Wi-Fi is a wireless networking technology that allows Wi-Fi-enabled devices to connect to a local area network. Using Wi-Fi, you can transfer data between devices on your local network or connect to the Internet if a connection is available. Most people probably know this, since we all use Wi-Fi every day, but how does Wi-Fi actually work?
WiFi Is Radio
The most fundamental fact about Wi-Fi is that it uses radio waves to transmit information. Radio waves are what we call a specific frequency range of electromagnetic radiation. Light is a part of the spectrum to which our eyes are sensitive, but it is made up of the same “substance” as radio waves.
WiFi uses two different frequencies for transmission: 2.4 GHz and 5 GHz. These are 2,400,000,000 and 5,000,000,000 cycles per second, respectively. This is quite a lot compared to FM radio, which is only around 100 MHz.
The exact frequency of a radio wave greatly affects its performance. The higher the frequency, the more information is in your signal. However, some frequencies do not have very large ranges.
Different frequencies also penetrate matter in different ways. Some frequencies may reflect off the atmosphere, so the transmitter and receiver do not need a line of sight to operate. The other frequencies just rush straight into space. This is useful if you want to communicate with a satellite, but not especially if the receiver is on Earth.
Waves on WiFi operating frequencies can reach hundreds of miles if you put enough power into the transmit power, nothing gets in the way and use the right antenna. However, standard home Wi-Fi typically has an unobstructed range of 30-50 meters (approximately 100/150 feet). 2.4GHz Wi-Fi has a longer range, 5GHz Wi-Fi has a faster speed.
Wi-Fi is radio, but it is digital radio. This means that radio waves are modulated to transmit a digital code. Wi-Fi is completely filled with digital information.
The latest and greatest WiFi technology has a theoretical speed limit of 4.8Gbps while using four 1.2Gbps data streams at the same time. That’s 600 megabytes per second! Of course, theoretical speeds are determined in laboratory conditions under optimal conditions, but even in real conditions, modern Wi-Fi is very fast.
WiFi has standards and protocols
WiFi has been around for a long time. The first commercial version of the technology was released back in 1997. The Institute of Electrical and Electronic Engineers (IEEE) has codified the WiFi standard, which is officially known as IEEE 802.11. The first generation of WiFi is known as 802.11a, but newer, better WiFi versions have been developed over time:
WiFi is not fully backward compatible. You won’t find many modern devices that can still communicate with 802.11a devices. Many Wi-Fi devices have â€œbgnâ€ and will work with these three standards, all of which use the 2.4 GHz frequency band. 802.11ac uses the 5 GHz band, but most of these routers are “dual band” and also offer 2.4 GHz for communication with older devices using older standards.
In practice, backward compatibility with WiFi is unstable because some devices are bound to a specific speed within each respective standard. New routers can’t afford to be slow!
Anyone can intercept Wi-Fi radio waves, but thanks to digital encryption, they cannot simply eavesdrop on what is sent and received. At least that’s the case if your Wi-Fi network is password protected.
Your Wi-Fi password is also an encryption key, so anyone with a password can see all data packets without filtering. This is why you should only use HTTPS enabled websites and always use a VPN service if you are using a public Wi-Fi hotspot!
Your WiFi devices are most likely using WPA2. WPA is short for WiFi Protected Access and is a very strong encryption scheme for WiFi connections. However, over the years, hackers have discovered various exploits that, in some cases, allow them to break into WPA2 encryption protocols.
In 2018, the WiFi Alliance, which is the custodian of Wi-Fi technology, announced WPA3. This new version improves security and closes security holes found in WPA2. Of course, it will take some time before all existing equipment supports the new safety standard.
WiFi Direct is something
Wi-Fi was designed to use a central device such as a router to control communications between devices. However, Wi-Fi can also be used to directly connect two devices in a so-called “peer-to-peer” connection. This is very convenient when, for example, you want to send a large file from yours to someone’s smartphone.
It is also a type of Wi-Fi that is often used to stream video from a phone to a smart TV. When you use devices such as GoPro cameras or certain drones with WiFi cameras, you also use a direct WiFi connection. Bluetooth is getting the most attention in the world of peer-to-peer wireless connectivity, especially since it’s so energy efficient, but Wi-Fi Direct is fast and just as easy to use.
Routers, Repeaters, and mesh
While direct Wi-Fi connections have become commonplace these days, the Wi-Fi that we all use most of the time is of a hub and spoke design. In other words, all of your WiFi devices connect to a central device that acts as an intermediary. For most people, this will be a regular WiFi router.
Modern routers boast multiple antennas separating different frequency bands, and equipment that sends and receives WiFi data. These routers also handle your internet connection and any wired Ethernet devices on your network, allowing wired and wireless networks to communicate with each other.
However, as we said above, WiFi signal ranges are quite limited. This means that the further you are from the router, the worse the signal strength. A Wi-Fi repeater can be used to increase the signal at the edge of the coverage area.
While repeaters work reasonably well, there is a new trend towards â€œmeshâ€ WiFi systems. There is no central router here. Instead, multiple small routers are scattered throughout your home, connected to each other, and providing a seamless Wi-Fi cloud. This is the Wi-Fi technology most used by large companies, but now it has become available for home use.
Wi-Fi surrounds us more than ever as now all kinds of devices need a network connection. However, Wi-Fi is not the only competing technology when it comes to wireless data transmission. When it comes to low-power, short-range connections, Bluetooth reigns. In future versions of Bluetooth, perhaps even Wi-Fi will earn its money when it comes to speed and range.
However, WiFi‘s biggest competitor may well be 5G. Fifth generation cellular technology provides lower data rates and coverage in dense urban areas. 5G may not replace WiFi in the home, but 5G offers an alternative to public Wi-Fi hotspots, which have become popular mainly due to the high cost of mobile data.