How many times in your workday do you hear the term Wi-Fi? When you’re on an FTTH install job, when you’re quoting on an FTTP project, when you’re choosing enclosures, when you’re answering customers’ questions, and when you’re reading about it. Maybe 20 to 30 times a day?

Google-search “WiFi” and expect 508,000,000 results, give or take a thousand. In addition to a list of industry associations, WiFi comes up in dozens of news articles on an almost hourly basis. From the latest smart appliances to adopt the technology (Wi-Fi coffee grinder sorts the beans from the has-beens) to cities across North America granting free Internet access (Toronto library hopes to bridge ‘digital divide’ by lending free Wi-Fi), everyone is touched by this somewhat invisible data conduit.

But despite this term becoming a household word, few industry folk actually know what it means. So, here’s a primer for you – the broadband installer – on what WiFi is and how it works.

For starters, the correct term is Wi-Fi. It’s often used as another name for WLAN or Wireless Local Area Network. With this technology radio waves are used to transmit data between devices instead of using an electrical signal sent through a cable. The name was originally chosen back in 1999 as a play on the words Wireless Fidelity and the term Hi-Fi.

For wireless products to use the trademarked Wi-Fi logo, they must be certified by the Wi-Fi Alliance, a non-profit society that promotes Wi-Fi technology and products. It conforms to standards defined by the Institute of Electrical and Electronics Engineers (or IEEE) and is based on their IEEE 802.11 protocol, which first appeared in 1997.

Basically, the way Wi-Fi works is by using IEEE protocols to translate digital data into radio signals and then back again. These signals are transmitted between devices equipped with a wireless adapter and some form of wireless access point, or WAP, which is often built into a hub or router. The access point connects the Wi-Fi signal it receives with a LAN or local area network, which in turn is usually connected to the Internet.

The area that surrounds the WAP from which it can receive a signal is often called a hotspot. One of the main advantages of Wi-Fi is that multiple devices within range of the hotspot can communicate with the access point and obtain an Internet connection. However, hotspots are limited in size by the range of the transmitters and receivers in the equipment as well as by physical boundaries such as walls and ceilings that block radio frequencies.

Ideally, the WAP should be placed in an optimal location that will give maximum Wi-Fi coverage but still have easy access to the LAN. When using a central distribution enclosure to accommodate this equipment it’s important to use ones that are made from Wi-Fi transparent materials.

As Wi-Fi uses radio waves there is also the potential of interference from other radio signals and electrical equipment. Wi-Fi uses frequencies of either 2.4 GHz or 5GHz that are much higher than cell phones, walkie-talkies and televisions but potentially not far off from microwave ovens, cordless phones and Bluetooth devices.

Wi-Fi protocols

There are now several different Wi-Fi protocols all based on the original IEEE 802.11.

  • 802.11a uses the 5 GHz wavelength and can transmit data at 54 megabits a second or Mbps. It also uses the more efficient OFDM waveform  that can reduce interference.
  • 802.11b from 2000 uses 2.4 GHz and can only send data at 11 Mbps.
  • 802.11g from 2003 also uses 2.4 GHz but by using the same OFDM waveform as 802.11a can send data up to 54 Mbps.
  • The IEEE approved 802.11n in 2009. It is the most popular protocol and is backwards compatible with 802.11a, b and g. It operates on both the 2.4 and 5 GHz bands and can achieve speeds as high as 150 Mbps and can handle four streams of data.
  • 802.11ac was published at the end of 2013 and is built on 802.11n. It has wider channels and can handle eight streams of data rather than four. Each stream can transmit data at up to 433 Mbps with a potential of Gigabit speeds over multiple streams.