When we talk about Wi-Fi, what Kind of Wireless Networking are we actually talking about?

Wi-Fi is the industry name for wireless local area network (WLAN) communication technology related to the IEEE 802.11 family of wireless networking standards. Wi-Fi technology became popular starting with 802.11b, introduced in 1999 and the first standard in that family to enjoy mainstream adoption. For more about the name “Wi-Fi”, see: Wi-Fi - The Technology Formerly Known as Wireless Fidelity

Wi-Fi and 802.11

The Institute of Electrical and Electronics Engineers (IEEE) develops many technology standards for the industry, including a set of local area network (LAN) standards numbered as 802.

Among all the IEEE 802 standards, the workgroup specifically focused on WLAN technology is called 802.11.

Most people associate "Wi-Fi" with one of the five general-purpose 802.11 WLAN standards:

l  802.11a

l  802.11b

l  802.11g

l  802.11n

l  802.11ac

In addition to these base standards, various other related 802.11 standards also exist:

l  802.11 - defines the lesser known original Wi-Fi technology ratified in 1997, before 802.11a and 802.11b were created. Original Wi-Fi supported data rates of only 1 Mbps.

l  802.11e - Quality of Service (QoS) extensions to 802.11a/b.

l  802.11ad - a 60 GHz wireless protocol (not a replacement for 802.11ac)

l  802.11ah - a future Wi-Fi standard that also supports lower frequency (900 MHz) communication

l  802.11X - a security feature for Wi-Fi access points

Wi-Fi Products

Mobile devices, laptop computers, game consoles and an increasing number of consumer gadgets build Wi-Fi radio transmitters and receivers into their hardware.

These devices in turn connect to either wireless broadband routers (on home networks) or wireless access points to communicate with each other and with outside networks (including the Internet).

Consumer versions of Wi-Fi products have maintained backward compatibility over many years. For example, 802.11b, 802.11g, and 802.11n equipment all can communicate with each other, and mixed Wi-Fi networks with devices running multiple of these standards are commonly referred to as "802.11b/g/n" networks.

802.11ac equipment also communicates with each of these others. (The old 802.11a technology. used mostly in business networks, is not compatible with these others and has fallen out of mainstream usage as a result.)

The Wi-FI Alliance industry body certifies vendor equipment to ensure new Wi-Fi products entering the market follow the various 802.11 specifications.

Issues with Wi-Fi

Wi-Fi has become so popular that people in casual conversation sometimes refer to any kind of wireless network connection as "Wi-Fi" - even if they are referring to cellular, Bluetooth or other wireless technologies instead.

Wi-Fi connections often run over the 2.4 GHz signal range that is shared with other consumer radio equipment like garage door openers, microwave ovens, and some cordless home phones. Besides signal interference from these sources, the popularity of Wi-Fi sometimes also causes radio congestion in a local area. Home Wi-Fi networks can easily conflict with those of their neighbors, for example. To know the exact speed of you home Wi-Fi, you can conduct a wifi speed test with some softwares or apps.

How Fast Is a Wi-Fi Network?

The network speed of a Wi-Fi wireless connection depends on several factors. Like most kinds of computer networks, Wi-Fi supports varying levels of performance depending on which technology standards it supports.

Theoretical vs. Actual Network Speeds

Each Wi-Fi standard is rated according to its maximum theoretical network bandwidth:

l  802.11b offered up to 11 megabits per second (Mbps)

l  802.11a and 802.11g offer up to 54 Mbps

l  802.11n offers up to 300 Mbps

l  802.11ac offers up to 1 Gbps (1000 Mbps)

The performance of Wi-Fi networks practically never approach these theoretical maximums. 802.11b networks, for example, generally operate no faster than about 50 percent of theoretical peak, around 5.5 Mbps. Likewise, 802.11a and 802.11g networks generally run no faster than 20 Mbps. And even though 802.11n rates at 300 Mbps compared to wired Fast Ethernet at 100 Mbps, the Ethernet connection can often outperform 802.11n in real world usage. Wi-Fi performance continues to be improved with future generations of the technology, though.

Factors Limiting Wi-Fi Connection Speeds

The disparity between theoretical and practical Wi-Fi performance comes from network protocol overhead, radio interference, physical obstructions on the line of sight between devices, and the distance between devices. In addition, as more devices communicate on the network simultaneously, its performance will also decrease.

A Wi-Fi network connection operates at the highest possible speed that both devices (endpoints) can support. An 802.11g laptop connected to an 802.11n router, for example, will network at the lower speeds of "g".

On home networks, the performance of an Internet connection is often the limiting factor in end-to-end network speed.

Even though most residential networks support sharing files within the home at speeds of 20 Mbps or more, Wi-Fi clients will still connect to the Internet at the usually lower speeds supported by Internet providers.