In this lesson,
we're going to cover wireless standards.
Now, the wireless standards we use today
for our Wi-Fi networks are actually codified
in the 802.11 standard as set forth by the Institute
of Electrical and Electronics Engineers, known as the IEEE.
Now, the 802.11 standard defines the technology
that we use for wireless local area network communications
like Wi-Fi.
Over the years, these standards have evolved
to meet the growing needs
for faster wireless data transfer speeds
and for more reliable wireless networks.
So in this lesson,
we're going to take a look at the various 802.11 standards,
like wireless a, wireless b, wireless g,
wireless n, wireless ac, and wireless ax.
Now, as we move through this lesson, I'm going to provide you
with a lot of facts and figures about each
of these different wireless standards.
You need to memorize the standard's name such as wireless a,
as well as the frequency band it utilizes,
like 2.4 gigahertz,
five gigahertz, or six gigahertz,
as well as the maximum speed and the maximum distance
or range for each of these different wireless standards.
All right, with that said, let's go ahead and get started.
Now, first, we have wireless a.
Wireless a operates in the five gigahertz band at a speed
of up to 54 megabits per second with a range
of around 35 meters.
Wireless a, or more formally the 802.11a standard
required radios that were more expensive
to build and manufacturer at the time they came out
in the late 1990s,
but it did give us a good amount of speed
since they operate at 54 megabits per second.
Unfortunately though wireless a was pretty expensive
to procure and install, so only business users
really ended up using it.
Now, because wireless a wasn't gaining much traction
in the retail markets due to its cost,
manufacturers developed a new standard known
as wireless b or 802.11b
to create something that was cheaper
and easier to manufacture.
To accomplish this, wireless b moved
into the 2.4 gigahertz band
because those radios that worked
within the 2.4 gigahertz band were much cheaper
to manufacture than the ones
that were supporting the five gigahertz band.
In fact, the 2.4 gigahertz frequency band
was already being commonly used
by a lot of household devices that we use today,
including security cameras, walkie-talkies, baby monitors,
microwaves, and many others.
This made the radios in the 802.11b wireless devices
much cheaper and easier to get,
and it led to widespread adoption of Wi-Fi throughout homes,
businesses, and schools.
Now, using this cheaper chip set
and the way the frequencies work,
this actually slowed down our networks all the way down
to 11 megabits per second,
which today sounds extremely slow,
but all the way back in the late 1990s
when this was released,
this was actually still considered pretty fast
for most home users.
Wireless b supported a maximum range around 140 meters,
which was significantly longer than the 35 meters provided
by wireless a networks.
Now, the third one we have is what's known as wireless g.
Wireless g, also known as the 802.11g standard,
operates in the 2.4 gigahertz band,
but it can operate at speeds of up to 54 megabits per second
and a range of about 140 meters.
Basically, wireless g provided the same speed
and distance as the more expensive wireless a,
but it uses the same cheaper frequency band
as the wireless b standard, which made it cheaper
and easier to install for most users.
Eventually, users demanded faster
and faster wireless networking speeds as more smartphones
and tablets were entering the market.
So in response to that, a new standard was developed,
and this brings us to the fourth wireless standard we have,
which is known as wireless n, 802.11m,
or Wi-Fi 4 since it was the fourth generation of Wi-Fi.
Now, to reach these higher speeds
that our users were demanding, the wireless networks
had to switch back over to the five gigahertz band.
By operating in the five gigahertz band,
users could get speeds of up to 600 megabits per second
and cover a distance of about 35 meters.
Now, this allowed for really fast networks,
but the problem was this newer five gigahertz spectrum
wasn't compatible with all the existing 802.11b
and g devices that were already out there.
So a lot of people were resistant
to buying wireless n at first when it came out.
Now, by this time, the prices had actually come down
because five gigahertz radios had gotten cheaper
to manufacture, but this backwards compatibility
was a big issue.
So to overcome this,
manufacturers started making hybrid devices
that were marketed under the name wireless n,
and these type of wireless access points
actually had two sets of radios in them,
one for the 2.4 gigahertz spectrum
for backwards compatibility,
and one for the new five gigahertz spectrum that was used
for those faster speeds.
This way, if you had an older 802.11b or g device,
you could connect it
to the slower 2.4 gigahertz spectrum radio
that provided speeds of around 300 megabits per second
at a distance of up to around 70 meters in range.
Now, wireless n also introduced another new technology
for us known as MIMO,
and this increases your data transfer speeds.
Now, MIMO stands for the multiple-input
and multiple-output, which means
that your access point can actually use multiple antennas
to send and receive data at faster speeds than it could
with a single antenna.
This data is essentially being split
across multiple antennas, and which received,
it's going to be multiplexed back into a single data stream
for processing and use by your computer.
This is why you'll often see wireless n access points
having one, two, three or even five antennas on them
because the more antennas they had,
the more data transfer they could support simultaneously.
Now, the fifth type we had is known as wireless ac,
which is also known as 802.11ac or Wi-Fi 5
because it's the fifth generation of Wi-Fi.
Wireless ac operates exclusively inside
of the five gigahertz spectrum, and technically,
it does not have any backwards compatibility support.
Now, these 802.11ac networks can operate at speeds
of up to 6.9 gigabits per second or more,
which makes them really, really fast.
Now, to achieve this higher speed though,
802.11ac networks had to use a new technology,
and this one is known as MU-MIMO.
Now, this stands for multiple-user, multiple-input,
multiple-output, and it's a newer variation
of the MIMO technology that was developed
for the 802.11n networks.
MU-MIMO is a multi-path wireless communication technology
that allows multiple users to access the wireless network
and access the access point at the same time.
Now, this is different than a regular MIMO connection
where a single user is supported at one time
and then the access point switches between the users
to share the bandwidth across all the users
who are requesting services.
With MIMO, the wireless network acted more like a hub,
but with MU-MIMO, it begins to act more like a switch
and helps to avoid collisions
and congestion, which gives you higher speed
and higher levels of reliability.
Now, the sixth and final wireless standard we have
is what's known as wireless ax
and wireless ax is also known as the 802.11ax,
or Wi-Fi 6 because it is the sixth generation of Wi-Fi.
Now, wireless ax was first introduced back in 2021,
and it can be used in the 2.4 gigahertz
and five gigahertz spectrum under the marketing term Wi-Fi 6
or in a newer and faster six gigahertz spectrum
under the marketing term Wi-Fi 6E, also known
as Wi-Fi 6E enhanced or high efficiency Wi-Fi.
Now, the Wi-Fi 6 and Wi-Fi 6E networks
can actually reach speeds of up
to 9.6 gigabits per second using that MU-MIMO technology.
Also, because these access points
have three different radios inside of it,
including the 2.4 gigahertz band,
the five gigahertz band,
and the six gigahertz band inside of them,
they're going to be fully backwards compatible with all
of the previous versions of wireless networks,
including wireless a, b, g, n, and ac.
Now, for the exam, I want you to remember
that there are different wireless networking standards,
including wireless a, b, g, n, ac and ax.
If it helps you to group them, I want you to remember
that b, g, n and ax all support the 2.4 gigahertz band.
If it's an a, n, ac or ax network,
then it's going to support the five gigahertz band.
And if you're using Wi-Fi 6E inside of the ax standard,
you can now also use the six gigahertz band too.
Now, as you move to newer versions
of the wireless standards, you're going to see
that as your speed goes up,
you're going to see that in general,
the distance you can cover
with a single access point is going to go down.
This is important because on the exam,
you may get questions
about the different frequencies being supported
by a particular standard or their distance.
For example, which of these frequencies
doesn't support five gigahertz?
Wireless a, wireless b, wireless g, or wireless n?
Well, the answer here would be both wireless b
and wireless g because wireless a
and wireless n both support the five gigahertz band,
but wireless b and wireless g only operate
in the 2.4 gigahertz band.
Alternatively, they might try
to make the question a little bit more difficult for you
by asking it in more of a troubleshooting scenario.
For example, let's say you're working
as a network technician and an older laptop is failing
to connect to your wireless ac network.
You check the laptop and you see
that it has a wireless b network card inside of it.
What might be the problem?
Then you'll check the answers
and find that it has something to do with the fact
that there's a frequency mismatch
because wireless ac only supports five gigahertz
and wireless b, that network card in your laptop,
is only going to support 2.4 gigahertz as its frequency band.
Now, the last thing I want to mention for the exam
is that you need to rely only on the information I presented
in this lesson and not what you think is the right answer
because of something you read on a Wi-Fi access point box
at the store.
Now, the box at the store
that you're going to read is going to contain information
that was written by marketers, not technicians,
and they often will mislabel things to make it easier
for consumers to understand,
which helps them make more sales of those wireless devices.
So for example, if you're talking about wireless ac,
you need to remember that the wireless ac standard located
in 802.11ac only specifies operation inside
of the five gigahertz frequency band.
But if you go to the store today
and you try to buy a wireless ac access point at the store,
that box is going to tell you
that it supports both five gigahertz
and 2.4 gigahertz bands, and that is actually a lie.
It's simply not true,
and if you remember that,
you're going to get the question wrong on the exam.
The reason is the real truth
is that wireless ac only operates
in the five gigahertz spectrum according to the standard.
When you buy a wireless ac access point
and it says it supports both the five gigahertz
and the 2.4 gigahertz frequencies,
it's actually a wireless access point
with two separate radios in it.
One radio is using the five gigahertz band for wireless ac
as speeds of up to 1,300 megabits per second,
but the other one is using a 2.4 gigahertz radio
that's being used with wireless n at speeds of up
to 300 megabits per second
using a MIMO antenna configuration.
So the bottom line here is that while in real life
it's a lot easier to talk
to your end users about the fact
that wireless ac access points are backwards compatible,
and they support both five gigahertz
and 2.4 gigahertz bands,
if you answer that way on the exam, you're going
to get it wrong because the official standard states
that wireless ac only supports the five gigahertz band
for use in its operations.
According to the official wireless standards,
there are only two dual band standards that we use today:
wireless n and wireless ax.
Wireless n and wireless ax both operate in the 2.4 gigahertz
and five gigahertz frequency bands
per the official 802.11 standards,
and all the others only support a single band,
either 2.4 gigahertz in the case of wireless b and g
and five gigahertz
in the case of wireless a and wireless ac.