Our mobile devices can communicate using many different network technologies. In this video, you’ll you’ll learn how your phone’s broadband radio, 802.11 wireless, and Bluetooth networks work together to connect your devices to yourself and each other.
Our mobile devices are some very technologically advanced radio transmitters and radio receivers. Inside of our phones is something called a baseband radio processor that’s responsible for creating the interface to this wireless network. This is not the Wi-Fi network or the Bluetooth network that’s in your phone. This is a completely different radio that’s handling the communication to your mobile provider.
This baseband radio processor has its own firmware. It has its own memory. It’s running a real-time operating system so that everything is happening as quickly as it can. Voice communication has to happen instantly, and we rely on this baseband radio processor to be able to send information back and forth as quickly as possible. The firmware for this processor is usually updated over the air, or OTA. It’s all invisible to us from an end user perspective, but it’s used to keep your radio up to date with all of the latest details.
Another update that your phone might receive is a PRL update that stands for Preferred Roaming List, and this is used on CDMA networks. In the United States, that’s Verizon or Sprint networks. This is going to contain information about radio bands, sub-bands, and service provider IDs that need to be updated inside of your phone. It makes sure that your phone is then able to connect to the right tower on the mobile network, and all of these could be updated over the air.
Another update you might get is a PRI update that stands for Product Release Instructions. The PRI contains radio settings, which might be ID numbers, network codes, country codes, and other important information that allows your phone to connect to the right mobile provider’s network. And just like the PRL updates, the PRI updates also occur over the air.
Every phone has an IMEI. This stands for International Mobile Station Equipment Identity. This is a unique identifier that allows the mobile provider to identify your specific physical mobile device. Every phone is going to have a different IMEI, and this can be used by your mobile provider to allow or disallow access to the mobile network.
Another important identifier in your phone is an IMSI. This stands for International Mobile Subscriber Identity, and this is identifying you as the user of this device. This is usually provisioned in the SIM card, and if you need to move from one phone to the other, you can grab the SIM card and move it, and your identifier will move with that SIM card.
There are also networks on your mobile device that we use external to the wireless network provider, such as our Wi-Fi network and our Bluetooth network. And we can turn on and off each one of these types of networks independently. In iOS, you’d find this under Settings and Cellular. Under Android, it would be under Settings, Wireless and Network Settings, and under Windows Mobile, you would also find this under Settings under the Wi-Fi section.
The Bluetooth radio that’s in our phones allows us to have what we call a personal area network, or PAN. It’s got a personal area network, because it has a short range of about 10 meters in length, but it allows us to connect our mobile phones to other devices, such as headsets or automobiles or speakers. Once you pair these up with Bluetooth, they are connected and can work together whenever they’re in range, and they’re able to connect and disconnect automatically.
To be able to use this Bluetooth network, you need to be able to pair your mobile device to the Bluetooth device. So the first thing you have to make sure you do is enable Bluetooth on both devices. On Android and iOS, you do this under Settings, Bluetooth. You would then set the devices to be in what we call a discoverable mode. That way the devices can be seen on both sides. This may require a special key sequence on the Bluetooth device itself.
On your phone or mobile device then, you should be able to see the Bluetooth device listed in the available list of devices. When you select one of these mobile devices, you’ll be asked to enter or confirm a personal identification number, and they should match on both of those devices. Once you’ve confirm the PIN, you should now be able to communicate to that Bluetooth device. Now that you’ve gone through this pairing process, you’ll be able to connect and disconnect to that Bluetooth device automatically whenever you’re in range.
If your phone and your wireless carrier support it, you may be able to enable tethering on your mobile phone. This turns your mobile phone into a Wi-Fi hotspot that uses the wireless carrier’s network to connect to the internet. This may require additional charges for you to pay, but it does allow everyone around you to be able to connect to your phone to get internet access.
Another important mode in your wireless device is airplane mode, where you have one button that turns off all of the radios that are in your phone for safety whenever you’re flying. You can then enable individual radios if you need it. That way you can turn on airplane mode, and then enable just the Wi-Fi features so that you can use the wireless network inside the plane when you’re in the air.
Just as a laptop or desktop can connect to a remote location through a virtual private network, we can also have our phone be an endpoint on a virtual private network. This feature uses software that’s usually built into the mobile operating system, so you won’t need to load any additional software for this capability. If you are connecting this phone through a VPN to a remote site, you may require some additional configuration settings. You can see here that you need server information, account details, password, and secret information.
You may also see that your operating system supports multi-factor authentication using technologies like RSA SecureID. This token generator is used when you connect to the VPN. It will ask you for username information, password details, and it may also ask for the pseudo random token that’s on the front of the RSA key.