality

• Copper transmits data at a much slower rate, and has a much lower bandwidth compared to fibre optic

Advantages & disadvantages of wired networks

What is a wireless network?

• A wireless network is a network where connections are made using radio waves to transmit data through the air

• The most common types of wireless connections are:

  • Wi-Fi

  • Bluetooth

  • Zigbee

  • NFC/RFID

What is Wi-Fi?

• Wireless fidelity (Wi-Fi) is a common standard for wireless networks

• Wi-Fi is common in most homes and offices to connect devices such as laptops, tablets & smart phones

• Using Wi-Fi, devices communicate with a wireless access point (WAP), which can be a standalone device or built into a router or switch 

What is Bluetooth?

• Bluetooth is another common standard for wireless networks

• Bluetooth is common in most homes and offices to connect devices such as headphones, controllers, keyboards & mice

• Bluetooth is used typically for a direct connection between two devices 

What is Zigbee?

• Used for two-way communication between sensors and control systems created by the Zigbee Alliance

• Short range (10-100m)

• Only used for sending simple data

• Low transfer rate

• Ideal for devices with:

  • low cost

  • low power

  • low data usage

  • long battery life

What is NFC/RFID?

• NFC is used for wireless data transfer between 2 devices in very close proximity (<10cm)

• No pairing code in necessary

• An NFC chip inside one device is activated by a chip in another device

• Small amounts of data can be transferred when held close to each other

• Developed from radio frequency identification technology (RFID)

• Used in mobile phones/devices to allow wireless payment methods

Advantages and disadvantages of wireless networks

Characteristics of Wired & Wireless Networks

What are the factors that affect network performance?

• 5 key factors can impact how well a network performs

  • Bandwidth

  • Speed

  • Range

  • Latency

Bandwidth

• Bandwidth is the amount of data that can be sent and received at any given time

• Measured in bits per second

• A smaller bandwidth means that less data can be sent and the network can slow down, potentially to the point of becoming unusable

Speed

• Speed is the actual rate of data transfer in a given time

• Measured in bits per second

Range

• The range of a network is the maximum distance a signal is able to reach

Latency

• Latency is the delay between data being sent and received, measured in milliseconds