Wireless networks

Networks can be classified as wired or wireless. A wired network uses cables (copper or fibre optic) to form the connections between the networked devices. Ethernet is a protocol that describes how data is transmitted in wired networks.

A wireless network uses wireless Wi-Fi signals to connect nodes. Wi-Fi signals use radio frequencies in the 2.4 gigahertz (GHz) and 5 GHz wavebands. Each node has a radio transceiver, which allows it to connect to a wireless access point (WAP). WAPs can be physically connected by wire to a network switch, or wirelessly to other WAPs.

Wi-Fi wavebands can be separated into channels, or sub-frequencies. WAPs use several channels to allow many devices to connect wirelessly without their transmissions interfering with one another.

Advantages and disadvantages of using Wi-Fi

Using Wi-Fi brings many benefits to a user:

  • new nodes can easily be added without interruption to the network
  • users can move around freely and still stay connected

However, there are disadvantages to using Wi-Fi:

  • Wi-Fi signals have a limited range, usually no more than 50 metres.
  • Wi-Fi signals can suffer from electromagnetic interference from other devices and even other Wi-Fi signals. They can also be blocked by walls, leading to dead spots where no signal can be found.
  • Each WAP only has so much bandwidth to share among connected nodes. The more nodes that are connected, the less bandwidth each receives and the slower communication becomes.
  • Wi-Fi signals pose a security risk as they can be intercepted by unauthorised users. To overcome this problem, messages need to be encrypted.

Wi-Fi in use

Wi-Fi has seen an increase in popularity because it is easy to connect a node to a network. Many different types of device, such as laptops, tablets, smartphones, interactive TVs, media centres, games consoles and security cameras, can easily connect to a network when needed, without having to run a cable to each device.

Wireless networks give freedom of movement. They are therefore popular in homes, schools and any organisation that has a constantly changing number of connected nodes.