Networking 101: How does WiFi work?

We all use it and take it for granted, but very few of us are aware of how WiFi actually works.

Do we care? Probably not that much; but without it we’d still be tied to that forever-too-short ethernet cable to get our fix of the latest hilarious video clips on YouTube, or our friends’ cat photos on Facebook – and who wants to plug a phone or tablet into their router or rely on patchy 3G to check emails? No, me neither.

WiFi was developed for just that purpose – to replace the ethernet cable – but it’s grown and evolved into the go-to technology for device interconnectivity, as well as being able to serve up the fast internet we are all so used to nowadays.

WiFi now carries more than 60% of the world’s internet traffic, which is pretty incredible for a technology that is basically radio waves. Ok, so it’s a little more complicated than the FM receiver in your car or home – WiFi is basically two radios communicating back and forth using a low power output, over much shorter distances. It’s these two radios – one in your router or access point, one in your laptop or phone, etc. – that allow the two-way communication required for delivering content to, or sending it from, your device.

Any type of communication needs a common language, be it English, French, Klingon, Binary or Semaphore, and the Internet is no different; hence Internet Protocol (IP) – or, if we’re being formal, Transmission Control Protocol/Internet Protocol (TCP/IP) – the language of the internet. Putting it (very) simply, IP’s task is to deliver packets of data from source to destination, and it’s this routing of data that makes the internet work.

It’s not completely plain sailing from there though. All this data magically dancing about on radio waves is subject to interference from a variety of sources, in the same way your ordinary FM radio doesn’t like hairdryers. Modern WiFi can broadcast at two frequencies – 2.4GHz and 5GHz – and through a choice of channels within them, try and avoid this unwanted interference. FM radio typically operates between 87.5MHz and 108MHz – the much lower frequencies allow it to travel the long distances from transmitter to receiver. So, using elementary physics (about my level), the 2.4GHz band can therefore reach devices further away, but the 5GHz band is still more than capable of providing coverage to the average home – and with a cleaner signal too.

Most WiFi access points or routers will automatically select the best channel to broadcast on, in order to minimise interference from other WiFi networks, microwaves, cordless phones, Bluetooth devices, baby monitors, etc., which are operating in the same range. A network using a 5GHz signal is much less prone to this interference, having almost eight times the total number of channels available, and 23 non-overlapping channels compared to just three on the 2.4GHz frequency. This means there’s much more likelihood of finding a clean channel to broadcast on.

WiFi can also be secured to make the job of intercepting this data more complicated and prevent unauthorised devices from connecting to your WiFi network. Wired Equivalent Privacy (WEP) was the original encryption standard for wireless, and although still available as an option, it has been superseded by far better solutions. WiFi Protected Access – now in its second generation as WPA2 – includes something called Advanced Encryption Standard (AES), a very secure protocol used in many different applications, both software and hardware, to encrypt data.

But perhaps one of the most important and useful features WiFi has is that it’s completely backwards compatible, so your new PS4 will quite happily connect to an old freebie router from your ISP, and your battered Blackberry with the broken thumbstick will still easily log-on to free town centre WiFi.


Get In Touch

Whether you’re a local authority looking to provide public WiFi or seeking a connectivity solution for Smart Cities, the IoT or 5G / Small Cells in your town or city, or if you are interested in partnering with us around the Connected City Platform in any of our forthcoming town and city roll-outs, we’d love to explain more about who we are and what we do.

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