Blog post by Purple WiFi
What is WiFi and how does it work?
WiFi is a way of getting broadband internet to a device without using wires. WiFi uses a wireless transmitter to send information to your computer. A transmitter converts information from the internet into a radio signal. This allows an electronic device to exchange data with the transmitter, sending information to and from the wireless device.
In the beginning
WiFi was first released for consumers in 1997, when a committee called 802.11 was set up. IEEE802.11 was the name for a set of standards used when setting up a WLAN – or wireless local area network. A basic specification for WiFi was created, which allowed for two mega-bites per second of data transfer. Engineers immediately began to work on prototype equipment to comply with it. In 1999, the release of routers sparked the beginning of the wide use of WiFi in our homes.
WiFi uses electromagnetic waves that run at a specific frequency. There are two main frequencies used for WiFi, 2.4Ghz (802.11b) and 5Ghz (802.11a). Using 2.4Ghz worked with mainstream devices and was the one that most people used. 802.11b was the WiFi of choice for some years, mainly due to the fact that 11a was more expensive.
- WiFi Timeline sourced from http://chimera.labs.oreilly.com/books/1234000001739/ch01.html#history
In 2003, faster speeds and distance coverage of the earlier versions combined to make the 802.11g standard. Routers were getting better too, with higher power and further coverage than ever before. WiFi was beginning to catch up – competing with the speed of the fastest wired connections.
2009 – The arrival of 802.11n
2009 saw the final version of the 802.11n, which was even faster and more reliable than before, as it was built with more antennas and multiple streams of data. ‘Multiple input multiple output’ data (MIMOs) describes the use of multiple antennas to enhance communication of both the transmitter and receiver. This gave us significant increases in data without the need for higher bandwidth or transmit power. It does this by spreading the same total transmit power over the antennas to achieve power and efficiency.
The 2.4 Ghz extended range meant that more and more devices (from baby monitors to bluetooth) were using the same frequency, causing the frequency to become over-crowded and slower. This meant that 5Ghz became the more attractive option.
Simultaneous dual band routers
Simultaneous dual band routers that supported both frequencies at the same time were then created. Dual-band routers contain two different types of wireless radios that can support connections on both 2.4 GHz and 5GHz links. This means that when a device is in close range of 5GHz there is a fast speed, but if further away or behind walls the 2.4Ghz could be used. Basically, the user’s device picks up the strongest WiFi signal and connects to it.
801.11ac aimed to make the 5Ghz range better, with four times the speed than WiFi 801.11n, a greater width and the ability to support more antennas, meaning that data could be sent more quickly. The concept of Beamforming emerged in 2012 as well. Beamforming is explained by Eric Geier as focusing signals and concentrating data transmission so that more data reaches the target device, instead of radiating out into the atmosphere. He notes: ‘Instead of broadcasting a signal to a wide area, hoping to reach your target, why not concentrate the signal and aim it directly at the target?’
The use of WiFi today is summed up nicely by Rethink Wireless: “WiFi performance continues to improve and it’s one of the most ubiquitous wireless communications technologies in use today. It’s easy to install, simple to use and economical too. WiFi Access Points are now set up at home and in public hotspots, giving convenient internet access to everything from laptops to smartphones. Encryption technologies make WiFi secure, keeping out unwanted intruders from these wireless communications.”