Networks

Local Area Network

A small geographical area located on a single site

The organisation that uses it

Both

1) businesses 2) schools 3) universities

Wide Area Network

LANs that are in different geographical locations

1) telephone lines (copper or fibre optic) 2) satellite links 3) radio links

The Internet

Personal Area Network

Devices over a very short range

1) smartphones 2) smartwatches 3) headphones

Bluetooth

1) sharing files is easier - network users can access the same files, work on them at the same time and copy files between machines 2) you can share the same hardware (like printers) between multiple devices 3) you can install and update software on all computers at once, rather than one-by-one 4) you can communicate easily across a network cheaply and easily 5) user accounts can be stored centrally, so users can log in from any device on the network

1) they can be expensive to set up, as you often need a lot of extra hardware 2) networks can be vulnerable to hacking, and malware can easily spread between networked computers 3) some networks are dependent on one or more servers. If those servers go down it can be very disruptive for people trying to use the network 4) large networks are difficult to manage and may require employing a specialist to maintain them

Allows a device to connect to networks

To connect devices on a LAN

1) to transmit data between different networks 2) to connect to the Internet

The amount of data that can be sent across a network in a given time

All the devices are connected to a central switch or server that controls the network

1) if a device fails or a cable is disconnected, the rest of the network is unaffected 2) it’s simple to add more devices to the network, since each device is connected to the switch using a separate cable 3) star topologies tend to have better performance than other setups - data goes straight to the central device so all devices can transmit data at the same time 4) there are very few data collisions on a star network compared with other network topologies

1) in wired networks, every device needs a cable to connect to the central switch or server. This can be expensive 2) the switch itself is also an expensive piece of hardware 3) if there is a problem with the switch or serer then the whole network is affected 4) the maximum number of possible connections on the network is determined by the switch - if you need more, you might need to buy a new one

Bus topologies use a single ‘backbone’ cable, called a bus, to connect all the devices

1) to stop data reflecting back along the bus 2) without the terminators, reflected signals would cause interference and potentially make the network unusable