Wired and Wireless Connections

Wired and Wireless Connections

1. Wired Connections

   • Ethernet (wired) networks can use different types of ethernet cables to connect devices on a LAN
   • Cables
     • CAT 5e and CAT 6
       • They're twisted pair cables containing four pairs of copper wires which are twisted together to reduce interference
     • Coxial cables
       • Made of a single copper wire surrounded by a plastic layer for insulation and a metallic mesh which provides shielding from outside interference
       • Used for cable TV and broadband in some locations
     • Fibre optic cables
       • Transmit data as light
       • They're high performance and they do not suffer interference and can transmit over very large distances without loss of signal quality
       • They're expensive
       • Can give a much better performance than copper cables
       • Greater bandwidth, transmission is faster, cables do not break as easily as copper cables
       • Not affected by electromagnetic interference unlike copper cables
   • Generally faster and more reliable than wireless
   • Wired Connections
     • Fast and consistent transmission speed
     • Costly to add extra devices as additional cabling and switches may be required
     • Copper cable can be susceptible to electrical or magnetic interference. Fibre optic cables avoid this.
     • Ethernet cable maintains a good strength up to 100m, fibre optic cable can be much longer
     • Data sent along cables cannot be easily intercepted

2. Wireless Connections

   • Use radio waves to transmit data
   • More convenient than wired networks as you can move around while still being connected
   • Cheaper as you need fewer wires
   • Bluetooth
     • Usually a direct connection between two devices so that data can be shared
     • Connection range varies but mobile devices are typically 10 metres
     • Low bandwidth compared to WiFi
     • Often used in mobile/wearable devices
   • WiFi
     • Can be used by multiple devices to connect a LAN at the same time
     • Connections have a range between 40 and 100 metres
     • High bandwidth compared to Bluetooth
     • Often used in the home
     • Needs a wireless access point WAP which is a switch that allows devices to connect wirelessly
       • WAP receives data from a network via its physical connection. The transmitter then converts this data into radio waves which are then transmitted. Any device on the network receives this radio signal via a WiFi adaptor which allows it to communicate or download data from the data source. It works in the reverse direction when a device wishes to send data over the network to another computer.
   • Performance depends on signal quality as things such as interference from other wireless networks and physical obstructions can affect it
   • Risks
     • Often connected to in house private networks so intruders may completely bypass any hardware firewall. Unauthorised users can use the wireless connection to hack into the network and cause damage by planting viruses or launching DoS attacks.
     • Bandwidth stealing - by using the internet connection to download music, games, and other software, outside intruders can slow the network down and reduce productivity.
     • If any network is not encrypted before transmission, an intruder can gain access to confidential information.
   • Wireless Connections
     • Typically slower than cabled connections
     • Easy to connect additional devices, for example mobile and IoT devices, but additional devices will share the available bandwidth and increase the traffic
     • Wireless signals can be reduced by walls and interference from other wireless devices. This affects the connection speed.
     • Wireless hotspots are limited to a very small local area and require repeater devices to expand the range
     • WiFi signals may be easily intercepted without adequate encryption security

3. Bandwidth is the amount of data that can be transferred in a given time. The greater the bandwidth, the better the network can perform.