One of the big connectivity advantages of a smartphone
is that it's connected to the internet.
It has data connectivity through your mobile provider.
And that means that you could use that device
to be able to connect other devices to the internet
as well.
One common way to do this is by turning your phone
into a hotspot.
You simply turn on the hotspot capabilities on one smartphone.
And then everybody else who's on that 802.11 wireless network
can now use your phone to be able to get internet access.
This functionality and the amount
of data you're able to use over this connection
is often managed by your wireless service provider.
So make sure you check with them before enabling
this capability.
If you're the only one who needs this internet access
through your smartphone, you can simply turn on tethering.
This means you can connect your laptop to your mobile device
using the USB connection.
Or if your laptop supports Bluetooth,
you can enable that and create your tethered connection
over that Bluetooth link.
Once that tether is in place, you're
able to use the internet from your laptop
by using the internet connectivity
from your smartphone.
Again, your wireless provider would
be able to enable or disable this tethering feature.
And there may be additional charges
for tethering your laptop.
There are many different wireless networks
that you can enable or disable on your smartphone.
There's, of course, your cellular network
for communicating to your mobile provider.
There's 802.11 Wi-Fi network connectivity.
There's probably Bluetooth radio inside of your smartphone.
And many smartphones also include
near-field communication, or NFC networks.
Many smartphones have an airplane mode
that allow you to disable or enable
all of these networks simultaneously.
This way if you're getting on an airplane
and you need to disable all of these networks
during takeoff and landing, you can click one button
and everything will turn off.
After takeoff if you then want to take advantage of the 802.11
wireless network on the plane, you
can simply enable just the 802.11,
and leave all of the other radios disabled.
Even if you're not on a plane, you
may want to have control over which
wireless networks are in use.
For example, if you're not using Bluetooth devices,
you may want to disable the Bluetooth functionality.
In iOS, you can go to the Settings
to manually enable or disable these different networks,
or use the Control Center that you can swipe down
from the top of the screen and enable or disable
the different networks from there.
There are many different ways to do this on Android.
One common way is to go to Settings
and then Wireless and Network Settings
to be able to control what networks you'd like to use.
Bluetooth is what we call a personal area
network, or a PAN.
It allows us to connect to devices
that are in our local area, usually about 10 meters
from us.
So we can connect keyboards and headsets and speakers,
all in our local area.
To be able to use this Bluetooth device,
we have to initially pair with the device.
So if you're using Bluetooth in a car,
you would pair with the car.
Then when you leave the card and come back,
the car and the phone will remember that they once
paired together, and you don't have
to go through the pairing process again.
The pairing process is relatively straightforward.
You would first enable Bluetooth on your smartphone
and on the device that you would like to pair with.
Then you would put those devices in discoverable mode.
And you should see the devices show up
on your screen that are able to be discovered.
Usually the name of a discovered device
will appear on the other Bluetooth device.
That way you know you're choosing the right one.
So you would then choose the name of the device
you want to connect to.
And usually a PIN will appear on both sides
so that you can confirm that you have indeed
selected the correct device.
Once you've confirmed the PIN, you then choose to connect,
and the devices are paired.
To be able to connect our smartphone
to a cellular provider's network,
there needs to be a radio inside of this device that's
providing that communication.
This is called a baseband radio processor.
This is different than the Wi-Fi, Bluetooth, or NFC radios
that are inside of your smartphone.
This one is specifically designed
to communicate with the cellular provider's network.
It has its own firmware.
It has its own memory.
And even though you're making phone calls
over the cellular network, you really
never see this particular part of the phone operating.
This baseband radio processor uses a real-time operating
system.
This allows your phone to set a priority
and be able to communicate over that cellular network.
The firmware associated with this baseband radio processor
occasionally needs to be updated.
And most often this update is occurring over the air, or OTA.
You don't really see this happening,
although sometimes you may get a message that
says that the radio has been updated
for your cellular network.
One set of updates you might get are PRL updates.
This is the Preferred Roaming List.
These are common to CDMA networks,
which are Verizon and Sprint networks here
in the United States.
These updates tell your phone which
tower it should be communicating with.
And usually these updates are provided over the air.
Another set of updates you might receive are PRI updates.
These are Product Release Instructions.
These have specific radio settings, like ID numbers,
network codes, and country codes so
that your phone knows exactly how
to use the wireless network.
These are also updated over the air.
So you may never know that a PRI update has occurred.
Every mobile device on these wireless carrier networks
can be tracked through a unique code called an IMEI.
This is an International Mobile Station Equipment Identity
code.
Every smartphone has a different IMEI
so your wireless carrier can allow access or disallow access
based on this IMEI value.
If you're purchasing a phone, you
may want to check the IMEI to make sure that it's not locked.
So when you receive the phone, it's
able to be activated on your carrier's network.
A different type of identifier is an IMSI.
This is an International Mobile Subscriber Identity.
This is an identity that is associated with you and not
with the mobile device.
This IMSI could be provisioned in the SIM card, which
means you can move the SIM card between different phones
and still maintain access to your wireless provider's
network.
If you want a secure channel of communication
between your smartphone and another device,
you may want to enable VPN functionality.
This stands for virtual private network.
This creates a secure channel between your smartphone
and another device.
The software you'd need to enable this VPN
is often built into the phone operating system,
although there is third party software you can install
onto many phone operating systems that provide VPN
connectivity.
This may require additional configuration on your side,
for example, things like the VPN server
that you'll be connecting to, the account name that you'll
be using, whether you'll be using an RSA secure ID
token generator, and other requirements as well.
Sometimes the VPN administrator will send you
a single file that will then update your phone
with the correct VPN details.