WLAN
Wireless Local Area Networks
Wireless local area networks are networks that perform the same function as a normal LAN, but use wireless radio signals to transmit  data instead of an ethernet cable. Wireless networks usually consist of a wireless access point, usually connected to a router, and a number of client devices, each equipped with a wireless network interface controller WNIC (Aka Wifi card).
Home Network Lan
In home networks your home router box usually functions as:
- Wireless Access Point – Allowing devices to connect to the network and handling encryption
- Switch – forwarding packets between devices on the network using their MAC address
- Router – Forwarding packets to/from the internet using IP addresses
- Modem – handling the different data transmission protocol use on telephone networks
Pros and Cons
Pros and Cons of Wireless Networks
Pros
- Wireless networks don’t require as many cables, so are easier to set up.
- The positioning of client devices aren’t limited by cable length.
- They are easier to use in public areas where cables would pose a safety risk.
- No limit on the number of devices that can be connected at any one time (with wired you need a spare Ethernet port on the switch)
Cons
- Less secure than wired networks as you can’t control where the signal is broadcast.
- Much lower bandwidth than wired connections.
- Susceptible to electronic interference
- Limited effective range.
- Poor signal through solid walls.
Encryption
Wireless Network Encryption
Because wireless data is transmitted using radio signals, it is easily intercepted. This means that wireless data needs to be securely encrypted if it is to be kept secret. Over the last decade there have been a number of different wireless encryption protocols.
Wired Equivalent Privacy (WEP)
This was the original form of encryption used by wirless networks, however due to a security attack technique known as ‘packet sniffing’, the encryption technology was very easy to break.
- Uses a 64/128 bit key
- Static Hex key
WPA
The weaknesses in WEP led to the development of the more secure WPA/ WPA2 encryption technologies. These are far more secure specifications, however they can still be hacked eventually.
- Released in 2003 to replace WEP
- 256 Bit Key
- Temporal Key
- Still exploitable
WP2
- Uses military AES Standard encryption
- Two modes Pre-shared Key PSK / Enterprise Mode EAP
- Addressed problems with WPA
WPA3
- Newest version of encryption
- Not widely used yet
- Not all hardware supports it
Video
Bluetooth
Bluetooth Wireless Networking
Another wireless specification is Bluetooth. This technology is general more widely used to connect peripherals (such as headsets, speakers, etc) to host devices, rather than connect to general purpose networks. Bluetooth can also be used to create an ‘ad-hoc’ network between two devices to allow for file sharing.
Advantages
- Better for easy connection of peripherals
- Can quickly and easily create an ad-hoc network
Disadvantages
- Slower than wifi
- Less secure
Ad-hoc networks
Ad-Hoc Networks
Ad hoc networks are peer-to-peer networks ( not client / server) that are usually temporary and quick to set up. They are usually used for temporary file and resource sharing, where a larger client-server network is not needed. Each device connected to an Ad-Hoc network is a ‘node’, and each node forwards on data to all other nodes in range.
Advantages
- Quick, easy and cheap to set up – no server, switch or routers required.
- Decentralised, meaning that if one ‘node’ goes down, the network still remains up.
Disadvantages
- No access the the facilities that servers provide ( file backup, use authentication)
- Less secure than standard networks