Instructor: In this lesson,
we're going to talk about mobile wireless connectivity.
This includes Wi-Fi or wireless networks, cellular,
hotspots, Bluetooth, and near-field communications.
First let's talk about Wi-Fi or wireless networking.
Now with Wi-Fi, there are many different types of Wi-Fi
including wireless, a, b, g, n, ac, and ax.
As you move down the list of letters,
we're going to be moving into faster and faster modes
of using wireless networks.
Now, to be able to use one of these wireless networks,
you need two things.
You need a wireless radio inside of your device
which could be your smartphone, your tablet, or your laptop,
and you need a wireless access point
that you're going to be connecting to.
Depending on which wireless access point
is being offered in the area you're at,
the speed you're going to be able to connect at
is going to be based on those two things,
either the wireless card inside your device
or the access point.
Whichever one is more limiting or slower
is the one that you're going to be operating at.
For example, let's say I have a newer iPhone
and it has a wireless 802.11 ac adapter inside of it.
That means my card will actually support
either a, b, g, n or ac.
But if I'm trying to connect to a wireless access point
at the library,
and they only have a wireless G wireless access point,
my card is going to downgrade itself into wireless G mode
and I will get those slower speeds.
This is an important thing to remember
when you're trying to troubleshoot
wireless networking connectivity issues
because it may be the device,
but it may also be the access point
that you're trying to connect to.
Now, when it comes to wireless network connectivity,
one of the biggest issues you're going to find
is that wireless productivity on smaller devices
is going to be slower than it is on larger devices.
For example, if I'm using an iPhone versus an iPad,
the iPad will normally outperform the iPhone.
Now, why is that?
Well it's because of the size of the antenna
that's being used in that device.
If you have a larger device, you can have a larger antenna
and larger antennas can actually pick up signals
from further away and they can pick those signals up
with more strength, giving them faster speeds.
So this is another thing to keep in mind.
When you're looking at a mobile device,
the wireless antenna
is usually going to be inside of that device.
This means if you pick up your smartphone
or your tablet and you look at it,
you're not going to visually see that wireless antenna.
But if you actually opened up the device,
you would see that wireless antenna
is actually embedded along the outside edge of your case.
The closer the antenna is to the outside of the case,
the better it's going to be able to pick up signals
from outside of the device.
And so this again is something
that is a design consideration.
When it comes to wireless networking,
you can enable and disable Wi-Fi on your devices as well.
This can be done through the settings area
of your mobile device, or if you're using a laptop,
there could be a physical switch
or key on your keyboard that you would click
to be able to turn off or turn off your wireless card.
When you turn off your wireless card,
this means that the computer will no longer use it,
and there will be no wireless activity going to
or from your device.
And if you work in a high security environment,
you may have to do this
before bringing your devices into that area,
because they may only allow wired networks
and not wireless networks inside those areas.
The next area of wireless connectivity
that we need to talk about is cellular connectivity.
When I'm talking about cellular,
I'm really talking about the cellular data networking
that allows us to connect to the internet
using our devices cellular radio inside of the handset
and then connecting to our network service provider.
Now, in terms of cellular technologies,
we're going to be operating
on one of two different underlying technologies.
This is either GSM or CDMA,
and which one of these you're going to use
is really going to be determined
based on the area of the world that you live in
and which provider you're using in your particular area.
For example, here in the United States
if you're using T-Mobile or AT&T,
they rely on GSM,
but if you're using Verizon, they normally rely on CDMA.
Now, if you live in Japan or South Korea,
you're likely using CDMA,
but if you live anywhere else in the world,
most of the time you're going to be using GSM.
So what exactly does GSM and CDMA stand for?
Well, GSM is the Global System for Mobile Communication.
And it's a cellular technology
that takes your voice during a call
and converts it into a digital format.
Then the device is given a channel and a time slot
so that your service provider can combine your call
with several other calls
to maximize the efficiency of their overall network.
So let's pretend that you need to provide services
to four users simultaneously.
You could actually give each of them a quarter of a second
to transmit their digital data.
Then when it reaches the other side,
it gets combined back together
and converted into the analog voice
that you hear through your speakers.
So the person on the other end
is now going to hear what you're saying
and they won't even notice there was that delay
because it's all happening in the background.
This basic example I just gave you
is a form of time division.
And that's what was originally used back
in the GSM 2G standard.
But over time, it was modified
into using different code division mechanisms
inside of 3G, 4G, and 5G networks with GSM.
Now, CDMA on the other hand
stands for Code-Division Multiple Access,
and it's a cellular technology that uses code division
and splits up the channel using this code division.
So instead of using time,
we're going to be using some kind of an encryption
or some sort of an algorithm
for every single call that's being made
that's going to have data going over our network.
This is going to take the data.
It's going to encode it using a unique key
and then that data stream can be transmitted
over the same channel as all of the other data
without getting it mixed together.
Now, on the other side of this equation,
the receiver's going to pull it out based on the unique key
for each of those calls.
It divides it out and then it sends 'em back over
in an analog format to the person on the other end
so they can hear what you're saying.
Now CDMA is actually a more powerful
and flexible technology than GSM.
In fact, when 3G GSM came out,
it actually adopted a lot of the parts from CDMA
and termed it WCDMA or Wideband CDMA, or UMTS.
the Universal Mobile Telecommunications System
So you may be wondering which one is better?
CDMA or GSM, and which one should you get?
Well before 3G, 4G and 5G networks were out there,
there really was a huge difference
between these two technologies,
but ever since 3G was introduced,
they pretty much are the same
and they're using a lot of this CDMA format
even when you're buying a GSM phone,
because those are now using WCDMA
or one of those evolutions from it.
So the only reason I'm really bringing up this idea
of CDMA versus GSM
is so that you can realize there is a difference in support
based on where you live in the world,
because those underlying technologies
are two different things.
As I said, GSM is by far
much more widely supported across the globe.
So if you are your business travels a lot,
you're going to want to carry a GSM supported smartphone
or hotspot with you.
Remember, it's important
to check with your cellular provider
for hotspot options in your area,
especially if you plan to work out of that area
for a long time before you head out
to make sure what you have is going to be compatible.
Most modern smartphones can also act as a hotspot for you
by using either tethering over a USB cable,
using a Bluetooth connection
or doing internet connection sharing over Wi-Fi.
For example, whenever I travel,
I carry a cellular modem with me,
and this is a wireless access point
that's combined into a small form factor device
that includes a cellular device inside of it.
This way I can carry it with me
whenever I get to where I'm going,
I can simply turn on this device,
and I have a wireless network
that I can connect my laptop, smartphone, and tablet to
and they can all connect to that cellular hotspot
and use that single connection to get out to the internet.
Now, there is one other major difference
with a GSM phone over a CDMA phone,
and this is the ability to use a SIM card.
Now, a SIM card is how you identify yourself
to the network in a GSM network.
But if you're using a traditional CDMA phone,
they didn't use SIM cards.
And instead they used an electronic code
inside the handset itself.
This meant that that CDMA device
was actually going to be configured
and locked to a certain cellular provider
and you couldn't always travel with it
and change providers when you were overseas.
For this reason, a lot of people preferred GSM phones
because you can simply pull out your SIM card,
put in a new one in the place you're traveling to
with a local service plan,
and that is a lot cheaper
to be able to access data on your phone,
using international roaming
with one of your American cellular providers.
These days though,
all modern phones do support electronic SIMs as well.
This allows you to simply download an app from the App Store
and change your SIM electronically to a local provider
to get the data service you want
as soon as you get off the airplane.
This again can save you a ton of money
overusing international roaming.
And it is a much cheaper way of getting data service
when you're overseas.
Now, your cellular modem
is going to be embedded into your mobile device,
and it needs to know how to connect
to all these different cellular towers
that are all over the world and their associated networks.
To do this,
your device is going to have something known as a PRL.
The PRL is the preferred roaming list.
And this preferred roaming list contains all the information
about all the different cellular towers
that your particular device and your service provider
are going to support you using.
If you need to update your PRL,
you can do this under the settings menu on your smartphone,
or you can enter a special code
using your phone's numerous keys
like star, two, two, eight.
That said, most modern smartphones
will automatically update their PRL
or preferred roaming list for you.
And so you're not going to have to do this
unless you're troubleshooting a cellular connectivity issue
on a particular device.
Now, when it comes to cellular data,
you can enable or disable the cellular radio in your device
by going into the settings menu on your device
or dragging down your finger from the top of the screen
and turning off the cellular modem
by pressing the icon for the cellular radio.
In addition to this,
all mobile devices also have what's known as airplane mode.
If you turn on airplane mode,
this will turn off your cellular modem for you
as well as turning off your Wi-Fi on some older devices.
This is because previously
airlines didn't allow you to use Wi-Fi while on the plane
but that has changed in recent years.
So most modern devices
will only turn off your cellular radio
when you put it into airplane mode.
On some devices, airplane mode can be very restrictive
to the point that it will turn off
not just your cellular modem, but also your Wi-Fi,
GPS Bluetooth and near-field communications receivers.
But again, this does vary from model to model
and depending on the country
that you have bought your device in.
But at a minimum,
airplane mode will at least turn off your cellular modem
because no airlines allow you to travel
with the cellular modem still enabled.
The next wireless connectivity option we need to cover
is Bluetooth.
Now, Bluetooth is used as a short range
point-to-point network connection
between your mobile device and some kind of an accessory.
For example, if you're using your smartphone with a headset,
usually this is going to have a Bluetooth connection
between those.
When you're going to use a device with Bluetooth,
you first have to pair that device
by going into discoverable mode or pairing mode.
When in this mode,
your Bluetooth accessory can then be discovered
by your mobile device.
Once you find that accessory,
you're going to click on it in the menu,
and it's going to try to pair
between your mobile device and that accessory.
To make sure you're pairing to the right accessory,
you need to enter a pin code or a pass key
to be able to validate that connection request.
If you're not sure the pin code for your device,
check your manufacturer's website
or try using zero, zero, zero, zero,
or one, two, three, four.
as these are the default combination for many devices.
In addition to this, some devices in accessories
will have an easy pairing mode
where they will send the pin number
from the accessory to your mobile device,
and it will display it on the screen.
And you'll just say yes or no
whether or not you want to accept that device for pairing
based on that code.
For example, if I'm renting a car
and I want to connect my smartphone to the rental car,
I can do that by adding it as a Bluetooth device to the car.
The car will display a six digit number.
It will also display that six digit number on my smartphone
and I can say yes, or accept on my smartphone
to accept that pairing between the car and my phone.
Now, once you have finished pairing those devices,
you want to validate that it is working properly
by testing your connection.
If you've connected something like a headset,
you can do this by simply playing some music
and making sure you can hear it through that headset.
If you've done a connection between your car and your phone,
you can then test that
by trying to make a phone call through the car
and seeing if it uses your cell phone to do it.
Once you validated that connectivity and tested it,
you now know that your device has been properly paired
and has a good connection over Bluetooth.
The last wireless connectivity option
we're going to discuss
is known as NFC or near-field communication.
Now, most of our modern smartphones
do have an NFC transceiver built into them.
This allows your device to receive
and send information in the NFC format.
Now, NFC is a near-field communication standard
that allows for the transmission data
over very short distances,
normally between two to four inches
but even going as high as about eight inches.
This translates roughly
to about the distance from your wrist to your fingertips.
The whole idea with NFC
is to be able to have a very trusted connection
when you are in the same place as something else.
And most of the time NFC is going to be used
as a payment gateway.
For example, if you use Samsung Pay, Google Pay
or Apple Pay on your smartphone,
you are using NFC for that transaction.
Anytime you go to buy your coffee
and you use your Apple Pay at the register,
that is using NFC to transmit your payment information
from your phone to that register,
and then receive the authorization from that terminal
back on your handset.
If you want to disable NFC,
you can do this from within your settings
inside of your mobile device.
Now it is important to note,
NFC is not solely a payment technology.
NFC and its communication standard can be used for anything.
If you had a headset that supports NFC,
you can actually pair that device to your phone
just like you could with Bluetooth,
but your big limitation here
is you only have up to eight inches of distance
for that transmission.
And so if I had my smartphone in my pocket
and I had an NFC capable headset on my head,
that's actually greater than eight inches
and they would no longer work.
For this reason, you almost always see NFC being used
for payment transaction purposes
or wallet type applications.
But I did want to point out that this technology can be used
for other applications as well.
For example, if you buy a new pair of AirPods from Apple
and you have an iPhone, you can grab the AirPods
still in their case, place it next to your phone
and your phone will recognize that those are AirPods
and then it can make a Bluetooth connection
for you with them.
Now, the AirPods themself,
won't be communicating over NFC to play your music
or make phone calls,
instead, it's going to use Bluetooth for that,
but the pairing process can be done automatically
by using this NFC connection,
and therefore we can use it as a form of validation
and a trusted connection
between the smartphone and the AirPods
before moving to that longer range Bluetooth connection
for our daily usage.
So keep in mind, there are lots of different ways
to use wireless connectivity with your devices.
This can include things like wireless or Wi-Fi,
cellular, hotspots, Bluetooth
and near-field communications.