WiFi definition
WiFi technology (IEEE802.11) can be broadly categorised to IEEE802.11 a/b/g/n/ac. Each is an improvement in transmission speed and/or signal range from the previous, although these days only ‘G’ and ‘N’ are used.
The standard G versions of networking devices have an optimal transmission speed of 54 Mbps with an indoor range of approximately 40 m whereas the N versions have a theoretical maximum speed of 300 Mbps (practical of approximately 150 Mbps and above) with an indoor range in the region of 70 m.
In addition to this, N variations offer the choice of two frequency ranges; 2.4 GHz or 5 GHz. The higher frequency has no impact on the range but offers a potentially less polluted frequency to help reduce crosstalk noise.
Both the G and the N devices utilise the same channel capabilities but these vary regionally. In Europe (including UK) a channel system of 1-13 is used whereas in the US the system uses 1-11. Both use the same frequency ranges resulting in an approximate frequency void of 16.5 MHz at the end of the 2.4 GHz range.
Japan utilise a different system still, expanding the 2.4 GHz range beyond the acceptable ISM guidelines by 10.5 MHz to allow for an additional 14th channel with 11 MHz of non-interference from other channels (see Figure below) [80], [81], [82].
Image. 22MHz channel allocations for WiFi 2.4GHz frequencies, with curvatures implying affinities for intra-channel frequency selection.
The figure above shows the affinities for the frequency selection within each 22 MHz channel and the overlap between channel frequencies. The same would be seen for 40 MHz channels with the obvious exception that there would be twice the amount of overlap between channels, leaving fewer isolated channels. The solid lines show the 3 channels in the US 11 channel system that do not encroach on each other’s range at all. Each WiFi access point will secure its own channel and use that channel for all communications. Multiple channels will not be utilised by one access point other than during overlap.
WiFi communication protocols are Internet Protocol (IP) based where the destination address is in packet headers allowing large amounts of data to be transmitted through a network of nodes at high speed. This means that on any WiFi network a central control node (network coordinator) will allocate all IP’s in the network on discovery allowing for any packets to be addressed and routed to a connected device [82].
This article was created by --BRE. It was taken from The future of electricity in domestic buildings, a review, by Andrew Williams, published in November 2014.
NB The term 'WiFi' was coined by the Wi-Fi Alliance as shorthand for wireless local area network (WLAN) products based on the Institute of Electrical and Electronics Engineers' (IEEE) 802.11 standards. It did not specifically 'stand for' anything. It has popularly been adopted to mean Wireless Fidelity but this is not correct.
[edit] Find out more
[edit] Related articles on Designing Buildings Wiki
- Bluetooth.
- CAT5.
- Ethernet
- Extranet
- Glossary of electrical terms.
- ICT and Automation (ICTA) Scoping Study Report.
- In-building wireless.
- Information and communications technology.
- Internet of things.
- Internet of things in commercial buildings.
- Local area network.
- Smart buildings.
- Smart cities.
- Smart technology.
- The future of electricity in domestic buildings.
- WiMax.
- WiredScore.
- ZigBee.
[edit] External references
- [80] E. G. Villegas, E. López-Aguilera, R. Vidal and J. Paradells. Effect of adjacent-channel interference in IEEE 802.11 WLANs. Cognitive Radio Oriented Wireless Networks and Communications, Orlando, 2007.
- [81] Butler J. Wireless Networking in the Developing World, Copenhagen: Creative Commons, 2013.
- [82] Institute of Electrical and Electronics Engineering, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. IEEE Standards, 2012.
Featured articles and news
Reform of the fire engineering profession
Fire Engineers Advisory Panel: Authoritative Statement, reactions and next steps.
Restoration and renewal of the Palace of Westminster
A complex project of cultural significance from full decant to EMI, opportunities and a potential a way forward.
Apprenticeships and the responsibility we share
Perspectives from the CIOB President as National Apprentice Week comes to a close.
The first line of defence against rain, wind and snow.
Building Safety recap January, 2026
What we missed at the end of last year, and at the start of this...
National Apprenticeship Week 2026, 9-15 Feb
Shining a light on the positive impacts for businesses, their apprentices and the wider economy alike.
Applications and benefits of acoustic flooring
From commercial to retail.
From solid to sprung and ribbed to raised.
Strengthening industry collaboration in Hong Kong
Hong Kong Institute of Construction and The Chartered Institute of Building sign Memorandum of Understanding.
A detailed description from the experts at Cornish Lime.
IHBC planning for growth with corporate plan development
Grow with the Institute by volunteering and CP25 consultation.
Connecting ambition and action for designers and specifiers.
Electrical skills gap deepens as apprenticeship starts fall despite surging demand says ECA.
Built environment bodies deepen joint action on EDI
B.E.Inclusive initiative agree next phase of joint equity, diversity and inclusion (EDI) action plan.
Recognising culture as key to sustainable economic growth
Creative UK Provocation paper: Culture as Growth Infrastructure.
Futurebuild and UK Construction Week London Unite
Creating the UK’s Built Environment Super Event and over 25 other key partnerships.
Welsh and Scottish 2026 elections
Manifestos for the built environment for upcoming same May day elections.
Advancing BIM education with a competency framework
“We don’t need people who can just draw in 3D. We need people who can think in data.”
Comments
WiFi does not stand for Wireless Fidelity. It is not an acronym. It is a term to define the ieee 802.11 standard.
WiFi was coined by the Wi-Fi Alliance as shorthand for wireless local area network (WLAN) products based on the Institute of Electrical and Electronics Engineers' (IEEE) 802.11 standards. It did not specifically 'stand for' anything. It has popularly been adopted to mean Wireless Fidelity but this is not correct.