peak in activity, it may not be able to deliver high speed
streaming to a customer. So, the cellular operator offloads
the data streaming to their Wi-Fi network. That works, but
eats up spectrum that could otherwise be used by other
The real question is where does Wi-Fi go from here?
Up to now, the IEEE 802.11 standard group has focused
mainly on incremental boosts in data rate and capacity. At
this point, more speed may not be necessary.
For example, an upgrade of the 11ad 60 GHz standard
designated 11ay is in the works. It offers a channel
bandwidth of 8 GHz and a 4x4 MIMO configuration that
can generate a max speed of up to 20 Gb/s. Do we need
Also consider that Wi-Fi has multiple offshoots that
have not been based on the speed/capacity upgrade
path. For example, a modified version of 802.11a called
802.11p has been proposed for vehicle-to-vehicle (V2V)
communications systems that are planned to enhance the
advanced driver assistance systems (ADAS) that are now
being installed in most new cars. V2V allows cars to talk
to one another so as to share location, speed, direction,
stopped, or turning condition, and other data that can help
Then, there are the 802.11af and 802.11ah standards.
Both use a version of the Wi-Fi protocols but in different
frequency bands. Both target Io T applications. For
example, the 11af version uses the available “white space.”
White space is the empty 6 MHz wide VHF and UHF TV
channels commonly available in most areas. These lower
frequencies in the 54 to 698 MHz range permit longer
range communications of many kilometers. Traditional Wi-Fi range is typically only up to about 100 meters.
As mentioned, the 11ah standard also targets Io T uses.
It’s designed to use the 902-928 MHz ISM band in the US.
Using 1, 2, 4, 8, or 16 MHz channels, it can achieve data
rates up to about 100 kb/s. Speed is not usually needed
in most Io T uses, so it’s not a problem. The propagation
capability in the 902-928 MHz band is excellent and
under good conditions like high antennas, range can be a
kilometer or more.
Neither 11af or 11ah have been widely adopted. Most
Io T applications today are the slower Wi-Fi standards,
Bluetooth, ZigBee, Z-Wave, or some variation of the
802.15.4 standard like Thread. All of these with the
exception of the Z-Wave operate in the already crowded
2. 4 GHz band.
Another emerging wireless technology is Li-Fi or Light
Fidelity. It uses visible light as the data carrier. White LEDs
illuminate spaces and are modulated by the data. High
data rate downloads are easily accommodated. The range
is limited because of the direct line of sight (LOS) path light
takes, but it could be useful in some office or industrial
settings as it is very secure. Li-Fi is not officially part of the
Wi-Fi family, but who knows what will happen?
Finally, the big question is how does the new fifth
generation (5G) wireless network impact Wi-Fi? 5G
will deliver Wi-Fi like speeds to homes and businesses.
Theoretically, it should complement Wi-Fi but it may also
replace Wi-Fi in some applications. We shall see. NV
If you want to dig into Wi-Fi in more detail, you can
start at these websites:
IEEE Working Group 802
THE LATEST IN NETWORKING AND WIRELESS TECHNOLOGIES
88 July/August 2018